Topographic complexity and biotic resilience to climate change

Abstract

Topographically complex alpine terrains create a mosaic of diverse microclimates over short distances. This study investigated the extent of small-scale variation in temperature and soil moisture using dense arrays of temperature loggers and moisture measurements, and how this microclimatic variation influenced vascular-plant species richness and intra-specific trait variation across five pairs of 40x40 m landscape plots of contrasting complexity in alpine tundra at Finse, Norway. Spatial variation in mean temperature within landscape plots was in the range of 2-4 °C, similar to what is expected across large altitudinal or latitudinal distances, suggesting an important ?buffering capacity? of such landscapes in the event of climate warming. Rough landscapes contained more species than flatter ones, while patterns of within-species phenotypic variation were less clear and differed between species. These results suggest that local reshuffling and short-distance migration will be important biotic responses to climate change in this system, with assumed associated changes in biotic interactions and ecosystem function. The study also highlights the importance of mountains as target areas for biodiversity conservation.