The orderly change in the inhabitants of a habitat (an area) over time is called succession. It can also be defined as the step by step orderly and gradual replacement of communities of organisms that leads to a climax community.
An illustration of succession is that of a pond. Rain carries sediment from surrounding land into the pond, filling it and making it shallower. Algae that live in the pond die and eventually fall to the bottom, adding organic materials to the sediment. Some plants such as pond weeds grow at the bottom. These plants make up the pioneer community. The pioneer plants are the first to inhabit the changing environment. The roots of these underwater plants hold much silt, quickly building up the bottom cover of the pond. As they die, their organic matter accumulates at the bottom. The water along the edges becomes so shallow that water lilies and other floating plants replace the pioneer plants.
The final stage of succession in a particular area is called climax community. The species that constitute the climax community differs from biome to biome. A climax community is also a stable community because its appearance and species composition are stable. To become climax, the community would have gone through a sequence of changes.
