Biogeographic patterns of desert springs in the Great Basin with an emphasis on regional aquifer thermal springs as refugia for vulnerable crenobiotic species
Abstract
The desert springs of the Great Basin Region in western North America provide ideal systems to study biogeographic and evolutionary patterns. In arid regions, springs are biodiversity hotspots because they often provide the sole source of water for the biota within and around them. In the Great Basin, springs provide critical habitat for diverse and extensive crenobiotic flora and fauna comprising over 125 endemic species. These aquatic environments represent island ecosystems surrounded by seas of desert, and researchers have compiled large databases of their biota and chemistry. Consequently, desert springs are excellent systems for biogeographic studies and multivariate statistical analyses of relationships between the chemical and physical characteristics of the springs and the biological communities that they support. The purpose of this study is to elucidate the relationships between the physicochemical characteristics of springs and their biota using multivariate statistical analyses to characterize 1325 springs, including regional aquifer springs, local aquifer cold springs and geothermal springs. The analyses reveal that regional aquifer thermal springs harbor disproportionate numbers of crenobiotic species including endemic gastropods, fishes, and aquatic insects. However, these regional aquifer springs also contain significantly more introduced species than cold and geothermal local aquifer springs. Springs are threatened by anthropogenic impacts including groundwater depletion and pollution, alteration of flow regimes, and the introduction of exotic species. In this study, one of the major factors that distinguished regional aquifer thermal springs from cold and geothermal local aquifer springs was the higher number of introduced species found in regional aquifer springs. This may be due to the influences of the same physicochemical characteristics that allow regional aquifer springs to serve as refugia for endemic species--species that are able to gain access to these environments and cope with their extreme physicochemical characteristics may be provided with refuge from extinction. The disproportionate number of endemic crenobiotic species found in regional aquifer thermal springs, as well as in some local aquifer geothermal springs, within the Great Basin strongly suggests that these hydrothermal habitats represent important biodiversity hotspots, and efforts to conserve and restore these unique ecosystems should be a major priority to ensure that the valuable information that these species can provide is not lost forever.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.B31D0437F
- Keywords:
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- 0400 BIOGEOSCIENCES;
- 1800 HYDROLOGY;
- 1000 GEOCHEMISTRY;
- 1803 HYDROLOGY Anthropogenic effects