Carabid Beetles under the Influence of Megafires in Pine and Secondary Forests of Central European Russia

Abstract

The identification of patterns and mechanisms of wildfire effects on biodiversity is of significant conservation importance. The research was conducted in a zone of mixed and broad-leaved forests. Carabid beetles were studied in eight sample plots that varied in relation to the 2010 and 2021 fires through 2022 and 2023. A total of 8667 specimens of 108 species of carabid beetles were counted. In 2022, plots were clearly differentiated by the pyrogenic disturbance in terms of the carabid species structure. As the pyrogenic disturbance increases, the total abundance of brachypterous as well as herbivore species decreases sharply. The carabids that were the most prevalent in an undisturbed forest (Carabus arcensis, Carabus glabratus, Pterostichus oblongopunctatus, and Amara brunnea) demonstrated sensitivity to the 2010 fire. The pyrophilous species Pterostichus quadrifoveolatus and Sericoda quadripunctata were attracted to a moderately burned area. Poecilus lepidus is confined to areas burned in 2010 and not affected by the 2021 fire. A moderately burned area was characterized by increased abundance and number of species. In 2023, the degree of similarity of carabid populations between sample plots did not generally increase, but only the 2010 fire was identified as a significant factor in population differentiation. The abundance of carabids decreased in a moderately burned area and an unburned area near the fire edge. The abundance and number of species increased markedly in heavily burned areas due to open habitat species, while the abundance of Carabus arcensis and Amara brunnea decreased in unburned areas. Forest megafires threaten the biodiversity of carabid beetles in pine and secondary forests.