Phenological responses to climate change across taxa and local habitats in a high-Arctic arthropod community

Climate change has led to pronounced shifts in phenology, varying across taxa. The Arctic is experiencing particularly rapid warming, but long-term data on phenological changes are rare in this region, especially for arthropods-a diverse taxonomic group that form important links to other trophic levels. Understanding the environmental drivers of arthropod phenological variation is necessary for predicting future trends across taxa and habitats to climate change. Here, we analyze temporal trends and climate associations in arthropod phenology using 25 years of standardized monitoring data from four habitat types in high-Arctic Greenland. We observed earlier peak activity in the arthropod community, with responses varying considerably among families and habitats. Snowmelt timing was a key driver of peak activity, especially for late-active taxa, while temperature was a less important driver, but arthropods generally exhibited earlier activity with warming. Responses in the duration of activity were more complex, with family- and habitat-specific responses to climate variation. Notably, taxa in habitats with late snowmelt responded strongly to snowmelt timing, while those in the pond habitat responded strongly to temperature. Mixed feeders and parasitoids showed rapid peak phenological shifts to earlier snowmelt and warming; however, mixed feeders shortened their activity periods, while parasitoids extended theirs. Our findings highlight the complexity of arthropod community phenological responses to climate change, with potential implications for trophic interactions dependent on temporal overlap. By analyzing phenological metrics across entire activity seasons for taxa with different functional and life-history traits, we identify general trends and consistent patterns that enhance our understanding of arthropod responses to climate change.