Hai Xuying, Li Jianping, Li Jiwei, Liu Yulin, Dong Lingbo, Wang Xiaozhen, Lv Wenwen, Hu Zhenhong, Shangguan Zhouping, Deng Lei
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China.
School of Agriculture, Ningxia University, Yinchuan, China.
Front Plant Sci. 2022 May 19;13:881282. doi: 10.3389/fpls.2022.881282. eCollection 2022.
Water use efficiency (WUE) plays important role in understanding the interaction between carbon and water cycles in the plant-soil-atmosphere system. However, little is known regarding the impact of altered precipitation on plant WUE in arid and semi-arid regions. The study examined the effects of altered precipitation [i.e., ambient precipitation (100% of natural precipitation), decreased precipitation (DP, -50%) and increased precipitation (IP, +50%)] on the WUE of grass species ( and ) and forb species () in a temperate grassland. The results found that WUE was significantly affected by growth stages, precipitation and plant species. DP increased the WUE of and generally, but IP decreased WUE especially in . And the grasses had the higher WUE than forbs. For different growth stages, the WUE in the initial growth stage was lower than that in the middle and late growth stages. Soil temperature, available nutrients (i.e., NO , NH , and AP) and microorganisms under the altered precipitations were the main factors affecting plant WUE. These findings highlighted that the grasses have higher WUE than forbs, which can be given priority to vegetation restoration in arid and semi-arid areas.
水分利用效率（WUE）在理解植物-土壤-大气系统中碳循环与水循环之间的相互作用方面起着重要作用。然而，关于降水变化对干旱和半干旱地区植物水分利用效率的影响，人们所知甚少。该研究考察了降水变化[即环境降水（自然降水量的100%）、降水减少（DP，-50%）和降水增加（IP，+50%）]对温带草原禾本科植物（ 和 ）以及杂类草植物（）水分利用效率的影响。结果发现，水分利用效率受生长阶段、降水和植物种类的显著影响。一般而言，降水减少提高了 和 的水分利用效率，但降水增加降低了水分利用效率，尤其是在 中。并且禾本科植物的水分利用效率高于杂类草。对于不同的生长阶段，初始生长阶段的水分利用效率低于生长中期和后期。降水变化条件下的土壤温度、有效养分（即硝态氮、铵态氮和有效磷）和微生物是影响植物水分利用效率的主要因素。这些发现突出表明，禾本科植物的水分利用效率高于杂类草，在干旱和半干旱地区植被恢复中可优先选择禾本科植物。
