Chironomidae of the Western Carpathian spring fens: an overview of current research.
|Year of publication||2017|
|MU Faculty or unit|
|Description||The Western Carpathian spring fens are unique and vulnerable habitats and represent important elements in landscape. This specific type of helocrenes springs provides minerotrophic, groundwater-fed and nutrient-limited environment with specific low productive vegetation dominated by sedges (Cyperaceae) and bryophytes. Studied fens represent a wide variety of different habitat types, from mineral rich sparsely-vegetated or bryophytes-rich covered fens to acidic peaty sites. Such diversification allows the creation of highly diverse assemblages, in which Chironomidae usually dominate in both species richness and abundance. We examined chironomid assemblages of 46 small, treeless sites, which are highly isolated from each other by the terrestrial environment constituting dispersal barriers such as the east-west oriented mountain ridges and valleys. The dataset covers the whole length of the gradient of mineral richness, the main ecological gradient of spring fens. The quantitative benthic samples were taken in two seasons (April/May, September) from two main mesohabitats. As our study sites were homogeneous in vegetation cover, the main differences between mesohabitats was given by the differences in flow conditions and some substratum characteristics. The most distinct mesohabitats were the trickle, mesohabitat with flowing water and coarser substratum, and water-logged soil with standing water. Simultaneously, relevant environmental variables were recorded in field and the dataset was completed by substratum granulometry analysis, water chemistry analysis, climatic data and habitat size and age. The aim of this study was to provide a comprehensive overview of chironomid assemblages inhabiting the unique environment of spring fens and factors driving the metacommunity structuring. We examined species diversity and assemblage composition, explored the role of local environmental conditions and their effects on assemblages of different mesohabitats and evaluated the effect of the size and age of study sites on metacommunity structuring. Moreover, the influence of predation pressure of invertebrate predators and the effect of predation and disturbance by Gammarus fossarum Koch, 1835, was examined. Finally, we determined individual species requirements and their binding to this specific environment. The Western Carpathian spring fens host nearly 100 chironomid taxa with a significant proportion of species adapted to specific conditions of spring-fen microhabitats and the local environment is assumed to be crucial for maintaining the high species richness of spring-fen assemblages. Thus, appropriate management and protection of these vulnerable sites is essential. This research was financially supported by the Czech Science Foundation (P505/16-03881S).|