Dispersal promotes compensatory dynamics and stability in forced metacommunities.

Publication/Presentation Date

8-1-2011

Abstract

Understanding the factors that govern the stability of populations and communities has gained increasing importance as habitat fragmentation and environmental perturbations continue to escalate due to human activities. Dispersal is commonly viewed as essential to the maintenance of diversity in spatially subdivided communities, but few experiments have explored how dispersal interacts with the spatiotemporal components of environmental perturbations to determine community-level stability. We examined these processes using an experimental planktonic system composed of three competing species of zooplankton. We subjected zooplankton metacommunities to varying levels of dispersal and pH perturbations that varied in their degree of spatial synchrony. We show that dispersal can reverse the destabilizing effects of environmental forcing when perturbations are spatially asynchronous. Asynchrony in pH perturbations generated spatially and temporally varying species refugia that promoted source-sink dynamics and allowed prolonged persistence of zooplankton species that were otherwise extirpated in synchronously varying metacommunities. This, in turn, increased local species diversity, promoted compensatory population dynamics, and enhanced local community-level stability. Our results indicate that patterns of spatial covariation in environmental variability are critical to predicting the effects of dispersal on the dynamics and persistence of communities.

Volume

178

Issue

2

First Page

159

Last Page

170

ISSN

1537-5323

Disciplines

Diagnosis | Medicine and Health Sciences | Other Analytical, Diagnostic and Therapeutic Techniques and Equipment | Radiology

PubMedID

21750380

Department(s)

Department of Radiology and Diagnostic Medical Imaging

Document Type

Article

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