The study of species diversity patterns and their causes remains a central theme
of ecology. Work conducted over the last few decades has shown that both historical
and ecological factors are important in determining species diversity patterns.
Additionally, different causal mechanisms are important at different spatial and temporal
scales. At the regional scale, species diversity patterns can best be studied in terms of
three diversity components (alpha, beta and gamma). This study used the amphibians
and reptiles of Costa Rica to examine these species diversity components at the regional
scale. To accomplish this, existing species lists were compiled from the literature.
Additionally, three herpetofaunal surveys were conducted at under surveyed sites to fill
knowledge gaps.
A survey of Parque Nacional Carara, a transitional zone site on Costa Rica’s
central Pacific coast, gave evidence of a rich herpetofauna, containing species from both
the dry tropical forest to the north and the wet lowland forest to the south. Survey
results show that Carara’s herpetofaunal assemblage is more similar to that of the wet
forest than the dry forest, and suggest many species from both assemblages reach their
range limit at or near the park. Surveys of four sites in the eastern Área de Conservación
Guanacaste showed rich herpetofaunal diversity and validated the newly purchased Rincón Rainforest as an important conservation area. A survey of Reserva Natural
Absoluta Cabo Blanco provided a preliminary list of amphibian and reptile species of the
lower Nicoya Peninsula and highlighted the importance of Laguna Balsitas to the local
amphibian fauna. A comparison of amphibian and reptile alpha diversity among 17 sites
throughout Costa Rica showed highest alpha amphibian diversity in the lowland
rainforests of the Pacific versant and highest reptile alpha diversity in lowland
rainforests of the Atlantic versant. An analysis of beta diversity produced dendrograms
showing sites within lowland ecoregions being most similar. A Canonical
Correspondence Analysis (CCA) of environmental variables showed two climate
gradients, an elevation/temperature gradient and a sun/rain gradient, to be important in
determining species diversity patterns for both amphibians and reptiles in Costa Rica.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1675 |
| Date | 15 May 2009 |
| Creators | Laurencio, David Edelman |
| Contributors | Fitzgerald, Lee A. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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