Transcript Ecological succession

Ecological succession is the sequence of
community changes after a disturbance
• Ecological succession is ...
• Two kinds of Succession: Primary & Secondary
• Primary succession is…
• 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