In the Arctic tundra, wood ants play an important ecological role in aerating the soil, cycling nutrients, for seed dispersal and, as biological control by preying on forest pest insects during outbreaks. The increase in temperature, caused by climate change, is positively associated with ant abundance.  This could accelerate the wood ants’ effects on the ecosystem, with potentially dramatic consequences for associated taxa. It is, however, still unclear to what extent the ants influence the vegetation and arthropod community. The aim of this study is to investigate the effects ants have on the Arctic tundra ecosystem and how climate change may modify these effects. The study was conducted in Abisko national park, north Sweden, were two study sites were selected: one at low altitude and one at high altitude. I found that wood ants had a substantial effect on the vegetation community close to the mound, with a positive effect on different kind of vascular plant species, and a negative effect on rushes, mosses, and lichens. All the arthropods taxonomic orders and most of the families were positively affected by the presence of ant mounds. Ant mound abundance and volume were positively related with annual insolation and GPP, which indicates that climate change will increase ant abundance in the Arctic tundra. Thus, my results suggest that future climate change will have significant effects on Arctic tundra vegetation and arthropod communities, via positive effects on ant abundance.