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ECOLOGY COURSE SYLLABUS Course Code: 3 Credits: Period of teaching: E 00 EC 273 3(2 - 0 - 3) First semester Course objectives: • • • • To explore and develop one’s understanding of the concepts, principles, and processes of ecology, the study of the relationships between organisms and their environment, emphasizing an evolutionary perspective. To study current issues in the major subdisciplines of modern ecology. To observe and analyze ecological principles in action in natural ecosystems. To communicate in ways appropriate to the biological and environmental sciences about the processes studied and results obtained. Course Synopsis: 3 undergraduate credits. This lecture-lab course covers basic principles of ecology including evolution, natural selection, ecosystem components, population, and community, terrestrial and aquatic ecosystems. Fieldwork demonstrates ecological sampling techniques. Labs include some physico-chemical analyses and use of computers for statistical analyses. Course Structure: This course consist of 9 major chapter: 1. 2. 3. 4. 5. 6. 7. 8. 9. Introduction to Ecology. Ecosystem Energy transfer Biogeochemical cycles Individual and species Population Community Major Terrestrial Ecosystem Freshwater Ecology Teaching and Evaluation methods Teaching: • • • • Evaluation: • • • • Lecture Seminar Excursion Assignment or/ and case study Class participation Seminar Assignment Final examination 15% 5% 30% 50% Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Code E 00 EC 273 Prerequisite Chapter Course Outline Subject Ecology 240 BI 111 (General Biology) Credit 3 (2 - 0 - 3) Topic Time Lec 1. Introduction Lab Se Excu Definition, history, roles, scope of Ecology, and relationship with other disciplines • Structure: Abiotic components, biotic components • Limiting factor: Law of limiting factors, Temperature, Humid, light, Soil and Nutrient, fire and Gases • Productivity, • Pattern of energy transfer • Trophic structure and ecological pyramid) • Water Cycle • Asmospheric Cycles - Carbon Cycle - Nitrogen Cycle - Oxygen Cycle • Lithospheric Cycles - Phosphorous Cycle - Sulfur Cycle • Individuals • Ecological equivalence • Character displacement • Natural selection and Behavior • Population density • Factors affect on population density • Population growth • Biotic potential and environmental resistance • Population fluctuation • Population age distribution • Internal distribution patterns • Population aggregation • Interaction between two species • Ecological dominance • Species diversity in communities • Pattern in communities • Ecotone • Ecological succession 1 8. Major Terrestrial Ecosystem • • • • 5 2 2 10 9. Freshwater Ecosystem • • • 5 2 2 10 35 10 10 20 2. Ecosystem 3. Energy in the Ecosystem 4. Biogeochemical cycles in the Ecosystem 5. Individual and species in the ecosystem 6. Population 7. Community Soil: Main component of terrestrial ecosystem Climate Terrestrial Community Structure Ecosystem of Lao and National Protected Area (NPA) Phisico-chemical factors Ecology of Lotics, Lentics and wetlands. living organisms in fresh water and there’s adaptation Summary, Final examination Time total (75 hours) 3 6 3 2 5 2 4 5 2 4 Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version RUC, October 2 2007 Core course: Ecology. A plan for 9 chapters has been delivered covering 35 - one-hour - lectures. Further more 40 hours are arranged for laboratory work and excursions. 8 chapters have been translated to English and submitted for comments. Chapter 8 is missing for unknown reasons. Important ecological aspects are defined and presented in the 8 chapters and references are in the text so the students have a possibility to read more. A reference list is missing. The flow in the lecture note is traditional in international ecological literature going from inorganic aspects, to individuals/species, populations, communities and ecosystems. Important ecological concepts like energy flow, and ecological cycles, biodiversity, ecological succession and climax are presented in a qualified way. The society and its activities play a minor role in this core course material and the possibilities to use the interdisciplinary ecology as a link to other core courses are not used sufficiently. For example in chapter 9 about freshwater ecosystems it could be mentioned that invertebrates in lotic water can be used in a water quality management, and that could be a reference to the pollution core course. Many of such kind of links could made and in that way raise the quality of the environmental bachelor program. The English language is sometimes difficult to understand revealing that a person not familiar with ecological science has performed the translation. Compared to what has been available in English about lecturing in ecology at NUOL this lecture note represent a great step forward and after a minor revision it should be printed. Even chapter 8 is missing I got a good impression of the core course material and it is certainly acceptable. Henning Schroll Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Chapter I Introduction Organisms are open systems that interact continuously with their environment. The scientific study of the interactions between organisms and the environment is called ecology. Ecologist also study how interactions between organisms and the environment affect phenomena such as the number of species living in a particular area, the cycling of nutrients in a forest or lake, and the growth of populations. Because the term ecology is so often misused in popular writing to refer to environmental concerns, it is important to clarify the different between ecology and environmentalism. Miline (1957) gave detailed “Every things in the world are affected to organism’s need”. Before this many scientist believe that environmental in the world is necessary for the organism such as radiant from the sun, light of the moon are also necessary for the behavior and reproductive of life. To study organisms and the environment were interested for long time, and defined it in other sciences such as St. Halaire (1859) defined it for the first time as “Ethology” which investigates organisms in relation in sociology or in family. Mivart (1864) defined ecology as “Hexicology” which study the relations of the organisms with their environment can be considered at various levels: how the particular component of the environment (as light, temperature etc.). In Greek there are many scientists such as Aristotle and other scientist wrote the articles about “relations of the organism with their environment” at that time the word ecology are not well known in the world. However, Ernst Haeckel, another German biologist, defined it in 1869, as “Ecology” and used it up to now. . The word “Ecology” (from the Greek Oikos = home, habitat, and logos = study, science) was coined over a century ago. The word ecology is widely to define, because it investigates organisms in relation to their environment. And it is necessary to reduce a study of the non-living environment to understand property the inter-relationships. Ecology is concerned with ranges organisms, population, communities, ecosystems, biome and biosphere. Ecology is can be started to study from population that means to study in population and community. A population is a group of individuals of the same species living in a particular geographic area; a community consists of all the organisms of all the species that inhabit a particular area; it is an assemblage of Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version populations of many different species; and an ecosystem consists of all the biotic factors in addition to the entire community of species that exist in a certain area. An ecosystem-a lake, for example may contain many different communities. Many ecosystems combine to gather become ecosphere or biosphere. Biotic components Gene Cells Organs Organisms Populations Communities + Abiotic components Bio systems Matter Genetic System Energy Cell System Organ System Organism System Population System Ecosystem The study of ecology can be made in several ways and accordingly, ecology is divided into various sub-divisions. According to the species is divided into various sub-divisions: 1. Plant Ecology 2. Insect Ecology 3. Microbial Ecology 4. Vertebrate Ecology etc. According to the habitat is divided into various sub-divisions: 1. Freshwater Ecology 2. Marine Ecology 3. Estuarine Ecology 4. Terrestrial Ecology etc. Beside of these, ecology can also be divided into many ways depend on the habitat and extent such as grassland, rain forest, ponds, desert, etc. v Ecology study in two levels: 1. Autecology which study of individuals of the species such as mammal animal, insect, bird or some plant species. This study is emphasis on live cycle and adaptation behavior. 2. Synecology which study about group of organisms living in the same habitat such as study of group of organisms in forest or group of organisms in water etc. this study emphasis on relationship between organisms and environment. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Studying of ecology to be understanding, it is necessary to get the knowledge in science especially the field of biology (Fig. 1.1). The figure compares with a cake of science which relating to organism or biology. When we cross-section or cut a cake into two pieces: basic division layers and taxonomic division slices, the pieces of a cake in horizonal are divided into various sub-division of biology such as: molecular biology, developmental biology, physiology, genetics, ecology and morphology etc. However, the pieces of cake in vertical are taxonomic division such as zoology, botany and microbiology. And it can be divided into sub-division such as phycology, protozoology, mycology, entomology and ornithology etc. Because of its great scope, ecology is an enormously complex and exciting area of biology, as well as one of critical importance. And it is the basic of the biological science that is emphasizing on some species organism such as zoo ecology, plant ecology, entomology ecology etc. Figure 1.1 Diagram of relationship in the field of biology (Odum.E.P. 1997). Chapter II Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The Ecosystem An ecosystem consists of all the abiotic factors in addition to the entire community of species that exist in a certain area. In ecosystem ecology, the emphasis is on energy flow and chemical cycling among the various biotic and abiotic components. The term ‘ecosystem’ was coined by Tansley (1935) who stated his ideas in the following words: ‘The more fundamental conception is the whole system in the same of physics, including not only the organism complex but also the whole complex of physical factors forming what we call the environment of biome the habitat factors in the widest sense. The word ecosystem however has also the advantage of laying emphasis on the functional integration of the biological components into a stable whole unit which is inherent in the word system. Like any other system, then the ecosystems have certain structural components (the organisms and the physical environment) interacting among themselves (through the processes of energy flow and cycling of materials) to accomplish the goal of continuance of life. The outer layer of the planet Earth can be divided into several compartments: the hydrosphere (or sphere of water), the lithosphere (or sphere of soils and rocks), and the atmosphere (or sphere of the air). The biosphere (or sphere of life), sometimes described as "the fourth envelope", is all living matter on the planet or that portion of the planet occupied by life. It reaches well into the other three spheres, although there are no permanent inhabitants of the atmosphere. Relative to the volume of the Earth, the biosphere is only the very thin surface layer which extends from 11,000 meters below sea level to 15,000 meters above. However, according to the characteristics of all ecosystems, the components of ecosystem can be defined into two major components: biotic components and abiotic components. 2.1 Structure of the ecosystem The ecosystems consist of two major components: abiotic component and biotic component. Both components exhibit definite structural organization of which some features are given below: 2.1.1 Abiotic components Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The abiotic component of the ecosystem consists of 3 majors such as: energy, chemical components and physical components. a. Energy: The energy used for all the life processes is derived from solar radiant energy. Plants and other photosynthetic organisms convert solar energy to chemical energy, but the total amount of energy does not change. The total amount of energy stored in organic molecules plus the amounts reflected and dissipated as heat must equal the total solar energy intercepted by the plant. During the digestion of the food by the animals, the complex organic molecules are broken down to simpler molecules and new compounds are resynthesised. As a result a large part of the energy is again lost as heat and a small fraction is stored in the animal tissues. b. Chemical components: Chemical components can be divided into 2 categories such as: inorganic substances for example: water, oxygen, carbon, nitrogen and other minerals. Organic substances: protein, carbohydrate, vitamin and other chemicals that is necessary for organism. c. Physical components: It has important part of abiotic component to determines the structure and function of the ecosystem and can be used for indicating kinds of ecosystem and 2.1.2 Biotic components The biotic components of the ecosystem can be divided into 2 categories depend on the organisms such as: Producer and consumer a. Producers or autotrophic organisms: Most autotrophs are photosynthetic organisms that use light energy to synthesized sugar and other organic compounds, which they then use as fuel for cellular respiration and as building material for growth. Plants, algae, and photosynthetic prokaryotes are the bioshere’s main autotrophs, although chemosynthetic prokaryotes are the primary producers in certain ecosystems, such as deep-sea hydrothermal vents. b. Consumers or heterotrophic organisms, which directly or indirectly depend on the photosynthetic output of primary producers. These can again be divided into two kinds: Macro consumers and Micro consumers. v Macro consumers also divided into three kinds: - Primary consumers refers to some animals feed directly on the plants and other primary producers. These are called herbivores. For example: cow, sheep, buffalo, rabbit, glass shopper and zooplankton. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version - Secondary consumer refers to some animals feed on animals which eat plants or eat herbivores. These are called carnivores. For example: some insects, frog, bird, etc. That means animals in this consumer are consuming only herbivores, for example: caterpillar → bird, zooplankton → insect larvae. - Tertiary consumers refers to some animals feed upon both the plants and animals or carnivores that eat other carnivores. These are called omnivores. For example: chicken, duck and including human. v Micro consumers are consumers that get their energy from detritus, which is nonliving organic material, such as the remains of dead organism, feces, fallen leaves, and wood. The prokaryotes, fungi, and animal that feed as detritivores form a major link between the primary producers and the consumers in an ecosystem. They are also known as decomposers because of their role in decomposition of dead organic matter. Detritivores decompose the organic material in an ecosystem and transfer the chemical elements in inorganic forms to abiotic reservoirs such as soil, water, and air. Producers can then recycle these elements into organic compounds. All organisms perform some decomposition, breaking down organic molecules during cellular respiration, for example. But an ecosystem’s main decomposers are prokaryotes and fungi which secrete enzymes that digest organic material; these decomposers then absorb the breakdown products. Decomposition by prokaryotes and fungi account for most conversion of organic material from all trophic levels to inorganic compounds usable by primary producers, there by closing the loop of an ecosystem’s chemical cycling. To consider of ecosystem components, the size of ecosystems are different depend on their sizes such as ponds, lakes, rivers all of these are ecosystems. Homeostasis is means ecosystem consists of most components and can be control the ecosystem to be stable for a short times or a long times. For example, the density of predators are always depends on density of preys. When the preys are increasing due to predators have increased sharply. When predators have increased sharply due to preys had decreased slightly, finally predators are also decreasing because of insufficient food. These are called feed back. On the other hand, the parameters can be changing the ecosystem components such as: season change and time. Changing on time can be caused succession, which caused from different adapted of organisms. Who can adapted to environment are can be survived, who can not adapted have to move or disappear. Odum (1971) suggested that succession can be induced more equilibrium and stability. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The important thing to study ecosystem should be understand the components of that ecosystem. For example ecosystem suitable for initial studying is pond (Fig.2.1). Pond is kinds of ecosystem and can be divided the components into two types such as: Abiotic components: organic mater and inorganic mater, for example water, carbon dioxide, oxygen, cesium, nitrate, and phosphorus including amino acid and humic acid. These components provide important nutrient and physical components to organism in the river. Some of nutrients that plant can be used directly almost become to the sedimentation or residue fall down on the bottom. Biotic components: producer, consumer and decomposer in the pond. Producer in pond ecosystem can be divided into two majors such as plant has got roots, or big or small floating plants. Big floating plants living on the riverbank or shallow such as lax sedge, lesser reedmace, water orchid, taro etc. Some these plants can be floated on the water such as gooseweed, neptunia, water lettuce, water weed etc. Small floating plants are distributed around the light pass through we call phytoplankton. Consumers can be divided into three majors such as: animal that consumes plant for example zooplankton, some insects, some fish, and turtle and amphibian larvae. Canivore is an animal that eating herbivore such as: insect, fog, snack, fish, bird and otter Detritivore is kinds of animal that eating organic digested for example mollusca, shrimp and worm species. Decomposers consist of flagellate bacteria and fungi and can found every where in the water especially surrounding the bottom that contains a lot of dead organic substance. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 2.1 Diagrammatic of pond ecosystem 1. Abiotic components B. Phytoplankton II.A. Producer has root I.B. Zoo plankton III.IA. Primary consumers 2. Secondary consumers 3. Tertiary consumers IV. Decomposers 2.2 Limiting factors Limiting factor is one that controls a process, such as organism growth or species population size or distribution. The availability of food, predation pressure, or availability of shelter is examples of factors that could be limiting for a species population in a specific area. Limiting factors are the abiotic factors that mean physico-chemical factors. These factors are one that controls a process, such as organism growth, reproductive or species population size or distribution. For example of these factors: light, temperature, humidity, acid and base, oxygen and other minerals, etc, 2.2.1 Law of limiting factors As early as 1840, Justus von Liebig had purposed a law of minimum. It was shown in a study on the growth of crop plants that the growth I dependent on the amount of the nutrient that is available in minimum quantity. Later, Blackman (1905) observed that the rate of photosynthesis is governed by the amount of the factor that is operating at a limiting level. For example, the photosynthesis is affected by the light intensity and the availability of carbon dioxide. If all other factors are at the optimum, a small quantity of carbon dioxide would be limiting and simply increasing the light intensity will not enhance the rate of photosynthesis. This is now known as the principle of limiting factor. Shelford (1913), an animal ecologist, discovered later that a factor may be limiting not only in low quantities or intensities but too light quantity or too high intensity of that factor may also be limiting to the growth or other physiological activity of the organism. This maximum limit was incorporated in the law of tolerance formulated by Shelford. Thus, each environmental factor which affects an organism has a minimum and a maximum limit to which the organism can respond or tolerate. These are the limits of tolerance of that organism towards that factor. This concept is shown diagrammatically in (Fig. 2.2). It must be pointed out here that the various environmental factors do not affect the organism independently. The intensity and quality of each environmental factor are modified by other factors, and thus, the organisms respond to the totality of the environment. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version There have been numerous studies on the effects f various environmental factors and their interactions on the morphology, growth and reproduction of plants and animals. Preferendum; centre of distribution; greatest abandance Optimum Range of Optimum Organisms absent Upper limit of tolerances Zone of physiological stress Organisms infrequent Population density tress Zone of physiological Organisms infrequent Zone of intolerance Population density Organisms absent Population density Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Lower limit of tolerances Minimum population density Low Figure 2.2 Limiting Factors High Range of tolerance for an organism v General meaning of the law of tolerance: 1. Some organism may be tolerant to some limited factors in widely, but can be tolerant to the other factors in narrow. 2. If the living can be tolerant to the limited factor in the widely, which can be widely expanding. 3. Each limiting factors are relating to the organisms such as some grass species, if the lack of nitrogen is induce to water stress. Whereas if enough of nitrogen it is tolerance to water stress. 4. The limiting factors is not suitable for the organism that can be survived but depend on which organism can be adapted to the environment where they live. 5. The effect of limiting factors on the reproductive of organisms in their life cycle. For example the adult stage is tolerance to limited factors than larva stage. There are some specific words that used in the front of limited factor such as steno = narrow, eury = wide. If related to temperature changing is using the word stenothermal- eurythermal; if related to salinity is using the word stenohaline-euryhaline; if related to water or humidity is using the word stenohydric-euryhydric. For example: Trematomus berracchi is a fish in the South Pole that is stenothermal between -2 °C to 2 °C or 4 °C, while Cyprinodon macularius is the fish live in the desert that is eurythermal between 10 °C to 40 °C. The limiting factors that necessary to the organism are temperature, light, humidity, mineral and gas etc. 2.2.2 Temperature Temperature is a measure of heat energy content in an object, and it is noted against a centigrade scale on which the freezing and boiling points of water are taken as 0 and 100 respectively. The temperature which organism can survive is between -200 °C to 100 °C, and thus most of the organism can tolerate these narrow rages of temperature. For most animals can tolerate temperatures up to 50 °C. A few blue-green algae also occur in hot waters at 73 °C, Certain bacteria, blue-green algae and lichen are among those which can tolerate sub freezing temperatures. In the North Pole also found some species of algae occur at -200 °C. The animals are grouped into two categories on the basis of their ability to regulate the body temperature. The homoiotherms (warm blooded animals) maintain their body temperature at about 37 °C irrespective of the atmospheric temperature. The birds have a body temperature of about 42 °C. On the other hand, poikilotherms (cold blooded animals) are unable to regulate their body temperature and become inactive at temperatures below 8 °C and above 40 °C. None of the animals can tolerate a temperature beyond 60 °C. The desert locusts (up to 60 °C), the larvae of nematoceran Scatella (50 °C), protozoan Hyalodiscus, and the snail Bithynia thermalis (53-54 °C) are among the most tolerate taxa. Some rotifers are known to survive for a few minutes at temperatures near absolute zero and also above boiling point of water. The temperature is an important factor in the life processes of all the organisms because water is a major constituent of the cytoplasm, and the proteins, particularly enzymes, are highly sensitive to temperature changes. Indirectly, the increase and lowering of the temperature affect the availability of moisture in the soil and atmosphere. At near freezing temperatures and at high temperatures the water becomes unavailable to the organisms. In plants the dry winds cause rise in transpiration losses of water. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The effect of temperature on various physiological processes is expressed in terms of temperature coefficient (Q10) which is the ratio between the rate of a process at a particular temperature and the rate at a temperature higher by 10 °C. In general, the rate of most physiological processes increases to a certain temperature (optimum temperature) and decreases thereafter. The optimum temperature for photosynthesis is much below that for respiration and therefore at high temperatures, the respiration exceeds the photosynthesis resulting in retarded growth or even death. Temperature affects the germination of seeds and sprouting of buds considerably. Most of seeds germinate at temperatures between 25 °C and 35 °C, but the leguminous seeds require in general a higher temperature. In some seeds a pre-treatment to lower temperature (stratification) is necessary before they germinate at a relatively high temperature e.g., Sisymbrium irio. The lower temperatures affect the root growth and water absorption adversely. Like light, the temperature changes during the day have great influence on vegetative and reproductive growth. The plants differ in their temperature requirements for flowering; they may flower at specific low or high temperatures or may remain unaffected by it. In many temperate plans, subjecting them to very low temperatures for a short duration may result in rapid and more flowering when returned to normal temperatures. It is referred to as vernalisattion. The rise and fall in temperature affect the poikilothermic animals most. In the homoiotherms the changes in the respiratory rate regulate the body temperature. Different birds have ability to compensate for low temperature (sub-freezing) up to different levels. Within the same species, races may also exhibit preferences to different temperatures (e.g., Drosophila funebris). In poikiotherms, the development is accelerated by rise in temperature. Various animals adapt themselves to unfavorable temperature conditions in various ways. Most poikiotherms go under a state of hibernation (no activity) at low temperatures. The reptiles adjust themselves by frequently moving under sun and shade. The desert animals are burrow dwelling and nocturnal so that during the day they remain at relatively low temperatures in their burrows. Among birds and animals, the development of feathers, fur and a subcutaneous layer of fat are important adaptations to temperature. 2.2.3 Humidity One of the most variable characteristics of the atmosphere, humidity is an important factor in climate and weather: it regulates air temperature by absorbing thermal Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version radiation both from the Sun and the Earth; it is directly proportional to the latent energy available for the generation of storms; and it is the ultimate source of all forms of condensation and precipitation. Humidity varies because the water-holding capacity of air is determined by temperature. Water is the most important factor in the life of an organism as it is the major constituent of the protoplasm. The water becomes available to the organisms in the form of rainfall, snow, dew, etc. The total amount of the precipitation and its distribution over time is highly variable in different part of the world and this result in the diversity of distribution patterns. Large amounts of water are lost in run-off, percolation and evaporation, and only the amount of free water available in the soil, and the water vapors in the atmosphere are of importance to the organisms. The amount of water vapors in the atmosphere is referred to as absolute humidity. However, of greater significance is the relative humidity which is the ratio of the actual amount of water vapors in the atmosphere to the amount that can be held in the air at a particular temperature and pressure. Water affects all life processes directly. In plants, the rate and magnitude of photosynthesis, respiration, absorption of nutrients, and other metabolic processes are influenced by the amount of water available. Low relative humidity increases water loss through transpiration and affects growth. The germination of seeds and establishment of seedlings are directly affected by water. In lower plants, water is essential for fertilization, and among higher plants, pollination and dispersal are effected through the agency of water in many cases. The availability of water is largely affected by temperature, and their interactions govern the type of vegetation developing in an area. The plants which have the ability to maintain growth under conditions of water stress (and also high temperature) are true xerophytes. The plants are woody trees, shrubs or herbs. The leaves are generally small or absent. Among grasses, the leaves roll inward to protect stomata and help in reducing water loss. The resin and latex cells are present. The cuticle is thick, and the hypodermis is sclerenchymatous or may possess some chlorophyllous tissues. Like plants, the animals in dry habitats are also adapted to conserve moisture. The adaptations are mostly behavioral. Most desert animals are nocturnal and suck dew drops on the surface of soil and plants. Like the annual plants, many animals pass through a long period of aestivation underground. They are also able to develop from the eggs into mature adults within a short period. The animals which remain active throughout the year Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version have several other physiological adaptations. Many of these animals obtain their water supply from their own metabolic processes. They do not possess any sweet glands. Their urine is highly concentrated and the faces are in form of dry pellets. During the day, these animals remain in the burrows where the temperature is much lower and the humidity is high. 2.2.4 Light Light is defined as the visible part of the spectrum of solar radiant energy. It comprises radiations of wave-lengths ranging from 390 nm to 760 nm, and constitutes about 48 % of the total energy received on the earth’s surface. Light is among the most important factors for life, and in fact, life could not exist without light. Light is directly essential for photosynthesis on which all other organisms depend for their energy supply (as food). The light affects the daily and seasonal activities of plants and animals in many ways. Te effects depend upon the intensity, quality (wave-length of the radiations) and duration of light. The effect of light intensity and quality on photosynthesis is well known. The red light is absorbed by chlorophyll and only in certain marine algae other regions of the light spectrum are utilized. Recent studies have shown that the photorespiration is enhanced in blue light and hence the C4 plants can utilize blue light also for photosynthesis. The light affects the movements in plants (phototropism) and the growth of the shoot towards light has been found to be affected by blue light. The blue light has also been found to affect the respiration, protein synthesis, cytoplasmic movement and opening of stomata. The most important influence of light in plants is on reproduction. Several investigations have shown that the flowering is controlled by the light duration. The light also affects the animals in several ways. The growth, coloration of plumage, migration, reproduction and diapauses are affected by light in various insects, birds, fish, reptiles and mammals. Many animals prefer to remain in dark while others like hydroids fail to survive in absence of light. While the plants respond to light with the help of several pigment systems as chlorophyll and phytochrome, among the animals various kinds of photo-receptor systems exist. These include ‘eyespots’ consisting of amylum granules as in protozoa; flat ocelli in jellyfish; pit eyes in gastropods; vesicular eyes as in polychetes, mollusks and some vertebrates, and compound eyes of arthropods. Light has been also observed to influence the development of these visual organs. Besides, the light is responsible for the skin coloration of most of the animals. In several animals, the color changes occur in response to light. These changes may be Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version physiological or morphological, and they help in protection from damaging radiations or predators and in thermoregulation. Another response to light among the animals is seen in their orientation and movement. The movement of insects and some coelenterates towards light is positive phototactic movement. Several insects (hymenoptera, caddis flies, and butterflies) and birds maintain a sense of direction from the angle of sun’s rays and this helps them in returning to their nests. Low light intensities particularly the decreasing light levels influence the behavior of such animals as owls, bats and nocturnal rodents which come out of their hiding places in the night. The reproduction is also affected by light in numerous animals. Among the insects, the feeding, mating and development to maturity are governed by light. The gonadal activity of birds and mammals, and also the duration of refractory period in birds (period of little gonadal activity) are controlled by light duration. Mention may be made here of the biological clock or circadian rhythm (or endogenous rhythm). In many organisms, both plants and animals, certain physiological processes are observed to follow a definite rhythmic pattern. For example, the flowering in Partulaca, the bending of inflorescence axis in water hyacinth, migration in birds, nocturnal activity off many animals, emergence of insects as Drosophila from pupae are known to observe a circadian rhythm in which a definite time lapse occurs. Since the time requirement of the rhythm is definite, the mechanism is known as a biological clock. The rhythmic activity is considered to be in response to light involving a phase of light favored activity and another phase of light inhibited activity. However, there are also rhythmic phenomena which cannot be correlated with environmental stimulus and are truly endogenous. v Photoperiodism and Control of Flowering An early clue to how plants direct seasons came from a mutant variety of tobacco, Maryland Mammoth, which grew tall but failed to flower during summer. It finally bloomed in a greenhouse in December. After trying to induce earlier flowering by varying temperature, moisture, and mineral nutrition, researchers learned that the shortening days of winter stimulated this variety to flower. If the plants were kept in light-tight boxes so that lamps could manipulate “day” and “night” flowering occurred only if the day length was 14 hours or shorter. It did not flower during summer because at Maryland’s latitude, the days were too long during last season. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The plants produce flowers only when grown in light of certain duration in daily cycle. This light period is called critical photoperiod. The plants are classified into two major categories on the basis of their photoperiodic requirements. The long-day plants require photoperiod longer than the critical day length and the short-day plants flower at photoperiods below the critical. The researchers called Maryland Mammoth a short-day plant because it apparently required a light period shorter than a critical length to flower. Chrysanthemums, poinsettias, and some soybean varieties are some other short-day plants, which generally flower in late summer, fall, or winter. Another group of plants will flower only when the light period is longer than a critical number of hours. These long-day plants will generally flower in late spring or early summer. Spinach, for example, flowers when days are 14 hours or longer. Radish, lettuce, iris, and many cereal varieties are also long-day plants. 2.2.5 Soil and Nutrients The soil may be defined as the upper layer of earth’s crust to which most of the plant are anchored and from where they derive their water and nutrient supply. Soil is also the main source of nutrients for all water plants, rooted or submerged or free-floating. The soil is also important for the animals. Many of them like nematodes, polychaetes, insects, rodents, etc., live under the soil. A close examination of the soil reveals that it comprises numerous mineral particles of various sizes, organic substances and a large variety of micro-organisms as bacteria, algae, fungi, protozoa etc. This soil develops over very long periods from the rock material by the action of several physical, chemical and biological processes. As said earlier, the soil influences more directly the plants than the animals. The nature of the parent material determines the availability of nutrients to plants and also the physical properties of the soil. The alluvial soils are more fertile as minerals and organic matter are added to them along the river course. On the other hand the aeolian soils are unstable and poor in nutrients and hence support very little vegetation. 2.2.6 Fire Fire is an essential element in our ecosystem as natural management technique to control species dominance, noxious invasion, healthy plant production, and successful germination. Fires do not have a natural detrimental effect on grasslands. There are factors however that can influence the change in vegetative response to fire. Grazing and fuel loading impacts fire behavior and vegetation changes after fire. Grazing can reduce Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version the amount of biomass and potential fuel, resulting in fire suppression. Weeds can be introduced, making it difficult for the perennials to compete for space. The new growth after a fire is more productive and palatable for herbivores than prior to the burn. These new sprouting plants are not only nutritious but they are also greener, larger, and higher in water content. Animals grazing burned areas gain more weight and have less problems with ticks, mites, and flies. The ecological benefits of wildland fires often outweigh their negative effects. A regular occurrence of fires can reduce the amount of fuel build-up thereby lowering the likelihood of a potentially large wildland fire. Fires often remove alien plants that compete with native species for nutrients and space, and remove undergrowth, which allows sunlight to reach the forest floor, thereby supporting the growth of native species. The ashes that remain after a fire add nutrients often locked in older vegetation to the soil for trees and other vegetation. Fires can also provide a way for controlling insect pests by killing off the older or diseased trees and leaving the younger, healthier trees. In addition to all of the above-mentioned benefits, burned trees provide habitat for nesting birds, homes for mammals and a nutrient base for new plants. When these trees decay, they return even more nutrients to the soil. Overall, fire is a catalyst for promoting biological diversity and healthy ecosystems. It fosters new plant growth and wildlife populations often expand as a result. Disadvantages: Fire can cause soil damage, especially through combustion in the litter layer and organic material in the soil. This organic material helps to protect the soil from erosion. When organic material is removed by an essentially intense fire, erosion can occur. Heat from intense fires can also cause soil particles to become hydrophobic. Rainwater then tends to run off the soil rather than to infiltrate through the soul. This can also contribute to erosion. In actuality, the negative effects of fires on soils are often exaggerated, and many fairly intense fires in western United States forests cause little soil damage. There is also the potential for alien plants to become established after fire in previously uninfested areas. 2.2.7 The important gases for the organism Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly (by molar content/volume) 78% nitrogen, (normally inert except upon electrolysis by lightning and in certain biochemical processes of nitrogen fixation), 20.95% oxygen, 0.93% argon 0.038% carbon dioxide, trace amounts of other gases, and a variable amount (average around 1%) of water vapor. This Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version mixture of gases is commonly known as air. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night. Carbon dioxide is an end product in organisms that obtain energy from breaking down sugars, fats and amino acids with oxygen as part of their metabolism, in a process known as cellular respiration. This includes all plants, animals, many fungi and some bacteria. In higher animals, the carbon dioxide travels in the blood from the body's tissues to the lungs where it is exhaled. In plants using photosynthesis, carbon dioxide is absorbed from the atmosphere. Carbon Dioxide is present in water in the form of a dissolved gas. Surface waters normally contain less than 10 ppm free carbon dioxide, while some ground waters may easily exceed that concentration. Carbon dioxide is readily soluble in water. Over the ordinary temperature range (0-30 C) the solubility is about 200 times that of oxygen. Calcium and magnesium combine with carbon dioxide to form carbonates and bicarbonates. Aquatic plant life depends upon carbon dioxide and bicarbonates in water for growth. Microscopic plant life suspended in the water, phytoplankton, as well as large rooted plants, utilize carbon dioxide in the photosynthesis of plant materials; starches, sugars, oils, proteins. The carbon in all these materials comes from the carbon dioxide in water. When the oxygen concentration in waters containing organic matter is reduced, the carbon dioxide concentration rises. The rise in carbon dioxide makes it more difficult for fish to use the limited amount of oxygen present. To take on fresh oxygen, fish must first discharge the carbon dioxide in their blood streams and this is a much slower process when there are high concentrations of carbon dioxide in the water itself. Natural sources of atmospheric carbon dioxide include volcanic out gassing, the combustion of organic matter, and the respiration processes of living aerobic organisms; man-made sources of carbon dioxide come mainly from the burning of fossil fuels for heating, power generation and transport. It is also produced by various microorganisms from fermentation and cellular respiration. Plants convert carbon dioxide to carbohydrates during a process called photosynthesis. They produce the energy needed for this reaction through the photolysis of water. The resulting gas, oxygen, is released into the atmosphere by plants, which is subsequently used for respiration by heterotrophic organisms, forming a cycle. All of the limiting factors that are mention above can be found in common. Another important limiting factor that is necessary for growing and distribution such as humidity, pressure, salinity etc. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Chapter 3 Energy in Ecosystem The energy used for all life processes is derived from solar radiant energy. The sun is far from the earth about 1,490 billions km or 93 million miles. Energy come from nuclear reaction is similar to hydrogen reaction. It is the combination from atom to become the macromolecules such as to combine hydrogen (1.008 g) to become the helium (4.003 g). When combine 4 atoms hydrogen to be helium, each atom has a different mass: (4 × 1.008) – 4.003 = 0.029 g. Some of them are converted to energy. The rule of equation given by Einstein can explain the process: E = Mc2 E = energy (ergs) M = mass (gram) c = speed of light = 3 x 1010 cm/s Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The estimated that there is about 120 million ton of hydrogen had burn in the universe in a second. The earth receive energy about 5.5 × 1023 Cal per year or 100.000 Cal/cm2 /year. From calculator a half of these are used by transpiration and about 67.000 Cal/cm2 /year are used for photosynthesis and activities of organisms. The radiant energy produced in the sun travels through the space in form of waves ranging in wavelengths from 0.03 A to several km. While most of the radiations are lost in space, those of wavelengths from 300 mm to 10 m and above 1 cm (radio waves) enter the earth’s outer atmosphere. Even as the radiations pass through the atmosphere, some of them-the ultraviolet (300-390 mm) are absorbed by the ozone layer in the outer stratosphere. The energy reaching the earth’s surface consists largely of the light (390760 mm) and the heat radiations (infra-red). The dust and water vapors in the atmosphere also cause great changes in the amount of energy reaching the earth as some of it is absorbed or refracted back to the space. Wavelengths (λ) in Nanometers Wavelengths (λ) in Meters Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 3.1 Demonstration of light wavelength 390-760 mm pass prism (Hancy, A.W. 1978). The radiant energy produced in the sun travels through the earth in form of electromagnetic radiation by pass the space in the universe. This radiation is energy that calls photon or quantum and can be calculated by the equation below: E = hv E = energy (HZ) h = Planck’s constant = 6.62 × 10-27 HZ/s v = hertz/s c = vl (speed of light = hertz × long wave) It is equivalent 3 × 1010 cm/s. So, if the long wave is longer it caused the hertz is shorter and the quantum also decreasing. Quantum can be reaction when their energy higher than critical reaction. For example quantum X can be shoot the electron of atom and can be produced ionizing radiation. The quantum of light that we can see it is lack of the energy to produce ionizing radiation. But it can be reduced CO2 by using H2 from photolysis which in form of component in high energy during photosynthesis. The infrared can not produce this reaction, but can be the molecular excitation that contains less energy. The energy used for all the life processes is derived from solar radiant energy. It is fixed by the green plants during photosynthesis by converting the light energy to chemical (potential) energy in the form of ATP (Adenosine Triphosphate) and NADH (Nicotine adenine dehydrogenase). Plants are the most obvious examples of producers; plants take energy from sunlight and use it to convert carbon dioxide into glucose (or other sugars). The mechanism of the process is explained below: Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The energy is fixed by the green plants during photosynthesis move through ecosystem via the trophic structure of feeding relationships. All of these can be explaining by thermo dynamic’s law: First law of thermodynamics: Energy can be changed from one form to another, but it cannot be created or destroyed. The total amount of energy and matter in the Universe remains constant, merely changing from one form to another. The First Law of Thermodynamics (Conservation) states that energy is always conserved; it cannot be created or destroyed. In essence, energy can be converted from one form into another. The second law of thermodynamics states that "in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state." This is also commonly referred to as entropy. A watchspring-driven watch will run until the potential energy in the spring is converted, and not again until energy is reapplied to the spring to rewind it. A car that has run out of gas will not run again until you walk 10 miles to a gas station and refuel the car. Once the potential energy locked in carbohydrates is converted into kinetic energy (energy in use or motion), the organism will get no more until energy is input again. In the process of energy transfer, some energy will dissipate as heat. Entropy is a measure of disorder: cells are not disordered and so have low entropy. The flow of energy maintains order and life. Entropy wins when organisms cease to take in energy and die. 3.1 Productivity in Ecosystem The energy used for all life processes is derived from solar radiant energy. It is fixed by the green plants during photosynthesis by converting the light energy to chemical (potential) energy and making it available to other organisms as food. We can calculate the energy storage in trophic level organisms. We can determine energy that is containing in each trophic level by measured productivity in 4 levels: 3.1.1 Gross primary productivity (GPP) is the amount of light energy that is converted to chemical energy by photosynthesis per unit time. Not all of this production is stored as organic material in the growing plants, because the plants use some of the molecules as fuel in their own cellular respiration. 3.1.2 Net primary productivity (NPP) is equal to gross primary production minus the energy used by the primary producers for respiration (R): Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version NPP = GPP - R Both gross and net primary productions are in units of mass / area / time. In terrestrial ecosystems, kg of carbon / m2 / year is most often used. 3.1.3 Secondary productivity The amount of chemical energy in consumers’ food that is converted to their own new biomass during a given time period is called the secondary production of the ecosystem. 3.1.4 Net community productivity (NCP) Net community productivity that means the rate of organic collection that is not used during a given time period, normally it calculated in the period of 1 year or 1 season. The NCP is equal to total organic substrate that consumer used minus the net primary productivity of the community: NCP = NPP - RH Energy flow through an ecosystem is follow by the second law of thermodynamic. Time table 3.1 The relationship between radiant energy produced in the sun travels through the earth and rate of secondary productivity (%). (Odum, E.P. 1971) Order Energy from Fixed by the Gross primary Net primary the sun green plants productivity productivity Highest rate 100 50 5 4 Average of 100 50 1 0.5 100 <50 0.2 0.1 community in suitable condition Average of biosphere Much of the solar radiation that reaches Earth’s surface lands on bare ground and bodies of water that either absorb or reflect the incoming energy. Only a small fraction Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version actually strikes plant leaves, algae, and photosynthetic prokaryotes, and only some of this is of wavelengths suitable for photosynthesis. Of the visible light that does reach photosynthetic organisms, only about 1 % is converted to chemical energy by photosynthesis, though this yield varies with the type of organism, light level, and other factors. Although the fraction of the total incoming solar radiation that is ultimately trapped by photosynthesis is very small, primary producers on Earth collectively create about 170 billion tons of organic material per year. Figure 3.2 The distribution of primary productivity rate in the major ecosystems (kcal/m2/year). (Kormondy, E.J. 1979) 3.1.5 Measurement of primary productivity It is difficult to measure of primary productivity from solar radiation that reaches Earth’s directly. So we can measure by indirect such as measuring of organic material or measuring of crude material that used for synthesis. There are many ways to measure for example: a. Harvest method This method is suitable for measuring of crops that can grow in one season such as rice, sugarcane, maize, and soybean. This method can start from initial growing until harvest. The primary productions rate is in units of mass / area / time. And then measure of energy from fresh weight. b. Oxygen method Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version In aquatic systems, primary production is typically measured by using oxygen method: This technique uses variations in the concentration of oxygen under different experimental conditions to infer gross primary production. Typically, three identical transparent vessels are filled with sample water and stoppered. The first is analysed immediately and used to determine the initial oxygen concentration; usually this is done by performing a Winkler titration. The other two vessels are incubated, one each in under light and darkened. After a fixed period of time, the experiment ends, and the oxygen concentration in both vessels is measured. As photosynthesis has not taken place in the dark vessel, it provides a measure of respiration. The light vessel permits both photosynthesis and respiration, so provides a measure of net photosynthesis (i.e. oxygen production via photosynthesis subtract oxygen consumption by respiration). Gross primary production is then obtained by subtracting oxygen consumption in the dark vessel from net oxygen production in the light vessel. The technique of using 14 C incorporation (added as labelled Na2CO3) to infer primary production is most commonly used today because it is sensitive, and can be used in all ocean environments. As 14 C is radioactive (via beta decay), it is relatively straightforward to measure its incorporation in organic material using devices such as scintillation counters. Depending upon the incubation time chosen, net or gross primary production can be estimated. Gross primary production is best estimated using relatively short incubation times (1 hour or less), since the loss of incorporated 14C (by respiration and organic material excretion / exudation) will be more limited. Net primary production is the fraction of gross production remaining after these loss processes have consumed some of the fixed carbon. 2. Energy transfers in ecosystem Organisms can be either producers or consumers in terms of energy flow through an ecosystem. Producers convert energy from the environment into carbon bonds, such as those found in the sugar glucose. Plants are the most obvious examples of producers; plants take energy from sunlight and use it to convert carbon dioxide into glucose (or other sugars). Algae and cyanobacteria are also photosynthetic producers, like plants. Other producers include bacteria living around deep-sea vents. These bacteria take energy from chemicals coming from the Earth's interior and use it to make sugars. Other bacteria living deep underground can also produce sugars from such inorganic sources. Another word for producers is autotrophic. Energy flow through an ecosystem by two ways: food chain and food web. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 2.1 Food chain A food chain is the path of food from a given final consumer back to a producer. Another definition is the chain of transfer of energy (which typically comes from the sun) from one organism to another. A simple food chain is like the following: Producer → Herbivore → Carnivore → Omnivore Rose plant → aphids→ beetle → chameleon → hawk Grass → grasshopper → mouse → snake → hawk In this food chain, the rose plant and grass is the primary producer. The aphids and grasshopper are the primary consumers. The beetle and mouse is the primary carnivore because it eats the aphids and grasshopper. The chameleon and snake are secondary carnivore, eats the beetle and mouse. The hawk is the tertiary carnivore because it eats the secondary carnivore, the chameleon and snake. The hawk eventually dies and its remains are broken down by decay-causing bacteria and fungi. v Food chain consists of 4 types such as a. Predator chain or grassing food chain This food chain, the energy fixed by producers (green plants) passes along the herbivorecarnivore-omnivore. This kind of chain consists of predator and prey. Phytoplankton → zooplankton → fish larvae → fish → hawk b. Parasitic chain This kind of chain consists of host and parasite, the energy pass along host through parasite-hyper parasites. Host → parasites → hyper parasite Chicken → chicken mite → protozoa → bacteria → virus c. Detritus chain This kind of chain start from decay and the dead organic substance (detritus) is fed upon by certain detritivores which in turn are consumed by other carnivores and then by higher carnivores. Thus most of the energy is passed through detritus to other organisms and such a food chain is calling the detritus food chain. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Warm → bird → snake Dead organic Fungi → mite in soil d. Mixed chain Mixed chain consists of many kinds of organisms such as producer, predators, and parasite. Producer → consumer → parasite Algae → snail → snail parasite Ficus → bird → bird mite 2.2 Food web In an ecosystem there are many different food chains and many of these are crosslinked to form a food web. Ultimately all plants and animals in an ecosystem are part of this complex food web. Hawks don't limit their diets to snakes, snakes eat things other than mice, mice eat grass as well as grasshoppers, and so on. A more realistic depiction of who eats whom is called a food web; an example is shown below: Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version It is when we have a picture of a food web in front of us that the definition of food chain makes more sense. We can now see that a food web consists of interlocking food chains, and that the only way to untangle the chains is to trace back along a given food chain to its source. The food webs you see here are grazing food chains since at their base are producers which the herbivores then graze on. While grazing food chains are important, in nature they are outnumbered by detritus-based food chains. In detritus-based food chains, decomposers are at the base of the food chain, and sustain the carnivores which feed on them. In terms of the weight (or biomass) of animals in many ecosystems, more of their body mass can be traced back to detritus than to living producers. v The food web stable because; • Producers are usually larger than consumers. • Some consumers can be consumed more than one trophic level. • So, if the size of the individuals’ consumer is changing quickly it will cause the food web change. In ecosystem consists of energy flow and inorganic nutrient flow in each trophic level. The inorganic nutrient flow is a circuit; the flow of energy is linear (Fig.3.3 and 3.4). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 3.3 Energy flow through the ecosystem Figure 3.4 Inorganic nutrients flow through the ecosystem The diagram above shows how both energy and inorganic nutrients flow through the ecosystem. We need to define some terminology first. Energy "flows" through the ecosystem in the form of carbon-carbon bonds. When respiration occurs, the carboncarbon bonds are broken and the carbon is combined with oxygen to form carbon dioxide. This process releases the energy, which is either used by the organism (to move its muscles, digest food, excrete wastes, think, etc.) or the energy may be lost as heat. The dark arrows represent the movement of this energy. Note that all energy comes from the sun, and that the ultimate fate of all energy in ecosystems is to be lost as heat. Energy does not recycle!! The other components shown in the diagram are the inorganic nutrients. They are inorganic because they do not contain carbon-carbon bonds. These inorganic nutrients include the phosphorous in your teeth, bones, and cellular membranes; the nitrogen in Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version your amino acids (the building blocks of protein); and the iron in your blood (to name just a few of the inorganic nutrients). The movement of the inorganic nutrients is represented by the open arrows. Note that the autotrophs obtain these inorganic nutrients from the inorganic nutrient pool, which is usually the soil or water surrounding the plants or algae. These inorganic nutrients are passed from organism to organism as one organism is consumed by another. Ultimately, all organisms die and become detritus, food for the decomposers. At this stage, the last of the energy is extracted (and lost as heat) and the inorganic nutrients are returned to the soil or water to be taken up again. The inorganic nutrients are recycled, the energy is not. To summarize: In the flow of energy and inorganic nutrients through the ecosystem, a few generalizations can be made: 1. The ultimate source of energy (for most ecosystems) is the sun 2. The ultimate fate of energy in ecosystems is for it to be lost as heat. 3. Energy and nutrients are passed from organism to organism through the food chain as one organism eats another. 4. Decomposers remove the last energy from the remains of organisms. 5. Inorganic nutrients are cycled, energy is not. 2.3 Trophic efficiency Trophic efficiency is the percentage of production transferred from one trophic level to the next. Trophic efficiencies must always be less than production efficiencies because they take into account not only the energy lost through respiration and contained in feces, but also the energy in organic material in a lower trophic level that is not consumed by the next trophic level. Trophic efficiencies usually rage from 5% to 20%, depending on the type of ecosystem. In other words, 80-95% of the energy available at one trophic level is not transferred to the next. And this loss is multiplied over the length of a food chain. For example, if 10% of energy is transferred from primary producers to primary consumers, and 10% of that energy is transferred to secondary consumers, then only 1% of net primary production is available to secondary consumers (10% of 10%). When energy is transferred to the next trophic level, typically only 10% of it is used to build new biomass, becoming stored energy (the rest going to metabolic processes). As such, in a Pyramid of Productivity, each step will be 10% the size of the previous step (100, 10, 1, 0.1, 0.01, 0.001 etc.). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 3. Ecological pyramids An ecological pyramid (or trophic pyramid) is a graphical representation designed to show the biomass or productivity at each trophic level in a given ecosystem. Biomass pyramids show the abundance or biomass of organisms at each trophic level, while productivity pyramids show the production or turn-over in biomass. Ecological Pyramids begin with producers on the bottom and proceed through the various trophic levels, the highest of which is on top. Trophic levels and the energy flow from one level to the next can be graphically depicted using an ecological pyramid (Fig. 3.5). Three types of ecological pyramids can usually be distinguished namely: pyramid of number, pyramid of biomass and pyramid of energy. Figure 3.5 Ecological pyramid The above energy pyramid shows many trees & shrubs providing food and energy to giraffes. Note that as we go up, there are fewer giraffes than trees & shrubs and even fewer lions than giraffes ... as we go further along a food chain, there are fewer and fewer consumers. In other words, a large mass of living things at the base is required to support a few at the top ... many herbivores are needed to support a few carnivores. 3.1 The Pyramid of Numbers Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Small animals are more numerous than larger ones. This graph shows the pyramid of numbers resulting when a census of the populations of autotrophs, herbivores, and two levels of carnivores was taken on an acre of grassland. The pyramid arises because; • Each species is limited in its total biomass by its trophic level. • So, if the size of the individuals at a given trophic level is small, their numbers can be large and vice versa. • Predators are usually larger than their prey. • Occupying a higher trophic level, their biomass must be smaller. • Hence, the number of individuals in the predator population is much smaller than that in the prey population. Figure 3.6 Comparison between two ecosystems of pyramid of numbers P = Producer C1 = Primary consumer C2 = Secondary consumer C3 = Tertiary consumer 3.2 The Pyramid of Biomass Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Ecological pyramids demonstrated of each trophic level expressed in Dry weight or Fresh weight or Calorie value/m2 or /m3. This pyramid indicated that the relation of organism in terms of energy flow between one trophic level to the next is clearly (Fig. 3.5). Figure 3.7 Comparison between two seasons of pyramid of biomass Biomass is fresh weight of living tissue or dead tissue, but can still working per area or volume. Dry weight is means that we take the sample of living thing to dehydrate by drying until constant such as dry weigh of rice. Fresh weight is means after we collect the sample and we can weigh it directly. Normally the sample contain water differ depend upon the kinds of sample, so fresh weight almost more weigh than dry weight. 3.3 The Pyramid of Energy The Energy pyramid indicates the total amount of energy present in each trophic level. It also shows the loss of energy from one trophic level to the next. An energy pyramid shows clearly that the energy transfer from one trophic level to the next is accompanied by a decrease due to waste and the conversion of potential energy into kinetic energy and heat energy. The energy pyramid is more widely used than the others because comparisons can be made between trophic levels of different ecosystem. It is, Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version however, more difficult to compile an energy pyramid than it is compile the other types of pyramids. The pyramid of energy represents net production at each trophic level expressed in 2 kcal/m /yr (Fig. 3.7). Figure 3.8 Pyramid of Energy P = Producer C1 = Primary consumer C2 = Secondary consumer C3 = Tertiary consumer S = Saprptrop Chapter 4 Material Cycles in the Ecosystem Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The growth and life processes of the organisms require about 30-40 elements. According to the necessary can be divided into three majors such as: 1. Macronutrient: that means element contain in the dry weigh of organic in the tissues. It varies from 0.2 – 1 % up such as carbon, nitrogen, oxygen, phosphorus, sulfur, chloride, potassium, calcium, magnesium, iron and copper. The amount of necessary is different depend on the species. So elements in this group were divided into two groups such as major macronutrient and minor macronutrient. 2. Micronutrient: that means element contain in the dry weigh of organic in the tissues. It is lower than 0.2 % such as aluminum, boron, brome, chromium, cobalt, fluoride, gallium, iodine, manganese, molybdenum, selenium, silicon, strontium, tin, titanium, vanadium, Zinc. Table 4.1 Comparison of materials Macronutrient Macronutrient Micronutrient (>1% dry weigh) (0.2-1% dry weigh) (<0.2% dry weigh) Element Element Element Symbol Symbol Symbol Carbon C Calcium Ca Aluminums Al Hydrogen H Chlorine Cl Boron B Nitrogen N Copper Cu Bromine Br Oxygen O Iron Fe Chromium Cr Phosphorus P Magnesium Mg Cobalt Co Potassium K Fluorine F Sodium Na Gallium Ga Sulfur S Iodine I Manganese Mn Molybdenium Mo Selenium Se Silicon Si Strontium Sr Tin Sn Titanium Ti Vanadium V Zinc Zn Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version A biogeochemical cycle consists of three general categories such as: (1) Hydrologic cycles. (2) Atmospheric cycles (3) Lithospheric cycles 4.1 Hydrological Cycle It has been estimated that the total quantity of water on the earth is 1,385,984,640 3 Km of which 97.54 % is in the sea, 1.8 % in polar ice caps, and 0.63 % in the most important cycle among all the materials is that of water. Water is not only vital for life; it determines the structure and function of the ecosystem. It has important interactions with the energy resulting in the variations of physical and biological environment. The cycling of all other elements is also dependent upon water as it provides the solvent medium for their uptake, and H+ for reduction of carbon dioxide in photosynthesis. The water cycle unites the various components of the ecosphere (hydrosphere, atmosphere, lithosphere and biosphere) into a whole. The water cycle is show diagrammatically in Fig. 2.17. The water from the oceans, lakes and rivers, etc. is evaporated by the solar energy. The water vapors gather in form of clouds and move with the wide over the earth. Later, these vapors condense and precipitate in the form of rain, snow, hail, dew, etc. over the earth’s surface. A large part of the rainfall occurs over the oceans themselves. While most of the precipitation as rain runs off over the ground through rivers and streams back to the oceans, some of it gets evaporated back to the atmosphere and some infiltrates in to the soil. Under the ground the water becomes accumulated over hard impermeable rocks from where it is extracted by man for his various needs. A very small fraction of water absorbed by the plants and consumed by animals, cycles through the food chain in the combined form. It is released again as vapors during respiration and also the transpiration of plants. The cycle operates at a very fast rate but the large differences in the distribution of water over the earth’s surface are responsible for the great diversity of life in different parts of the globe. Water collection Total water (%) Fresh water (%) Liquid of fresh water Oceans 97.54 - - Ice 1.81 73.9 - Ground water 0.63 25.7 98.4 Lake, stream and river Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version divided into two: - Marin water 0.007 - - - Fresh water 0.009 0.36 1.4 0.001 0.04 0.2 Atmosphere Figure 4.1 Water cycle 4.2 Element cycle in atmosphere Element cycle in atmosphere almost inform of gas. The distributions of these gases are slightly changing or constant. For example the cycle of these elements: oxygen, carbon and nitrogen. 4.2.1 Carbon Cycle It is among the simplest cycles of all others (Fig. 4.2). The carbon dioxide is present in the atmosphere in small quantities about 0.03 % which is the source of all carbon that passes through the organisms along the food chains. The carbon dioxide on Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version being reduced during the photosynthesis gets incorporated in a variety of organic compounds which form the food of all the organisms. Some of these substances are oxidized during respiration to release back the carbon dioxide. The rest are oxidized in the decomposition process after death (or being wasted in excreta). The composition is a comparatively slow process and releases carbon dioxide gradually. During the earth’s long history, huge quantities of carbon were incorporated into the tissues of giant plants and animals that once inhibited the earth. However, their death did not result in complete decomposition of all the organic matter but their remains are now available in the form of fossil fuels (coal, petroleum). These storages of the past have undoubtedly created problems for man who is drawing on the atmosphere’s oxygen reserves to burn these fuels. It has resulted in increased concentration of carbon dioxide in the atmosphere. The carbon dioxide has the unique property of absorbing infra-red radiations. While the small quantities of CO2 were helpful in keeping the earth warm, the increased quantities have resulted in rise in the atmospheric temperature which affects the organisms adversely. Carbon is found in great quantities in Earth's crust, its surface waters, the atmosphere, and the mass of green plants. It is also found in many different chemical combinations, including carbon dioxide (CO2) and calcium carbonate (CaCO3), as well as in a huge variety of organic compounds such as hydrocarbons (like coal, petroleum, and natural gas). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 4.2 Carbon cycle (www.windows.ucar.edu/.../images/carboncycle.jpg) In addition to the above noted relatively simple carbon cycle, there is yet another significant part of the cycle that operates in the oceans. The oceans play an important role in regulating the carbon dioxide content in the atmosphere. The oceans contain about 50 times more CO2 than in the atmosphere, in the form of carbonates. The carbon dioxide dissolves in water to form carbonic acid which converts carbonates to bicarbonates. As the bicarbonates are dissociated during photosynthesis, the carbonates get precipitated. HO2 + CO2 H2CO3 H2CO3 H3O+ + HCO3 - HCO3- + HO2 H3O+ + CO3 - - The sea water being rich in calcium and being alkaline helps accelerate this process of carbonate deposition. Such deposits in the form of coal reefs and calcium carbonate rocks are common in the tropical regions of the oceans. In warm climates, high temperature and greater salinity and alkalinity favor the process and it is also reflected in thicker shells of mollusks. 4.2.2 Nitrogen cycle The nitrogen cycle is among the most complicated and significant cycles of the ecosystem. Nitrogen is a component of amino acids, proteins, and nucleic acids and is a crucial and often limiting plant nutrient. Through present in abundance in the atmosphere, Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version the gaseous nitrogen cannot be used by any organism unless it is converted to a reduced (NH4+) or oxidized (NO3-) water soluble form. Animals can utilize only organic forms of nitrogen (such as amino acids or proteins). During the cycle, both the reduced and oxidized forms are involved at one or the other stage. Only a few bacteria and blue-green algae are able to convert the gaseous nitrogen into nitrates and make it available for other organisms. The nitrates are reduced in the plant tissues to amino form and are then converted to amino acids and then to proteins. Both the plant and animal proteins are oxidized during decomposition of the dead organic matter, to nitrates or gaseous nitrogen. Thus, the cycling involves several steps which may be looked into some details. 1. Nitrogen fixation. The conversion of gaseous nitrogen into nitrates is termed nitrogen fixation. And it divided into two ways: 1.1 Electrochemical and photochemical fixation: it is partly done through electrochemical means during lightning. In the tropics where thunderstorms and lightning are more common, greater quantities of nitrogen are turned into nitrates. 1.2 Biological fixation: the other more important conversion is by the agency of micro-organism. Biological fixation is divided into two types: a. Symbiotic nitrogen fixers: the symbiotic bacteria Rhizobium is among the most important nitrogen fixers. It is associated mostly with the root nodules of leguminous plants. Similar symbiotic nitrogen fixing bacteria are also associated with the roots of species of Pinus, Ginkgo, etc. The most important major in mechanism of nitrogen fixation is enzyme nitrogenase, which is converted nitrogen into ammonia N2 → 2N (1) 2N + 3H → 2NH3 (2) The experiment found that used of energy to converted nitrogen into ammonia at less 147 kcal. The first reaction has to use energy at less 160 kcal. And the second reaction can produce energy 13 kcal. In nature is not necessary to use a lot of energy, because of enzyme nitrogenase can do it quickly. b. Free living nitrogen fixers such as blue-green algae, bacteria and yeast. - Blue-green algae such as: Anabaena, Nostoc, Tolypothrix, Thrichodesmium, Osicillatoria and Lyngbya. - Bacteria such as: Azotobacter, Clostridium, Rhodosperillum and Bacillus. - Yeast such as: Rhodotorula and Pullularia. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Azotobacter is the most active of the bacteria fixation. It is estimated by Hutchinson, 1944 that the biological fixation adds up to 140-700 mg/m2/year, biological fixation is the major. And fixation by electrochemical and photochemical fixation is 35 mg/m2/year. 2. Ammonification. The proteins in the dead organic matter are decomposed by a group of micro-organism to produce amino acids and ammonia. Each molecule of amino acid (as glycine) yields 176 kcal energy for the decomposer organism. The ammonia so formed is either released into the atmosphere or retained in the soil to be absorbed by the plants. Under certain conditions, it is oxidized to nitrates. High pH, low cation exchange capacity, dryness and high temperature favour release of ammonia as gas into the atmosphere. The organisms responsible for ammonification are mostly actinomycetes and species of Bacillus (B. subtilis, B. mesenterilus). Important bacteria responsible for ammonification from organic compound are ammonifying microorganism. The reactions given below explain the process: (1) From glycine H2NCH2COOH + ½ O2 2CO2 + H2O + NH3 (2) From alanine CH3CHNH2COOH + ½ O2 CH3COCOOH + NH3 3. Nitrification. The conversion of ammonia to nitrates again mediated by a group of micro-organisms is termed nitrification. It is completed in two steps. Firstly, the nitrites are formed and later nitrites are converted to nitrates. The first phase is accomplished by bacteria like Nitrosomonas, Nitrosocytis and Nitrosococcus, and the second phase is brought about by Nitrobacter and Nitrosococcus. Both the steps yield energy as shown in the equations below: 2NH2 + 3O2 2HNO2 + 2H2O + 66 Kcal HNO2 + ½ O2 HNO3 + 17.5 Kcal 4. Denitrification. Some nitrates in the soil are reduced again to gaseous nitrogen or oxides of nitrogen or ammonia. Mostly in the anaerobic conditions, the oxygen in the nitrate molecule is used by the micro-organisms to oxidize carbohydrates. Some sulfur and iron bacteria also utilize this oxygen for their chemosynthetic activity. Some of reactions given below explain the process: C6H12O6 + 6KNO3 5C6H12O6 + 24KNO3 6CO2 + 3H2O + 6KOH + 3N2O + 545 Kcals 30CO2+ 18H2O +24KOH+12N2+ 570 Kcals/mole of glucose The process of denitrification and other related steps of nitrogen cycle are shown in the (Fig. 4.3). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 4.3 Nitrogen cycle (www.epa.gov) 4.2.3 Oxygen cycle Oxygen, like carbon and hydrogen, is a basic element of life. In addition, in the form of O3, ozone, it provides protection of life by filtering out the sun's UV rays as they enter the stratosphere. In addition to constituting about 20% of the atmosphere, oxygen is ubiquitous. It also occurs in combination as oxides in the Earth's crust and mantle, and as water in the oceans. Early in the evolution of the Earth, oxygen is believed to have been released from water vapor by UV radiation and accumulated in the atmosphere as the hydrogen escaped into the earth's gravity. Later, photosynthesis became a source of oxygen. Oxygen is also released as organic carbon in CHO, and gets buried in sediments. Oxygen is highly reactive. A colorless, odorless gas at ordinary temperatures, it turns to a bluish liquid at -183° C. Burning or combustion is essentially oxidation, or combination with atmospheric oxygen. Figure 4.4 shows a very broad overview of oxygen cycling in nature. The environments of oxygen in numerous reactions make it hard to present a complete picture. Oxygen is vital to us in many ways (beside the most obvious--for breathing). Water can dissolve oxygen and it is this dissolved oxygen that supports aquatic life. Oxygen is also needed for the decomposition of organic waste. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Wastes from living organisms are "biodegradable" because there are aerobic bacteria that convert organic waste materials into stable inorganic materials. If enough oxygen is not available for these bacteria, for example, because of enormous quantities of wastes in a body of water, they die and anaerobic bacteria that do not need oxygen take over. These bacteria change waste material into H2S and other poisonous and foul-smelling substances. For this reason, the content of biodegradable substances in waste waters is expressed by a special index called "biological oxygen demand" (BOD), representing the amount of oxygen needed by aerobic bacteria to decompose the waste. Figure 4.4 Oxygen cycle (www.telstar.ote.cmu.edu/.../cycleoxygentest.png) 4.3 Lithosphere Cycle 4.3.1 Sulfur cycle Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The sulfur cycle is very much similar to the nitrogen cycle in as much as it also involves the oxidized (SO2) and reduced (H2S) phases and that the plants can use it only in the form of sulfates. However it differs from the nitrogen cycle by the fact than the residence time of sulfur in the atmosphere is too small, and the reserve pool of the element is in the soil. Sulfur is gradually made available to the plants in the soil by the activity of sulfur bacteria which can use elemental sulfur. Some quantities are added to the atmosphere by the burning of the fossil fuels. Later sulfur dioxide and hydrogen sulfide return to the soil as sulfate (or sulfuric acid) with the rain. Only certain lichens can use gaseous sulfur dioxide. The sulfur is incorporated in the tissues of organisms in the form of proteins. The decomposition of proteins releases sulfur. Under aerobic conditions Aspergillus and Neurospora, and under anaerobic conditions the bacteria like Escherichia and Proteus are largely responsible for the decomposition. Under anaerobic conditions as are common in submerged or waterlogged soils, sulfides particularly hydrogen sulfides are formed. Here the bacteria like Desulfavibrio, Echerichia, and Aerobacter utilize the oxygen in the sulfur molecule to oxidize carbohydrates and other organic compounds to obtain energy. These bacteria used sulfate to fix hydrogen, the reactions involved can be expressed by the following equation: 4H2 + H2SO4 H2S + 4H2O Another step in the cycle is the oxidation of elemental sulfur and sulfides into sulfates by bacteria like Beggiatoa and Thiobacillus. Thiobacillus thio-oxidans remains active under highly acidic conditions (up to pH 0.6) and can convert sulfur to sulfuric acid of 10 % concentration. A generalized sulfur cycle is shown in Fig. 4.5 Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 4.5 Sulfure cycle (www.scienceclarified.com) 4.3.2 Phosphorus cycle The phosphorus cycle (Fig. 4.5) is relatively simple but assumes great importance for the reasons that phosphorus is mainly the energy carrier (in form of ATP) and it is now known to create many environmental problems. The phosphorus is made available to the plants from the phosphoric rocks by show weathering process. The phosphates are metabolized in the plant body and pass through the food chain. The decomposition of the organic matter releases the phosphates in the soil for reutilization. The element has no gaseous phase and at no time occurs in the atmosphere except in the form of solid particles. The water soluble phosphate is lost through runoff to the deep sediments of the oceans from where the return to the earth is not well understood so far. It has been said that some quantities of phosphorus are returned back to the earth in the form of bird guana (excreta) and fishes. The excessive use of phosphoric fertilizers and the detergents are considered responsible for accelerated loss of phosphorus to the oceans and other fresh water bodies. The harmful effects of this increased supply of phosphorus will be discussed later. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 4.6 Phosphorus cycle (www.ikzm-d.de) Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Chapter 5 Species and Individual in Ecosystem Species and individual is a little unit of the community, the different community will have species and individual of the different life or at the same community, it isn’t necessary to consist from the same species life. The things that importance to be both consider as: habitat and ecological niche of that life. Habitat means the area of the life lives there, such as Donex sp. lives at beach that water up and down. Achatina fulica lives in underground which highest wet. Ecological niche or ecology limited is significant more than habitat out of it means to habitat area , it still means to position, niche in community and include the situation of that life on conditional environment that will be able to live there. So, according to ecological niche, they divided into three types such as: 1. Spatial or habitat niche 2. Role that concern with the energy moving and reaction behavior to environment physical and biology, including these changing 3. All environment s have good condition to be a life can able to live and altogether 5.1 Ecological Equivalent In the different geography, if there is the same physical situation. It will be happened the same system, but the species consists in the same ecological niche in the different geography, it is not necessary the same all, such as: the grass field ecosystem species of grass and grass consumers are not necessary to the same, that these difference will be more different between the geography area that divide many ways or the different continent. Example: we can see in these cases such as: grass- eating animal in grass field of four other continents, we can see that herbivore that live nearly border continent, it will be contacted to taxonomy each other. In opposite way, if in the continent that far away it will contact, the living thing that live in different geography, but there is the same ecological niche, these life beings have ecological equivalence. Continents Kind of herbivores North American bison, pronghorn antelope Eurasian horse, saga antelope Africa zebra, antelope Australia kangaroo 5.2 Character Displacement The two species that a characteristic is quite similarity and also their lineage, when they are separate geography or they are allopatric to each other they will be similar, whereas when they are living at the same geography or they are sympatric to each other they will be different. This evolution is call character displacement. For example of this case we can see in the bird nuthatches; Sitta spp of two strains (Vaurie, 1951) explained that bird nuthatches two strains are homologous and they are similar and difficult for identifying. If the bird two strains are sympatric its can be different and easy to identify, especially their lips and black line on their faces are different, one strain has a small line and another one is bigger (Fig. 5.1). The different in size of their lip is good for find different food. As descries above character displacement can cause in term of adaptation such as: To reduce competition and to increase different ecological niches. To produce species diversity and genetic segregation Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 5.1 shown the two strains of bird character displacement (Odum, E.P. 1971). They have more the same appearance when they have been allopathic to each other and they will be clearly difference, when they have been sympatric to each other, as we will see from ‘mouth and black line on their faces of birds. 5.3 Natural selection and speciation The speciation is happened when it changes the appearance in genetic has prevented from isolating mechanism. Casual, they are happened two cases such as: when they divide from ancestor by geography situation (allopatric speciation) and are happened by not to be divided from geography, because of sympatric speciation. Charl Darwin has summarized the knowledge that he got from his survey: the closing life in blood will be from the same ancestor .then he has done the theory of natural selection that has explained motivate point that happen development and happen the other life. This theory has summarized contents that: which the life has adjusted to more natural , it can be able to live in general .until able to descend from to the future and the life has not adjusted, it will be disappeared in natural Variations of lineage are happened through process natural selection when it has a lot descend ages it will be happened a new life. As in case of Eohippus that has the same appearance with horse right now, but there are short legs , when they have given children and some one is new appearance as its legs are more longer than one and new appearance children can adjust with environment better than on, they can live and descend until now , when they have mutation appearance and they have rapid result to children, because they can expand to hybridize very much and more rapid so these appearance are expanded to population and finally have new species horses as nowadays . Horses (Mesohippus), these horses have different from Eohippus that are ancestor of them for a long generation time. The producing of new species that we had explained above. It is a new sympatric species in general, they will happen with high level vegetable. Nowadays the human have a role to do these species by adjustment the genetic for response to themselves. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The happening a new allopathic species, is able to happen when they are separated from the old earth of parents thus happen from external barrier such as :mountain and sea, so there are adjustment with new environment in the same time there are always new union of gene combination and genotype until there are different appearance from the old and finally became a new species life In fact, the old separated species may be opportunity to reunion with the old population as the Fig.5.2. For example , the becoming a new species are development of birds on Galapagos finch, as Darwin discover that: the happening a new allopathic species, nowadays these birds have fourteen species, every species have ancestor are sparrows that eating weed on the earth , they immigrate from America continent, as picture 5.3 means to the appearance of other species birds that there are adjustment from the same ancestors, but there are adjustment to find the food in different location , such as : the group that eating vegetable , weed in the ground , there are three species , find the food on cactus , two species , group that find vegetable weed in the ground and on the cactus one species , out of that find the food on the other trees , and there is one species as camarhynchus pallidus find the food along the trees like a Huakhuan bird they use its mouth to bite cactus pin and then use its mouth along to cactus hole and then insects come out there and the birds immediately eat them. These cases are adjustment on behavior of survival to become a lot species that we call adaptive radiation Figure 5.2 the way to be population isolated When the population are isolated and separated from the old completely population on preventing external barrier. B.C.D. when the barrier is finished, it make the population that are separated come back to be union more, perhaps it still does not has changed appearance in genetic (B) or it will be changing genetic appearance when they have union they become hybridization in some Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version group (C) or it will become union in genetic appearance had completely changed when the living areas are together, it become to sympatric (Suthers, R.A. & Gallant, 1973). . Figure 5.3 to show radius in adjustment of rice bird in fourteen species, this makes structure of their mouth different, including habit to find food differently to avoid conflict. (Suthers, R.A. and Gallant, 1973). 5.4 Behavior All species of life beings have how to react environments happen differently. It begins from the prokaryotic that they are reacting to environmental in many ways, sometimes it look more difficult than we think. Their reaction might happen quickly or slowly depending on their special character of species. Reaction to the change of external and internal environment of the life beings that is called behavior. So, behavior of life beings have changed all the time because life beings have to process adjustment to environment changed quickly. 5.4.1 Behavior of plant Plant can also show the behavior to the change of the environment but there is different from behavior of animal in common. Behavior of animal is happened by coordination among nervous, bone and muscular systems, including the out and in glands. Plant show reaction by moving growth slowly, it is not able to see clearly and quite the same, even different species. Such as the leaning for bright (positive phototropism). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Growth of root according to pulled power of the earth ( positive geotropism).growth of stem along with way opposite to pulled power of the earth ( negative geotropism) while it is seen clearly because of pushed power such as going down of the sunk grass Behavior to the change of environment in the plant is divided into two sorts, they are (1) reaction because of growth that happen from difference in the expansion rate of stem cell in all the sides and (2) according to not concerned growth that happen from pulling cell bigger , response like this happen after growth fully. response because of growth happen from difference in stretching cell in each side , there is concern with hormone level in each cell in some parts of different plant such as bending of branch and leaf which is caused from cell in the above side of branch that there is more expanse that the below quickly. Becoming angle of branch and stem to become bush in many ways of the tree happen each place. Which is defined as response to environment to grow up and expand itself reaction of plant is not concerned with growth which it can be seen in general such as going down of the sunk grass at night and going up at day, going down and up of leaf in this case, it night be caused from the change of pressure in melting of leaf cell which it has reaction to bright .for example if the pressure of melt element in leaf cell is high, it will bloom, becoming fragrant of night flower at night and stopping fragrant at day , that is reaction to bright and temperature together , in this case of evening blooming flower , this flower will be up in the evening and at night, noon blooming flower will be up fully at noon , going down of leaf at less bright or at dark is also reaction to the change of bright quantity The blooming of plant is the response to environment which it is defined as a behavior of plant. Environment such as photoperiod or day length, temperature etc, all of them have key role for blooming of plant. Some plants are short day plant such as strawberry need a little photo period for stimulating bloom. Some plants are long day plants for example wheat, potato and onion must need photoperiod much every day for stimulating bloom, behavior of bloom reaction photo period of plant s are not equal, this behavior can be seen as usual in the plant of warm zone and cold zone because of photoperiod in each season has much difference, therefore, plant in these zones have difference from tropical plant namely corn, custard, cucumber, coconut, carambola and others also. During blooming of these plants must not depend on photoperiod. Reaction to the change of environment has another sort that is open-close of cell ( stomata) where it is a place for changing the air whenever cell is strong it will open and whenever cell is weak it will close , that the stem soak water , that the leaf become torn, dried leaf and wax cover bark and other sorts . All happen according to the nature to adjust an existing in the different environments for example drought, flood, pollution, being interrupted or damaged and etc. 5.4.2 Behavior of animal Behavior of animal is result from coordination between heredity and environment which gene is heredity unit and control expanse of parts of animal that become key factor causing behavior for example nervous, hormone, muscular systems and others also, while environment or experience are met by animal, behavior will be changed later much or little, it depends on its case and each body of species, we can not define heredity and experience, which will show key role more to cause behavior. What a difficult behavior depends on key factor of growth as shown in graph that cause that behavior. example growth level of receptor unit , data processing center , order and sense responded unit in animals , behavior of animal will happen as procedure as summarized in graph below. Sense receptor unit means cell react other things very quickly and it will change energy received from stimulating of environment to sense current through nervous lines Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version and send sense to central nervous system or data processing center and order . there are many forms of sense receptor unit , it may consist of little cell until it may consist of many cell to gather and become sense organ for example ear, eye , nose , tongue and skin in high level animal, for low level animal for example protozoa , sponge ,they have not still nervous system that bring sense current quickly but some parts of body that it has duty as nervous system such as coordinating fiber of paramecium, sense receptor unit of high level animal will connect nervous system, if it is stimulated by sense receptor unit which each has duty and react quickly to only a stimulated power such as chemoreceptor will be stimulated by appreciate chemistry in quantity of two or three molecule. Basic physiological behavior Almost behavior of animal is related to daily living for achieving good life. As the example of basic behavior as follow: Maintenance behavior Daily living of animal , bright is key external stimulation to make animal start their activities , animal which find out food at day , it will start its activities early morning (sunrise) while animal find out food at night , it will start its activities at sunset ( shine less until mid night) , however , its activities of daily living is not only for finding food , it also rest , sleep or not any more , while its time leave it will use for finding food , eating and clean its body , behavior of taking care of itself of bird and mammal have many ways and very interesting which all behavior shown is adjusted with environment and living such as preening and grooming of mammals . mammals like to rub its body with things using mouth lick or bite and nail scratch , for the bird like to use beak peck at its feather, shake feather, use oil from gland above anus to help preening , bathing , dust covered and sun feather. There is also have many behavior concerning to taking care for itself of mammal such as covering its stool, putting out tongue to relieve hot. 2. Habitat selection All kinds of animals have behavior to select habitat to escape danger and being suitable for living, engendering for generation to generation, this can be seen from low level animal such as protozoa until mammal. It is believed that it is heredity to show by nature and imprinting is first .learning, especially experience when it was born which crisis phase was remembered with environment in touch well. This is key role to select habitat and it is transfer to generation to generation for example fish remember river where it leave roe every year. There are many factors to select habitat namely force with other groups. there is enemy a hunter, climber violate , factor of physiology and chemistry in each place , some animal like to live in the place where it was born forever but some move to other places , mammal which move to other places , most of them are Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version males , while the bird move to other place , it is female . Because o avoiding breeding with the same group (in breeding) and avoiding taking by force in the same group Habitat selection of animal nay depend on heredity which become key controller, but showing behavior can change when it is forced by environment long time enough until adjustment 3. Foraging behavior Foraging and eating food behavior is important behavior in living of animal which there is impact for escaping to exist its group. Animal like to adjust its body and behavior to forage as amount as energy used, besides it think about safety at foraging, including fighting may happen at the time as well. So animal has to find out the appreciate place to forage and the most convenient factors .example , there is Great tit par us major study that it will hide to forage in general areas later, it will forage at the place with most food , this is behavior of usefulness ( exploitation) so bird has to find information about where the food is much first and then it will forage there, in fact , plenty of food in the places are not the same and difference of food that animal must choose food what it like less or not suitable for hunting and big food will not be seen in general, so most of them will hide to forage in most appreciate areas, besides it can select the place to forage already , it also think about its safety , so animal like to forage in the place covered or it is necessary to forage open air , it spend the shortest time, taking food by force in the some species or different species is a problem for animal to adjust and free from competing with behaviors for example foraging different time distribute food at the shortage and gather to find food Another factor which hunter meet when it start namely plant and animal as food change kind and amount according to season , it make animal adjust after, at least , it has to adjust to find many kinds of food and in the long time , there will be adjustment along with food changed until it make adjustment permanently in the shape and behavior example hiding and catching bait, dissimulate or copy lesson from dangerous less animal to trust bait and ease to catch bait and keep some food for at the shortage , eating many kinds of food 4. Social behavior Social behavior expresses relationship with other members in the same group which consists of showing itself as leader, protecting boundary and behavior about all engendering examples flirting, choosing partner and having sex, bringing baby up and other behaviors, to transfer its group successfully Competition and aggression like happening among members in the same group and different group but showing off in the same group reduce violation to avoid danger to life which may damage its population by stopping of leader, proclaiming itself as leader cause order and confess leader ‘s power , most leaders are strong animals , having good experience in living and be able to win other ones in the same group because of this , leader has chance to choose partner, sex, food and other resource first 5. Dominance hierarchies Fighting among members in the same group cause from need of living as the same. Such as food and habitat, fighting will happen between males and barrier boundary or not expressing behavior in protecting boundary will often happen when living condition change such as food and habitat conclusively animal will protect boundary for object in key renderings three types 1. The place where food can serve long time 2. Increase the chance to have sex 3. Increase the chance to bring up baby in the place with food perfectly Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version As the case above can conclude that behavior in protecting boundary concern with ecology very much including habitat and density of population so behavior in protecting of boundary is the same as adjustment itself to ecology to use habitat existed effectively 6. Reproductive behavior Process of reproductive by using gender, it is seen that male has chance to produce baby more than female because male can produce sperm much every time that have sex and can connect to egg from female a lot during life. So male will find female to cross-breed and can choose more than one , there fore , there is cross breeding in many systems which the type of cross breeding cause looking after type of cross breed in animal are following 1. Monogamy is cross breeding between a male and a female (only a husband and a wife) which they may live together forever or only breeding season in this case, parents help each other to bring up roe and baby example hornbill and gibbon 2. Polygyny is a male with more female together or one by one, in the female will bring up egg and baby example rice bird, most mammals, lion. 3. Polyandry is female with male more than one at the same or different time. In this case, male bring up baby example bird under water, pond bird, bird with short neck and quick feet 4. Promisculity, in this case male and female can have sex in group; any gender can bring up egg or baby. Behavior of a animal impact to another or others in the same species Social behavior is communicated behavior in the same group of animal. Communication behavior helps descending a lot. Example showing its art before having sex, communication can be used many ways example communicating by sound, action, touching or chemistry Bee will communicate with dance along with vertical side around beehive if the food is nearby. It will dance round which it will dance round a direction then it will dance round another direction, other worker bee will fly out of beehive every direction to find food near beehive Communicating by chemistry of many kinds of animals will put out chemistry to stimulate other animals in the same species, this chemistry is called pheromone, this element may be used by encouraging sex or used for lead-way example moth has pheromone which female send out, it can stimulate male far away 3 km, ant is seen that it climb after each other, as line in the group of moth by making pheromone of queen In high level animal , some mammals make pheromone which it has bad smell , it has specific gland near gender organ , example rabbit and deer which people brew them for perfume , in reproductive season, male dog use its nose smell female gender organ area to stimulate having sex Physical contact, this behavior has most importance in mammal because mother will hold baby to keep warm always to cause more development in emotion then baby is feed with milk and baby bring up well. They will not cause social problem. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Lesson 6 Population The life consist of ecological niche as the life population of any group, thus it will be producer role, consumer and digestion. The study of population is a basic knowledge to study and be able to know about the word “population” mean is a group of individuals of the same species live together in the same place on one distance, say that “population” such as: a crowd of turkey, shoal of tilapia, crowd of buffalo, population usually is composed from each individual of living thing in the same kind. The basic style can measure population is size and density of population. Motivate density of population chance it such as natality, mortality and migration, thus migration composes immigration and emigration. The populations have to living thing in the single species some population should live in some place, some distance time, they create population density which perhaps it changes by the size of population maybe increase or decrease. The populations will distribution of age which means that has a difference age in the each other group of population mien with total population. Which populations communicate with another population in one style such as: hunter, parasite and helpful together. 6.1 Population Density. Population density means that member of population for place, as goat is 50 per 1600 maters for. Living things live in the water and land, which calculate population density with evolume unit as Frankton 3 billion per raise up third maters, which biological measure style of weight die who act to be able to find population density maybe species, so that population density separate 2 styles. Thus it has crude density mean of the number or atom. A: Crude density means number or metric system biological metric system per all surface units or volume. B: Ecological density means number or metric system per surface unit or volume that population live Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version (Habitat). For sample: a area in forest 50 kilometers have Tonchard about 10.500 but total analyses see Tonchard born in area only 30 kilometers, so Tonchard density have as below: all number of Tonchard Population density = 10,500 = All surface 50 all number of Tonchard Population desity = = 210 Tonchard/ Km3 10,500 = Place for live = 350 Tonchard/ Km3 30 When aalyde for fish density meet: when water decrease in dry season, total density decrease too, but density ecology increase, because fish come to joinly and live in smal pont that have a little water. Hundred birds will hatch in distance high eclogy density, because they have enough food for their baby. 6.2 Density Mearsurement There are many ways tofind population density, which up on characteristic of populatiion what kind of them or movement and what activity. Analyse for population density by calcute from 2 bigs rule as: absolute densityof population by directcount or by randomsampling population relative density is to search for density of the same kind but live in other place. 6.2.1 Real population density. This model can count many ways as: 1. Total count: when they have a tittle population, don’t move or move slowly such as: teak wood in forest, wild eleplant, people in bus, student in class or census population. This way is so long, use a lot of expense because we have to count every body of animals, but certainly maybe drive census or aerial photographs, and aerial surveillance. A: Drive census is driving foole road that we want surway then count animal which we meet when the car passed. B: Aerial photographs by photographs in plane, usually use to count wild animal in wide field. From photographs we will see every animal then take tthat photograph to look and count in lab. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version C: Aerial surveillance is usually use to count wild animal in wide field, and there have a little tree. D: random sampling is random from each place then compare to all surface. This model usually use but counter or randomer must not bias such as: don’t random sampling only bueatiful place or perfacet place. Random sampling will be diferance follow each kind of population and how to spreading such as: A: Small quadrate Population distribute equal such as: search for grass population by separate lines on schedule 1 m. If grass field have 8000 m we will get 8 square, then take number of each square and draw lots next begin count only square that draw lots then search for avreage of that squarehow many grasspopulatrion of grass in this square then multiply with 800 after that we will get grass population in that field. Case population not distribute equal. If population not distribute equal have to separate count by density such as: couting population in separate that have difference density as: place that high density and low density, by pick a sample to average than mutiply with all surface. B: bacteria couting Because bacteria is very high density that difficult to count. So, counting bacteria population we can make bacteria dilute as: stock 1.1ml put in to botle stock 2 which have sterillized water 9 ml so stock will gradually insipide 1/10. If make many time prevalence rate 1/10, 1/100, 1/1000,1/10000, 1/100000 as asample. Supposing that: count stock 5 get 40 cells from 1 ml that show stock 5 must have 40 cells per 1 ml because it can make bottle insipide 1/10. So that when we have 5 stocks. Bacteria population = 40 × 10 = 4,0 × 10 cells / 1 ml. C: capture and recapture method. Technical to make symbol than recapture and then capture for reinspect is a general use surway for assess animal populatiion size that usually move don’t stay usualand wide distribute for sample: fish, turtle, bird. This way we catch animal then stick symbol and then release to live with old group, after that catch they again, when we catch they again some of them have symbol and some of them don’t have any symbol. Finally, this is a information to use to average for population size that we had assess. There are many average and it is diferance ways to average assess for population number, some average Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version or this average give information about live and immigration or emigration with some population. Each average and each way were explain indetial ( in Heyer E.T A.L 1994). By use this average. Number that have symbol × Number of all catched Population = Number that have symbol all catched For example: catch fish from pond in a school 50 fishs, stick symbol in their body then release to old pont and then catch again we get 30 fishs. In 30 fishs only 5 fishs that have symbol , so population of fish in that pont. 50 × 30 All population of fish = = 300 fishs 5 For stick symbol have to follow the rule as below: 1. Time (distance) between : First search population number and next time shouldn’t long as first, the population wont increase or decrease in that time. 2. Long time to release the fish for make population which have symbol can combine to live with general population in old group. 3. Animal that have symbol and don’t have symbol have a chance to catch too. 4. The symbol have to adhesive and easy to see. 5. If population die, the population that have symbol or don’t have symbol has the same chance. 6.2.2 Search for population density compare. This way can not tell about population density, but can use to comparing that have many method such as: 1. Count the clue that animal live such as: Earthworm excrement, Crab hole, Chrysalis case. 2. Count the fish that catch in each time for use to tell about size of fish population on water that they live, how many or little of them. 3. Count excrement heap such as: rabbit, dear, pig and elephant excrement for sample. It can use to mark indicator to tell body size of population. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 4. Use snare to catch them such as: mouse trap, firelight can tempt insect. 5. Look for food quantity that they eat such as: looking for pig population by leave some food quantity in a distance then watch the food in at last, there are many or little food. 6.3 Factor that effect to change population density. Population density maybe usually change, because of many factor such as: natality, motality, migration. Population density change can show by communicate map between each factor that disturb population to change as below: Immigration (+) (+) Natality (-) Density Mortality (-) Emigration - Natality and immigration can make population density increase, show by (+) - Mortality and emigration can make population density decrease, show by (-) - 6.3.1 Natality Natality mean natural ability of population may increase in demography, number of population increase in a distance call: natality rate, this natality including increase number by any way such as: hatch, born germinate and divide. Birth rate of population show from symbol below. ÄNn When B= Ät B: Mean birth rate. ÄNn: Mean number of new mumber make from all population. Ät: Mean past time. ÄNn Or when b = Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Ät b: mean birth rate per one unit of population. N: mean all population or just one part to make new member v Birth of population has two ways: A: Maximum or absrute or physiological natality Mean birth underneath a environment don’t have limit factor.Just maximum increase population in theory this birth rate can looking by observe engender rate of each population, which they live in suitable environment at testrom or maybe assess value of it. From natural, because by natural the population usual have maximum birth rate in a distance of year, thus distance time have suitable environment. B: Ecological or realized natality mean increase rate of populatiion underneath environment factor limit also, this birth rate often move and maybe change follow size and consistency of population, include environment anatomy. To analyse main birth rate will analyse in one year .For population that have long round life, for short round life part maybe use one day for living or more it is up on suiable. For the factor that communicate with birth rate, there are many part such as: distance time can make hybridize, number of eggs or baby born in each time, give egg rate or give birth, ratio of sex that communicate with animal hybridize. Monogamous animals but polygamous animals maybe have difference hybridize rate. 6.3.2 Mortality Death is a natural event of population, a cause to decrease population density. Death number of population in a distance can call: death rate. In populatism symbol show about death rate in mathematics use the same of birth rate and the same style death of population maybe separate to 2 parts. A: Minimum mortality decrease population just only theory, that have real value in each population , according they era determind by length of life physioligical longevity livingthing that specy especially they era not contact with any limit factor. B: Ecological or realized mortality mean death rate of population underneath limit factor environment, the death happen under natural environment. Thus, this death Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version rate often move and maybe it will change by size and population consistency, hold with anatomy environment. This is other kind, which usual use such as: specific mortality mean number of population death under limit distance, that average to percent of population when we start surway. Death rate of population in each period age really difference, maybe can show by table call: life table or can show by curve call: survivorship curve, usually use because we can look easier. Analyse for living which useful then analy for death, curve of living can draw from number of livingthing information that the livingthing stay at verticalcoordinate with each distance time thus stay at horizontalcoordinate as a Figure at 6.1 Figure 6.1 show about the kind of living draw from number of living population per 1,000 log scale verticalcoordinate, average to percent of age: A. convex curve, B1. stairstep curve, B2. Theoritic curve, B3. Sigmoid curve, C. concave curve. (Odum, E.P. 1971) 6.3.3 Migration Migration mean population moving from this place to other place. Normally will feeding ground and breeding ground,that is a activity which we always see in many kind of animals such as: bird, mammal and fish era for sample sometimethese animal travel Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version very long for many hundred and thousand killometers, then reture that call: reture migration. Usual many kind of animal have their boundary to live and look for food especailly their own boundary, which we can call: home range and they have their special boundary which tight protact we call: territory. 6.4 Population Growth The population have their own grouth model or increase certainly number, they can seerate to many model and can mesure the population grouth as : When we have measure population of livingthing then analyes it, after that we will get each curve as Figure 6.2 below. Figure 6.2 population growth curve. First distance like a “ S “ that the distance have a bit livingthing and lag phase. Then increase population number, birth rate higher than death rate which we can lok easy the curve very steep ( II ) log phase if we take population change in this distance to change to curve in log then get straight curve that increase like Geometrical, next population increase very slow and stationary phase or dynamic equilibrium which birth rate and death rate era equal because limit environment and ( IV ) at last exlinetion the population decrease very fast, death rate higher than birth rate maybe all of them will die. Birth rate and death rate is a factor that control population growth. Birth increase population but death decrease population, if birth rate more than death rate population increase only and if death rate more than birth rate population will decrease. Relation btween birth and death are not certainly, population are often increase like Geometric Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version progression and they wont increase when population stay at some level, the curve will straight follow horizontally beside that population release and collect poison is a cause to decrease birth rate to equal with death rate, population only stay at level don’t move up and down ( like a Figure 6.3 A, B and C ) Figure 6.3 population growth curve A: Show population increase like Geometric stay at some level don’t move. B: Drosophila growth that feed all the time . C: Show sheep population in anniversary 120 years. The drosophila when population density increase eggs rat will decrease and population stable but, if drosophila which we try to feed in bottle and continue feed on, Population will decrease and all of them die because of they missed food or infection disease on the Figure show about feeding Frangton by two kinds of food ( Figure 6.4 ) In natural the livingthing have their own control population size at when they stay at some level population are not increase for sample: flour of bug if they are have high population density they will release poison to their baby and adult will lose hybridize , so if they have a lot of population the poison is a lot too it is good control of population size. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 6.4 Increase plankton population curve Figure 6.4 Graph shown increasing of plankton populaation. Population size not change or Biology factor control in some population group such as: flour bug for sample, but only abiotic factor. Result to change population size such as: bird, fish, butterfly they migration when the weather cold to look for food in warmer place John Emlon does a test with mouse by giving food 250 Kram everyday,mouse increase very fast and food not enough the mouse begin emigration util birth rate equal with escape migration rate is a result to stationary phase population show food is a result to emigration of population. Next the same test but mouse can not emigration when mouse increase a lot util food not enough birth rate decrease and population not increase last time give food to they until they be lelf the mouse increase a lot and they can not emigration, the mouse begin to bite each other because place to stay is narrow all baby are die population decrease because of they are do not have enough place to live. From summarise test result: population size make factor below: 1. Food is livingthing need enough energy from food for living, if food is not enough for the growth livingthing can not live, maybe weak and at last they will die. 2. Place: the livingthing is porsible place for their routine such as: for searching food, for living, reproduce and look after their baby. 3. Environment and other such as: quantity of water, temperature, weather and acid-base of that place. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 6.5 Biotic potential and environmental resistance Small population livingthing such as: bacyllus and amiba can always separate from one to two ( binary fisson ), they have very hihg growth rate population. If enviropmet has suitable population ability that can increase their size under suitable environment and don’t have any limit say that: biotic potential. This ability is only in theory, which in the natural has environmental resistance for control population growth is not too much, so environmental resistance make result to decrease birth rate or increase death rate or maybe both birth rate and death rate, if draw a limit line which natural resistance is K. so from logistic show about population growth rate we will get logistic logistic below: dN rN ( K – N ) = dt K dN = population growth rate dt r = increase rate per one population unit ( r only birth, not about death and migration that maen: b = r ) dN rN = dt So that, state has under the miscellaneous environment it will have result for extent of population will not receive equality timitation highest inagnifiction of population which has under environment said that “ carrying capacity that environmental has limit occur cause from missing food and residance, beside that it is occur suddenly limit that will do model make magnificaton of population is Figure (J) because of biology enery decrease suddenly after highest but perhape ability magnification of population size extent population increase and decrease oscillating pattern which has high increasion first time, Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version there are complet food and decreasion when the food wil miss food, so that there are increasion sometime such as: 6.5 which have this magnifiaction as we see the number of insect and vegetation for communicating between biology energy magnification of population and resistance of environment as it is show S in Figure 6-6. Figure 6.5 population growth curve like “ J “ folow by increase and decrease population in ability level perceive that show by a curve ( from Boughey ) Figure 6.6 Show about relation between biotic potential population growth and environmental resistance ( from Boughey, A.S. 1968 ). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 6.6 Population Fluctuation When population growth perfect population density will change up and donw direction folow ability level recince that maybe get result from conduct fluetualation enviroment or each other againstion in population group or both two reasons in natural maybe separate population size change to two styles as below: 1. seasonal flutuation, which is almost adaptation with change of enviropment follow seasonal fluctuation. 2. Annual fluctuation which maybe happen from difference between enviropment annual fluctuation has happen from each other againstion in populatipn such as: hunter, snatch and disease. Populatiuon density change fluctuation happen with most living things that season hybridize limit especial short circle of life and migration that animal eats only one kind food, animal population make decrease when food nearly does so we can see contract curve between hare and lynx as Figure 6.7 Figure 6.7 Hare and lynx population fluctuation curve. ( from: Odum, E. P. 1971 ) Hare population fluctuation curve show if hare population ( bait ) increase lynx population ( hunter ) increase too. If hare population decrease, lynx population decrease too. As cyclic oscillation Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 6.7 Population Age Distribution When we talk about population structure one thing that important is population ages make mean with animal ability reproduce that population live. In priciple population separate ages to three parts such as: - Pre - reproductive - Reproductive - Post - reproductive • If compare with people Beginning of age 1 – 15 years is beginning pre-reproductive, middle of age 15 – 40 years is reproductive, the end of age 40 and more than is post - reproductive.If we hold 3 distance ages to draw line up curve by pre-reproductive first the Figure as age pyramid. 1. Population are increasing because of birth rate as pre-reproductive have a bit population than reproductive. 2. The population desn’t move is a time that birth rate equal with death rate. 3. The population increase is a time that birth rate higher than death rate as Figure 6.8. Figure 6.8 Pyramid of age ( From: Odum, E. P1971 ) A: Declining stage B: Stable stage C: Growing stage 6.8 Spread in population group Characteristic spread in population group member can divide to 3 parts as Figure 6.9 Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 1. Divide random this divide quite rare meet in natural if we compare with other divide we can see this divide random when environment have one model or have rare limit factor come to concerning and they don’t make a group by themselve of number. 2. Divide uniform is order divide of member maybe happen when strong snatch between member or all member kill each other that live in the same place such as: small tree in forest have to snatch sunshine for live, bush grass in dessert have to snatch for wet as sample. 3. Divide clumped when member make group by difference size or the same size and this population group maybe divide clumped or uniform or two, three smalls group make other group as below: Random clumped, uniform clumped and aggregated clumped. Understood divide member has a resilt for population structure, useful for analyse that population group. Figure 6.9 Divide population maybe model ( From: Odum, E. P. 1971 ) 6.9 Population Aggregation Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Population aggregation because of many cause such as: ( 1 ) place difference in each place, ( 2 ) weather change in everyday and season, ( 3 ) descend model and ( 4 ) scial communication of high level animals. Some kind of plant and low level animals aggregation is up on distribute chalacteristic of organ that use to disseminate such as: seed and SAPOR as sample. Plant that have disseminate structure which and not more often density aggregation around their mother plant or aggregation around the place that bird aet seed and pour out, but for some grass that have solf seed or can fload in the wind easy, will general distributio, do not aggregation. When we consider about result of aggregation number which live see that the plant live by aggregation can make good defend to the wind more than stay a lone, and can save the water better, but when they aggregation of seed have the result by snatch sunshine and food but for crow aggregation some kind of animal maybe have more advantage, because good lasting for poison environment more than stay a lone. For human, have many evolution about this story and aggregation or human social like to importance for living Alee’s research, he make a rule call: population growth and live will up on member size when they live with each other in group is importance, some kind of population have good growth and high ability for live when they have a little population, but some kind of population growth and have good ability for live when population stay at middle level, this rule call: Alee’s principle, which show by curve as Fig. 6.10. Figure 6.10 Show about growth rate and live when they have difference population density. A: Some kind of population grow and live when they have small size of population. B: Some kind of population grow and live when population stay at middle level. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 6.10 The communication between 2 livingthings in a community In livingthing group when two species of them live together, ofcourse they communicate with each other in some chalacteristic , that show by this symbol: + mean get useful from some part of them. - mean lose useful to some part of them. 0 mean don’t get or lose useful ( equal ) Communication between 2 species of livingthing have many style as follow: 1. Predation (+ ; Œ) In predation, the predator kills the prey and directly feeds on it. Predation consists of predator and prey such as: rat is hunted by the cat, dear is hunted by the tiger but some time predator maybe hunt by other livingthing such as: insect was eaten by frog , but frog was eaten by hawk. This communication who predator are got useful, but who is hunted prey lose useful. 2. Protocooperation (+ ; +) These intereactions are beneficial to both the organisms in lesser or greater degree. The communication of two species are get useful too and when they separate from each other they don’t lose any useful such as: singing mina on buffalo back singing mina eat tick on buffalo back, for buffalo geet useful from singing mina as alarm by shout or fly away when anemy come. 3. Mulualism (+ ; +) Communication between two species which different part get useful too but they both can not separate from each other, if separate from each othe they will die such as: the symbiosis associations between fungus and algae, that we called lichen. Fungus give wet and mineral for algae, algae will produce organic metter for fungus to eat with or termite eat wood but can not digest they have to rely up on prokaryotic which live in intestine of termite help to digest first, after that termite intestine will suck for using. 4. Commensalism (+ ; +) It is a relationship between two organisms of which one is benefitted by the other who remains unaffected. Among the plants the orchids and epiphytic ferns are the best example. The orchid which live in big tree, orchid get place for living, but big tree do not get recieving and will not lose useful. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 5. Parasitism (+ ; Œ) The parasite derives its food from the host and may live inside (endoparasite) or outside (ectoparasite) its body. The parasite does not inten to kill the host but gradually the host certainly dies. The pasasite may then die or change its host. A: Endoparasite This parasite which is parasite will eat food and live in host body of parasition such as: each kind tape worm, round worm and each other bacyllus. B: Extoparasite This parasite stay with out side parasition such as: louse, flea, tick, scrub thyphus, dermatitis, plenyasisversicdlor. 6. Saprophytism (+ ; 0) This living is fungus and bacteria that live in corpse of livingthing by pour enzyme out for digest that corpse then they intentine chemical that get from digest in to cells in form of liquid. Livingthing that live like this can call: Decomposer. Indigestion is not communication between livingthings two species but it is living between who digeste with livingthing corpse, so that corpse is mean 0. 7. Antibiosis (0 ; Œ) This communication is livingthingone part will leave chemistry out side of cells, which chemistry has result for growing up livingthing each specy such as: paramecium releases antibiosis out, it stop resulting from growth bacyllus, especially paramecium will not lose useful from releasing that chemistry but bacyllus is lost useful their part. Microcystis release chemistry name: hydroxylamine releaase out to pont when animal drink water in that pont they will death. 8. Amensalism (0; Œ) This communication has happen when a livingthing one species can do other livingthing not grow up but it is not leave chemistry out such as: big tree hide small tree, it is a result for small tree do not grow up and big tree do not get or lose any useful. 9. Competition (Œ; Œ) Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version It includes all those interactions among two organisms of the same species or different species which affect their growth and survival. The effect may be due to proximity of the individuals or availability of a common resource in short supply such as: animal snatches place, food and female for hybridize. This communication has happen in the same kind, they will be violenter than between difference kind of animal. 10. Neutralism (0 ; 0) This communication is a communicate that 2 parts of livingthing live together but each part do not have any useful such as: In the field of grasses have rabbit and Outh bird live together but they both do not communicate with each other. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Chapter 7 Biotic community The most visible part of the ecosystem is the biotic, the vegetation and animal life. The assemblage of plants and animals in any given physical environment is a community. Thus a community can be considered not only as the combination of populations of different species, but also as the assemblage of organisms whose interrelationship involves various patterns such mutualism, commensalisms, predators, or parasitism. Organisms form integrated community of varying sizes. In ecology, community can be divided into two groups as following: 1) Autotrophic or major community: This group is not dependent on other organisms for nourishment and require from the outside only the energy of the sun ray. For such instances, deciduous forest communities, rain forests, and oceanic communities in various area. 2) Heterotrophic or minor community: This group is dependent on the major community for its energy source. This type of community includes the organisms inhabit in rotten log, community in the hollow of a tree, and community in aquatic environment. Although communities are varying in sizes, but they are similar in common features including dominant species, species richness, community structure, community development and succession, and metabolism. 7.1 Dominant species In general, the biotic community consists of the living organisms of ten, or hundreds, or thousands species, but all these organisms do not equally interact on each other. Some species are more importance on the other lives, some are less. The common species are often considered the dominants, and in the community they may exert some influences over other organisms. The organisms called dominants, in a community, may be: a) the most numerous b) possess the highest biomass c) Preempt the space d) make the target contribution to energy flow e) control or influence the rest of the community. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version In a practical sense, it’s difficult to define the role of the dominant organisms to those that are numerically superior. But numerical abundance alone is not sufficient. A species of plant, for example, can be widely distributed over the area and yet exert little influence on the community as a whole. In a forest the small or understory trees can be numerically superior, yet the nature of the community is controlled by a few large trees that over shadow the smaller ones. In such a situation the dominant organisms are not those with the greatest numbers but those with the greatest biomass or that preempt most of the canopy space and thus control the distribution of light. Ecologists measure such dominants by biomass or basal area. Or the dominant organism may be relatively scarce yet by its activity control the nature of the community. In many situations dominance may result from the coactions between two or more species that have got similar ecological requirement and function of ecological niche. Thus in order to determine the dominance, it must consider the individual community in each situation. For instance, the community might change along with changes the seasons. Some species could be dominant in specified season, but disappear in others, such plankton. In addition, dominance is considered as species more specified in their environmental requirements and more tolerant on the limited factors than the other species. To determine dominance, ecologists have used several approaches. One can measure relative abundance of the species involved, comparing the numerical abundance of one species to the total abundance of all species. Or one can measure relative dominance, which is the ratio of the basal area occupied by one species to total basal area; or one can use relative frequency as a measure. Relative abundance = Numerical abundance of A species x 100 Total abundance of all species Relative dominance = Frequency = Basal area occupied by A species x 100 Total basal area Numerical spot occupied by A species Total spots in which all samples are collected Relative frequency = Frequency of A species Total frequencie s of the total species Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 7.2 Species diversity From equator to the earth poles, it appears that numerical species are decreased as the equatorial lines increased. This point of fact gives the origin of the phrases such species abundance, species diversity and species richness that have the same meaning. These phrases mean the number of species found in a given space. So it’s obvious that a community that contains a few individuals of many species will have a higher diversity or richness than will a community containing the same number of individuals but with most of the individuals confined to a few species. Thus a biotic community in the tropical region usually has a higher diversity of species and lower in the cool region. At the higher latitude, species diversity is usually higher than at the lower latitude, as showing in the table 7.1. Some organisms increase along with the increase of latitude such penguine, pine tree, and salamander (stiling, 1992). The common features of a community are: there are only 2-3 species to be found in a great number and are common but others are scarce. There are many studies in the nature that implies the fact, viz the study of moth using light-trap. In England, 1935, the rare species found reached up 37 species, but only one individual could be found as a representative of each rare species. For the common species, there were 1,097 individuals from the total number of butterflies collected, 6,814 butterflies. All butterflies were confined to 197 species in which only 6 species were assumed to be common species occupying 50% of the total number of collected butterflies. Table 7.1 The diversity index in different species, comparing with the position of latitudes. (Source: Brown and Gibson, 1983 cited from Nitiya Laohachinda, 2003). species Geographic region Latitude Density of species Land mammals North America 8° - 66° N 160 - 20 Bats North America 8° - 66° N 80 - 1 Breeding land birds North America 8° - 66° N 600 - 50 Reptiles United States 30° - 45° N 60 -10 Amphibians United States 30° - 45° N 40 -10 Marine fish California coast 32° - 42° N 229 -119 Ants South America 25° - 55° N 220 - 2 Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Calanid Crustacea North Pacific 0° - 80° N 80 -10 Gastropod mollusks Atlantic coast of North America 25° - 50° N 300 -35 Bivalve mollusks Atlantic coast of North America 25° - 50° N 200 - 30 Planktonic Foraminifera World oceans 0° - 70° N 16 - 2 In order to quantify species diversity for the purpose of comparison, a number of indexes have been proposed, but the most common one are Simpson’s index and Shannon - Winner index. Both means have different values when the quantity of species, or the distribution of the individuals of species, have changed. If using index from both formulas for comparison of two types of communities, it must use random sample or if it needs to count directly the number of population, must operate in the same size of the area of both communities as following: D= Simpson’s index N(N - 1) n(n - 1) D = Diversity index N = Number of the total individuals in a community n Shannon − Wiener index = Number of individuals of a given species H ' = −∑ Pi log e Pi i =1 Pi = Proportion of species i and the total species (= H ' = Shannon − Wiener ni ) n index Modified formula: 1 D = 3.322(log10 n. .n1 log 10 ni ) n ( Smith, 1974) D = Diversity index ni = Number of individuals of each species. n = Number of the total species. By using this formula, diversity index decreases, if the species distribute not even, as illustrating in table 7.2. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Table 7.2 Comparison of diversity index of species distributed not even within a community. Number of species in a community Relative density of species in a community H’ Species 1 Species 2 Species 3 2 species 90 10 - 0.33 2 species 50 50 - 0.69 3 species 80 10 10 0.7 3 species 33.3 33.3 33.3 1.10 The maximum value of H’ or the maximum diversity index of each community could quantify, if the density of all species within the community are the same, then using the maximum value of H’ for counting the evenness of biotic community. J '= H' H ' max J’ = evenness ranging from 0 -1 There are many theories, on the species diversity in a community, written by Smith (1974) and Stiling (1992). They are as following: 1) The time theory: According to this theory, species diversity of living organisms is related to their evolutionary time. Thus a community with more time for the evolution has experienced sufficient time for species to diverge, adapt to, or occupy completely the changed environment. For that reason, communities in the tropical regions have more species than those in the glacial regions. On the other hand, environmental conditions in the tropical regions are more stable that result in wide range of species distribution and diversity. 2) The theory of spatial heterogeneity: This theory holds that the more complex the structure of the community, the more potential niches it possesses. That allows a greater opportunity for speciation among organisms to exploit those niches. Thus a tropical rain forest, with its complex vertical structure, provides many more niches and is able to support many more species, for instance a variety of birds. 3) The climate stability theory: Diversity is related to the physical environment. In the stable climate, the number of species is increased. This theory has got evidence Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version from the studies on the biotic communities in the tropical regions through out the world. The studies show that, in duration of evolution of the biotic organisms in the tropical regions, the conditions of physical environment are more stable. Thus natural selection resulting in existence of new species is caused from competition among species in the same habitats. 4) The competition theory holds that in a more variable environment such as the Arctics, the natural selection forces come from the physical environment. In a more stable environment such as the tropics, selection forces are largely biotic, especially intraspecific competition. Competition favors specialization, resulting in smaller niches. 5) The predatory theory involves in population relationship. This theory holds that a random or selective removal of prey species by a predator reduces the level of competition among them. That allows more species to coexist locally than would do so in the absence of predation, because populations of competitors are held low enough to prevent anyone from becoming dominant. Especially, in the tropical region there are more predators and parasites than in the grazing region. 6) The stability-time hypothesis holds that diversity is inversely related to stress and extreme environmental conditions. Only the few species of organisms capable of resisting such conditions or specially adapted to them will be present in a stressed community. Thus the diversity of a polluted stream bed is low compared to that of nearby undisturbed areas. 7) Productivity theory: This theory was proposed by Wright, 1983. It states that the more resources available in the form of nutrients, plants, or prey species, the more species are able to specialize. The tropical rain forests, with a long growing season and a large variety of plant species, have a high primary production. For that reason they are able to support many more animal species than temperature or arctic regions, with their much lower productivity. The more energy available in a usable form for organisms, the more species the ecosystem can support. Above all there is the direct relation between factors providing the high productivity and the numerous species, viz the evapotranspiration related to the primarily productivity of the community. 8) Area theory: It holds that diversity is inversely related to isolation. Islands tend to be much less diverse than ecologically similar continental areas. This is due partly to the difficulty that many species have in reaching the island. Many species of organisms also may become locally extinct (and can not be readily replaced) as a result of Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version random events. Moreover, isolated areas are likely to be small and to possess a low variety of habitats and potential ecological niches. 9) Animal - pollination theory in the tropical area and high wet, less and not severe winds. The plants exist continuously and densely. The pollination of these plants exerts the animals including insects, bats, and birds. Both plants and animals exist in coevolution. However, It is quite difficult to test the hypothesis on these diversities, especially in the real environment but the study has showed obviously that species diversity has closely relation to the structure or the condition of their habitats, physical environment, climatic condition, quantity of foods distributed in the community, quantity of the minerals and raw material, and duration of the community development. 7.3 Community structure Different patterns of community structure occur because of the existence of distribution of living organisms and variety of influence on the environment, Odum, 1971 concluded the patterns of the community structure as following: 1) Stratification patterns. A distinctive feature of a community is vertical stratification, example: forest community consists of variety of plant size and has several layers of vegetation. From the bottom to top, they are the herb or ground layer on which there are small mixed herbaceous or seeding, the understory which consists of tall shrubs and understory trees, and the canopy. The variety of life in the forest related directly to the number and development of the layers of the forest. Distribution of living organisms in these patterns contributes coexistence. This is due to the competition for the shelter, and other factors are reduced. For the animals such insects and birds forage in different vegetative strata, wren are found on the understory trees with dense leaves, but hawk on the top of tall shrubs. In addition, aquatic community as pond, lakes and sea or ocean has similar stratified structure, as minnow and other small fish like to forage in the surface water, while catfish is in the bottom stratum. 2) Zonation patterns. This type of community structure is caused primarily by differences in climatic conditions, the nature of the soil, its structure and moisture conditions. For example, the distribution of plant in the marsh from the shallow water to deep water is in such order: shallow-water emergent as grass, deep-water emergent, floating plants, and submerged plants. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 3) Activity patterns. This is caused from distribution which is resulted from the response of living organisms to the environment and then brings about variety of activities. Example, response of living organisms to the physical factors such light and temperature results in carrying out the activities or behavior. 4) Food web patterns. That is structure occurring by transferring energy in the food web. 5) Reproductive patterns. This is occurred from distribution which results from reproduction. 6) Social patterns. This is a community structure resulting from coexistence as a group or troop. 7) Coactive patterns. 8) Stochastic patterns. Distribution of life in different pattern, as said above, results in complexity of community structure. In any community where the stratified distribution is more, the living conditions is higher 7.4 Ecotone Ecotone is the zone where two or more different communities meet and integrate, for example, a zone between a field and a forest or a zone between muddy land by the river and sandy. Organisms living in this zone are often similar of characteristics to those of adjacent community. The variety and density of life are often greatest in ecotones. This is called “edge effect”, and the species found in greatest number in this zone are called “edge species”. Example, the study showed that birds found in the ecotone, between forest and field, reach up 22 species, but only 14 species found in the forest. 7.5 Naming the community Ecologists have two views of natural communities exist. One regards communities as distinct natural units or associations, and boundaries between communities should be fairy sharp. Another holds that, the community is as a collection of species surviving under similar environmental conditions. To give order to the study of communities, some systems of classification are needed. There are a number of approaches to classify the communities. Communities classified are usually named after: Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 1) The dominant form of life found in the community. 2) Habitat being well defined 3) Activities of the community such metabolism. This classification may be controversial for some communities, but suit to others. Example for naming after the dominant form of life, Ecologist’s viewpoint holds that the composition of any one community is determined in part by the species that happen to be distributed in the community, thus the community classification should be after the dominant specie. This classification system is suitable, if the community consist only of 1-2 species. Nevertheless, in some cases the dominant specie could not be welldefined and still has seasonal change. Examples for such cases are community of pine, Reason of naming the community after the habitat is that the habitat has less change, so naming by this system might more suitable and understandable such as sandy community, muddy community, freshwater community. Based on the above attribution, community in each area has its own characteristic and develops until stable state, then changes along with the changes of the environment over period of years. These changes are resulting from the exploitation of resources by the species in the community. This brings to the instability of the community in which species face the inadequate environment and finally death. When any one species was depleted, other new species succeeded. 7.6 Ecological succession Biotic community has constantly changed, such as abandoned cropland is a common sight in agricultural regions, particularly in areas once covered with forest. No longer tended the lands grow up in orderly in grasses, shrubs, and then trees. Many years later, the abandoned croplands will be back in forest. The changes involved in the return of the forest are not haphazard but orderly, and barring disturbance by man, or natural events. This orderly and progressive replacement of one community by another until a relatively stable community occupies the area is called ecological succession. Each of the changes that take place in the successional process is called a seral stage. The whole series of communities, from grass to shrub to forest, that terminate in a final stable community is called a sere. As succession proceeds, one community replaces another in part because of the modification in the physical environment brought about by biological community. The change is gradual by variety of activities such as: metabolism, growth, Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version reproduction, and death. These influence on the environment that are inadequate for species. Thus, species are invaded and finally death. Another species that more fitted to the new conditions of environment are succeeded the preceded species. There are two types of ecological succession such following: 1) Primary succession is that took place in the habitat not substantially influenced by previous biotic communities, often on new existed isolated lands, bare rock surface or in anywhere that was not supported by preceded living organisms. 2) Secondary succession is that took place on the old field and proceeded from a state in which other organisms and some form of soil were already present, but disturbed by man, animals, or natural forces. Ecologists, on the studies of succession, concluded that early stages in succession characterized by relatively few species, by low biomass, and dependence on an abiotic source of nutrients, by high ratio between gross primary production and biomass, by higher net community production than respiration. Energy is channeled through relatively few pathways to many individuals of a few species; a production per unit is high. Food chains are short, linear, and largely grazing. The matures stage in the succession are characterized by greater diversity of species, by higher biomass and a nutrient source largely organic in nature, by high net production and a low ratio between gross production and biomass, and by gross community production that about equals respiration, as shown in the table 7.3 Table 7.3 Comparison of the early and the complete stages in succession (source: Mc Naughton and Wolf, 1973) Stage in ecosystem development Attribute Early stage Mature stage Biomass Small Large Gross production / community respiration > 1 or < 1 Gross production / biomass High Low Biomass supported per unit of energy flow Low High Food chains Short, grazing Long, complex Stratification Less More Species diversity Low High Niche specialization Broad Narrow 1 Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Feeding relations General Specialized Size of individuals Smaller Larger Life cycles Short, simple Long, complex Population control mechanisms Physical Biological Fluctuations More pronounced Less pronounced Mineral cycles Open More or less closed However, all indicators shown in the above table are more pronounced for the terrestrial ecosystem, but not usually, to the aquatic or ecosystem bearing the fluctuations and being controlled by limited factors such in desert with high temperature, low wet; or in the fast stream. Only few species could survive in such ecosystem since they could adapt to such kind of environment. In addition, in the water sources, distribution of planktons in different seasons changes with seasonal change. As the terrestrial communities expend over 10 years in order to the succession take place. Succession mostly takes place in one direction and generally ends with a community whose populations remain stable until disrupted by disturbance. This late successional community is called the climax community. Fig. 7.1 shows the level of succession happened in the community that consists of 1 to 10 species. species Changes of population species Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 7.1 Level of succession of variety species against the time Figure above shows the population size against time. Low figure shows the rate of population increased against time unit. The graphs shows obviously, while the increasing rate declined to the point of extinction and on that point new specie developed to the maximum point. Different forms of succession consist of similar sub-stages such following: pioneer stage or colonization, site modification and species replacement. 7.6.1 Pioneer or colonization stage. Pioneer stage is the first step in succession. This stage includes colonization of the earliest forms of life and increases in species diversity. Different communities have different changes. Generally, in a community where the climatic conditions are not much stresses, the numbers of species increase faster than those the climatic conditions are extremely unstable. First colonization of new species may take place by the natural events such wind, stream or other organisms, especially animals. Species diversity increases through the time. In the same time, some species, unable to adapt to the new environment, would died. Pioneer species grew up on the terrestrial land are usually in the long time of retention. When adequate environment is available species diversity developed concurrently again with reproduction. 7.6.2 Site modification Colonization of pioneer species on an area brings about modification of the area. It is caused from exploitation of resources by the pioneer species, excretion of waste, and releases the energy to environment. This results in increase of organic substrates. This process facilitates the existence of new species on the area. The most common pioneer Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version specie is likely variety of microorganisms including moss, lichen such penicillium simplicissium that is able to digest the rock by releasing organic acid like citric acid. Then the microorganisms exploit these minerals such silicon, aluminum, magnesium and ferric on the decay rock for their growth. In the terrestrial succession, plants are mostly important factors in modification of environment, especially the quality of soil as follows: modify acid-base of the soil, composition of the nutrients; and finally new species of plants exist to succeed the earlier ones in the community. New species modify the environment in such a way that it becomes less suitable for themselves and more suitable for species characteristic of later successional stage. In addition, the pioneer species of plants developed largely and related to evaporation. Generally, evaporation in the early stage of succession is about 2.5 more than that in the mature stage. Thus, the pioneer plants developed in this community have grossly affected on the environment and the behavior of the new arrival animals in the community as well. In succession, the plants have importance that brings about modification of niches and other environmental factors. All these changes result in existence of species to succeed the others. 7.6.3 species replacement Replacement of early succissional species by later succissional species could take place when the earlier environment was modified by the earlier species themselves colonizing the area in the relevant stage. These result in increase of population, competition between them, and accumulation of different substrates from life activities of early species. Eventually the outcome facilitates colonization by later succissional species. In other words, the early species modify the environment in such a way that it becomes less suitable for themselves and more suitable for species characteristic of later successional stages. Early successional species disappear as they make the environment less suitable for themselves and more suitable for other species. Replacement of early successional species by later succitional species continues in this way until resident species no longer facilitate colonization by other species. This final stage in a chain of facilitations and replacements is the climax community whose average species composition reaches an equilibrium. For instance, succession in different environment in early stage may take place in the xeric condition such in rocky, Lava rocky, or sand dune; or in the hydric condition Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version such in puddle, pond, swamp, and ect. When both conditions are under some changes, their environment changes to the mesic condition. (a) Xerosere. Succession in the xeric conditions such in rocky, the pioneer species mostly are cyanobacteria who modified the rocky to be able getting some wets, and crustose lichen contributes to absorb moisture and dust from air. In the same time, lichens release acids to decompose the rocky. The decomposed rocky becomes probably the soil. When this lichen species die out, it causes an increase in nutrients and moisture that favors the foliose lichens to develop and then the latter succeed the earlier organisms. Thus, this stage of succession is called lichen stage. The later one is moss stage. Modified environment in the earlier stage supports the development of moss. These species are usually found in a break or an open of rock. In this stage, apart from moss, organisms such earthworms and other insects are also established. Afterwards, moss stage succeeds by weed stage, fern o r ²õ©ìí´ì÷¡. Development of successional plant species depend on the amount of light and moisture, for instance, fern develop well under the condition of more light and high moisture; but weed of more light, less moisture. Tree stage is a final stage preceded the climax stage. This stage consists of shrubs and tree of different sizes. Generally, this stage lasts no longer time, however it depends on limited factors of each geographic area. Many animals migrate more to the area in order to rely on the thick canopy. For instance, terrestrial succession following the volcanic eruption in Krakatua, Indonesia, in 1883, occurs gradually and up to 1995. It takes 112 years to become the forest (Fig. 7.2). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig. 7.2. Primary succession in island Krakatua, following the volcanic eruption in 1883, becomes the stable forest in 1995. (b) Hydrosere. Instance for hydrosere is shallowness in a pond and a swamp, resulting in existence of terrestrial community. In common water resources, evaporation and precipitation increased gradually more and more through the long time, bring about shallows. Accumulation of the soil along the edge of the ponds, or swamps results in growing newly the grass, small shrubs, big shrubs, and then trees. Finally, it becomes completely a terrestrial community. (Fig. 7.3). Stages of shallowness to become the complete terrestrial community can be divided as follows: (1) Submerged vegetation stage. This stage consists of different kinds of algae such: red algae, .......... (2) Floating stage. It is consists of floating plant such morning glory, ........ (3) Emerging vegetation stage. It consists of plants that have parts of the stem emerge the water surface, but the another parts of stem and their roots are found in the water, such ............... (4) Marsh or temporary pond stage. The soil accumulated in water that makes probably the ponds or swamps dry or muddy in the dry season, or poorly drained in the rainy season in a stage. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version (5) Tree stage or climax stage. It is a final stage in conversion of water basin to the complete soil. Plants existing in the first stage are gradually sequent succeeded by tree in this stage, and then become completely the terrestrial forest. Development of species diversity occurs when the soil condition modified. Biotic communities in different geographic region have its own characteristics. Consequently, a community is mostly named after its characteristics. Population having great effects on other population in utilization of energy and its life activities becomes dominant. In development of a population to be dominant in society, the population structure must be stable and increases in population could mostly occupy the natural resources. These communities are considered as natural broad biotic units called biomes that will be introduced in next chapter. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig. 7.3 Gradual succession of the aquatic communities to the forest in the climax stage. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Chapter 8 Terrestrial community The terrestrial habitats are mostly familiar to the human since they exploit the soil to be their shelter and to survive. Terrain is assumed as habitat, the environment of which are great variable to aquatic. Differences of significant environment between terrestrial and aquatic are following (1) Moisture. Organisms live in a moisture environment, ranging from environments entirely aquatic to those deficient in moisture, either physically (as in arid regions) or physically (as in saline habitats. Terrestrial organisms, however, are usually faced with a severe problem of water balance that is rarely happened with aquatic organisms. Evaporation or evaporative water loss from terrestrial plant leaves is a process utilizing lots of energy, compared to that from aquatics. For instance, in order to uptake 1 g of carbon dioxide, terrestrial plants needs to pump the water approximately 100g from the soil, using lots of energy. The water absorbing from the soil passes into the plant tissues then evaporates. But for the aquatic organisms, evaporation occurs less. (2) Temperature. Air temperature generally fluctuates more than water temperature resulting partly from high capacity of water to absorb heat energy without changing temperature (more details will be discussed in next chapter that concern with freshwater community). Air temperature fluctuate both daily, in period of 24 hours, and seasonally. (3) Essential gas for living organisms. Oxygen and carbon dioxide are inorganic molecules and abundant in the earth’s atmosphere. These element and compound are less in the water and in depth soil, or unwell-drained soil. (4) Soil. Soil is the foundation upon which all terrestrial life and much aquatic life depend. It is a medium in which organisms grow, and the activities of those organisms, in turn, affect structure. (5) Isolated land. It is the land separated from the continent and surrounded by aquatic environment. Distribution of organisms is limited by isolation of the terrestrial continent. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version (6) mineral-rich soil. Soil is rich of variety of minerals both elements and compounds that make the soil different in each area. Soil has the major influence on the growth of the living organisms, especially directly on plants, and indirectly on the animals since the latter, in survival, rely on the plants. In conclusion, terrestrial communities in different geographic region or biome have existed by 2 cooperative factors: The first is climatic such temperature, moisture or quantity of rain, and light. The second is the soil conditions, in which the living organisms survive. 8.1 Soil - the major component of the terrestrial community. Soil is the collection of the natural bodies at the earth’s surface that is comprised of minerals and organic matters, which are derived from decomposition of the minerals themselves following disintegration of the rocks, and organic debris, respectively. Composition of the soils in each area is different, depending upon the rocks as the source of inorganic matter, and organism debris. Composition of the soil and soil horizons. The composition of the soils have four major parts, being the important factors that affect the growth of plant communities. These parts are an inorganic matter, organic matter, water in the soil, and air in the soil. Inorganic matter. These matters are derived from the weathering, disintegration of rocks and follows by decomposition of the minerals themselves. All these processes take place by the chemical, physical, and biochemical methods. Inorganic matters are the nutrient resources for the plants and soil microorganisms. In addition, this inorganic component also indicates the characteristics of the soil texture, and identifies the sort of soil. Organic matter. It is the soil component derived from decay organisms and decomposition of the living organism debris. A part from inorganic matter, organic is a resource for the soil microorganisms as well. The major elements that play important roles in growth of plants are such nitrogen, phosphorus, potassium, and sulfur. Water in the soil. Water molecules as a resource of moisture are dispersed between the particles of the soil. In the soil, water contributes to dissolve the minerals, so that plants could absorb them to utilize. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Air in soil. Air in soil is in gaseous state that disperses among the particles of the soil. The air comprises nitrogen, oxygen, and carbon dioxide. Plant roots and microorganisms utilize the oxygen in soil for respiration. Reaction of carbon dioxide and water results in formation of carbonic acid which plays important role in the Chemical process of the soil: microorganisms in the soil. Carbon dioxide is a source of carbon for the Nitrogen is another one element that is important to microorganisms as well. Chemical composition of the soil is shown in the following figure (fig. 8.1). The figure shows the composition of the soil that is adequate for agriculture. Based on the figure 8.1, the inorganic matter comprises 93% of total dry mass, and the rest is organic matter - 7% that consists of both death and lively organisms (fig. 8.2). In the composition of the living organism in soil (edaphon), 40% is fungi, and algae; another 40% - bacteria and actinomycetes; and the rest 20% other organisms inhabiting in the soil (the details of these organisms will be discussed in the topic related to the under ground community). Organic matter 5% Water 25% È Minerals Air 25% Fig. 8.1 Composition (in volume) that is adequate for the growth of the plants. Soil The ratio of organic Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version ( Department of soil science, 2541) fig. 8.2 Composition of the soil expressed as percentage of the dry mass, and the portion of edaphon. Soil structure can be observed by digging a soil pit. In a soil pit you see one of the most significant aspects of soil structure, its vertical layering (fig.8.3). In general soils are divided into several discrete horizons as following: The surface soil lies on the top of the profile. This layer characterized by major organic matter accumulation, decomposition of which is different with depth. The subsoil contains a mixture of mineral materials, such as clay, iron, aluminum, silt, and sand, and organic material derived from the surface soil. The parent material is the third layer in the soil pit. It consists of weathered parent material. Weathering slowly breaks the parent material into smaller fragments to produce sand, silt, and clay-sized particles. Because weathering is incomplete and less intense than two layer above, this layer may contain many rock fragments. The bed rock is the layer containing the unweathered parent material, which is often bedrock. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig. 8.3 The soil profile comprised the surface soil, subsoil, the parent material, and bed rock. (Department of soil science, 2541). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig. 8.4 Comparison of the soil profile of 3 biomes: rain forest, pine forest, and weeds. The layer comprised the parent material, and the above layer next to the parent material is called regolith; and the layers are above the parent material are called solum, which is, in the nature, divided to several horizons such as: The A horizon lies on top of the profile. The most superficial layer of this horizon is made up of freshly fallen organic matter. Sometimes this horizon is called O horizon. The A1 horizon, in which organic matter is decomposed and becomes humus. The A2 horizon is the layer that humus leached slowly through the soil profile until it is deposited in the B horizon. A2 is light-colored horizon, In different communities of plant, soil structure is usually different with depth of each horizon. Fig. 8.4 shows the difference of thickness of the horizons between 3 types of communities. The community that has the most thickness of A horizons is the weeds, the second after weeds is pine forest, and the last one which has smallest A horizon is rain forest. The B horizon contains the clays, humus, and other material that have been transported by water from the A horizon. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The C horizon consists of weathered parent material broken into smaller and smaller fragments. The R horizon is the layer of consolidated bed rock. Each horizon varies in thickness, color, texture, structure, consistency, porosity, and composition. The soil profile is, however, essentially a continuum, often there is no clear-cut distinction between one horizon and another. Horizon subdivisions, lowercase letters, are used to indicate significant qualitative departures from the central concept of each horizon. Of all the horizon of the soil, none is more important or ecologically more interesting than the forest floor or the organic horizon. Soil in different geographic region varies in the composed horizon. In the studies of the soil, the soil sort is identified by its organic and inorganic composition. Development of different horizons will not be discussed here. In conclusion, soil is the foundation of terrestrial communities and much aquatic life. It is the medium in which plant life is rooted, a reservoir of mineral nutrients needed by plants upon which, in turn, animal life depends. Vegetational activities of these organisms influence the development of soil, its chemical and physical properties, and its organic matter content. 8.2 Climate Climate in each geographic region is an essential factor to identify types of biomes or terrestrial communities. Climate in each region usually include sunlight and temperature, air circulation and precipitation. The earth is a sphere, thus the sun’s rays are most concentrated where the sun is directly overhead. Consequently, the earth is always immersed in uneven heating by the sun. However, the latitude at which the sun is directly overhead changes with the seasons. This seasonal change occurs because the earth’s axis of rotation is not perpendicular to its plane of orbit about the sun but is tilted approximately 23.5° away from the perpendicular. Because of this tilted angle of rotation is maintained throughout earth’s orbit about the sun, the amount of solar energy received by the Northern and Southern Hemispheres changes seasonally. During the northern summer the Northern Hemisphere is tilted toward the sun and receives more solar energy than the Southern Hemisphere. During the northern summer solstice on approximately June 21, the sun is directly overhead at the tropic of Cancer, at 23.5° N latitude. During the northern winter Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version solstice, on approximately December 21, the sun is directly overhead at the tropic of Capricorn, at 23.5° S latitude. During the northern winter, the Northern Hemisphere is tilted away from the sun and the Southern Hemisphere receives more solar energy. The sun is directly overhead at the equator during the spring and autumnal equinoxes, on approximately March 21 and September 23. On those dates, the Northern and Southern Hemispheres receive approximately equal amounts of solar radiation. The seasonal shift in the latitude at which the sun is directly overhead drives the march of the seasons. At high latitudes, in both the Northern and Southern Hemispheres, seasonal shifts in input of solar energy produce winters with low average temperatures and shorter day lengths and summers with high average temperatures and longer day lengths. Meanwhile, between the tropics of Cancer and Capricorn, seasonal variation in temperature and day length is slight, while precipitation may vary a great deal. Variation in climates, especially prevailing temperature and precipitation, bring about species diversity of plants in the region of low attitude (near the equator) and in that of high latitude (near the earth’s poles). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig. 8.5 The seasons in the Northern and Southern Hemispheres. 8.3 Biogeographical regions The earth’s area consists of 7 continents: North America, South America, Europe, Asia, Australia, Africa, and Antarctica. These continents possess the difference, may be less or more, in climate resulting in species diversity. Biologists in the studies of plants and animals in different area through out the world separated all these continents into the biogeographical regions or realms, based on the living organisms found. Botanists, in time, noted that the world could be divided into great blocks of vegetation including deserts, grasslands, coniferous, temperate, ant tropical forests. These divisions they called formations, even though they had difficulty drawing sharp lines between them. Later, in 1964 Good separated the geographic region, based on the flowering plant, into six regions (fig. 8.6) as following: (1) Boreal includes continents as North America and North Europe, and the North of Asia. (2) Paleotopical include the geographic tropics in a part of Asia and Africa, subdividing as following: (2.1) Africa embraces Africa continent and Madagascar island, excluding the south part of the continent. (2.2) Indo-Malaysian includes the area of India, Sri Lanka and the countries in South East Asia including Laos. (2.3) Polynesian contains the Islands of South Pacific. (3) Neotropical contains Central and South America continent. (4) South Africa includes the extremity of the Africa continent. (5) Austrlian contains the Australian continent and Tasmania. (6) Antarctic includes the area of South Pole of the earth such the extremity of South America continent, Fordland islands and New Zealand. Geographical division based on the zoogeography began to study by the earlier of th 20 century. Divisions, mostly, are carried out with terrestrial animal species, especially, birds and mammals. The master work in zoogeography was done by Alfred Wallace, even several parts are modified. These geographical areas, dividing on the major animals found in the area, include 6 regions (fig. 8.6 b). 1. Palearctic region contains the whole of Europe, all of Asia north of the Himalayas, northern Arabia, and a narrow strip of coastal North Africa. In this region, Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version the major animals found are wolf, the moose, the caribou, the bison, different species of birds such loon and tit. 2. Ethiopian (African) region includes the continent of Africa south of the Atlas Mountains and Sahara Desert. It contains the most varied endemic vertebrate fauna such Gorilla, chimpanzee, lion, zebra, giraffe, hypothalamus, Africa elephant, antelope, and hyena. Fig. 8.6 a. Geographical separation based on the endemic fauna b. Geographical separation based on the means of Alfred Russel Wallace. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 3. Oriental region includes India, Indochina, South China, Malaya, Philippines, and the western islands of the Malay-Archipelago. The majority of Oriental animals are Indian elephant, tiger, orangutan, gibbon, and peacock. 4. Australian region includes Australia, Tasmania, New Guinea, and a few smaller islands of the Malay Archipelago. The endemic animals are such kangaroo, kiwi, duck-billed platypus, spiny anteater. This religion is separated from Oriental by Wallace’s line, which runs between the Philippines and the Moluccas in the north, then bends southwest between Bomeo and the Celebes, then south between the islands of Bali and Lombok. Although these two religions are 32km in distance, but species diversity of animals found are more than in those between British island and Japan which both located in different hemisphere. 5. Nearctic region contains North America and Greenland. The endemic animals are such caribou, musk-ox, raccoon, puma, and skunk. 6. Neotropical region includes all of South America, part of Mexico, and the West Indies. The fauna of the Neotropical are anteater, sloth, alpaca, marmosets, vampire, kiwi. Two regions, the Palearctic and the Nearctic, are quite closely related; they used to be combine in the region of Bering canal. In fact the two are often considered as one, the Holarctic. Both are quite alike in their faunal composition. 8.4 Terrestrial community structure. Living organisms in the terrestrial community are very diverse comparing to those, in the aquatic community. Consequently, identification of the terrestrial organisms is unable to carry out in the same way as that of the aquatic organisms. Ecologists recognize and contrast the terrestrial communities, based on the predominant source of their nutrition, as producers, consumers and decomposers. Each groups have been discussed in the previous chapter on ecosystem. Thus, some common characteristics of them will be proposed in this topic. (1) Producers belonging to the terrestrial communities contain largely green plants. The big green trees manufacture not only food, but are also a shelter for other organisms. Plant species developing in different area of the earth contribute to regulation of the climatic conditions of the area where they inhabit. Consequently, species diversity on the earth is often developed and has its own characteristics that correspond with the Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version environment conditions, under which they survive. Such characteristics can be used to describe the growth forms such as woody plants, herbaceous plants, trees, shrub, grass, and forbs. In addition, the plants are able to be divided, based on their ability in adaptation with the environment conditions such the quantity of moistures or other factors, as hydrophytes, mesophytes, xerophytes, and halophyte. Perhaps a more useful system is the one designed in 1934 by Raunkiaer. Instead of considering the plants’ growth forms, and the amount of the moisture, he classified plant life by the relation of the embryonic or meristemic tissues that remain inactive over winter or a dry period (perennating tissue) to their height above-ground. Such perennating tissue includes buds, bulbs, tubers, roots, and seeds. He recognized six principle life forms as shown in the Figure 8.7. Figure 8.7 Classification by Raunkiaer’s life form. Number 1-6 is representative plant group classified by considering the height of the perennial tissue aboveground. Plant classification by Raunkiaer indicates that all the species in a region or community can be grouped into these six classes providing a life form spectrum of the area that reflects the plants’ adaptations to the environment, particularly climate. Life forms of the plants in the first group are characterized by the plants growing on other plants; roots up in the air. For the second group, perennial buds carried well up in the air and exposed to varying climate conditions; tree and shrubs over 25 cm; typical of moist, warm environments. The third and fourth groups characterized by the perennial buds at Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version the surface of the ground, where they are protected by soil and leaves. Many plants are characterized by rosette leaves and are characteristic of cold, moist climates. The fourth group, perennial shoots or buds are on the ground to about 25 cm above the surface. Buds receive protection from fallen leaves and snow cover. For the fifth group, perennial buds are buried in the ground on a bulb or rhizome, where they are protected from freezing and drying. Plants are typical of cold, moist climates. . The last group: annuals, with complete life circle from seed to seed in one season. Plants survive unfavorable periods as seeds and are typical of deserts and grasslands. (2) Consumer: Terrestrial consumers are divided into several levels. Each species adapt differently to their environment that result in variety of shelter and life condition forms. Primary consumers or herbivores range small organisms such plankton, different species of insects to organisms of big size such as cow, buffalo, elephant, horse, and etc. Within these organisms, a part from insects, other animals such centipede, millipede, scorpion, tick, and etc. are most abundant. These animals are essential components of the terrestrial ecosystem as well. Since the number of organisms is large and species are diverse as well, ecological studies are carried out on specific group of animals such: ecology of insects, ecology of birds, ecology of mammals, etc. It appears, however, that terrestrial producers are mostly large size and manufacture, thus, more foods but less in use, because of that some animals are unable to digest cellulose and lignin. These part, therefore, of manufactured foods are used by decomposers and detrivors that are abundant in many types of forests. (3) Decomposers: The decomposers make up the so-called final feeding group of organisms, plant and animals. These organisms utilizes the food stored by autrotrops, rearrange it, and finally decomposes the complex materials into simple, inorganic compounds. These organisms include microorganisms, yeast, mold, unicells, and other small animals. Microorganisms playing the roles in decomposition of dead organisms are divided into 4 groups: - Fungi, mold, yeast. - Heterotrophic bacteria - Actinomycetes - Protozoa as amiba, cilia, colorless fragellates These may be found on the surface aboveground, in the pile of fallen leaves. The steps of decomposition by these organisms might take place orderly as following: Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Yeast, mold, and microorganisms bearing spore Microorganism not bearing spore Mycobacteria Actinomycettes The first groups of microorganisms digest the simple organic compounds such as sugar, amino acid, and proteins of small size. Afterwards, microorganisms enabling to digest cellulose are active; and finally, Actinomycetes are the last one that continues in decomposition of the compounds to produce humus. 8.5 Underground community structure. The number of different species found in the soil is enormous, representing microorganisms, and practically every invertebrate phylum. Thus, in the studies of fauna community in the soil, these organisms are divided into 3 groups as shown in the Figure 8.8. (1) Microbiota: The representatives of this group are green algae and blue-green algae in the soil, bacteria, fungi, and protozoa. The size of these organisms is less than 0.16 nm. (2) Mesobiota: The organisms belonging to this group are wireworm, white worm (enchytraeids), insects of small size, and small arthropod as oribatis mites, springtail, and others whose size is approximately 0.16 -10.24 mm. Their representatives are shown in the Figure 8.9. (3) Macrobiota: This group contains plant roots, larger soil insects as soil beetles, and other larger arthropod such millipedes, centipedes, land isopod, earthworm, snail, and includes several species of vertebrates such rats, salamander, etc. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure 8.8. Identification of animals found in soil (Leadley Brown, 1978) There are a number of ways to study on the relationship between organisms in the terrestrial community, based on the efficiency of energy transfer. A. One useful measure of efficiency of energy transfer is net primary production (NPP) or net production. Net primary production is gross primary production minus the amount utilized by producer respiration. Net ecosystem production is expressed as net production minus total energy dissipation by consumers including both animal and Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version decomposer respiration. It’s apparently that all production of 5-10% in the abandoned crop field or in the most forest is exploited by herbivores. The rest is approximately 90% or more are utilized and accumulated underground. In the field, although, there are numerous numbers of herbivores, the rest of energy reaches up 40-50% transferring to the underground community. Figure 8.9 The representatives of arthropod, the size of which ranges from 0.16 10.24 mm. 1A - Oribatis mites, 2- Proturan, 3- Japigid, 4- thrips, 5- Symphylan, 6-Pauropod, 7- Rovebeetle, 8- Springtail, 9-pseudoscorpion, millipedes, 11- centipedes and 12- Grub. (saurce: Odum, 1971). B. Another one way used to measure the efficiency of energy transfer is calculation of the rate of the decomposed fallen leaves on the ground. By this mean, the nylon plastic bag is used to collect the fallen leaves. After weighing, the bag with the leaves is left to stand for decomposition naturally of the leaves. The bag is periodically weighted in order to recognize the rate of decomposition of the fallen leaves in a period. This mean excludes the utilization or respiration of living organisms in soil. C. One more method is to measure the number of carbon dioxide in soil. The measure is gained from respiration of organisms surviving in the soil. The results of the studies on the forest of oak, maple, and pine, showed that the rate of utilization of carbon dioxide in summer is accounted for 3 littres/m2, in winter-1.2 littres/m2; the annual average is approximately 766 l/m2. Energy can be calculated by using these values, when Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version it’s known 1litre equal 5.3 kcal. Consequently, the average of energy utilization of terrestrial organisms through a year is about 766 x 5.3 = 4.060 kcal/m2/year. 8.6 Types of terrestrial community Biotic communities, ranging from logs in the nature to large matters such grass land, forest, and desert, may possess different sizes. Classification which embraces several plant communities, but includes all animal life associated with them is called a biome. A biome is a broad ecological unit characterized by the distinctive life forms of the climax species, plants or animals. Biomes are characterized by their predominant plants and associated with particular climates. In this chapter, each type of biomes will be discussed. Figure 8.10 shows classification of biomes proposed by Odum, 1971. Figure 8.10 Distribution of biomes in different area on earth. 8.6.1 Tundra biomes The tundra rings the top of the globe, covering most of the land north of Arctic Circle, about 15% of the earth’s land area; three fourth is a soil area that is often underlain by a layer of permafrost that may be many meters thick. The tundra climate is typically Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version cold and dry. Average annual temperatures are less 0°C. The tundra usually doesn’t get quite as cold in the winter or quite as warm in the summer. As a consequence, though winter temperatures are less severe, the summers are shorter. The season supporting the well-growth is summer that last only 2 months. Precipitation on the tundra varies from less than 200 - 300 mm/year to a little over 600mm. Generally, water is not a limited factor for tundra, but the prevailing climate in which the number of species tends to be few. The open tundra landscape is dominated by a richly textured patchwork of perennial herbaceous plants, especially grasses, sedges, mosses, and lichens. The lichens are eagerly eaten by reindeer and caribou. The woody vegetation of the tundra consists of dwarf willows and birches along with a variety of low-growing shrubs. The tundra is a biome on earth that still supports substantial numbers of large native mammals, including caribou, reindeer, musk ox, bear, and wolves. Small mammals such as arctic foxes, weasels, lemmings, and ground squirrels are also abundant. Resident birds like the ptarmigan and snowy owl are joined each summer by a host of migratory bird species. Insects are also very abundant. Each summer, swarms of mosquitoes and black flies emerge from the many tundra ponds and streams. Ecosystem in tundra, may exist on the high mountain in the warm area of the world, and is called alpine tundra. In general the alpine tundra is a more severe environment for plants than arctic tundra. The atmosphere is thinner in the alpine tundra, and because of this, light intensity, especially ultraviolet, is high on clear days. 8.6.2 Taiga, coniferous forest The largest vegetation formation on Earth is the Taiga or coniferous forest. Taiga is confined to the Northern Hemisphere. It extends from Scandinavia, through European Russia, across Siberia to central Alaska, and across all of central Canada in a band between 50° and 65° N latitude. There are two types of climates: a cold continental, the temperatures of which ranges from about -70 °C in winter to over 30°C in summer; an average temperatures is about -5°C. The second type is cold maritime in which an average temperatures is higher then in continent. Precipitation is moderate, more than that in tundra, ranging from about 250mm to 500 mm/year or may reach up 800 mm/year. Taiga is generally dominated by evergreen conifers through the year. There are 2 types of vegetation: One is the main coniferous forest including different gymnosperm such as spruce, fir, tamarack, and, in some places, pines. The shrubs and herbaceous Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version developed unwell in this type of forest. Another type of coniferous forest is that growing in the coniferous-mixed forest ecotone where the coniferous forest grades into mixed forest of Southern Canada and the northern United States. This type of the mixed forest is called moist coniferous forest biomes. In this area, the temperatures are low, precipitation and fog are more dense. Most of the plants in this area are cold-tolerable. Decomposition occurs slowly that causes the accumulation of plant debris converted, finally, to Mire or peat bog. Taiga soils tend to be of low fertility, thin, and acidic. Low temperatures and low pH impede decomposition of plant litter and slow the rate of soil building. Taiga is home to many animals. This is the winter home of migratory caribou and reindeer and the year-round home of moose and woodland bison. The wolf is the major predator of the coniferous forest. This biome is also inhabited by black bears and grizzly bears in North America and the brown bear in Eurasia. A variety of smaller mammals such as lynx, wolverine, snowshoe hare, porcupines, and red squirrels also live in coniferous forests. This forest is the nesting habitat for many birds that migrate from the tropics each spring and the year-round home of other birds such as crossbills and spruce grouse. For most of history, human intrusion in the Taiga forest was relatively light. More recently, however, harvesting of both animals and plants has become intense. 8.6.3 Deciduous Forest Biome 8.6.3.1 Temperate deciduous forest biome Temperate deciduous forest on the earth can be found between 30° and 55° latitude. However, the majority of this biome lies between 40° and 50° . In Asia, temperate deciduous forest originally covered much of Japan, eastern China, Korea, and eastern Siberia. In Western Europe, this type of forests extended from southern Scandinavia to northwestern Iberia and from the British Isles through eastern Europe. In the Southern Hemisphere, temperate deciduous forests are found in southern Chile, New Zealand, and southern Australia. Deciduous forests occur where temperatures, generally, are not extreme and where annual precipitation averages anywhere from about 650mm to over 3000 mm. Deciduous trees usually dominate temperate forests, where the growing season is moist and at least 4 months long. In deciduous forests winters last from 3-4 months. Though snowfall may be heavy, winters in deciduous forests are relatively mild. The few deciduous trees are largely restricted to streamside environment, where water remains abundant during the drought-prone growing season. While the diversity of trees found in temperate forests is Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version lower than that of tropical forests, temperate forest biomass can be as great, or greater. Like tropical rain forests, temperate forests are vertically stratified. In addition, in the driest habitats, all trees drop their leaves during the dry season; but in an area the forests consisting more of pines may be evergreen. 8.6.3.2 Tropical deciduous forest Tropical deciduous forests are different from rain forests by possession obviously of rain season and drought season, which affect on the plant species and their living. In drought season leaves are fallen in order to keep the water in the plants. Tropical deciduous forests occupy a substantial portion of the earth’s surface between about 10° and 25° latitude. In Africa tropical deciduous forests are found both north and south of the central African rain forests. In the Americas, tropical deciduous forests are the natural vegetation of extensive areas south and north of the Amazon rain forests. Tropical deciduous forests also extend up the west coast of Central America and into North America along the west coast of Mexico. In Asia, tropical dry forests are the natural vegetation of most of India and the Indochina peninsula including most area of Laos. The climate of tropical deciduous forests is more seasonal than that of tropical rain forests. For instance, a dry season lasting for 6 to 7 months followed by a season of abundant rainfall. This wet season lasts for about 5-6 months. The seasonal rains in the tropical deciduous forests come during the warmer part of the year. The plants of the tropical deciduous forests are strongly influenced by physical factors. For example, the height of the tropical deciduous forest is highly correlated with average precipitation. Trees are tallest in the wettest areas. In the driest places, where the trees are smallest and the landscape more open, the tropical deciduous forest may appear similar to the tropical savanna or even desert. The tropical deciduous forests shares many animal species with the rain forest and savanna. The number of people settling in the tropical deciduous forests is higher than tropical wet and rain forests, especially, in the development countries. Heavy human settlement has devastated the tropical deciduous forests. Tropical deciduous forests are more vulnerable to human exploitation for settlement and agriculture than tropical rain forests because the dry season makes them more accessible and easier to burn. 8.6.4 Temperate Grassland Biomes Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Temperate grassland is the largest biome in North America such Perry, and Steppe in Eurasia. Temperate grasslands receive between 300 and 1,000 mm of precipitation annually. Though wetter than deserts, temperate grasslands may experience occasional drought, and drought may persist for several years. A rate of evaporation is quite high. These conditions are too light to support a heavy forest and too great to encourage a desert. Temperate grassland is thoroughly dominated by herbaceous vegetation. The length of the root system varies from about 10 to 15 cm, considering being tallgrasses. These grasses are more tolerant in the wet forest. In addition, animal life in the temperate grassland dominated by grazing and burrowing species. Grasslands, however, are not exclusively a climatic formation, because most of them require periodic fires for maintenance, renewal, and elimination of encroaching woody growth. Associated grasses are a variety of legumes and composite plants. 8.6.5 Tropical Savanna Biomes The one ecosystem that defies any general description is the tropical savanna. Most tropical savannas occur north and south of tropical dry forests within 10° to 20° of the equator. In Africa south of the Sahara Desert, tropical savannas extend from the west to the east coasts, cut a north-south swath across the east African highlands, and reappear in south-central Africa. In South America, tropical savannas occur in south-central Brazil and cover a great deal of Venezuela and Columbia. Tropical savannas are also the natural vegetation of much northern Australia. The savanna climate is generally drier than that of tropical dry forest. Life on the savanna cycles to the rhythms of alternating dry and wet seasons. The mean rainfall is within the range 300-500 mm. Some savannas receive as much rainfall as a tropical dry forest. Other savannas occur in areas that are as dry as deserts. However, seasonal drought combines with another important physical factor, fire. The fires kill young trees while the grasses survive and quickly resprout. Consequently, fires help maintain the tropical savanna as a landscape of grassland and scattered trees. The tropical savanna is populated by wandering animals that move in response to seasonal and year-to-year variations in rainfall and food availability. The wandering consumers of the Australian savannas include Kangaroos, large flocks of birds, and, for at least 40,000 years, humans. The African savanna is home to a host of well-known mobile consumers, such as elephants, wildebeest, giraffes, zebras, lions, and, again, humans. The Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version diverse mammalian herbivores of the African savanna harvest all parts of the vegetation, from low herbs to the tops of trees. As noted, fires play a key role in maintaining the savanna landscape. Frequent fires have selected for fire resistance in the flora. The few tree species on the savanna resist fire well enough to be unaffected by low-intensity fires. Humans are, in some measure, a product of the savanna and the savanna, in turn, has been influenced by human activity. Humans began to purposely set fire to the savanna, which, in turn, helped to maintain and spread the savanna itself. Originally, humans subsisted on the savanna by hunting and gathering. In time, they shifted from hunting to pastoralism, replacing wild game with domestic grazers and browsers. Today, livestock ranching is the main source of livelihood in all the savanna regions. In modernday sub-Saharan Africa, however, the combination of growing human population, high density of livestock, and drought has devastated much of the region known as the Sahel. 8.6.6 Desert biomes All deserts have in common low rainfall, average less than 25 mm per year, high evaporation, and a wide daily range in temperature from hot by day to cool by night. The temperatures between day and night differ more 20°. Rain when it falls, is often heavy and, unable to soak into the dry earth, rushes off in torrents to basins below. The main deserts are: Australia desert, Sahara in Africa, desert in Tibet, and in Bolivia. Deserts are not the same everywhere. Differences in moisture, temperature, soil drainage, topography, alkalinity, and salinity create variations in vegetation cover, dominant plants, and groups of associated species. Plant cover is absent from many places, exposing soils and other geological features. Where there is plant cover, it is sparse. The plants themselves look unfamiliar. Desert vegetation often cloaks the landscape in a grey-green mantle. This is because many desert plants protect their photosynthetic surfaces from intense sunlight and reduce evaporative water losses with a dense covering of plant hairs. Other plant adaptations to drought include small leaves, producing leaves only in response to rainfall and then dropping them during intervening dry periods, or having no leaves at all. Some desert plants avoid drought almost entirely by remaining dormant in the soil as seeds, which germinate and grow only during infrequent wet periods. In deserts, animal abundance tends to be low but diversity can be high. Most desert animals use behavior to avoid environment extremes. In summer, many avoid the heat of the day by being active at dusk and dawn or at night. In winter, the same species Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version may be active during the day. Animals (as well as plants) use body orientation to minimize heat gain in the summer. 8.6.7 Tropical rain forest The tropical rain forests straddle the equator in three major regions: Southeast Asia, West Africa, and South and Central America. Most rain forest occurs within 10°C of latitude north or south of the equator. Outside this equatorial band are the rain forests of Central America, Southeastern Brazil, eastern Madagascar, Southern India, and northeastern Australia. The tropical rain forest climate is warm and wet year-round. Average temperatures are about 25°C to 27°C. Annual rainfall ranges from about 2000-2400mm, and some rain forests receive even more precipitation. In a rain forest, a month with less than 100mm of rain is considered dry. Though rain forests have a reputation for being extremely hot places, they are not. Tropical forests do not form a continuous belt around the terrestrial equatorial region. They are discontinuous, broken up by differences in precipitation. General characteristics of tropical rain forest are: (1) The tropical rain forests are the area above the sea level about 200m, called lowland forests. The storey of the trees dominates the rain forests. Trees dominate the rein forest landscape and are approximately 70%, and are evergreen through the year. One hectare of tropical rain forest may contain up to 100-1000 trees with different height. Some reach 50-60m, but mostly are within 30-40, being the forest canopy and dividing into 3-5 storey based on their height (A, B , C ,D and E). A is uppermost layer consisting of emergent trees whose deep crowns billow above the rest of the forest to form a discontinuous canopy. The second, B layer consisting of mop-crowned trees with about 20m high, forms another, lower, discontinuous canopy. Not clearly separated from one another, these two layers form and almost complete canopy. The third, C layer is the lowest tree stratum, and made up of trees with conical crowns. The D later usually poorly developed in deep shade, consists of shrubs, young trees, tall herbs, and ferns. The E stratum is the ground later of tree seedlings and low herbaceous plants and ferns. A conspicuous part of the rain forest is plant life dependent on trees for support. Such plants include epiphytes (herbaceous and woody epiphytes), and lianas. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Vertical strata in Pine Vertical strata in deducious forests Vertical strata in rain forest Figure 11. 3 types of vertical stratification of forest community. (Source : Smith, 1974) Temperature, moisture and light: The temperature profile of a rain forest varies with the growth form. In the uppermost later of the rain forest, the temperatures in day time are, higher than night time, about 10-20°C and may reach up 40°C. Average temperatures in the lower layers including the forest floor are approximately 25-27°C. In the uppermost layer of the rain forest, moisture at night is about 30-40% lower than in day time. In the lower and on the ground layer, the moisture ranges from 90 100%. Light tend to decrease through the lower strata including floor layer. Plants in the lowest layer of the forests, therefore, have broadleaf evergreen in order to receive much light. (3) Trunks and roots. Big trees possess gross roots to support the trunks, absorb water, nutrients and air. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version The grounds of trunks of some species expand as buttress roots; some are dependent on another trees to support columnar stem and some are aerial. (4) Leaves: Leaves of in the canopy strata have been covered by tick cuticles and waxes to protect transpiration, and have small thin leaves because of strong windy and sunlight. Leaves in the lower strata have broadleaf with stomata to assist transpiration. Since the moisture in the lower strata is high, some species developed their leaves to possess sharp and thin so that the rain could flow well through. This causes in assisting gas exchange that bring about photosynthesis. (5) Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Chapter 9 FRESH WATER COMMUNITY Fresh water is one of the important eco-systems as direct living condition for all living organisms including human. Although, fresh water is seen as lower quantity than the sea and ocean, but it is an eco-system which comprises abundant biodiversities. Fresh water community has diverse adaptation rather than sea and on-land communities, because it possesses some specific properties for living condition. 9.1 Morphological or physical and chemical properties. 9.1.1 Physical factors. Water possesses specific physical properties such as it is a liquid which contains different dissolved substances and gets density or its weight increases due to the low temperature and its density could low down when the temperature increases. Fresh water possesses specific property differed from an other liquid as: it attends the maximum density to the frozen point (0 c), the pure fresh water attends 4 c. However, water’s density does not only depend on temperature, it such relates to the other dissolved substances as: sea water could froze in -2 c and the maximal density is between -1, 5 to 1, 8 c. Water’s mass relates to its density, generally, 1m3 of pure water weights 998,4kg. Water’s pressure increases by various level of it deeper. Such as in around some deeper, the pressure is 4 atm or in each 10m deeper, the pressure increases in 1 atm. Differently from other liquid, water consist a specific heat. However, in the same temperature condition, water can keep the heating stage as longer than other’s liquids, moreover, water has the evaporation latent heat such as: for evaporating 1g of water in 20 c, needs to be used 585 cal; otherwise, 1g of alcohol needs 204 cal and 1g of petrol needs 67 cal. Whatever, the large water sources play main role in identifying local climate, when the warm wind blows thought surface of water, and a part of warm air disperses in water, and the warm air becomes a bit cold or decreases its potential. There are some main physical factors for living condition: Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version (A) Light Light persisting in water could create 3 kinds of phenomena: reflection by different angles, absorbed by water and penetration. Particularly, if the reflected angle on the surface of water is perpendicularly becoming to be large, the reflection is relatively increasing. The intensity of light through water could decrease by their deeper, whereas the absorbed light is caused by: (1) By water own self (2) By some dissolved substances such: some ions (Ca++, Mg++). If there are more Ca++, Mg++, the potential of light absorption could be decreased. (3) By suspended particles or materials in water, if there are more suspended particles, the absorption could by decrease. (4) Depending on intensities of light, the light’s intensity could vary on the existing of cloud and frost. (5) Depending on light reflection angle, thus may vary on season, time and the level of the location. Light can emerge directly through pure water by the level of spectrum (BlueGreen-UV-Fred- Infrarouge) – whereas, in natural water, the light disperses by spectrum (Green-Blue or Red-UV-Infrared). When light disperses through water, it reflects our eyes, we could see the color of water that is the same as the one’s of the light, that could attend a level so more deeper. Light zonation Light dispersed though water in 1% is called photic zone or euphotic zone or trophogenic layer. In the day period, water consists more oxygen caused by photosynthesis process, but in contrary, this is poor in the night period. Under the photic zone, the light changes forward by season, this is called T-photic zone or tropholytic layer. In this layer, the photosynthesis process is seen equal to the respiration process. The following picture shows the dependence of light reflection and temperature according to the physical condition within a lake (Fig. 9.1). (B) Colors Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Water’s colors as the same as the colors of light, which emerges in water, then reflects to our eyes. There are two kinds of water’s colors: (1) Real colour (true colour) which is caused by the substance components of water (2) Apparent colour caused by the suspended particles in water or by the scenery of natural surrounding. Figure.9.1 shows the light and temperature diffusion according to the physical component of lake water We can do an experiment to prove the real colour of water as: the real colour of water can be studied by separating the suspended particles as using Millipore filter or centrifugal method, then comparing the filtrated water with the blank or sample. The blank color is extracted by decreasing concentration through many layers of K2PtCl (Potassium chloro platinate) and CoCl2H2o (Caboltous chlorite), thus are a platinum cobalt unit (1unit = 1mg Pt/L) such value varies from 1 (firmly pure) up to 300 (extremely dark). According to this experiment we can conclude that the colour diffusion is depending whatever on the size of particles and the suspended materials in water. The colour of shallow water is the same as the bottom’s, where the bottom made from sand, Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version the colour of water is seen as yellow, as green where there are a lot of algae and moss, and as grey where there are a lot of plankton. Naturally, most of streams and rivers consist of their own colour which differs from each other from none to grey-dark tint. Whereas, pond and lake water composes grey-dark, some cases it could be a bit black, because of the bottom made from mud and dead bodies. (C) Turbidity Turbidity is caused accordingly to the suspended materials in water. Turbidity and purity of natural water are not the same. Water in the mountainous rivers are more clean than in the low land’s rivers, ponds and lake water, thus consist more suspended materials. There are 2 kinds of suspended materials: (1) Setting suspended mater (precipitation). (2) Non setting suspended matter (floated). Turbidity measurement could be studies with visual method by using Jackson Turbidity Unit (JTU) or Nephelometer (NTU-Nephelometer Turbidity Unit) or observation the light emergence in water (Transparency) by using such disc down-low in water following different deepness until we could see this disc. In conclusion, there are some components which include water’s colour: Some iron’s ion (FeSO4, Fe2O3) give yellow, Fe (OH)3 makes red colour. Green leaves that give green colour, dead leaves yellow and when this have been decomposed, they become dark and grey. CaCO3 is seen as green. Plankton, green-blue algae, moss, green, algae, Euglena and Nematod make water in red colour. Moreover, water’s colour relatively varies depending on season, rain quantity, sunlight, cloud, frost, vegetation and scenery of surrounding. (D) Temperature Water temperature always changes due to the emergence of light; therefore it could be transferred from light to heating energy. However, temperature plays an important role for the livings in water or aquatic livings: regulation of their reproduction, the growth of animals and plants, especially it contributes in thermal stratification. Cleary, in the large and deep water, temperature provides more roles in regulating chemical reaction and biological process for example: when water’s temperature increases, the process of dissolution of substances becomes active and microorganism develops faster. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Most of water sources in the temperate zone are deep. In summer, the temperature in each water’s layer is not the same, the temperature of upper layer or surface of water is higher then other’s, because it directly receives sunlight, this is called Epilimnion. The temperature in the middle layer is quiet low and often changes, as so called Thermocline. The bottom layer where sunlight can not disperse or poor light, so the temperature is seen lower and more stable as so called Hypolimnion. Due to the role of temperature, in the large lake of temperate zone attends 2 dimictic rounds per year as shown in fig.9.2. The division of water’s layers is always going on summer, whatever the dimictic rounds are absent or in which the upper layer and bottom layer water are not mixing or more stable. In autumn, the temperature of upper layer is continuously diminishing until the mictic movement has been stopped by its density. In winter, upper layer water become cold ever with higher density, then moves down to the bottom until it has been frozen. When coming Summer, upper layer water and begins to dissolve with higher density, then streams to the bottom, whereas the bottom layer water with soft weight streams up to the surface, the exchange process between both layers has renewed fertilization in water. The tropical water sources possess only one exchange movement as so called monolithic because the temperature of upper layer water is not lower than 4 C, therefore, the exchange movement between each layer is going on so often, but the mictic round is happening only one time a year in winter. Figure 9.2 show the mictic movement happened due to the change of temperature in each season and the relationship between temperature and quantity of dissolved oxygen in water. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version 9.1.2 Chemical factors. One of chemical properties of water is included that its molecule comprises 2 electrical poles; therefore, it can dissolve other substances, especially gas needed for the living organism. The soluble proportion of gas in water is converse proportion of this gas in atmosphere: in standard condition or STP, 100ml of water can dissolve 0,34g of CO2, 0,007g of O2 and 0,003g of N2. At the same time atmosphere consists around 3% of CO2, 21% of O2 and 79% of N2. Generally, the quantity of oxygen dissolved in water is seen quiet low. There are some important Chemical factors: (1) Dissolved oxygen Dissolved oxygen is necessary for all livings in water, especially for breathing. Oxygen regulates the adaptation and energy consummation process in water and indicates water’s quality. The quantity of oxygen in some period is depending on water’s temperature, air’s pressure and salty. Oxygen’s quantity could be decreased when water’s temperature increased. For example: oxygen can dissolve in 40% when temperature varies from 25 c to 0Ûc (Fig.9.2) The higher water salty could decrease the dissolution of oxygen. In 15 c, fresh water possesses soluble oxygen in 2mg/l more than sea water. Oxygen which dissolved in water is from some sources. First of all it is from air and emerges in water by wave on surface of water. Oxygen could dissolve more due to the low humidity and in contrary, water itself, evaporates oxygen to atmosphere. Oxygen also derives from photosynthesis process; otherwise, plant respiration causes the decrease of dissolving oxygen in water. Particularly, photosynthesis process is happening in Euphotic zone (limonitic zone for sea water), where the penetration of light has attended. In littoral zone, there are plants and phytoplankton which produce oxygen in water. In natural water source, due to the clean sky and cold air in the Euphotic zone, the quantity of oxygen becomes higher in the afternoon and lowdown at night time. The quantity of CO2 dissolution is converse proportion of O2. (2) Carbon dioxide (CO2) Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Carbon dioxide is very important for the aquatic eco-system, because green plants have used it for the photosynthesis. It also contributes as an adaptation role between carbon dioxide and oxygen in animal. Carbon dioxide dissolves well in water. Carbon dioxide dissolution proportion is a converse proportion of temperature, therefore, it is the same as oxygen somewhat it could dissolve less due to high temperature rather than it could dissolve well due to low temperature, but carbon dioxide dissolves well than oxygen. For example: atmosphere consists around 3% of CO2 and 21% of O2, but due to temperature 20 c, pressure 760mHg, proved that O2 has dissolved 6mg/l; at the same time CO2 has dissolved 4 mg/l. through calculation, proved that in animal, plants and water contain CO2 more than in atmosphere. Carbon dioxide in natural water is from: animal and plant respiration, assimilation from dead body by bacteria, underground water contains high quantity of CO2 which one has been broken down from underground organic matters; CO2 is also from chemical reaction happened between carbonate solution in the ground and water plus acid; CO2 in atmosphere also dissolves with rain. Follow the reaction below: CO2 + H2O H2CO3 (3) Nitrogen Nitrogen is one of important organic matters for the living organism. Plants and animals such as it is a part of protein and fat structure. Nitrogen contributes as main factor for fertilization for all water sources. Nitrogen in atmosphere penetrates in water, and then transfers in to different substances by aquatic animals and plants (assimilation). Moreover, the other source of Nitrogen is from: erosion of the ground, underground water including used water from family and kitchen. (4) Calcium and Magnesium The two metals constitute in fresh water in higher quantity than an others. Both of them possess the same property as they can dissolve in form of carbonate solution, Mg is very important for the molecule structure of chlorophyll. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Particularly, water source contains more Ca than Mg. for soft water or so called water in which there are under than 50mg/l of other dissolved substances contains around 48% Ca and 14% Mg, but hard water contains 53% Ca and 35% Mg. Scientist cans identity the quantity of Ca in water by using indicator. Ohle, the German scientist has identified: water in which Ca<10 mg/l is low fertilized; water which contains Ca in between 10-25 mg/l is a mid fertilized and the one in which Ca>25 mg/l is higher fertilized water. (5) Sodium and Potassium In overall water sources both substances are proved power than another substances with positive ion, and Na is always more than K. In soft water, Na covers second place after Ca. but in hard water, Na contains lower than Ca and Mg. In general, Na is seen in form of solution NaCl, some case in form of sodium tetra borate (Na2B4O7) or borax. (6) Phosphorus Phosphorus is an important substance in the eco-system, because it contributes in the energy transfer, for example: it constitutes in the structure of DNA and RNA. Particularly, water sources contain phosphorus in low quantity. Phosphorus which is in form of phosphate could be easier absorbed by plants, therefore, it can easier dissolve in water, so that, and there is a lot soluble phosphate. However, we can identity the value of total soluble phosphorus for all of the soluble substances. (7) Iron (Fe) Fe is an important metal for eco-system, because it contributes in the regulation of water breathing’s animals. Fe is main structure of hem globule of aquatic animals. Moreover, Fe involves in the chemical reaction in water. (8) Organic matter Some of water sources compose different kinds of or Organic matter, sometime water becomes in a normal colour. Therefore, these Organic matters include soluble and non-soluble Organic matters (soluble Organic matter and particulate Organic matter). Fertilized water contains more Organic matter than unfertilized water sources. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version There are 2 kinds of organic matters: 1) autochthonous - takes place from water itself. 2) allochthomous - held by alleviation (flood). However, soluble Organic matters are main alimentation source for the aquatic microorganism (plankton). 9.2 Fresh water community. The classification of the living thing in fresh water by ecological method can be practiced as below: Lining organism in the surface (benthos) lives on the bottom’s surface or hides in mud and they can be divided due to the food regime in small group: filter feeders that are mollusk; deposit feeders – that are oligochaeta. Periphyton – are organism which fix wit substrate or other materials in water, such organism are: algae, diatom, protozoa and could be included mono value mollusk and larva of aquatic insects. Plankton – is organism which slowly swims. There are two kinds of plankton: phytoplankton and zooplankton. Nekton – includes organism which can swim well, that are: fishes, amphibians and aquatic insects. Neutron – includes surface organism, that are Geridae, Gyrinidae, Dytiscidae. Referring to the specific character of water source, however to study about fresh water community could be divided in 2 kinds: Lentic community – the community of calm or tranquil water and Lotic community – the community of steamed water, there are some specific field of study according to the habitat such as: Litoral zone, middle zone, under stone, mud, sand areas…however, the living organism found in each environment are different from each other. In general, the producers in water are : algae, moss and some aquatic plant; the consumers are including 4 groups of animals, that are: Mollusk include bivalve and mooncalves gastropod, aquatic insects, daphnia or Cyclops, shrimp, crab(crustacean), fishes, fresh water worms, rotifera, protozoa, roundworm, flatworm and so all; for the decomposer group is including bacteria and some water monera. 9.2.1 Ecological character and adaptation of water organism. Lentic water sources include: Lake, reserved ponds (reservoirs), dam, swamp, march, prod. All of those water sources are temporary reserved which receive water from Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version the streams and river, then open forward by water canal. In some case, they receive from underground source or from rain. There are some kinds of Lentic: 1. Dam, reservoirs There are inartificial water sources used for electrical hydropower, agriculture and touristy business. Dam and reservoirs are temporary reserved water during a year, but the quantity of water has been changed due to the seasons. 2. Swamp It could be artificial or natural. More general, it locates in the low area where is often flood. This water sources are covered by bush plants and many kinds of grass. The bottom of swamp is covered mud. The surface of water is occupied by floated grass. 3. Marsh Marsh is smaller than swamp, but its physical and biological structures are quiet similar. Some of them contain water during a year and vary on the season. 4. Ponds Mostly, Ponds are artificial, used for fish culture. Most small and natural ponds lack water in dry season, but some can conserver water during a year. The ecologist has divided the large lentic water in 3 zones (Fig.9.3): Litoral zone: it is a non deeper area where sunlight can penetrate well and aquatic plants are more concentrate (Fig.9.4). Limnetic zone: this zone takes place from surface up until the limit of light penetration, in which photosynthesis value is equal to the respiratory value, as so called compensation level. This zone is occupied by living organism as micro algae, diatom, Cyclops, daphnia, larva of aquatic inserts, rotifers and some fishes. Profound zone: this zone occupies under the compensation level down ward to the bottom. This zone is found only in large water sources and mostly, occupied by the nonphotosynthesis living organism, for example: bacteria, water monera, red worm, chironomid, tubifex and monovalred and bivalved gastropod which consume organic substances (Fig.9.5). Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Figure.9.3 shows zones of lentic water: litoral, limnetic and profound zones. Fig.9.4 shows the main producer in still water. Gross producers: 1-3 emergents, 4- floating plants, 5-7 different types of algae. Small producers: 8-9 = green algae, 10-17 = diatoms, 18-20 = green-blue algae. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig.9.5 show the animals existing in each zone of still water: A – Zooplankton: 1-2: rotifera, 3-4: Daphnia, 5-9: red Cyclops. B – Surface water insects: 1-water strider, 2-3: Gridae. C – Organism in the bottom: 1-2: chimronimus; 3-Gastropod, 4-tubifex. Whereby, living organisms are more abundant, so their adaptations appear in different patterns that can be concluded as below: Plants: Aquatic plants possess very soft transport tubes; root system plays role in fixing with materials in water, reserves carbohydrate and reproduction. Root has less role in absorbing the mineral and water. Their trunks possess a lot of cell-guards, some of trunks contain spongeous structure and can float on the surface. Their leaves are large and thin by comparing with their trunks and contribute role in the gas exchange with water. Chlorophyll distributes in the epidermis and easier elaborate photosynthesis. Moreover the trunks of aquatic plants are covered by glutens substance which protects them from scratching water. Adaptation of aquatic animals: Aquatic animals possess diver form of adaptation than plants, that are included morphological, physiological and behaviourous adaptation. For example: they can act different movement such as: floating, lowing down in water; some of them can fix and Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version hide in the bottom. The surface of their body is suitable for accommodating with water condition (soft weight in water and easier float). The substance exchange in aquatic animal are diversified: the aquatic insects use the fine tubes at the end of their body to pick the surface of water, where the attend gas exchange, some animals use the respiratory tubes to suck the substance from water plants. Some animals possess an air sack under their wing, that they can reserve air while downing low in water. The larva hide in the mud of bottom where there is poor oxygen, they need less oxygen. The amphibians have two ways of respiration: by lungs when they are on land; though their skin when they are in water. Fishes use their gills as main breathing organ. The animals which can move so faster possess more advantage in behavioral adaptation. For example: in the un-appropriated season, they have immigrated to other place where the living condition is more suitable. Most amphibians and non-active animals such as gastropods and some insects due to bad condition, they continue their life in the dormancy stage until the new season which is more appropriated. 9.2.2 Ecological character and adaptation of living organism in streamed water or lotic water. Most lotic water include: rivers, streams and channel. Generally, from catchments: the top end of streams, rivers continue to join and meet together and form water shed area. Particularly, the water shed area takes place in the mountainous areas which are often covered by abundant vegetation. A water shed area where the vegetation is dense the streams appear through a year; and where the vegetation is to be herbaceous or small trees, the streams could be seasonal. Many branches of rivers and streams come to meet and join together, form a big and large river as so called water basin area. For example: Mekong river takes place from China, then continues to the south and composed by different rivers and streams and becomes a big river. There are some general characters of lotic water: particularly, in the top end water, the velocity is around 50 cm/s. If the velocity is over than usual, it could create negative effect to the bottom (bed rock) or the bottom becomes to be covered by course, sand and gravel with diameter varies from 5 mm. If velocity is under then 50 cm/s, the bottom could comprise the components lower than 5 mm. therefore, velocity has main role for the water bottom in each area, i.e. in the non-rapid stream is often seen a lot precipitation of materials which form mud. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Water stream can alleviate different food substances to another place. Therefore, lotic water is high fertilized than lentic water in 6-30 times. There temperature of the river is not similar through out the length of the river. The top end of river where velocity is high possesses low temperature, whereas the lentic area temperature increases step by step. Lotic water source has higher quantity of soluble oxygen than lentic water, because of water move during the tine. The animals in the lotic water are animals which need more oxygen to survive and lack of resistance due to the un-appropriated condition. The value of acid and base relates with the quantity of carbon dioxide in water. If pH is high, means that water contains carbonate solution or bicarbonate, and this is a suitable condition for the aquatic animals. If pH is low, it means that water lacks food substances and not available for the living organism. Most water sources receive energy from on-land producer, because the primary production is alleviated from land to the river. Therefore, the first consumers in water are often animals, because they can assimilate the dead bodies brought in water. Lotic water ecology is divided in 2 areas: the high spread stream area: rapid, riffle and deep pool area. These areas comprise the same ecological condition such as energy transfer and food cycle. Foe example: in riffle area possesses high productivity, abundant organism which fixes on the stone (diatom and moss). In the deep pool area contains and reserves a lot soluble substances which become food substances for the producers. The abundance of lotic water is depending on the bottom structure: the bottom made from sand is poor and less fertilized. Otherwise, in the rock bottom with high spread water, there are a lot organism which can resist to the rapid stream and they possess a special organ fixed to the rock. The stone bottom is more available for many living organism, especially the larva of different insects. In conclusion: animals and plants in the lotic water have different kinds of adaptation: -Thin form body which can release the hydro movement (fishes). -Possess special fixed organ. -Attached organs have developed on many parts of organisms. -Development of glutant substance (Fig.9.6). Plants also have large adaptation such as: moss develops large root system to tight with the material in water. The adaptation of aquatic plants also varies depending on each season. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version Fig.9.6 shows the representative animals in lotic water. Group A: the group of organism which lives in the high spread water: 1-Simulium; 2- Bibiocephalus; 3-Water penny, Psephemus; 4-5larva and Cadisfly F; 6- larva of Mayfly and 7-larva of Stonefly. Group B: the group of organism which hide themselves in the bottom: 1-larva of Mayfly and 2-larva of Dragonfly. Create PDF with PDF4U. If you wish to remove this line, please click here to purchase the full version
