An ecogeographic analysis of the mammalian fauna of Texas /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1985.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy Link to ProQuest copy |
| Abstract: | Mammalian distribution patterns were examined using classification and ordination techniques to test hypotheses of continuity and discontinuty in mammalian community organization in Texas and to relate distributional variation to environmental change. The prediction of mammalian species richness through a suite of climatic, topographic and productivity variables was investigated by regression methods to test theories of species diversity based on equilibrium and nonequilibrium conditions. Mammalian distributions in Texas are related to a major east-west trend of decreasing precipitation and productivity and a north-south trend of increasing temperature. Mammalian species ranges terminate in a clinal or stepwise fashion in the sense that faunal composition changes gradually across broad areographic regions. There is some evidence of coincidence or near coincidence of distributional limits in zones of physiographic or vegetational change but this concordance of range limits is weak. This suggests that mammalian species in Texas function independently of each other and form a distributional continuum rather than discrete communities. Competition among mammals is inferred to have been reduced through habitat diversification. This has resulted in a beta diversity (between habitat diversity) of 96 percent species replacement along an east-west environmental gradient of moisture and productivity. Beta diversity along a north-south gradient of temperature is 82 percent. Four mammalian faunal regions are recognized for descriptive purposes. A mixture of both equilibrium (resourse defined equilibrium) and nonequilibrium (not in competitive equilibrium because of fluctuating environmental conditions) hypotheses are supported as determinants of mammalian species diversity when total mammals, bats, rodents, and carnivores are considered. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Wildlife and Fisheries Sciences." |
| Physical Description: | xi, 95 leaves : illustrations, maps ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 75-82). |