In arctic tundra near Toolik Lake, Alaska, we incubated a common substrate in a snow addition experiment to test whether snow accumulation around arctic deciduous shrubs altered the environment enough to increase litter decomposition rates. We compared the influence of litter quality on the rate of litter and N loss by decomposing litter from four different plant functional types in a common site. We used aboveground net primary production values and estimated k values from our decomposition experiments to calculate community-weighted mass loss for each site.
Organic and mineral soil cores were collected from 18 transects differentiated by shrub height into three replica groups: high (average 64 cm ± SE 1.01); medium (39 ± SE 1); and low (18 ± SE 0.4); and percent plant functional group cover. Replica sample cores were taken from each transect, and after homogenization and K2SO4 extraction, if required, samples were analyzed for % C (carbon) and N (nitrogen); non-purgeable organic C (NPOC); total N (TN); dissolved inorganic and organic N (DIN, DON); microbial biomass C (MB-C) and N (MB-N).
In arctic tundra, near Toolik Lake, Alaska, we quantified net N-mineralization rates under ambient and manipulated snow treatments at three different plant communities that varied in abundance and height of deciduous shrubs.