Showing papers by "Tanja Pipan published in 2013"
TL;DR: The fauna of epikarst is dominated by copepods, but other groups, including some terrestrial taxa, are important in some areas and a number of factors have been found to be important in determining species distribution, including ceiling thickness, habitat connectivity and habitat size.
Abstract: Epikarst is not only an important component of the hydrogeology of karst and an active site of speleogenesis, it is habitat for a number of species adapted to subterranean life. Water in epikarst, with a residence time of days to months, is a highly heterogeneous habitat, and the animals are primarily sampled from continuously sampling dripping water or collecting from residual drip pools. While the subterranean fauna of cracks and crevices has been known for over 100 years, it is only in the past several decades that epikarst has been recognized as a distinct habitat, with reproducing populations of stygobionts. Dissolved organic carbon in epikarst drip water is a primary and sometimes the only source of organic matter for underlying caves, especially if there are not sinking streams that enter the cave. Typical concentrations of organic carbon are 1 mg L -1 . The fauna of epikarst is dominated by copepods, but other groups, including some terrestrial taxa, are important in some areas. Most of the diversity is β-diversity (between drips and between caves). In Slovenia, an average of nearly 9 stygobiotic copepod species were found per cave. In studies in Romania and Slovenia, a number of factors have been found to be important in determining species distribution, including ceiling thickness, habitat connectivity and habitat size. In addition to eye and pigment loss, epikarst copepod species may show a number of specialization for life in epikarst, including adaptations to avoid displacement by water flow. Several geoscientists and biologists have challenged the uniqueness and importance of epikarst, but on balance the concept is valid and useful. Fruitful future research directions include development of better sampling techniques, studies to explain differences among nearby epikarst communities, phylogeographic studies, and assessing the possible role of copepods as tracers of vadose water. adaptation; cave ecology; Copepoda; stygobionts; subterranean biodiversity
38 citations
TL;DR: A series of potential pitfalls (fallacies) in estimating subterranean biodiversity are outlined, and some standard procedures are suggested, and the value of such studies is emphasized.
Abstract: A series of potential pitfalls (fallacies) in estimating subterranean biodiversity are outlined: (1) provincialism—treating different regions differently, especially with respect to new discoveries and undescribed species; (2) equality of described and undescribed species—ignoring the possibility that undescribed species are not really new species; (3) isotropy—assuming all cave regions of similar size have equally rich faunas; (4) scale invariance—ignoring the affect of area on species richness; and (5) misuse of expert opinion—the over-reliance on experts estimates often without comparable estimates for all areas. Some standard procedures are suggested for subterranean biodiversity studies, and the value of such studies is emphasized.
33 citations
TL;DR: In this paper, the authors found that organic carbon in shallow underground habitats is lowest in epikarst, the uppermost zone of karst with extensive small cavities and channels.
Abstract: subterranean habitatsOrganic carbon is likely to be a limiting factor in shallow subterranean habitats (SSHs). Data on dissolved organic carbon (DOC) in three SSHs are reviewed: (1) hypotelminorheic and associated seepage springs (Nanos Mountain, Slovenia), (2) hyporheic zones (Rhone River, France and seepage streams on Nanos Mountain, Slovenia), and (3) epikarst (China, Slovenia, and USA). Hypotelminorheic habitats are superficial groundwater sites less than 1 m below the surface that exit from seepage springs. Hyporheic habitats are the underflow of streams and rivers. Epikarst is the uppermost zone of karst with extensive small cavities and channels. Nanos hypotelminorheic sites that harbored stygobiotic species had organic carbon values averaging 3.4 mg C L−1, and temporal variability was high. For hypoheic sites in the Rhone River basin and on Nanos Mountain, mean values ranged from 1.4 to 3.5 mg C L−1. In the more extensively studied Rhone River basin sites, temporal variability was low. Epikarst DOC ranged from 0.70 to 1.10 mg C L−1 in three caves in China (Shihua Cave), Slovenia (Postojna Planina Cave System) and United States (Organ Cave, West Virginia). These results suggest that organic carbon in aquatic SSHs is lowest in epikarst . Keywords: dissolved organic carbon, epikarst, hyporheic, hypotelminorheic, seepage spring. DOI: 10.3986/ac.v42i2.603 Normal 0 21 false false false EN-US X-NONE X-NONE
12 citations