Download COMMUNITY ECOLOGY

Warm-up 4/2:
• Define Inter and Intraspecies competition.
• Which has greater competition? Explain
•
Explain why parasites and hosts are
considered to be a good example of coevolution.
COMMUNITY ECOLOGY
cont
pp. 405-410
Species (organism)
Population
Community (interaction of different species)
Ecosystem
Biosphere
PROPERTIES OF A
COMMUNITY
• Species Richness
• Species evenness
• Species- Area Effect
Species Richness: # of
different types of species
• varies with latitude
(closer to equator the
more species)
• more sun, better climate
stability
• Species evenness: the abundance of each
species
• ↑species richness and ↑ evenness:
↑ stability (ability to withstand
disturbances in the ecosystem)
• Species- Areas Effect: larger areas contain
more species than smaller areas
KEYSTONE SPECIES
• most dominant species
in the community
• Dictates community
structure
• Demonstrated by
removal of keystone
species from
community
What would happen to the species richness if the
keystone species is removed from the ecosystem?
SUCCESSION
• Sequential and gradual growth of a community
• Two types:
primary and secondary
• Primary succession occurs when land is first
formed.
1. Microbes, lichens and mosses must create
soil before other plants can grow.
2. Pioneer species: first species to dominate
early in succession (small and fast growing)
• Secondary succession occurs when
succession must start over after the destruction
of a climax community (marked by the
domination of long-lived species and great
diversity).
- takes place on sites that have already
supported life
Homework
• Read pp 405-410
• P 410 #1-5, 8 Due Thursday