The rapid response of the ground beetle communities to the meadow steppe habitat loss in West Podillia (Ukraine)

Abstract

Ground beetles (Coleoptera: Carabidae) stand out as one of the most diverse families not just among insects but also among all living organisms on Earth. They have emerged as essential bioindicators of environmental disturbance, reflecting changes in ecosystems due to agricultural, forestry, and urbanization practices. The presence, abundance, and species composition of carabid communities serve as reliable indicators of habitat quality and ecosystem health. We conducted a comprehensive study of the meadow-steppe habitats, utilizing ground beetles as sensitive ecological indicators. We delineated four distinct groups of species based on ecological preferences and habitat affinities: I) steppe xerothermophilic stenobionts; II) steppe and ruderal xero- and mesophilic eurybionts; III) meadow and ruderal meso- and hygrophilous eurybionts; and IV) forest meso- and hygrophilous steno- and eurybionts. Our findings elucidate a distinct response of ground beetle species groups to transformation processes occurring within meadow steppes. Species belonging to group I (Brachinus crepitans, Ophonus rupicola, O. puncticollis, Leistus ferrugineus) expanded notably in distribution under conditions characterized by xerophilization and elevated temperatures. Conversely, species within group II (Harpalus atratus, H. caspius, H. hospes, H. solitaris, Ophonus azureus) and group III (Amara aenea, A. familiaris, Calathus fuscipes, Carabus cancellatus, C. convexus, Cylindera germanica, Harpalus affinis, H. latus, H. rubripes, H. xanthopus, Pterostichus atrorufus, P. cupreus, P. strenuus) showed a comparable response to the habitat, with a preference for higher soil mois­ture. Species within group IV (Abax carinatus, A. parallelepipedus, A. parallelus, Carabus arvensis, C. glabratus, C. linnei, C. nemoralis, C. ulrichii, C. variolosus, Cychrus caraboides, C. semigranosus, Leistus piceus, Limodromus assimilis, Molops piceus, Pterostichus melanarius, P. niger, P. oblongopunctatus) demonstrated an association with markedly different environmental condi­tions, characterized by significant moisture levels and relatively lower soil temperatures conducive to their existence. Steppe species (group I) were observed in only 12 out of 27 sample plots of meadow steppes, while a significant presence of species from groups II and III was evident in most cases, indicating mesophilization due to shrub and tree vegetation expansion. Forest species of ground beetles (group IV) were prevalent in the majority of meadow steppe sample plots, reflecting disruption of plagioclimax likely re­sulting from the cessation of traditional economic practices. Despite the presence of the meadow-steppe vegetation, steppe species of ground beetles were entirely absent, suggesting their potential as early indicators of ongoing changes in the meadow-steppe habitats.