Balance In Nature – An ecosystem is a self-sustaining system. Except for energy (light) it does not require any thing from outside. The system is capable of maintaining itself because of the delicate but complex interactions of its biotic and abiotic and abiotic components, as illustrated by food webs and natural cycles. Like the human body, the ecosystem has different parts that perform different functions, each crucial to the survival of the whole.
All natural ecosystems are stable. They maintain a state of balance, called equilibrium. If ecosystems are not balanced, they do not survive. An ecosystem gets this stability from the maze of interactions that link its parts. A disruption in one part of the ecosystem, such as a temperature change to a colder climate, is counteracted by charges in other parts of the ecosystem, such as the evolution of adaptation to cold weather. The disrupted ecosystem returns to a state of equilibrium.
Major disruptions cause dynamic changes as the ecosystem adjusts to the new conditions. Some disruptions can destroy whole ecosystems. But a new ecosystem will develop to replace the one destroyed (Fig 19.19).
Fig. 19.19 cutting of forests is one form of disrupting the environment and interfering with habitats.
It is very difficult to understand every detail of how even simple ecosystems function. We understand that changes in one part of a system can trigger changes in other parts. But we cannot always predict how change in one part of the ecosystem will affect another part.
At present, species are becoming extinct at the fastest rate since earth’s known history. The cause of these extinctions is human activity. Humans are also placing many other stresses, such as pollution and deforestation, on global environment without knowledge of the consequences and how will the consequences affect future generations and the global ecosystem in which they live?