* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Today we are going to discuss a very important topic namely
Ecological economics wikipedia , lookup
Natural capital accounting wikipedia , lookup
Biodiversity wikipedia , lookup
Agroecology wikipedia , lookup
Conservation psychology wikipedia , lookup
Biogeography wikipedia , lookup
Overexploitation wikipedia , lookup
Nitrogen cycle wikipedia , lookup
Molecular ecology wikipedia , lookup
Soundscape ecology wikipedia , lookup
Fire ecology wikipedia , lookup
Cultural ecology wikipedia , lookup
Conservation biology wikipedia , lookup
Habitat conservation wikipedia , lookup
Biodiversity action plan wikipedia , lookup
River ecosystem wikipedia , lookup
Biological Dynamics of Forest Fragments Project wikipedia , lookup
Lake ecosystem wikipedia , lookup
Renewable resource wikipedia , lookup
Reconciliation ecology wikipedia , lookup
Sustainable agriculture wikipedia , lookup
Pleistocene Park wikipedia , lookup
Human impact on the nitrogen cycle wikipedia , lookup
Natural environment wikipedia , lookup
Payment for ecosystem services wikipedia , lookup
Ecological resilience wikipedia , lookup
Theoretical ecology wikipedia , lookup
Restoration ecology wikipedia , lookup
Ecosystem Dr. G. Selva Mangai Today we are going to discuss a very important topic namely ecosystem and its components. The term ecosystem we have been hearing since our childhood days but today we are going to discuss in detail, what are its structural and functional components of an ecosystem and how are we going to study about the ecosystem and its significance. Well when we speak about ecosystem it comprises of both the living and the non living components. How do we define an ecosystem? It is a community of Living and Non living things together in a specific location. When we speak about Living (Biotic)-Plants, it includes animals, fungi and bacteria are all biotic or living factors. Non-living Components (Abiotic) - Abiotic, meaning not alive, are nonliving factors that affect living organisms. Environmental factors such habitat (pond, lake, ocean, desert, and mountain) or weather such as temperature, cloud cover, rain, is abiotic factors. So in detail we are going to study the interaction between the biotic and abiotic components and what is its significance in its day to day life. So ecology is nothing but the study about the interaction of organisms with one another and with the environment in which they occur. Ecosystem was coined in 1930 by Roy Clapham, to denote the physical and biological components of an environment considered in relation to each other as a unit. British ecologist Arthur Tansley later refined the term, describing it as the interactive system established between biocoenosis (a group of living creatures) and their biotope (the environment in which they live). We can study the ecology in Individuals, Population and Community. We will look into each of these in detail. First when we speak about individual ecosystem, let’s look at this picture. It denotes a banyan tree. Here we see an individual banyan tree. So if you’re going to study about the individual banyan tree’s relationship with the surroundings then we call it individual ecosystem. Individual ecosystem is also called Organismal Ecology (autecology). It is the study of the life history of an individual (i.e., species) & its response to its environment. So here in ecosystem there are Species that are all individuals that can potentially breed with one another and produce viable offspring. Individuals are concerned mostly about physiology, reproduction, development or behavior. And next we are going to discuss about population ecology. In the individual ecology we studied about a single banyan tree and its relationship with the surroundings. Here in population ecology we see a group of banyan trees. So here in population ecology we are going to study about this group of banyan trees interactions with the environment. In detail, Population ecology is the study of the abundance, distribution, productivity, & dynamics of a group of individuals of the same species. Population is a group of potentially interbreeding & interacting individuals of the same species living in the same place & time. Populations usually focus on the habitat and resource needs of individual species, their group behaviors, population growth, and what limits their abundance or causes extinction. Well now we have seen about individual ecology and population ecology. Individual ecology deals with a single species and their interaction with their surroundings and population ecology deals with the group of the same species belonging to the same community and their interactions with their surroundings. Well the last one we are going to see now is the community ecology. What is community ecology? Community ecology is the description & quantification of natural assemblages of different species/populations. Community is a collection of species/populations interacting directly and indirectly in the same place & time. So now we have seen what ecology is. Ecology is nothing but the study of biotic and abiotic factors in a given surrounding. And we saw who coined the term ecology, and we have also seen what the three levels are of study in ecology namely individual ecology, population ecology and community ecology. Now to study this ecosystem itself there are different levels. We are going to discuss each one in detail. Now ecosystems are divided into two basic categories. (i) Terrestrial or land based ecosystems. (ii) Aquatic ecosystems in water. If you’re going to study about the components included in the land or the terrestrial regions and their interactions with the surroundings, we call them as terrestrial or land based ecosystems. And if you’re going to study about aquatic organisms and their interactions with the surroundings then it is called aquatic ecosystems in water. Now what is a very important component about studying this ecosystem is, first of all as an individual we have to have knowledge of the ecosystem, so as to design an ecosystem study. So what we have to understand is there are different levels of study and for these different levels of study we have to have a thorough knowledge of the ecosystem and their interactions. So we are going to discuss what different levels in understanding the ecosystem are. Before that we will have to understand that there are two kinds of ecosystem. o Natural ecosystems that is already formed on land o Man modified ecosystems include agricultural land and urban or industrial land use patterns. So if we have to understand about ecosystem there are different levels of study. We have already discussed there are two kinds of ecosystem namely the man made ecosystem and natural ecosystem. To study about the understanding of the ecosystem, first of all we will have to have knowledge about What does the ecosystem look like?’ What is its structure? What you should see are its different characteristics. What is the composition of its plant and animal species? How does the ecosystem work’? Now we will discuss each of this is detail. First of all look at this picture. You see soil water, rainfall, distance to permanent water, hydrology, grass nutrients around a particular area. Now before we go about studying the ecosystem we have to have knowledge of the soil, water in that particular area, the grass biomass in that particular area, the grazing angulates in that particular area, the hydrology, soil fertility, everything. So you have thorough knowledge of their particular area, it will be very easy for us to study the ecosystem in one particular area. So ecosystem we can study in one particular area or we can study in different areas too. But having knowledge in that particular area is important to help us to design that ecosystem. We are going to discuss each thing in detail. What does the ecosystem look like? One should be able to describe specific features of the different ecosystems in ones own surroundings. A Field observation is very important. Take for example, you are residing in an apartment you have to have knowledge about your car parking area, your roof garden area, etc in your residing place for you to create an ecosystem in that particular area where you reside. Similarly if we discuss about the forest area you will have to have the knowledge of grassland, a water body, an agricultural area, a grazing area, around that particular area. So if you have the knowledge of that particular area then you will be able to create the structure of an ecosystem. Well that’s a one point we will have to discuss. What you should see are its different characteristics. For example, forests, you should know the kinds of forest, different types of vegetation in pond from periphery to center, change of vegetation in mountains, etc. What is the composition of its plant and animal species? For this, you will have to list the well-known plants and animals you can see. Document their abundance and numbers in nature: very common, uncommon, and rare. Wild mammals will not be seen in large numbers, cattle would be common. Some birds are common – which are the most common species? So you should have a thorough understanding of the ecosystem of that particular area. That is you will have to know about its structure, its various compositions, various plants and animals in that particular area. Next we will see how does the ecosystem work’? The ecosystem functions through several biogeochemical cycles and energy transfer mechanisms. Once you have knowledge about this, observe and document the components of the ecosystem which consists of its biotic and abiotic factors, and then you have to study the interactions between them. Then we will know how these bio systems works. So all this time in order to understand the ecosystem we have seen how do we study its different characteristics and what is its composition of plants and animals in that particular area and how does the ecosystem look like and what are its structures. Now all this time we have been discussing on the understanding of the ecosystem. A very important thing we have to discuss is the degradation of the ecosystem. Now we have seen what is an ecosystem, how does it interact with each other, what are its different components and how do we go about finding and understanding ecosystems. A very threatening factor about its ecosystem is its degradation that results in Environmental problem which diminishes the capacity of any species to survive Over exploitation of the resources because of rapidly increasing population Extinction of plants and animals that can live only in different ecosystem that is called ’keystone species’ Now because of the increase in population those animals are not able to survive in that particular ecosystem. So all these are the result of the ecosystem degradation. Apart from this, degradation also leads to Pollution from industry and waste from urban settings Forests are deforested for timber, wetlands are drained to create more agricultural land and semi arid grasslands that are used as pastures are changed into irrigated fields What happens is as a result of the ecosystem degradation many of the world’s species are gravely threatened. Various projections suggest that between 1975 and 2015; from 1 to 11 percent of the world’s species per decade will be committed to extinction. So it is only in our hands to protect this ecosystem. This is just a pictorial representation between the ecosystem services and human well being. So when we speak about ecosystem services to the mankind we see they provide food, fresh water, wood and fiber and fuel. And regulation of climate regulation, disease regulation, food regulation, water purifications. Now all these are supporting factors for mankind. Besides this, when we speak about the constituents of well-being of the mankind they provide security namely personal safety, secure resource accesses, security from disasters; basic materials for good life like adequate livelihoods, sufficient nutritious foods, shelter, access to goods. And with regard to health because of good ecosystem we have strength, feeling well, access to clean air and water and good social relationships. So what happens is ultimately when an ecosystem gets affected all these components get affected. So it is very important that we protect our ecosystem. This is also the pictorial representation of ecosystem degradation. So what happened is because of the law of bottomland hard wood forests for example has affected water quality, increased the risk of floods, and altered the distribution and abundance of animals that depend on these forests, such as the ivory-billed woodpecker. So there are series of pictorial representations of the deforestations. So this is pictorial representation of the Ugly tea shop at Bhojpasa, Garbage strewn in Gaumukh, Destruction of Juniper, Pilgrims with Birch branches. So what happens as a result of this degradation? Different problems arise because of the exploitation of natural resources. Deforestation Extinction of Species Forced Migration Soil erosion Ozone Depletion Water Pollution Natural Disaster This is again an example of the Dead wood of Birch at Bhojapasa, Bhagirathi Peaks. Well so we have been discussing on the various components of the ecosystem, understanding of ecosystems, the degradation of the ecosystems. So what is the solution of all this. Well resource utilization is a very important factor in order to protect these ecosystems. Now how are we going to protect these resources? Now there are two models in order to study this resource utilization. – Exponential Depletion – Peaked Depletion Now exponential depletion is the rate of use increases exponentially at a time. That is the resources used until it is depleted. Take for example, you have a certain important plant species around your area and until it is completely over we use the resources and after that we are not able to reproduce it. Next is your peaked depletion. So what do you mean by peaked depletion. That is the resources increases exponentially for a while in peaks and again declines. But the resources never get depleted like those of your exponential depletion. So we have to study the ecosystem resource utilization under these two categories. One is your exponential depletion and another is your peaked depletion. The reason for the depletion of natural resources is twofold – our rapidly exploding population that needs to sustain itself on resources The growth of affluent societies, which consume The key to this issue is the need for an ‘equitable’ distribution of all types of natural resources. A more even sharing of resources within the community can reduce these pressures on the natural ecosystems. Fine, now we will have to study about the structure and the functions of the ecosystem in order to utilize these particular resources. Now how should we study the structure and function of an ecosystem or what are its different components. By Architecture or Structure of an Ecosystem, we mean The composition of biological community including species, numbers, biomass, life history and distribution in space, etc. The quantity and distribution of non living materials like nutrients, water etc. The conditions of existence such as temperature, light etc. An ecosystem possesses both living components or biotic factors and non living or abiotic factors. Components that make up the structural aspects of an ecosystem include: 1) Inorganic aspects – C, N, CO2, H2O. 2) Organic compounds – Protein, Carbohydrates, Lipids – link abiotic to biotic aspects. 3) Climatic regimes – Temperature, Moisture, Light & Topography. 4) Producers – Plants. 5) Macro consumers – Phagotrophs – Large animals. 6) Micro consumers – Saprotrophs, absorbers fungi Then when we speak about the function of an ecosystem we study them under three categories namely Trophic level interaction Ecological succession Biogeochemistry Now what comes under your functional aspects are your 1) Energy cycles. 2) Food chains. 3) Diversity-inter linkages between organisms. 4) Nutrient cycles-biogeochemical cycles. 5) Evolution Trophic Level Interaction deals with how the members of an ecosystem are connected based on nutritional needs. Ecological Succession deals with the changes in features/members of an ecosystem over a period of time. Biogeochemistry is focused on the cycling of essential materials in eco system. This is an example of your sample food chains which deals with the trophic level. It goes like there are primary producers and from the primary producers goes to the secondary consumers, tertiary consumers and quaternary consumers. So these are different examples of the grassland biome, ocean biome and the pond biome. When we speak about grassland biome, first the primary producer here is the grass, the primary consumer is the grasshopper, it is again consumed by rats, again it’s consumed by the snakes, again its consumed by the hawks. So this is just a simple example of your trophic level interactions. When we speak about energy flow, it is like the energy flows through the ecosystem in one direction which is called the food chain. It’s like a pyramid. At the bottom you have the producers and then your consumers. The producers contain the most energy and they are the autotrophs and manufacture their own food. Next you have the consumers. These consumers they obtain the energy by eating the producers are heterotrophes. There will usually be several levels of consumers beginning with herbivores and then to carnivores and the omnivores. Finally they decompose and they obtain the energy from the waste and dead organisms. Examples are like those of your bacteria and fungi. So from the sunlight that is from the producers it goes to the consumers and in consumers there are many levels. As we move up each level, the energy level also decreases. Take for example; in grass the producer has 1000 kilo calories. The grass is eaten by the mice or the rats; the amount of calories gets reduced to 100 kilo calories. So when these mice or a rat is eaten by the ferrets the energy again gets reduced to 10 kilo calories. The ferrets are then eaten by owls then and finally the energy gets reduced to 1 kilo calories. So this is how the energy dissipates in a food chain. Now apart from food chain the energy flow also constitutes various cycles. Carbon cycle Nitrogen cycle Oxygen cycle When we speak about nitrogen cycle, mainly the nitrogen is being utilized by the plants for the fixation of atmospheric nitrogen. This is a pictorial representation of the nitrogen cycle. Nitrogen in the atmosphere is being fixed by the nitrogen fixing bacteria with the help of the root nodules in the legumes plants. Now what happens is this nitrogen fixing soil bacteria converts the ammonium into nitrates. So this process is called as amonification, conversion of ammonium into nitrates with the help of nitrifying bacteria, it is called as amonification. Next these nitrates are again converted to nitrites with the help of nitrifying bacteria and these nitrites are used by the plants in order to fix the nitrogen. So this entire nitrogen is important for the plants to fix the nitrogen in the atmosphere. Next we are going to see about the carbon cycle. This carbon cycle is said to biogeo chemical process by which carbon undergoes chemical reaction, changes forms and moves through the different reservoirs including living organisms. Now this is a pictorial representation of the carbon cycle in different reservoirs like those of soil carbon, microbial respiration and decomposition in ocean sediments, etc. so carbon is also a very important component like those of the nitrogen. Next is the oxygen cycle. The Oxygen cycle is the biogeochemical cycle that describes the movement of oxygen within its three main reservoirs: The atmosphere (air) The total content of biological matter within the biosphere (the global sum of all ecosystems) The lithosphere (Earth's crust). So this is a pictorial representation of the oxygen cycle reservoirs and its flux in lithosphere, in biosphere which is again used for respiration and in decay, again this oxygen is used in the photolysis, weathering, etc. So all this time we have been discussing on the ecosystem, its various components, how do we understand the ecosystem and how do we construct the ecosystem and we have been studying about the ecosystem and what are the threatening factors of the ecosystem. To sum up if you have to really constitute a good ecosystem what is our contribution to the society. First of all we have to understand What is the nature of the ecosystem? What is its structure and its functions? Who uses the ecosystem and for what purpose? How are these ecosystems degraded? What can be done to protect it from deteriorating in the long-term? So as I said in the beginning of my talk one impulse from a vernal wood would may teach you more of men than all sages can. So it is only in our hands to protect this mother nature. Each and every individual should take the responsibility that we have to constitute a good ecosystem for both the abiotic factors and the biotic factors to survive in a particular surrounding. To conclude we will have to understand what is an ecosystem and its various components and how do we constitute a very good ecosystem and with this knowledge how are we going to protect this resource and finally structure and study the functions of this particular ecosystem for the survival of the mankind. Thank you.