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There is increasing attention on the effects of seasonal snowpack on wintertime litter decomposition and the following processes in cold biomes.However, little information is available on how litter nitrogen (N) dynamics varies with snowpack variations created by tree crown canopies in alpine forests.Therefore, to understand the effects of seasonal snowpack on litter N dynamics during different critical stages, litterbags with fir (Abies faxoniana), birch (Betula albo-sinensis), larch (Larix mastersiana) and cypress (Sabina saltuaria) foliar litter were placed on the forest floor beneath snowpack created by forest gaps in the eastern Tibet Plateau.The litterbags were sampled at the onset of freezing, deep freezing, thawing and growing stages from October 2010 to October 2012.Mass loss and N concentrations in litter were measured.Over 2-year decomposition, litter N release rates were 41-49% for fir, 49-54% for larch,44-47% for cypress and 47-52% for birch, which mainly occurred during the first year, especially in the first winter.Litter N release rates in both the first year and entire two-year decomposition were relative higher in gap center than in closed canopy regardless of species.However, litter N release rates in winter decreased from gap center to closed canopy regardless of species, but vise versa in the growing season.Compared with broadleaf litter, needle litter N release showed much stronger responses to the changes of snow cover in winter and sunshine in growing season from gap center to closed canopy.As the decomposition proceeded, decomposing litter quality, microbial biomass and environment temperature were important factors related to litter N release rate.The results suggested that reduced snow cover in winter might slow down litter N release in the alpine forest in the scenario of winter warming.