Primary succession occurs in areas where no life has existed, whereas secondary succession happens when a disaster has devastated an area but has left some life in place. Succession begins with the colonization and activity of the pioneer species.Know More
In primary succession, bare rock or sand is the substrate upon which the pioneer species act. Primary succession occurs in places that are the result of lava flows or where glaciers have retreated. Soil is not yet present, so no plants or animals can survive in such a region.
Pioneer species are the lichens and moss. These organisms break down rock, turning it into soil for plants to put down roots. Shrubs and grasses then start taking advantage of the nutritive soil. Small trees come into the area, replacing the smaller plants. Leaves that fall from these shrubs and small trees produce leaf litter that decompose to produce nitrogen that acts as fertilizer for subsequent plant life. Bigger, fast-growing trees, such as cottonwoods, replace the smaller trees. Coniferous trees are the final plant life moving into the area. The climax community, or the goal of succession, is a forest of coniferous trees.
In secondary succession, the soil remains in place after the disaster. Remaining in the soil are the unharmed roots of some plants and the seeds of others. The process of rebuilding after a fire or other disaster is similar to primary succession and proceeds in much the same way; however, secondary succession occurs in less time.Learn more about Biology
Biological disasters are outbreaks of diseases or contagions of plant and animal life on an epidemic or pandemic level or infestations of animal or insect life on an epidemic or pandemic level. Examples of biological disasters include cholera and influenza H1N1 (swine flu).Full Answer >
Ecological succession is the process by which the species structure of a given biological community evolves over time. The two types of succession are primary and secondary.Full Answer >
Forests can grow from bare rocks in about 150 years, according to the U.S. Geological Survey. Many scientists study primary succession in Hawaii because the lava flows from volcanoes create places where primary succession can take place. Because primary succession requires the accumulation of soil, it happens far more slowly than secondary succession does. Secondary succession occurs when a habitat is disturbed, but the soil remains in place.Full Answer >
The four stages of pond succession are pond pioneers, submergent vegetation appearing around the pond, decaying matter raising the pond floor and a marsh being created. Ponds are shallow holes where water collects. They are formed by geological events.Full Answer >