Secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species.
Secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil.
A harvested forest going back from being a cleared forest to its original state is an example of secondary succession.
Secondary succession occurs after disturbance that leaves the soil intact. 1988 fires in Yellowstone
Early: plants typically small with short lifecycles and rapid seed dispersal,
Middle: plants typically longer lived, slower seed dispersal, and in woodland systems
Late: plants and animal species are those associated with older, more mature ecosystem.
A seral community (sere ) is the name given to each group of plants within the succession.
A pioneer species is a plant species which colonizes previously uncolonized land, usually leading to ecological succession.
Graphs showing changes in biomass and diversity with succession.
Moraine Succession Moraine is the general term for debris of all sorts originally transported by glaciers or ice sheets that have since melted away. retreating glaciers leave moraines. autotrophic bacteria are first colonizers. mosses and lichens are first macroscopic autotrophs. soil forms gradually pioneering plant species are next
Moraine Succession Succession continues until a climax community is formed. spruce replace alder and cottonwood final stage is a spruce and hemlock forest