Effects of climate change on soil factors and metazoan microfauna (nematodes, tardigrades and rotifers) in a Swedish tundra soil – a soil transplantation experiment

Abstract

In order to study the effects of climate changes on soil organisms and processes, a transplantation experiment was undertaken. Eighteen soil blocks from an ombrotrophic mire (Stordalenmyren) at Abisko in northern Sweden were transplanted to nine sites in Sweden, from Umeå in the north to Alnarp in the south. The study was part of the EC-project DEGREE (Diversity effects in grassland ecosystems of Europe). The development of populations of nematodes, tardigrades and rotifers was followed in a monthly sampling programme. Microbial biomass and inorganic nitrogen were determined by other partners in the project. Some effects could be related to climatic conditions at the transplantation sites and the most clear influence was found at open sites with great fluctuations in temperature and moisture. The parameters most clearly influenced were amount of mineralized nitrogen, numbers of bacterial feeding nematodes belonging to the Rhabditida, and numbers of tardigrades. These components had a fairly large coefficient of variation (CV = 0.9–1.2). Microbial biomass as indicated by the CFE and Ergosterol methods varied less (CV = 0.3). The Shannon index, Evenness and Maturity index varied very little (CV = 0.1). In most changing parameters the effect was most clearly seen during the autumn. The fluctuations of microorganisms, nematodes, tardigrades and inorganic nitrogen could indicate a food web interaction.