Communities undergo constant changes in response to environmental conditions, which occur in a predictable sequence and are paralleled by changes in the physical environment. Eventually, a community will reach a state of equilibrium with its environment, known as a climax community. This gradual and predictable change in species composition is referred to as ecological succession, and the entire sequence of communities in a given area is known as a sere. Each transitional community within the sequence is called a seral stage or seral community. As the seral stages progress, there is an increase in species diversity, the number of organisms, and total biomass.
Succession is a process that involves the orderly and sequential change in the composition and structure of communities in response to changing environmental conditions. It begins in areas without any living organisms, such as bare rock, and can occur through primary succession (where no living organisms have existed before) or secondary succession (where natural biotic communities have been destroyed). Primary succession occurs in newly cooled lava, bare rock, or newly created ponds or reservoirs and begins with pioneer species like lichens that secrete acids to dissolve rock, aiding in weathering and soil formation. Secondary succession occurs in areas such as abandoned farmland, burned or cut forests, or flooded lands, where some soil or sediment is still present. This process is faster than primary succession and leads to the formation of a stable climax community.
The process of plant succession is categorized as hydrarch or xerarch depending on the nature of the habitat, whether it is very wet or very dry. Hydrarch succession occurs in wet areas and progresses from hydric to mesic conditions, while xerarch succession occurs in dry areas and progresses from xeric to mesic conditions.
