准噶尔盆地南缘荒漠区梭梭维持水源初步研究

为了了解沙漠植物梭梭维持水源的利用情况,探明其对水源的利用策略,利用稳定性同位素技术定位取样,对准噶尔盆地南缘荒漠区梭梭进行了研究.结果表明,冬季,梭梭基本没有直接利用降雪；随着融雪后浅层土壤含水率的上升,梭梭明显利用浅层土壤水；梭梭利用水源中,地下水占有很大比例,这种比例在冬季和夏季最高,最高幅度可达到80％,平均占到30％左右；降雨也是梭梭利用的水源之一,在降雨后的3～5 d内,梭梭木质部δ18O值有明显趋近降雨δ18O值的趋势.因此,本研究区的梭梭维持水源有多个途径,地下水、融雪形成的浅层土壤水是其主要水源,中、大量降雨也是其利用的水源之一.

A Preliminary Study on the Water Sources of Haloxylon ammodendron at the Southern Edge Desert of Junggar Basin,China

In order to learn about the maintaining water sources of Haloxylon ammodendron, one of the most important desert plants in central Asia, and to detect its water source use strategy, we use stable isotope technology and serial samples to detect the water sources of H. ammodendron at the southern edge of Junggar Basin, China. Results show that H. ammodendron uses little snow in winter, but it can use shallow soil water from melted snow. The groundwater is a maintaining water sources for H. ammodendron, and the average proportion is 30% in winter and summer, and the maximum proportion can get 80% in water using of H. ammodendron. Moderate and heavy rainfall also influences this kind of plant. In 3-5 days after heavy rainfalls, the δ18O value of H. ammodendron xylem approaches the δ18O value of rainfall. This shows that H.ammodendron has different maintaining water sources. Groundwater and shallow soil water from melt snow are the most important water sources. Moderate and heavy rainfall is also one of important water sources.