Electronic Theses and Dissertations

Date of Award

2011

Document Type

Dissertation

Degree Name

Ph.D. in Biological Science

Department

Biology

First Advisor

Brice P. Noonan

Second Advisor

David H. Reed

Third Advisor

Gail Stratton

Relational Format

dissertation/thesis

Abstract

With the continued increase in the number of tourists visiting the Northern Gulf coast in the last century and the resulting development of this coastline the habitat of Arctosa sanctaerosae has become fragmented; and the sprawl of large cities along the coast has further degraded available habitat. In addition to anthropogenic disturbance to this coastal region, hurricanes are an additional and natural perturbation to the ecosystem. This habitat has seen a number of major tropical storms over the last decade and I have sought to explore the impact of habitat destruction and storm-induced disturbance on a species of spider endemic to the coastal dunes of the Northern Gulf Coast. Arctosa sanctaerosae, family Lycosidae, is a wolf spider endemic to the secondary dunes of the white sandy beaches of the Northern Gulf of Mexico. The data presented here explore the status of populations of this species spanning the entire known range and the factors influencing population demography. These findings demonstrate the significant impact of storms on both disturbed and undisturbed habitat and reveal factors influencing the recovery of the spiders, relating this to ecological factors including the height of the dunes and density of vegetation before and following hurricanes Ivan and Katrina. These results reveal habitat characteristics that appear to play a large role in population persistence and components of human disturbance of habitat that have the greatest impact on populations of spiders. Using microsatellite markers I characterize the current structure of the subpopulations of Arctosa sanctaerosae, and current and historical patterns of interpopulation migration. Contemporary modeling methods compare current and historical levels of gene flow and document the decline in migration due to habitat fragmentation. Since the introduction of dense human development along the Northern Gulf of Mexico Coast, Arctosa sanctaerosae has seen what appears to have been a single, contiguous population subdivided and the isolates reduced in size. These results point to the need for further exploration of the status and continued monitoring of the species.

Included in

Biology Commons

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