Another important aspect of ecosystem functioning that is how it maintains its ecological balance. By now, it must be obvious to you that an ecosystem is a dynamic system, wherein a lot of events take place. For example, animals eat and in turn are eaten, moisture and nutrients flow in and out of the system, and weathers change. In spite of all these happenings the ecosystems persist and recover from the slight disturbances. This capacity of an ecosystem to self-regulate or self-maintain is called homeostasis. Isn't this ability of ecosystems to recover from certain perturbations remarkable? Let us take a simple example to see that how is this balance maintained in spite of the fight disturbances in the ecosystem.
Consider a grassland, when there is a drought, do not grow well. The mice that eat the grass become malnourished. When this happens, their birth rate decreases. And also the hungry mice retreat to their burrows and sleep. By doing so, they need less food and are less exposed to predators, so their death rates decrease. Their behaviour protects their own population balance as well as that of the grasses which are not being consumed while the mice hibernate. Such a mechanism is known as feedback regulation and is very important to maintain the ecological balance. It is the prime regulatory mechanism for the ecosystem as a whole. You may know that there are several kinds of organisms comprising an ecosystem. So all the organisms in an ecosystem are part of several different feedback loops. A feedback loop may be defined as relationship in which a change in some original rate, alters the rate of direction of further change. In the above example, we had deliberately taken a very small group of living beings that has primarily the mice and the plants.