1. Changes in Communities
Chapter 20
Section 4

2. Succession
Series of predictable changes that occur in a community over time

3. Primary Succession Occurs in an area where NO soil or organisms exist
The 1st species to populate that area is called a pioneer species
Moss or lichen
Break up the rocks and provide nutrients to the soil
Over time seeds land in the soil and grow
Grasses and shrubs often replace the pioneer plants

5. Secondary Succession
Series of changes that occur in an area where the ecosystem has been disturbed, BUT soil and organisms are still present
Natural disturbances: fire, flooding…
Human disturbances: logging, farming…