Environmental drivers of carabid beetle communities in a historical urban park: a case study from Rusovce, Slovakia

Urban green spaces, particularly historical parks, serve as important refuges for biodiversity in cities. However, the traits that allow species to persist in these areas remain underexplored. Carabids are widely recognised as sensitive bioindicators of environmental change and habitat quality. We studied carabid beetle communities in seven distinct habitats within a historical park in Rusovce (Bratislava, Slovakia) from March 2019 to April 2020 using pitfall traps, recording 756 individuals belonging to 54 species. The community was dominated by three large, flightless forest species: Abax parallelepipedus, Carabus ulrichii, and Carabus coriaceus. Strikingly, flightless species as a whole made up only 17% of species richness yet 80% of all individuals, suggesting that the park sustains populations of poorly dispersing, disturbance-sensitive carabids at unusually high densities for an urban setting. Redundancy analysis showed that microclimatic conditions (soil, surface, and air temperature) and vegetation structure (tree and herb layer cover and richness, stand age, and litter depth) were the principal drivers of community composition, whereas among management practices, only invasive plant species and trampling significantly reduced beetle diversity; mowing, tree cutting, and monoculture plantations had no measurable effect. Comparing these results with our parallel studies of harvestmen and spiders from the same park revealed that each taxon responds to a distinct combination of environmental drivers, underscoring the value of multi-taxon monitoring for urban biodiversity assessment. These findings identify concrete, low-cost management levers, such as controlling invasive plants and limiting trampling, that city park managers can use to protect ground-dwelling arthropod diversity as urbanisation intensifies.