Ecological Succession Unit 2 Lecture 3 Succession the

Ecological Succession Unit 2 – Lecture 3

Succession – the replacement of one community by another [at a single location over time] this can [and does] occur at any time it is occurring all of the time – everywhere

Primary Succession bare rock can be volcanic or glacial lichens & mosses lichens secrete chemicals to break down rock chemically moss’ shallow root system breaks down rock physically

Primary Succession – cont’d lichens & mosses are pioneer species first organisms to appear in succession pioneer species are typically small organisms create a supply of nutrients with minerals [from rock] and organic matter called humus – long-lasting remnant of dead organic materials in the soil lasts until a hot fire burns through the area soil [see video – take notes]

Primary Succession – cont’d Grasses can survive in full-sun or in wind Shrubs provide some shade for greater biodiversity – diversity of life Trees provides shade for greater biodiversity

Primary Succession – cont’d Climax Community – final, steady-state stage of succession flora & fauna in state of equilibrium no more major changes occur

Secondary Succession occurs after a catastrophic event so that no life is left fire, flood, etc. events occur in same order as primary succession with one exception: begins with soil