中文摘要：

植物体内各水分来源的比例反映植物的适应特征．在水分作为限制因子的荒漠区．其更是物种间生态位分化、荒漠多样性维持的重要机理之一。通过检测艾比湖湿地自然保护区内4个生境（荒漠、河岸林、盐沼地和沙丘）的8科14种优势种的木质部，以及当地河水、地下水、4层不同深度（0—40，40—70，70一100cm和100—150cm）土壤水的稳定氧同位素值（δ18O），估算各物种和各科植物体内各种水分来源的比例，随后依据根系的空间位置再将14种植物分成13个中深根系和1个浅根系物种，进一步利用δ18O值分析深浅根系植物间的水分差别，以及各水源间的补给关系。结果表明：（1）艾比湖湿地自然保护区内，不同物种体内水分来源存在差别。将所有优势物种按科属归类后，类似物种水平，不同科属植物体内的水分来源也存在差别；（2）地下水是大部分植物的主要补给水源，多数植物很少利用0—40cm表层土壤水：（3）深浅根系植物的水分来源不同，深根系植物主要利用地下水和河水，而浅根系植物主要利用土壤水；（4）艾比湖湿地自然保护区内，地下水补给河水，随后两者共同从土壤深层至浅层依次补给土壤水。综上可知：干旱荒漠内，水源可利用性的多样化，导致不同区域植物体内各水分来源的比例存在差别。在离河岸距离、地下水位高低、土壤表层盐渍化程度等因素的综合影响下，多年生和盐渍环境生长的植物，趋向于吸收地下水、河水和深层土壤水，相反，一年生或短命植物趋向于利用其能触及到的各种水源。

英文摘要：

The proportions of water sources in plants are related to plant adaptation, and reflect the mechanisms of niche differentiation and diversity in arid desert regions. At present, traditional physical methods is hard to determine the proportions of water sources in plants. But, due to the stable isotopes does not existed fractionation when it transported from the roots to the leaves, the stable hydrogen-oxygen isotope content （δ18O and 6D） were essentially unchanged among roots, xylem, and the water sources. This resulted in the hydrogen-oxygen stable isotope analysis as a tool for accurately identifying the proportions of water sources in plants. In the present study,δ18O of the xylem of 14 dominant desert species in 8 families （including Apocynaceae, Chenopodiaceae, Tamaricaceae, Leguminosae, Salicaceae, Zygophyllaceae, Compositae and Polygonaceae） , river water, groundwater, and 4 layers soil water （including 0--40, 40--70, 70--100, and 100--150 cm） were measured respectively in desert, riparian forest, salt marsh, and sand dunes of Ebinur Lake Wetland Nature Reserve, Xinjiang, China. Based on the roots distribution and δ18O, 14 dominant desert species were firstly classified into 13 deep-rooted species and 1 shallow-rooted species, and then the proportions of water sources in plants, the differences of water utilization strategies between the deep- and shallow-rooted plants, and the replenishment relationships among water sources were analyzed. The results showed that ： （ 1 ） the proportions of water sources in plants were different among species and families in the Ebinur Lake Wetland Nature Reserve; （2） groundwater occupied the largest proportion in water sources in plants, whereas the 0--40-cm layer soil water was rarely used; （3） the proportions of water sources in plants differed between deep- and shallow-rooted plants. Groundwater and river water were the main sources for deep-rooted plants, whereas the soil water was the primary source for shallow-rooted plants; （4） groun