New publication from Iceland project

Dan Nelson's first manuscript from his dissertation is now out in Global Change Biology. In it, we describe how our experimental warming of Stream 7 at Hengill by 3.8 degrees C changed the structure of its invertebrate community. Somewhat surprisingly, average body size increased. Across all of Hengill's streams we can obviously find taxa with a wide range in thermal preference. It just happens that many of the invertebrates with higher thermal preference are relatively large-bodied (snails and black flies, for example) and these groups responded strongly to our whole-stream warming manipulation. Conversely, many cold-adapted taxa are quite small (many midges are obvious examples) and these groups declined. These results show that shifts towards lower average body size with warming are not universal, and that the combination of diversity in thermal preference and dispersal ability will dictate how communities reassemble as ecosystems warm in the future. Well done to Dan for all the hard work he put in to reveal these patterns!