Spatially variable habitat quality contributes to within-population variation in reproductive success.

Blaine D Griffen,Alexandra P Norelli

doi:10.1002/ece3.1427

Blaine D Griffen, Alexandra P Norelli

Open Access

https://doi.org/10.1002/ece3.1427

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Journal: Ecology and Evolution	Publication Date: Mar 6, 2015
Citations: 37	License type: CC BY 4.0

Affiliation: University of South Carolina

Abstract

Variation in habitat quality is common across terrestrial, freshwater, and marine habitats. We investigated how habitat quality influenced the reproductive potential of mud crabs across 30 oyster reefs that were degraded to different extents. We further coupled this field survey with a laboratory experiment designed to mechanistically determine the relationship between resource consumption and reproductive performance. We show a >10-fold difference in average reproductive potential for crabs across reefs of different quality. Calculated consumption rates for crabs in each reef, based on a type II functional response, suggest that differences in reproductive performance may be attributed to resource limitation in poor quality reefs. This conclusion is supported by results of our laboratory experiment where crabs fed a higher quality diet of abundant animal tissue had greater reproductive performance. Our results demonstrate that spatial variation in habitat quality can be a considerable contributor to within-population individual variation in reproductive success (i.e., demographic heterogeneity). This finding has important implications for assessing population extinction risk.

Highlights

Variation in habitat quality is common across marine, freshwater, and terrestrial systems
This variation can result from numerous forms of human-induced, spatially variable habitat degradation, such as habitat fragmentation resulting from urban development (e.g., Swenson and Franklin 2000), loss or deterioration of wetlands or other natural habitat as a result of human land use changes (Meyer and Turner 1992) or dam construction (Nilsson and Berggren 2000), chemical pollution from both point sources (e.g., Silliman et al 2012) and nonpoint sources (e.g., Howarth 2008), the accumulation of lost or abandoned fishing gear (UNEP 2005), etc
Ecology and Evolution published by John Wiley & Sons Ltd

Summary

Introduction

Variation in habitat quality is common across marine, freshwater, and terrestrial systems. This variation can result from numerous forms of human-induced, spatially variable habitat degradation, such as habitat fragmentation resulting from urban development (e.g., Swenson and Franklin 2000), loss or deterioration of wetlands or other natural habitat as a result of human land use changes (Meyer and Turner 1992) or dam construction (Nilsson and Berggren 2000), chemical pollution from both point sources (e.g., Silliman et al 2012) and nonpoint sources (e.g., Howarth 2008), the accumulation of lost or abandoned fishing gear (UNEP 2005), etc. These individual-level effects can result in reduced population growth rates (Sibly and Hone 2002) and increased risk of extinction (e.g., Crooks and Soule 1999), yielding a loss of biodiversity at the community or ecosystem levels (Fahrig 2003; Wilson et al 2008)

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