APES Ch. 5, part 3

Ecological Succession

Ch. 5 part 3

Big Idea #4

Succession is the process of change in the structure of the environment and the composition of species in an ecosystem as the environment changes

Where do forests come from?

They come about gradually through a process called ecological succession

2 types

Type 1: primary successionBrand new land

Primary succession

No soilFirst species to

come are called pioneers Mosses and lichen

Can grow on bare rock

As they grow they break apart the rock and form soil

Primary succession

After a loooong time, there will be enough soil to support small plants like weeds, grasses, and small shrubs Mosses and lichens die off

Primary successionFinally enough soil accumulates to

support treesAnd you get a climax community

2 typesType 2: secondary successionOld land that has been wiped out

somehow

Examples: Abandoned farmlandBurned forestsPolluted streamsFlooded land

Secondary Succession

The same thing happens, but much more quickly since there is already a soil base

SuccessionAnimal species change through the

course of succession as well