• Ecological succession is ...

• Two kinds of Succession: Primary & Secondary

• Primary succession is…

Ecological succession is the sequence of community changes after a disturbance

• The first colonizers are:

• An example after a glacier or volcanic rock.

• Next, grasses and small plants move in and take over the scant soil. Their death adds to the soil.

• Next shrubs and pioneer tree species move into the area. Outgrow earlier species & add to the soil.

• Next intermediate species (Doug fir) move in. Add to soil, retain moisture, but shade the forest floor.

• Lastly, climax species grow in forest shade supplanting earlier species (Western hemlock, & W. red cedar).

• Secondary succession is:

• Grasses grow first, then trees and other organisms.

• More than just communities change w/ succession, other factors also change, soil nutrients dramatically change over time.

Ecological succession in Glacier Bay