BIOL2060 - Lecture 31 - Nov 27, 2013

Observation communities with more predators have

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Unformatted text preview: ommunities with more predators have higher species richness Ocean zooplankton communities: Atlantic shelf: 81 total species (16% predators) Sargasso sea: 268 total species (39% predators) Intertidal communities: Washington: 13 species (2 predators ~15%) California: 45 species (11 predators ~ 24%) Source: Paine 1966, 1971 What stabilizes communities? Hypothesis: Strong top-down interactions stabilize communities Predators keep prey populations below carrying capacity Prevent competitive exclusion, by allowing the coexistence of many more species 7 What stabilizes communities? Hypothesis: Strong top-down interactions stabilize communities -Bob Paine (1960s) -Hypothesized that predation by the starfish Pisaster maintains diversity within rocky intertidal communities Paine RT. 1966. American Naturalist 100:65 What stabilizes communities? Hypothesis: Strong top-down interactions stabilize communities Paine RT. 1966. American Naturalist 100:65 8 What stabilizes communities? Hypothesis: Strong top-down interactions stabilize communities Paine RT. 1966. American Naturalist 100:65 What stabilizes communities? Hypothesis: Strong top-down interactions stabilize communities Paine RT. 1966. American Naturalist 100:65 9...
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This document was uploaded on 03/10/2014 for the course BIOL 2060 at University of Guelph.

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