Graduation Year

2007

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Biology

Major Professor

Earl McCoy, Ph.D.

Keywords

Aspidoscelis sexlineata, Community ordination, Plestiodon inexpectatus, Longleaf pine, Nonmetric multidimensional scaling, Scincella lateralis

Abstract

I examined the effects of fire frequency on reptile and amphibian community composition in a periodically burned sandhill habitat in west-central Florida. Plots burned in 2003 had lower species richness, diversity, and evenness indices than plots that had not been burned during the previous six years. Community composition was different among plots burned at different times and followed a gradient of change that corresponded to the time since the last fire. Aspidoscelis sexlineata were the most abundant lizards in recently burned plots, while Scincella lateralis and Plestiodon inexpectatus were relatively more abundant in unburned plots. Gopherus polyphemus were least abundant in unburned plots. Community composition among plots was correlated with mean leaf litter cover and herbaceous ground cover. Mean percent cover of leaf litter and herbaceous vegetation responded to the time since the last fire.

Fire indirectly affects community composition through changes in environmental variables, such as percent coverage of leaf litter and herbaceous vegetation.Additionally, I examined annual variation in reptile and amphibian community composition over a period of four years in the mid 1980s and again in 2004. Differences existed in number of individuals captured, diversity, and evenness among years. Community composition was different between all consecutive years except 1986 and 1987. Number of individuals captured per year and annual differences in community composition were correlated with summer rainfall. The annual pattern of variation in community composition over time was no different in unburned experimental plots than in experimentally burned treatments. The power to detect such a difference is low, however, because of low replication.

No apparent loss of species occurred between the 1980s and 2004, but the abundances of two non-native species were significantly higher in 2004 than in the 1980s. A third exotic species was documented at the site for the first time in 2004. Because of the increasing number of exotic reptiles and amphibians in Florida, the site is at risk of invasions of other species.

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