The concept and functioning of ecosystem

To understand the status and role of insects in the forest environment, it is first necessary to briefly discuss the concept and functioning of an ecosystem.

Nature is a highly complex, interconnected system. Links exist not only between the living components but also between living and non-living components. The significance of this complex interrelationship has been well captured by the concept of ecosystem. An ecosystem can be defined as a functional unit or entity consisting of a community of living organisms and the physical environment in which they live, interacting with each other so that there is a flow of energy from plants to the consumer organisms, and the cycling of some materials between living and non-living components, with all the living components existing in a dynamically steady state. It denotes a level of organization above the living community, integrating it with its abiotic environment. It provides a framework to organize our thoughts, as well as facts observed from nature. In practical terms, a forest ecosystem consists of the community of living trees and other vegetation, animals and micro-organisms and their physicochemical (i.e. abiotic) environment which function together as an integrated unit or system. It is difficult to delimit the physical boundaries of an ecosystem because of the continuity of interconnections, but for practical purposes it can be delimited according to our convenience.