Climate and productivity shape fish and invertebrate community structure in subarctic lakes

摘要: Summary Climate change and land-use intensification are increasing productivity in subarctic lakes. Simultaneously, fish invertebrate species adapted to temperate conditions expanding their range northwards into habitats. Community level studies required predict long-term effects of these dual stressors on freshwater ecosystems. We conducted a space-for-time study examining the fish, benthic pelagic zooplankton communities littoral, profundal habitats 19 lakes situated temperature, gradient northern Europe. Fish density (ranging between 0.5 150.5 per net series h−1) biomass (range 92 5,147 g increased significantly with lake temperature productivity. This was associated decreasing body size (26 12 cm total length; 174 19 g mass) shift community structure from salmonid (Arctic charr Salvelinus alpinus, whitefish Coregonus lavaretus), percid (ruffe Gymnocephalus cernua, perch Perca fluviatilis) ultimately cyprinid (roach Rutilus rutilus, bleak Alburnus alburnus) dominance. Changes composition were most apparent littoral zones. Benthic macroinvertebrate peaked mesotrophic lakes, highest at either end gradient, indicating habitat specific differences predation pressure top-down control. Body macroinvertebrates negatively related productivity. These results suggest that climate practices gradually turning warmer, less transparent more productive systems harbouring abundant, small-sized warmer communities.