Winter snowpack maintains a relatively warm environment for soil microorganisms and modulates soil biogeochemical cycles in cold ecosystems; however, snowpack reduction induced by climate warming may change soil dissolved nutrient leaching and microbial biomass. Here, we performed a snow depth manipulation experiment in an alpine forest on the eastern Tibetan Plateau. We assessed the following effects of snowpack reduction and removal during the snow formation, coverage and melt periods: the concentrations of dissolved organic carbon, nitrogen, ammonium and nitrate; microbial biomass carbon and nitrogen; and the microbial respiration rate. We found that dissolved organic carbon and nitrogen concentrations decreased after snowpack reduction but significantly increased after snowpack removal and that the soil nitrate concentration significantly increased after snowpack reduction. Microbial biomass carbon and nitrogen were significantly higher during the snow formation period than during the snow coverage and melt periods, although the microbial respiration rate was higher during the snow melt period than during the snow formation and coverage periods. However, the snowpack reduction did not significantly affect the soil microbial biomass carbon and nitrogen concentrations or invertase and urease activities. The effects of snowpack reduction on the soil nitrate concentration and microbial respiration rate were stronger in the organic soil than in the mineral soil. These results suggest that short-term snowpack reduction over the first winter of manipulation stimulated the leaching of soil available nutrient but did not change the microbial biomass. Overall, our study indicates that soil microbes have rapid adaptability to the negative effects of snowpack reduction. Although microbial activity and biomass are decoupled, a comprehensive interaction occurs with available nitrogen and enzyme activities at different soil horizons, which may represent a special ecological function in the underground decomposition mediated by the freeze-thaw cycle during a warmer winter.

冬季积雪为寒冷的生态系统保持了相对温暖的土壤微生物环境，并调节了土壤生物地球化学循环。然而，气候变暖导致的积雪减少可能会改变土壤中溶解的养分浸出和微生物生物量。在这里，我们在青藏高原东部的高山森林中进行了雪深控制实验。我们评估了降雪在积雪形成，覆盖和融化期间减少和去除积雪的以下影响：溶解有机碳，氮，铵和硝酸盐的浓度；微生物生物量碳和氮；和微生物的呼吸速率。我们发现，减少积雪后溶解的有机碳和氮浓度降低，但除去积雪后显着增加，并且减少积雪后土壤硝酸盐浓度显着增加。尽管降雪融化期间的微生物呼吸速率高于降雪形成和覆盖期间的微生物呼吸速率，但降雪形成期间的微生物生物量碳和氮明显高于降雪和融雪期间的微生物。但是，积雪的减少并没有显着影响土壤微生物生物量的碳和氮浓度或转化酶和脲酶活性。减少积雪对有机土壤的硝态氮浓度和微生物呼吸速率的影响要强于无机土壤。这些结果表明，在第一个冬季进行的短期积雪减少刺激了土壤有效养分的淋洗，但并未改变微生物的生物量。总体而言，我们的研究表明，土壤微生物对减少积雪的负面影响具有快速的适应性。尽管微生物活性和生物量是分离的，但在不同的土壤层层中，可用的氮和酶活性会发生全面的相互作用，这可能代表了在温暖的冬天中冻融循环介导的地下分解中的特殊生态功能。我们的研究表明，土壤微生物对减少积雪的负面影响具有快速的适应性。尽管微生物活性和生物量是分离的，但在不同的土壤层层中，可用的氮和酶活性会发生全面的相互作用，这可能代表了在温暖的冬天中冻融循环介导的地下分解中的特殊生态功能。我们的研究表明，土壤微生物对减少积雪的负面影响具有快速的适应性。尽管微生物活性和生物量是分离的，但在不同的土壤层层中，可用的氮和酶活性会发生全面的相互作用，这可能代表了在温暖的冬天中冻融循环介导的地下分解中的特殊生态功能。