Forty years of epikarst: what biology have we learned?

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 specializations 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

Epikarstic crustaceans from some Italian caves: endemisms and spatial scales.

“…The recorded species richness in Zubbia del Cavallo is comparable to that of other epikarst systems in carbonatic systems of Romania: for instance the estimated species richness including observed and unobserved species in five Romanian caves ranged from 3 to 6 (Meleg et al 2011), and the number of stygobiotic copepods ranged from 2 in a Slovenian cave to 33 in a Romanian cave (Pipan and Culver 2013). In Sicily, although data are limited and more caves should be investigated, caves in evaporitic gypsum appear to host more diverse stygobiotic copepod assemblages than the carbonatic ones, as already observed by Stoch et al (2009) for the groundwater fauna of upper Secchia Valley, in the Reggiano Apennines.…”

“…A positive correlation between distribution of epikarst specie, including an epikarst Parastenocarididae (Parastenocaris cf. andreji), and sodium concentration was reported by Pipan and Culver (2013) for the drip of a Slovenia cave.…”

Cave exploitation by an usual epigean species: a review on the current knowledge on fire salamander breeding in cave

“…Indeed, many subterranean aquatic habitats contain exceptional communities of organisms (Culver and Pipan 2009), which are receiving an increasing interest by zoologists as they can provide interesting ecological and evolutionary insights. Subterranean habitats have a high potential to permit the investigation of many aspects of modern ecology and biology (Pipan and Culver 2013). When analysing cave biota, it is important to recognize that underground habitats are not a closed system (Romero 2009): besides the exchange of abiotic components (e.g.…”

Ecotourism Development Strategy of Bukit Jaddih Karst, Madura

“…In addition, many types of plants and animals, including endemic species, are found in the karst area. Karst also becomes a unique microbial habitat [4]. However, karst areas are threatened by human activities, mainly by farming and agricultural practices, fire, mining, urbanization, housing and infrastructure development, drilling and piping, material transport, and vegetation removal [5,6].…”