Xuehua Ye, Zhilan Liu, Shudong Zhang, Shuqin Gao, Guofang Liu, Qinguo Cui, Juan Du, Zhenying Huang, Johannes H.C. Cornelissen. 2018. Experimental sand burial and precipitation enhancement alter plant and soil carbon allocation in a semi-arid steppe in north China. Science of the Total environment, (2018), doi:10.1016/j.scitotenv.2018.10.208

植物遭受沙埋是干旱半干旱地区的常见现象，沙埋影响着植物的生长甚至于植物群落的结构；而降水格局的变化，包括降水强度和频次的变化，也是该区域群落结构和功能的主要驱动因素。在鄂尔多斯生态站开展的一个2年的野外控制实验结果表明：沙埋没有显著改变植物群落碳密度，但显著影响了地上和地下植物碳密度的分配。沙埋的这种影响因群落中植物种类和生活型不同而存在着差异。仅仅改变每次降水的强度对植物碳及其分配没有显著影响，表明降水变化对植物的影响可能更多归于降水频次的改变。沙埋和降水增强降低了土壤碳含量，特别是土壤有机碳的含量。同时沙埋和降水增强促使土壤碳由土壤表层向更深层次的土壤中转移。研究结果有助于理解降水变化背景下沙埋如何影响干旱半干旱区草地生态系统中植物和土壤碳储量及其分配，从而深入探讨变化环境中的干旱半干旱区草地生态系统结构与功能。 

      Sand burial is a common phenomenon in inland semi-arid and arid areas, affecting plant growth and even plant community structure. Precipitation regime, including the variation of precipitation intensity and frequency, also drives community structure and functions in such areas. However, few studies have focused on the combined effect of sand burial and changed precipitation regime on community function, specifically its role in carbon storage. A 2-yr field experiment with factorial treatments of precipitation (control, slight enhancement and strong enhancement) and sand addition (control and 5 cm sand addition) was conducted to test the responses of plant and soil carbon content in a semi-arid typical steppe in N China. Results showed that sand burial had no significant effect on plant carbon density, but significantly changed the allocation of plant carbon from aboveground to belowground; these responses differed among species and life forms in the community. Precipitation enhancement had no significant effects on plant carbon and its allocation, perhaps because effects of precipitation on plants are due more to precipitation frequency than to precipitation intensity per event. Sand burial and precipitation enhancement decreased soil carbon, especially soil organic carbon, and promoted soil carbon to be distributed deeper down the soil profile. These findings will help to understand how sand deposition affects plant and soil carbon storage and their allocation in plant communities under a changing precipitation regime, and more generally, to understand carbon storage dynamics in early-successional sandy ecosystems in the context of global change.