Survival of carabids after windthrow of pine forest depends on the presence of broken tree crowns

Abstract

ABSTRACTA study of carabid assemblages (Coleoptera, Carabidae) was performed in pine stands disturbed by windthrow (Lipusz Forest, North Poland) in 2018, i.e. one year after the disturbance, in five treatments representing different classes of disturbance severity: least disturbed stands (canopy cover of 60–80%), moderately disturbed stands (canopy cover of 20–40%) and severely disturbed stands (canopy cover 0%). Moderately and severely disturbed stands were further subdivided into those with tree crowns lying on the ground and those without, or rather located between broken crowns. Based on the abundance and rarefied number of carabid species, the data did not confirm the hypothesis of higher abundance and species number in assemblages inhabiting the lying tree crowns compared with open windthrown stands without tree crowns. However, results based on carabid ecological traits confirmed the hypothesis of a higher contribution of late-successional species in assemblages under broken tree crowns than in assemblages living between such crowns. This association became stronger with the increasing severity of the windthrow disturbance. These results provide a rationale for leaving at least some lying tree crowns in windthrown stands so that the forest fauna can find refuge under the crowns.