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Effective size and the persistence of ecosystems
1Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA.
Oecologia
|March 18, 2017
Summary
Larger ecosystems persist longer due to their effective size, which includes physical structure. This reduces population density oscillations, keeping them farther from extinction thresholds, as shown by mathematical models and experiments.
Area of Science:
- Ecology
- Mathematical Biology
- Population Dynamics
Background:
- Ecosystems vary in size and physical structure, influencing their stability.
- Predator-prey interactions are fundamental to ecosystem dynamics and can exhibit population cycles.
Purpose of the Study:
- To present a mathematical model explaining why larger effective ecosystem sizes lead to longer persistence.
- To investigate the relationship between ecosystem size, physical structure, and population stability.
Main Methods:
- Utilized phase-plane graphs based on the Rosenzweig-MacArthur predator-prey model.
- Interpreted experimental data from protozoa (Gause & Luckinbill) and mites (Huffaker).
Main Results:
- Larger effective ecosystem sizes correlate with population density oscillations displaced further from extinction thresholds.
- Spatially homogeneous systems also show this effect, indicating size and structure are key factors.
- Experimental results support the model's predictions regarding persistence and population dynamics.
Conclusions:
- Effective ecosystem size, encompassing extent and physical structure, is a critical determinant of ecological persistence.
- Mathematical modeling and experimental evidence converge to explain the stability benefits of larger, more structured ecosystems.
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