Effects of fertilization on decomposition rate of Populus tremuloides foliar litter in a boreal forest

Rates of mass loss of foliar litter of trembling aspen (Populus tremuloides Michx.) were measured for 4 years after a single fertilization with N at 2 00 kg N/ha or a mix of N, P, K. Ca, Mg, S, and B. Foliar litter from fertil ized plots had higher N concentrations than litter from control plots; Litt er from the nutrient-mix plots had higher concentrations of N, P, and Ca. T he average rate of mass loss of aspen foliar litter was 60% after 4 years. The higher concentrations of nutrients in litter from fertilized plots did not affect the rate of decomposition. There was some difference in rates of decomposition of litter incubated in plots of the three treatments. Mass l oss was significantly slower in the nutrient-mix plots after 12 and 18 mont hs compared with control plots. This experiment provided no evidence that f ertilization of boreal aspen forests will increase rates of litter decompos ition.