Microbial community responses to seasonal variation and future climate change

by Jana Voriskova

Soil microbial communities represent key players in the decomposition of soil organic matter. Global climate models project strong future warming that is expected to be mainly pronounced at northern latitudes and to affect arctic soil ecosystems. The responses of belowground organisms to these changes and thus their altered effects on nutrient cycling and greenhouse gas production have received little attention, limiting our ability to predict future ecosystem functioning.

During the summer 2014, I carried out fieldwork on Disko Island, West Greenland. The project is part of the snow fence experiment that was established in Blæsedalen Valley in summers of 2012 and 2013 at dry and wet tundra area, respectively. I collected topsoil samples from sites with simulated winter warming treatment (simulation by elevated snow cover on one side of the snow fence raising soil temperature through the insulating effect of snow) and from control sites. In order to assess also seasonal variations in microbial community composition, soil cores were collected at four time points across the plant growing season. By the analysis of DNA extracted from the soil cores whole communities of bacteria and fungi will be compared. Further analyses also include assessment of microbial biomass, measurement of the activity of selected enzymes, and analysis of microbial genes coding for enzymes catalyzing important decomposition processes.