Macrodistributions and microdistributions of stoneflies of calcareous submontane rivers of the West Carpathians, with different land cover

Abstract

Stonefly samples were collected from disturbed and undisturbed regions of two river basins, tributaries of the Upper Váh River basin (the West Carpathians). Water temperature, oxygen content, coarse benthic matter and some stonefly metrics (abundance, biomass, richness, index of diversity, % predators, % shredders, stonefly total score and stonefly average score) were all negatively influenced by the extent of urban and field land cover. Rivers with a high proportion of human land-use activities were positively correlated with fine benthic organic matter and the share of collector-gatherers and saprobic indices (organic pollution), as well as with a higher trophic status of streams. Taxa of different species groups or genera have different demands for microhabitats. The cumulative curve of stonefly distribution in microhabitats of the river bed has, in the Ĺubochnianka River, an exponential form (reflecting an increase in stonefly density on coarse substrata and moss). In the human-influenced Revúca River, the curve's form is logarithmic, representing a reverse trend.