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Published on: March 11, 2015
Habitat structure and population persistence in an experimental community
S P Ellner1, E McCauley, B E Kendall
1Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853-2701, USA. spe2@cornell.edu
Nature
|August 3, 2001
Summary
Habitat structure, not spatial population dynamics, enabled long-term persistence in experimental exploiter-victim systems. This structure hindered predator success, creating asynchrony and preventing population collapse.
Area of Science:
- Ecology
- Population Dynamics
- Conservation Biology
Background:
- Spatial structure is theorized to enhance population persistence, especially in exploiter-victim systems prone to local extinctions.
- Previous experiments confirmed spatial structure's role in persistence, but specific mechanisms remain unclear.
Purpose of the Study:
- To identify the specific mechanisms by which spatial population processes affect persistence in experimental exploiter-victim systems.
- To differentiate the effects of habitat structure from spatial population dynamics.
Main Methods:
- Utilized a model-based approach with experimental systems of bean plants, herbivorous mites, and predatory mites.
- Compared population dynamics in isolated plants, spatially undivided systems, and systems with introduced habitat structure.
Main Results:
- Prey and predator populations collapsed in isolated and undivided systems.
- Introducing habitat structure led to long-term population persistence.
- Mechanistic models indicated habitat structure, not spatial dynamics, drove persistence by reducing predator foraging success.
Conclusions:
- Habitat structure, by disrupting predator-prey interactions, promotes population persistence.
- Spatial asynchrony, driven by habitat structure and random colonization, prevents local population cycles from collapsing.
- Spatially explicit models are not necessary to understand persistence in this system.
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