Xerothermophilous species of rove beetles (Coleoptera: Staphylinidae) in dry-warm habitats prefer their wetter niches

High temperatures that prevail at sun-exposed sites such as heaths, depressions, or on slopes, increase the risk of desiccation for rove beetles (Staphylinidae). Therefore, atmospheric and sub-atmospheric humidity determine the microclimates and thus habitat preference and activity of xerothermophilous species. In the nature reserve Marienfließ, a heathland in the south of Mecklenburg-Western Pomerania, Northeast German Lowlands, air temperature and humidity were recorded year-round along a transect at 10 sites, i.e. where the vegetation was more dense and more humid than where the vegetation was sparse and it was drier, using data loggers placed in the litter layer that recorded the conditions every 30 min in 2021. Monthly visits were made to determine the biomass of vegetation, soil and litter properties, edaphic rove beetle fauna and total abundance and and that of individual species at 1 m2 sites. Statistical analysis of 365 diurnal cycles per site, with pronounced amplitude in air temperature and humidity, clearly delineated the cooler and more humid sites from warmer and drier ones. Between 10 and 22 of the 30 xerothermophilous species (73.3%), such as, e.g. Quedius persimilis Mulsant & Rey, 1876, Xantholinus gallicus Coiffait, 1956, Cousya longitarsis (Thomson, 1867) and Euaesthetus superlatus Peyerimhoff, 1937, were recorded only at the cooler and moist sites on the heath. Comparison of the abundances and distribution of species revealed that the xerothermophilous heath-dwelling and desiccation-prone species prefer rather constant environmental conditions, i.e. niches in cool and moist habitats on warm and dry heathland.