Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Food Web and Food Chain Ecology - is the study of the interaction of organisms with one another and their environments. The environment is often divided so that scientist can assess the areas properly (See Next slide). The environments have both Abiotic Factor and Biotic factor the interaction between them is what makes up and ecosystem. Biotic- Means Living things Abotic- Means Non- Living things Each Organism in environment has both a Habitat and a Niche Habitat- is an area in an ecosystem where a particular organism lives. This is usually based on the resources available. Niche- is the role an organism play's in an environment. Population Dynamics Both the environment and the amount of energy in a given ecosystems is limited. Often when a species has little to no competition, meaning lots of access to food, exponential growth (making on increase in population size and density) occurs. During exponential growth the population doubles in size with each reproductive cycle cause a huge period of time also known as a population explosion. When the population reaches the limits of the ecosystem, this is known as an ecosystems carrying capacity. The population must be adjusted due to the resources cannot support the population. This cause competition between the organisms and also creates several unique relationships between organisms. Competition generally acts as a negative feedback interaction for both species involved. Predation is usually through a system where the population growth of one species; the predator is favored and the population growth of the other; the prey is negative; affected. Competition can often lead to Natural Selection in that the strongest organisms survive to reproduce. These are the organism that are best suited to the environment, have the ability to hide from predators, are the strongest against disease and the best at find food and meeting there nutritional needs. a. Competition also has benefits to both the predator and the prey populations. The predator helps keep the population of the prey below that of the carrying capacity helping to prevent disease and sickness. b. When an exotic species is introduced into a food web this puts a new predator into the system. This could have huge consequences in the population. i. For example when a mongoose was introduction to several Caribbean Island in an effort to control the rat population; the governments did not see the unintended consequence that it would have on the rest of the food web. The island saw the mongoose population explode do to no predator to keep this species in check. This lead to the island seeing mass extinction of many native birds, reptiles and small mammals. ii. Carrying Capacity – the amount of organisms that an ecosystem can support based on the resources that the ecosystem has availed. iii. Competition – this is where a species or organism must challenge another species or organism for resources such as for food water and habitat. Types of Competition Symbiosis- Any relationship between organisms that live in the same ecosystem. There are three different types. Parasitism Relationship where one organisms feeds on another. One organism is harmed or killed and one organism. Tapeworms Mutualism Relationship where both organism benefits Flowers and Bees Gopher tortoises Commensalisms A relationship where one species benefits and the other is unaffected Clown fish and sea anemones Example diagram Question you should be able to answer: What is the Oreo Effect? What happens if you remove green plants? What happen if you remove kites? What happen if you remove the rabbit and mouse? What happens if habitat is destroyed to a food web? 2. Food Chain- these are a sequence of organisms which have a predator/ prey relationship. The chain consists of a Producer, a Primary consumer, a Secondary Consumer and a Decomposer. Consumers are separated into to types Herbivores and Carnivores. 3. Components of a Food Chain i. Producers – are the plant life in an ecosystem. The total amount of energy that flows through and ecosystem depends on the amount of energy that is fixed by the producers. ii. Herbivores- role in the ecosystem is to convert the stored energy in plants (producers) tissue into animal tissue. With out this step there could be no higher levels in the food chain. Most of these organisms have high bacteria counts in their digestive systems in order to deal with the large quantities of digestible fiber. iii. Carnivores – eat herbivores or each other. First level carnivores eat only herbivores while 2nd level carnivores have the ability to also eat other carnivores. Usually 2nd level carnivores have adapted hunting skills and are considered very intelligent. iv. Decomposer- is also known as the final consumer. Their role is to breakdown plant and animal biomass after it has expired. This releases the nutrients and minerals that are contained in the carcasses for future use. There are two types of decomposer. Food Web This is looking at the ecosystem as a whole. Food webs show the connections to organism and what they eat Refresher of the player in a Food Web Producer Plants Autotrophic- gets energy from the sun (100% energy efficient) Consumers- Heterotrophs must obtain food from other sources First Order Consumer or Primary Consumers Eats plants only Also known as Herbivores Second order or Secondary Consumers Larger animals which eat Primary Consumers Also know as Carnivores Other consumers Omnivores - eats both plants and animals Scavengers- eats dead and dying organism Decomposers- organisms which brake down dead matter into simple compounds. Arrows in a food web point in the direction that energy flows. Ex. From Above: The energy from the green plant energy flows into the Rabbit and the Goat after they eat the green plants. Food webs are complex but often there is a central player known as a Key Stone Species that in one way or another count on this central player. The removal or decrease in the population of that organism will greatly impact the food web and most of the other organism populations suffer. Human Impact: Pesticides, Herbicides, Extinctions, over Development: All possible used in application and system question- if more detail needed ask. Energy Pyramid The Energy pyramid show how energy moves throughout the varying levels in a food chain. Producers are considered to be 100% energy efficient. This is because plants make sugar for energy production in the process of photosynthesis. This set of organism makes up the largest biomass (Living Material) on the planet. Herbivores have to move for food, this make them less efficient that plants in that they must burn energy to get energy. When looked at Herbivores are considered to be 10% efficient. Like energy efficiency the amount of organism or Biomass decrease do to the nutritional needs. Carnivores are the least energy efficient and often require large hunting area, speed and other adaptations in order for them to meet all nutritional requirements. Carnivores are the least efficient at 1%. Like energy efficiency the amount of organism or Biomass decrease do to the nutritional needs. Human Impact: The food webs and energy pyramid are disturbed with any of the following Invasive species- impacts the food chain and population numbers Extinction – food chain impact the other organism in the area-Keystone species. Habitat loss- No homes mean lower numbers of critical foods. Population Density Measurement that determines how crowded a population is. This is usually done for one species at a time but if it is part of a Field Experiment several populations can be looked at. Number of individuals / unit of volume This can only be an estimate because there is no way of counting every organism in a population. In order to get a population density number you must take multiple sample of the area in question and count the individuals that are visible. This is how close the individuals of a population are to another individuals of the same species POPULATION DISPERSION Dispersion- two types Even dispersion - animals or plants have antisocial behaviors Organisms want to be apart. Often seen in birds and gulls. Clumping dispersion - grouping organism in a pack, very social behavior. Often seen in fish, lion, elephants ect.