Climate Change-induced Drivers of Plant Communities in Subarctic Peatlands

Climate change in the (Sub)Arctic is expected to be more extreme and rapid compared to other regions in the world (IPCC 2007). Tundra and peatlands are the main ecosystem components at these northern latitudes, which are largely dominated by lichens and bryophytes fulfilling important ecosystems functions (see General Introduction, Longton 1988; Rydin & Jeglum 2006). As both biodiversity and vegetation cover in the High North are strongly determined by cryptogams (Wielgolaski et al. 1981; Matveyeva & Chernov 2000), investigations of changes of these indices under climate warming are of major importance. These changes in turn may have important repercussions for nutrient recycling. Therefore, the major aims of this thesis were (i) to identify the consequences of climate change for vegetation composition, specifically cryptogam composition, in the (Sub)Arctic at various temporal, spatial and functional scales and (ii) to investigate the implications of these changes concerning nutrient recycling via resorption and decomposition. Below I will discuss whether and to what extent the results presented in this thesis have fulfilled these aims.