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Unformatted text preview: urce: Power et al. 1996 7 ecosystem engineer = keystone species that AREN’T predators What stabilizes communities?
Do non-predator keystone species exist? Ecosystem
-species that stabilizes
community by inﬂuencing
the environment -NOT predators
Influence resource availability by modifying,
maintaining, and/or creating new habitats that are
subsequently used by other organisms.
Jones, C. G., J. H. Lawton, and M. Shachak. 1994. Oikos 69:373–386. Examples
-Indian Crested Porcupine
-Woodpeckers http://www.geocities.com/bobarnebeck/dams.html Do ecosystem engineers influence
community structure? Replicate: Individual white oak trees
• Removal of shelters from trees (R)
• Artificial shelters constructed
(no caterpillars) (R+T)
• Artificial shelters plus
caterpillars (R+T+C) Lill & Marquis (2003) Ecology 84:682 8 remove shelter = lower species richness
extremely small difference between R+T and R+T+C which shows that
- Shelter is more inﬂuential than ca...
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This document was uploaded on 03/10/2014 for the course BIOL 2060 at University of Guelph.
- Fall '12