Experimentally increased snow depth affects High Arctic microarthropods inconsistently over two consecutive winters

Climate change induced alterations to winter conditions may affect decomposer organisms controlling the vast carbon stores in northern soils. Soil microarthropods are abundant decomposers in Arctic ecosystems affecting soil carbon release through their activities. We studied whether increased snow depth affected microarthropods, and if effects were consistent over two consecutive winters. We sampled Collembola and soil mites from a snow accumulation experiment at Svalbard in early summer and used soil microclimatic data to explore to which aspects of winter climate change microarthropods are most sensitive. Community densities differed substantially between years and increased snow depth in winter had inconsistent effects. Increased snow depth hardly affected microarthropods in 2015, but decreased overall abundance and altered relative abundances of microarthropod groups and Collembola species after a milder winter in 2016. Although our increased snow depth treatment enhanced soil tempe...