Yue Yan-Peng, Cheng Long, Sun Ying-Tao, Pang Ying-Jun, Wu Bo, Shi Lin, He Jin-Jun, Jia Xiao-Hong
Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China.
Key Laboratory of Desert Ecosystem and Global Change, State Administration of Forestry and Grassland, Beijing 100091, China.
Ying Yong Sheng Tai Xue Bao. 2022 Jul;33(7):1861-1870. doi: 10.13287/j.1001-9332.202207.014.
Exploring and quantifying the impacts of biological soil crusts on soil hydrological processes and soil water budget in semi-arid ecosystems can provide a theoretical basis for vegetation restoration and reconstruction in deserts. Based on continuous observation of soil water content in different types of areas covered by biological soil crusts (, algae, moss) and bare sand in the Mu Us sandy land during the growing season (May to October) from 2018 to 2020, we examined the effects of biological soil crusts on soil water budget at a depth of 0-40 cm. Results showed that algae and moss crusts significantly reduced soil water supplement below 40 cm by rainfall and increased soil water evaporation loss, compared with that under bare sand. In the relatively wet year (2018), the amount of soil water expenditure (seepage+evaporation) covered by bare sand and the various types of biological soil crusts was less than that of rainfall, resulting in net soil water income. In the relative dry years (2019 and 2020), the amount of soil water expenditure covered by dominant algae and moss crusts was higher than that of rainfall, causing net soil water deficit, but opposite for bare sand. Biological soil crusts led to the imbalance of soil water budget of 0-40 cm depth and even soil water deficit in relatively dry years, which may lead to the succession of plant communities to be dominated by shallow-rooted plants in this area.
探索和量化生物土壤结皮对半干旱生态系统土壤水文过程和土壤水分收支的影响，可为沙漠植被恢复与重建提供理论依据。基于2018年至2020年生长季（5月至10月）对毛乌素沙地生物土壤结皮（藻类、苔藓）覆盖的不同类型区域及裸沙地土壤含水量的连续观测，我们研究了生物土壤结皮对0至40厘米深度土壤水分收支的影响。结果表明，与裸沙地相比，藻类和苔藓结皮显著减少了40厘米以下降雨对土壤水分的补给，增加了土壤水分蒸发损失。在相对湿润的年份（2018年），裸沙地和各类生物土壤结皮覆盖下的土壤水分支出（渗漏+蒸发）量小于降雨量，导致土壤水分净收入。在相对干旱的年份（2019年和2020年），优势藻类和苔藓结皮覆盖下的土壤水分支出量高于降雨量，导致土壤水分净亏缺，而裸沙地情况相反。生物土壤结皮导致0至40厘米深度土壤水分收支失衡，在相对干旱年份甚至出现土壤水分亏缺，这可能导致该地区植物群落演替为以浅根植物为主。
