关键词: 地膜覆盖, 夏玉米, 土壤净氮矿化, 树脂芯培养法

Abstract: Using leaf litters of three ectomycorrhizal woody species (Salix rosmarinifolia, Betula platyphylla, and B. fruticosa) and four ericoid mycorrhizal woody species (Vaccinium uliginosum, Ledum palustre, Chamaedaphne calyculata, and Rhododendron parrifolum) from a permafrost peatland in the Daxing’an Mountain of China, we compared the differences in carbon (C) mineralization and mass loss during litter decomposition at  10 and 20 ℃, and temperature sensitivity of C mineralization and mass loss between ectomycorrhizal and ericoid mycorrhizal woody species in a 315day laboratory incubation experiment. We found that ectomycorrhizal species had greater C mineralization and mass loss than ericoid mycorrhizal species during litter decomposition at both 10 and 20 ℃. Compared with ericoid mycorrhizal species, litters of ectomycorrhizal species had higher temperature sensitivity of C mineralization, but lower temperature sensitivity of mass loss. In addition, C mineralization and mass loss correlated positively with litter nitrogen (N) and phosphorus (P) concentrations, but negatively with C∶N and C∶P ratios. Temperature sensitivity of mass loss correlated negatively with litter N and P concentrations, but positively with C∶N and C∶P ratios. However, there was no significant relationship between temperature sensitivity of C mineralization and litter initial chemical properties. Our results  will help understand and predict the effects of climate warming and associated shifts in species composition on litter decomposition in boreal peatlands.

Key words: soil net nitrogen mineralization, plastic film mulching, summer maize, resin coreculture method.