摘要
应用一组自动称重式lysimeter对腾格里沙漠东南缘沙坡头地区半灌木油蒿 (Artemisiaordosica)与灌木柠条 (Caraganakorshinskii)植丛的蒸散与流沙区蒸发比较 ,在生长季节进行两年连续观测研究。结果表明 ,植丛生长季节蒸散约占同期降水量的 90 %以上 ,根层 2 2 0cm深度以下无降水补给作用。裸沙蒸发量与深沙层补给量分别占降水量的 70 5 %与 12 6 %。湿润年 (P =2 15 8mm ,其中生长季P =183 7mm)生长季内油蒿与柠条植丛日平均蒸散速率接近 ,分别为 0 86mm·d-1,0 87mm·d-1。干旱年 (P =12 1 0mm ,其中生长季P =114 0mm)油蒿植丛日平均蒸散速率降低为 0 6 8mm·d-1,而柠条植丛日平均蒸散速率仍然高达 0 80mm·d-1。由油蒿、柠条植丛月蒸散量比较 ,干旱年柠条在降水相对集中且丰沛的月份具有较高的蒸散量 (如 1991年 8月 ,ET为 6 6 3mm(相当于蒸散速率 2 15mm·d-1) ) ,致使根层年内贮水量亏缺量 (ΔS =- 42 .6mm)较油蒿植丛严重 (ΔS =- 18 7mm)。而油蒿植丛在全生长季保持低下蒸散水平 ,表明由于植物种利用水分的机制不同 ,其植丛ET随年降水变化差异明显。但是 ,较之于湿润年均呈现下降趋势。在湿润年 ,裸沙区日均蒸发量为 0 6 0mm·d-1,而在干旱年 ,其蒸发速率降低为 0 44mm·d-1,相应的月?
The evapotranspiration (ET) of xerophyte plants, Artemisia ordosica and Caragana korshinskii, was measured by the method of auto-weighing type lysimeter during the growing seasons from 1990 to 1991 at Shapotou on the edge of southeast Tengger Desert, China. The study showed that for the area replanted with A. ordosica shrub, the average ET rates were 0.86 mm·d -1, 0.68 mm·d -1 during the period from April 23 to October 31 in 1990 and 1991, respectively. In the case of the replanted area with C. korshinskii shrub, the average ET rates were 0.87 mm·d -1 and 0.80 mm·d -1. The comparable values of evaporation from the bare sand averaged 0.60 mm·d -1and 0.44 mm·d -1 in 1990 and 1991 respectively. During the experimental period of two years, the weekly maximum ET was 18.0 mm for C. korshinskii shrub, 15.2 mm for A. ordosica shrub, and 13.3 mm for bare sand in 1990. For monthly periods, the maximum ET of C. korshinskii shrub was 66.3 mm in June 1991, that of A. ordosica shrub was 48.2 mm in August 1990, but for the bare sand, it was only 38.0 mm in August 1990. We may conclude that in the semiarid desert region, the daily and the monthly evaporation from bare sand are almost the half of ET from shrub plot.
出处
《中国沙漠》
CSCD
北大核心
2002年第4期363-367,共5页
Journal of Desert Research
基金
国家重大基础研究发展规划项目"中国北方沙漠化过程及其防治研究" (G2 0 0 0 0 4870 4)
中国科学院知识创新重大项目(KZCX1 10 0 3
CACX2 10 0 31)
沙坡头开放站基金资助
