Unformatted text preview: ommunities?
Hypothesis: Strong top-down interactions stabilize
-When Pisaster was
removed, Mytilus (mussels)
colonized most of the
other species Starfish removal
decline from 15
to 8 after 2 years -Species richness
declined after 5 years,
only 2 species left -Pisaster a keystone
species keystone (in architecture) - the middle “stone” in an arch (the middle of a roman arch) What stabilizes communities?
Keystone species Keystone
-NOT necessarily the
-NOT necessarily the most
-IS the most inﬂuential
-ex: starﬁsh, alligator, etc... Keystone species influence communities more
than would be expected given their abundance
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This document was uploaded on 03/10/2014 for the course BIOL 2060 at University of Guelph.
- Fall '12