The effect of snow removal on litter macroinvertebrate community composition

Winter snowpack provides a protective thermal barrier for litter and soil organisms during winter. However, in Maine snowpack duration and extent is expected to decrease as a result of climate change. Research on the biogeochemical impacts of snowpack reduction has shown that snowpack loss alters carbon (C) and nitrogen (N) cycling in soil by reducing fine root biomass, changing microbial community structure, and reducing the springtime delivery nutrients during snowmelt. However, little information exists on the impact of snow loss on the macroinvertebrate communities that reside in litter. Macroinvertebrates play an important role in C and N cycling through decomposition of plant material and release of microbial nutrients via grazing, therefore a shift in macroinvertebrate community composition associated with snowpack reduction may impact soil nutrient cycling. The objective of this study is to determine the impact of snowpack loss on litter macroinvertebrate communities.  In February 2015, we initiated a snow removal project in a softwoods forest stand in Maine in which four experimental plots were kept clear of snow through the duration of the winter. We collected litter macroinvertebrates prior to snowmelt and following leafout to determine the impact of snow removal on macroinvertebrate community composition, biomass, and C and N stoichiometry. We predict that soil temperature will be an important driver of biomass and community composition, and that 1) freezing associated with snow removal will reduce macroinvertebrate biomass, and 2) earlier warming in the snow removal plots will have altered the community structure by changing the timing of emergence of different groups following snowmelt. Our preliminary results indicate that the wintertime samples from both snow removal and reference plots are dominated by Collembola.