Details

Autor(en) / Beteiligte

• Engel, A S

Titel

Observations on the biodiversity of sulfidic karst habitats

Ist Teil von

• Journal of caves and karst studies, 2007-04, Vol.69 (1), p.187-206

Erscheinungsjahr

2007

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Recognition of the metabolic process of chemosynthesis has recently overthrown the ecological dogma that all life on earth is dependent on sunlight. In complete darkness, complex ecosystems can be sustained by the energy and nutrients provided by chemosynthetic microorganisms. Many of these chemosynthetically-based ecosystems result from microbial manipulation of energy-rich sulfur compounds that can be found in high concentrations in groundwater. Subsurface environments in general can be highly stressful habitats (i.e., darkness, limited food, etc.), but in the case of sulfidic groundwater habitats, organisms must also tolerate and adapt to different stresses (e.g., toxic levels of gases or lethally low oxygen concentrations). Nevertheless, these habitats, and specifically cave and karst aquifers, have a richly diverse fauna. This review focuses on the biodiversity (as the number and types of species) of sulfur-based cave and karst aquifer systems. The relationships among ecosystem productivity, biodiversity, and habitat and ecosystem stresses are explored. The relatively high numbers of species and complex trophic levels could be attributed to the rich and plentiful, chemosynthetically-produced food source that has permitted organisms to survive in and to adapt to harsh habitat conditions. The geologic age and the hydrological and geochemical stability of the cave and karst aquifer systems may have also influenced the types of ecosystems observed. However, similar to non-sulfidic karst systems, more descriptions of the functional roles of karst aquifer microbes and macroscopic organisms are needed. As subterranean ecosystems are becoming increasingly more impacted by environmental and anthropogenic pressures, this review and the questions raised within it will lead to an improved understanding of the vulnerability, management, and sustainability challenges facing these unique ecosystems.