Secondary succession refers to the regrowth of a habitat in the area where a disruptive event has occurred and eliminated the existing, above ground plant life of the natural habitat. The disruptive event may be a forest fire, tree harvesting or a hurricane. The disruptive event causes only the plant life above ground to stop growing. Underground plants and seeds that have not sprouted above the ground’s surface are often preserved. These seeds and plants begin the secondary succession.
Secondary succession is only possible if some plant life remains after a disruptive event. The plant life may be underneath the ground as a new plant, or above the ground as a plant or tree, that has somehow survived the disruptive event. As the new plant life emerges from the soil and is pollinated and germinates into new plants of the same species, the plant life of the area is renewed.
At times, human intervention aids secondary succession. Some clear cutting companies employ a special team to aid the regrowth of deforested areas. Artificial support for secondary succession may include clearing away of ash, distribution of naturally occurring seeds and fertilization of seeds and existing plants.
Secondary succession differs from primary succession in that primary succession describes the growth of new life in areas where a previous habitat has not existed. Secondary succession occurs as a replenishment of a destroyed habitat, while a primary succession is the first generation of a new habitat. New habitats for primary succession include landslips, faces of quarried rocks and cliffs, and within the debris of volcanoes, where no previously existing plant life has survived.
Secondary Succession Stages
As a habitat revives from a disruptive event, the secondary succession is marked into different stages. The first stage includes the growth of pioneer species that attract birds and insects back to the area. The pioneer species include annuals and perennials like grasses and flowers and small bushes often found in fields. The second stage is the intermediate species of bushes, shrubs and evergreen trees that begin to develop about ten years after the disruptive event. The final stage, often referred to as the climax stage, is present after the intermediary stage has developed into a full habitat reminiscent of the area before the disruptive event.
The time it takes a habitat to regenerate through secondary succession takes between 30 and 60 years, dependent upon the types of trees and plants in the area. The final climax stage should be as the habitat was before and previous wildlife should begin to re-enter and constantly inhabit the area.