Thursday, 8 March 2018

Components and Types Ecosystem

Ecosystem Plants, animals and human beings live in association with a wide variety of other plants and ‘ animals. These communities of organisms are not mere ad hoc collections of individuals or populations but they represent a highly ordered dynamic and complex organization. Such complex natural organization with their living and non-living environments that controls them and from which the living organisms derive their sustenance are technically called as “Ecosystem” or an “ecological system”.

The interaction between living organisms and their environment is very much a two way process: organisms affect and are in turn affected by their surroundings. Professor Arthur Tansley, a British botanist, in 1935 proposed the term ecosystem and defined it as the “system resulting from the integration of all living and non-living factors of the environment”. he regarded ecosystem as not only the organism complex but also the whole complex of physical factors forming the environment. 

The concept of this interacting system has proved extremely valuable and the ecosystem is regarded as a basic unit for ecological studies.

Components of Ecosystem 

The components of the’ ecosystem can be categorized into abiotic or non-living and biotic or living components;

 Abiotic components: The important abiotic components are
  •  Energy: basically from the sun is essential for maintenance of life. In the case of plants, the sun directly supplies the necessary energy. Since animals’ cannot use solar energy directly they obtain it indirectly by eating plants or animals or both. Energy determines the distribution of organisms in the environment 
  • Materials: (a) organic compound-proteins, carbohydrates, lipids, humic substances which are formed from inorganic subsistence reconverted into them on . : decomposition. (b) Inorganic compounds — oxygen, nitrogen, carbon, carbon dioxide, water, Sulphur, negates, phosphates, and ions of various metals are essential for Organisms to survive. -. ______
  • Climatic factors: light, heat, temperature, wind, humidity, rainfall. snowfall etc. 
  • Edaphic factors (structure and composition of soil along with its physical and chemical characteristics) ; also exert significant influence on the organisms. 
Biotic components: Biotic components include living organisms comprising plants, animals and decomposers and are classified according to (heir functional attributes into producers and consumers.
  • Producers-  Autotrophs (self-nourishing) are green plants as they synthesis carbohydrates from simple inorganic raw materials like carbon dioxide and water in the presence of sunlight by the process of photosynthesis for themselves, and indirectly for other .non-producers. In terrestrial ecosystem, producers are basically herbaceous and woody L plants while in marine and fresh water ecosystems producers are various species of ;: microscopic algae. Chemosynthetic bacteria are also producers. However, unlike plants : which constitute the major producers, these bacteria, which are found in deep ocean trenches where sun energy is absent, derive energy by the process of chemosynthetic from the : hydrogen sulphide seeping through cracks in the sea floor. 
  • Consumers- Heterotrophs (other nourishing) am incapable of photosynthesis and depend on organic food derived from animals, plants or both. Consumers can be divided into two broad groups namely macro and micro consumers. (i) Macro consumers or phototrophs feed on plants or animals or both and are categorized on the basis of their food sources. Herbivores are primary consumer which feed mainly on plants e.g. cow, rabbit Carnivores feed only on animals. Secondary consumers feed on primary consumers e.g. wolves. Carnivores which feed on secondary consumers are called tertiary consumer e.g. lions which can eat wolves. Organisms which consume both plants and animals are called omnivores e.g. men. (ii) Micro consumers — Saprotrophs (decomposers or osmotrophs) are chiefy:’ bacteria and fungi which obtain energy and nutrients by decomposing dead organic substances (detritus) of plant and animal origin. Some of the products of decomposition such as inorganic nutrients released in the ecosystem are reused by producers and thus recycled. Earthworm and certain soil organisms such as nematodes, and arthropods are also detritus feeders and help in the decomposition of organic matter. 

Size of Ecosystem 

As you know an ecosystem may be as small and as simple as a cow dung pad or as complex and large as an ocean or the biosphere itself, comprising a wide variety of species. An interesting point to observe is that ecosystems occur within ecosystem. To take an example, cow dung ecosystem may be contained in a forest ecosystem which is contained in the biosphere.  

In some cases, like a pond ecosystem, the boundaries are well defined. In the case of forests, grasslands and deserts there are no sharp boundaries. These ecosystems often are separated from adjacent ecosystems by a transition zone or a diffused boundary zone called ecotone. Organisms of adjacent ecosystems intermingle in the ecotone zone; consequently they may have greater diversity of species than the neighboring ecosystems. 

Types of Ecosystem

Basically ecosystems are of two types: terrestrial and aquatic. If you travel from plains to the mountains in the Himalayas, you notice significant changes in the landscape. Deserts, grasslands, crop fields, forests and glaciers represent different terrestrial ecosystems. Oceans, estuaries, mangroves, coastal marshes, rivers, lakes, ponds and swamps are examples of aquatic ecosystem. Ecosystems can also be grouped into two categories, namely natural and artificial or man made as shown below:

Types of Ecosystem

Natural and Artificial Ecosystem 

  • Natural ecosystems are those which are mostly free from human disturbances, such as tropical forests, grasslands, oceans, lakes and deserts. 
  • Artificial or man-modified ecosystems are formed as à result of human modification of the natural ecosystems. For example, man has transformed natural forests and grasslands into crop fields. An extreme example of an artificial ecosystem is a city. Increasing human interference has destroyed many natural ecosystems and replaced them with artificial ecosystems, such as crop fields, urban centres and industrial estates.
All ecosystems are fully integrated with the neighboring ecosystems and communicate with each other in varying degrees through’ the import and export of both energy and nutrients.

An ecosystem is a dynamic system characterized by energy flow and nutrients cycling. Substances constantly flow through it, and there are sufficient supplies of energy within the ecosystem to allow for this flow to take place. See Fig 1.2 Ecosystems also possess considerable self-regulating ability, called homeostasis, due to which they lend to recover from minor perturbations. Fig 1.2 A diagram illustrating the manner in which nutrients cycle through an ecosystem. Energy does not cycle because all that Is derived from the sun eventually dissipates as heat.

Natural and Artificial Ecosystem

Fig 1.2 A diagram illustrating the manner in which nutrients cycle through an ecosystem. Energy does not cycle because all that Is derived from the sun eventually dissipates as heat.

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