Diversity and concordance in the composition of butterfly assemblages of the Transcarpathian (Bereg) plain (SW Ukraine)

In eastern Central Europe the abandonment of traditional land use represents a major threat for biodiversity. Evidence on species loss and shifts in assemblages is often based on butterfly surveys since these are known as sensitive indicators of habitat changes. Butterfly assemblages were studied in meadows of the Transcarpathian lowland in three consecutive years (2012–2014) with standard transect walks in six different sites (two transects/site). More than 6500 individuals of 66 species were recorded. The less disturbed habitats surrounded by natural forests have shown the highest diversity (Shannon-Wiener, dominance profiles). In faunal types the widely distributed, generalist Euro-Siberian species predominated with significant presence of Holo-Mediterranean and southern Continental elements. Three main types of habitats were separated and characterised by indicator species, i.e. we hierarchically classified the species according to their fidelity by the IndVal method. The dry sites were characterised by a few generalist species only, while the humid ones and mostly the transitional sites were inhabited by numerous habitat and/or food plant specialists. The assemblages were compared with multivariate analysis and the concordance of inter-annual changes of the assemblages were surveyed. The concordance profiles of the less diverse dry habitats were clearly separated from others while other sites with dominance profiles with longer sequence of scarce species have also shown similar concordance profiles. The importance of nature-like forest fringe structures was pointed out for both habitat and species conservation. Conservation efforts should be focused to sustain the general level of biodiversity by the preservation of nature-like habitats and the possible re-establishment of some kinds of traditional use.