The importance of microclimate and plant species richness for alpine arthropods in a Dryas heath at Finse

Abstract

Alpine ecosystems are characterized by low temperatures, strong winds, and high solar radiation, which can lead to harsh living conditions for flora and fauna. As climate changes, larger climatic variations and the number of extreme events are expected to increase. This affects the microclimate and plant richness. Few studies to date investigate how arthropods are affected by microclimate and plant richness. This study aimed to investigate how temperature, soil moisture, and plant richness affect arthropod composition and distribution to get a better understanding of how arthropods are affected by changing climate. The study was conducted at Mount Sanddalsnuten, Finse, in the southwest of Norway. 25 plots with high variations in temperature and soil moisture were used. 125 pitfall traps were placed evenly across the plots, and TMS-4 data loggers recorded temperature and soil moisture in each plot. The study found that 15158 arthropods, 3492 beetles, and 11666 other arthropods were collected in 24 plots at Sanddalsnuten, Finse, from June 20th to August 2nd. Linear models were used to analyze how microclimate and plant richness affected arthropod composition. The study found evidence that increasing temperatures affected parasitoids, the total number of beetles, beetle richness, and omnivore beetles negatively. Neither soil moisture nor plant richness was found to influence the arthropod community at Mt. Sanddalsnuten. Arthropod response to plant richness and microclimate changes are less studied, but time series monitoring programs can help to understand how arthropods respond.