The Southeastern United States has the most diverse and imperiled freshwater mussel (Unionidae) fauna in the world. The community structure and decline of these organisms is the result of complex interactions between biotic and abiotic factors, but the limited spatial scale of most community studies has failed to elucidate the underlying mechanisms shaping community structure. Basing community assessments solely on microhabitat variables alone has lead to stark contradictions in management recommendations and opposing definitions of habitat requirements for these organisms. However, with the introduction of GIS technology into aquatic management, it is now feasible to include variables from larger spatial scales and investigate previously undetectable mechanisms influencing unionid community structure.
In my study, I tested the hypothesis that patterns of mussel species richness and abundance in the Tickfaw, Tangipahoa Bogue Chitto and West Pearl rivers in south-eastern Louisiana were related to a combination of local-scale habitat variables, riparian-scale land use and geology variables, and sub-segment scale land use and geology variables.
ANOVA results indicated a significant difference between the upper three sub-segments and lower three sub-segments of these rivers. The Principal Component Factor Analysis (PCFA) results revealed that geology, land-use and fine sediment are components working together across spatial scales to produce a hydrologic variability mechanism, and a simple regression model based on the factor scores of each site was successful in predicting abundance and species richness.
Through comparing the ANOVA results with the factor score results for each site, I conclude that hydrologic variability, defined by geology type and land-use as well as fine sediment, is influencing the pattern in freshwater mussel abundance and species richness found in the Florida Parishes of Louisiana.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04052006-111228 |
| Date | 05 April 2006 |
| Creators | Bambarger, Anne Raynie |
| Contributors | William Kelso, Kyle Harms, Kenneth Brown |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04052006-111228/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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