Definition of ecosystem

In the year 1935, AG Tansley coined the term ecosystem. The definition of ecosystem according to Tansley is  “Ecosystem consists of organisms and inorganic components in a relatively stable state -equilibrium.  According to  E P Odum, "Ecosystem is the basic functional unit of organisms and their environment interacting with each other”. There are 2 components in an ecosystem; biotic and Abiotic components. Both of them complement and react to each other hence, they are inseparable while they coexist. The abiotic and biotic components interact with each other at different levels of the ecosystem through various means. As every ecosystem is open, the energy bound within the given system can be mobilized easily through different ecological levels from producers towards the consumers. The ecosystem is the system where all living organisms co-exist because there is a considerable degree of co-dependence and interaction between the species. As a result, the ecosystem is stratified into various levels in which an organism survives by consuming another organism belonging to the lower level. The ecosystem provides a framework within which all the organisms interact, live, reproduce and grow. It is a web of relationships in which every organism must compete, complement, predate, and adapt at different levels in order to survive. For example, cattle eat grass and plants similarly, grass and plants use the manure produced out of cattle dung. In a general sense, the ecosystem is the combination of various organisms interacting with each other by competing, complementing, predating and adapting.

Table Of Contents

1. Definition of ecosystem

2. Components of ecosystem

3. Structure and functions of the ecosystem

4. Classification of ecosystem

5. Factors affecting the ecosystem



Components of ecosystem

1. Biotic component

2. Abiotic component.

Both of them are essential to survive in the system. Abiotic factors include water, sunlight, oxygen, soil, and temperature, etc. On the contrary, biotic is the living component encompassing microbes, plants, and animals including human beings. A healthy interaction between the biotic and abiotic components is necessary for a balanced system. For example, if there are plenty of fish living in the pond, it must be complemented by the abiotic factors -water, and enough oxygen. In this case, the imbalance can occur if any one of these found to be too high or too low. 



Structure and functions of the ecosystem

As we already know, A healthy ecosystem is characterized by a balanced interaction between all living organisms, the interaction results in the proper structure. Species are arranged in a certain manner depending upon whether the individual is a predator or the prey. Hence, the identification and enumeration of species result in the hierarchy of the ecosystem. The process of vertically distributing the different species at different levels is called stratification. Stratification does vary between terrestrial, aquatic and other systems. But, the basic rule for stratification is that the weaker organisms take the bottom level of the chain and the stronger ones move up the pyramid. For an ecosystem to be organized and balanced, there must be a logical agreement between the productivity, decomposition, energy flow and nutrient cycling at all levels. Below is the diagram showing energy flow through various levels.



Classification of ecosystem

The ecosystem is primarily divided into Natural and Artificial (man-made) Ecosystems. Natural ecosystems can be aquatic( see, pond, river, channels, etc) or terrestrial( Forest, desert, Grassland), etc. The diagram below indicate how the ecosystem is classified.



Factors affecting the ecosystem

Ecosystems are directly or indirectly controlled by both external and internal factors. External factors also known as state factors. State factors exert their influence to bring overall control but are not influenced by the ecosystem. One of the most important external factors is climates. It determines the biome in which the ecosystem is found. Climate is the overall result of multiple factors such as rainfall patterns, seasonal temperatures, and any other natural forces. Climate influence photosynthesis resulting in a definite amount of water and energy available to the ecosystem. The type of soil and its level of fertility ca directly influence the availability of mineral nutrients. Topography can increase or decrease the force of water-flow resulting in a certain level of variation in the productivity of an ecosystem. For instance, ecosystems can be quite different if they are found in a small depression on the landscape instead of an adjacent steep hillside. The time and potential biota can also have a profound influence on the ecosystem's balance. Similarly, the set of organisms that can potentially be present in an area can also significantly affect ecosystems.  In addition to the external factors, internal factors can also affect the way the ecosystem is present. Internal factors are the processes that exist within the ecosystem. Some of them are decomposition, succession, and the types of species present in the given ecosystem. Both the external and internal factors are necessary for the balanced ecosystem. An ecosystem can recover from small changes through negative feedback, returning to its original state however, a drastic influence by the external and internal factors can lead to damage to the system.





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