Effects of microclimatic thresholds on the activity-abundance and distribution patterns of alpine Carabidae species

The goal of our study was to close gaps in knowledge regarding Carabidae distribution and activity in response to microclimate. We aimed to characterise the spatio-temporal distribution of Carabidae species along multiple gradients, and explain the activity-abundance of assemblages and their indicator species using microclimatic measurements to identify key determinants of Carabidae activity-abundance and distribution. We sampled 32 alpine sites using pitfall traps and data loggers, and identified species assemblages linked to distinct habitat types that follow the snow-cover patterns and dynamics. Moreover, we linked the activity-abundance and distribution of assemblages and characteristic species to different temperature thresholds using mixed models and spatial cross-validation to assess variable importance. Our results demonstrate that alpine Carabidae species show markedly different responses to thermal thresholds, which reflect the patterns of snow cover. The importance of snow cover for species distributions should thus be considered a hypothesis for future studies.