How Ecosystems Change

Has Soil

Has No Soil

Has Some Soil

none of these

Primary begins WITHOUT soil; Secondary begins WITH soil

Primary is the first state and secondary is the second stage

Primary builds plant community; secondary builds animal community.

Primary begins WITH soil; Secondary begins WITHOUT soil

foundational organisms

introductory organisms

primary organisms

pioneer species

grass - shrubs - lichens - trees

lichens - shrubs - grasses - trees

lichens - grasses - shrubs - trees

grasses - lichens - shrubs - trees

ecological recession

climax recession

ecological succession

climax succession

Humans cut down many trees in a small region

A volcanic eruption covers a village in lava.

Primary Succession

Secondary Succession

Both Take The Same Amount of Time

Last Species

Pioneer Species

Colonizing Species