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Density dependence at some time and place?
1Great Lakes Institute for Environmental Research and Biological Sciences Department, University of Windsor, Windsor, Ontario, N9B 3P4, Canada e-mail: sale@uwindsor.ca Fax: +1-519-9713609, , , , , , CA.
Oecologia
|March 18, 2017
Summary
Ecologists often assume density dependence is crucial for population persistence. This paper challenges this view, arguing that not all density-related changes involve biological feedback and other factors are also vital.
Area of Science:
- Ecology
- Population Dynamics
- Theoretical Ecology
Background:
- Widespread acceptance of density dependence as a universal ecological principle.
- Density dependence is defined as demographic rate changes driven by biological feedback.
- Recent literature includes processes not fitting this definition.
Purpose of the Study:
- To question the heuristic value of treating density dependence as a general ecological principle.
- To differentiate true density dependence from other density-related phenomena.
- To highlight the importance of density-independent factors in population dynamics.
Main Methods:
- Conceptual analysis of ecological principles.
- Review of existing definitions and applications of density dependence.
- Distinction between density-dependent and density-independent processes.
Main Results:
- Some processes labeled density dependent lack negative biological feedback.
- Marine recruitment examples illustrate density-related changes without feedback.
- Failure to distinguish these processes impacts understanding of population regulation.
Conclusions:
- The principle of universal density dependence in ecology warrants re-evaluation.
- Distinguishing true density dependence from density-related effects is critical.
- Density-independent factors significantly influence population sizes and require greater focus.
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