Winter snowfall is an important water resource for organisms in desert ecosystems. Changing snow depth is expected to exert a potential influence on growth and ecological functions of biological soil crusts (BSCs), which are known as a dominant functional vegetation unit of desert ecosystems. However, limited attention has been paid to this potential effect on BSCs. A field simulation experiment was conducted to measure the water content, nutrient concentrations (organic carbon; total nitrogen; available nitrogen; available phosphorus; available potassium; ammonium nitrate; and nitrate nitrogen), and microbial biomass (carbon, nitrogen, and phosphorus) in samples (cyanobacterial and lichen crusts and subcrust soil) under snow cover of different depths after a four year experiment (from October 2013 to April 2017) in the Gurbantunggut Desert. The results showed that water content increased with increasing snow depth (P < 0.05). Snow removal and snow cover reduction decreased nutrient and microbial biomass concentrations in both biocrust types (P < 0.05). The concentrations of most measured nutrients and microbial biomass decreased significantly when snow depth was increased to twice ambient conditions (P < 0.05). Moreover, the concentrations of nutrients and microbial biomass were significantly influenced by snow depth (P < 0.05), crust type (P < 0.001), and their interaction (P < 0.05). The results demonstrated that variation in snow depth adversely affect the carbon and nutrient availability and microbial biomass in BSCs. Such changes might lead to a cascading effect in species composition and function of BSC communities in arid regions.

冬季降雪是沙漠生态系统中生物的重要水资源。预计雪深变化将对生物土壤结皮（BSCs）的生长和生态功能产生潜在影响，生物土壤结皮是沙漠生态系统的主要功能植被单元。然而，对这种对 BSC 的潜在影响的关注有限。进行田间模拟试验，测量土壤中水分含量、养分浓度（有机碳、全氮、速效氮、速效磷、速效钾、硝酸铵、硝态氮）和微生物生物量（碳、氮、磷）。在古尔班通古特沙漠经过四年实验（2013 年 10 月至 2017 年 4 月）后，不同深度积雪下的蓝藻和地衣结皮和地表土壤样品。P  < 0.05)。除雪和减少积雪降低了两种生物结皮类型的养分和微生物生物量浓度（P  < 0.05）。当雪深增加到环境条件的两倍时，大多数测量的营养物质和微生物生物量的浓度显着下降（P  < 0.05）。此外，养分和微生物生物量的浓度受积雪深度（P  < 0.05）、地壳类型（P  < 0.001）及其相互作用（P < 0.05)。结果表明，雪深的变化对 BSC 中的碳和养分有效性以及微生物生物量产生不利影响。这种变化可能会导致干旱地区 BSC 群落的物种组成和功能的级联效应。