Xu Su-Han, Zhu Ya-Juan, Wu Cai-Xia, Li Yun
Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China.
Dongsheng Forestry Police Bureau of Ordos, Ordos 017000, Inner Mongolia, China.
Ying Yong Sheng Tai Xue Bao. 2020 Sep 15;31(9):2885-2892. doi: 10.13287/j.1001-9332.202009.007.
To understand the adaptive strategies of three tree species used for soil and water conservation in the hilly area of eastern Ordos Plateau, , and we measured the δO value of xylem water of branch and potential water sources and the δC value of leaves, and analyzed the relative contribution of each potential water sources to different tree species by multiple linear mixing model. We further compared the seasonal dynamic and inter-specific variation of water source and water use efficiency (WUE). The results showed that , and mainly used soil water in 10 cm layer in May, accounting for 88.5%, 94.0% and 91.6% of their total water uptake, respectively. In July, mainly used soil water in 10-25 cm layer (44.6%) and rain water (35.4%), mainly used rain water (93.7%), and mainly used soil water in 25-100 cm layer (55.9%) and rain water (36.8%). In September, mainly used soil water in 25 cm and 75-100 cm layers (88.9%), mainly used soil water in 10 cm and 50-75 cm layers (84.5%), and used that in 10-100 cm layer. WUE of in May was significantly higher than that in July and September. WUE of in July was significantly higher than that in September. WUE of was significantly higher than that of and in May and July. Three tree species use different depths of soil water or rainwater based on their availability in different seasons. and could improve their WUE to adapt to environmental change under drought, which might be more suitable for local semi-arid environment than .
为了解鄂尔多斯高原东部丘陵区用于水土保持的三种树种的适应策略，我们测定了树枝木质部水和潜在水源的δO值以及叶片的δC值，并通过多元线性混合模型分析了各潜在水源对不同树种的相对贡献。我们进一步比较了水源和水分利用效率（WUE）的季节动态和种间差异。结果表明，五月时，[树种一]、[树种二]和[树种三]主要利用10厘米土层的土壤水，分别占其总吸水量的88.5%、94.0%和91.6%。七月时，[树种一]主要利用10 - 25厘米土层的土壤水（44.6%）和雨水（35.4%），[树种二]主要利用雨水（93.7%），[树种三]主要利用25 - 100厘米土层的土壤水（55.9%）和雨水（36.8%）。九月时，[树种一]主要利用25厘米和75 - 100厘米土层的土壤水（88.9%），[树种二]主要利用10厘米和50 - 75厘米土层的土壤水（84.5%），[树种三]利用10 - 100厘米土层的土壤水。[树种一]五月的WUE显著高于七月和九月。[树种二]七月的WUE显著高于九月。[树种一]的WUE在五月和七月显著高于[树种二]和[树种三]。三种树种根据不同季节的可利用性利用不同深度的土壤水或雨水。[树种一]和[树种二]可以提高其WUE以适应干旱环境变化，这可能比[树种三]更适合当地半干旱环境。
