Shifts in soil bacterial and fungal community structure during a laboratory incubation with Betula nana leaf litter. Linkages between leaf litter decomposition and microbial community structure in sub-Arctic tundra heath and forest soils

Arctic and sub-Arctic tundra ecosystems are undergoing substantial changes due to the global climate change. Expansion and increased plant growth (“Arctic greening”) leading to increased carbon and nutrient pools to soil as well as increased decomposition rates of stored organic matter are predicted to turn the Arctic soils from carbon sinks to carbon sources. The mechanisms are, however, not well understood as we know little about the linkages between microbial community structure and function and how increased plant carbon pools affect them. In this study we incubated tundra and mountain forest soil samples with mountain birch (Betula nana) leaf litter in the laboratory and followed microbial activities (CO2 production and enzyme activities) and shifts in the bacterial and fungal communities by Ion Torrent amplicon sequencing.