关键词: 裸沙植丛, 蒸散, lysimeter, 沙坡头

Abstract: 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.

Key words: xerophyte shrubs, evapotranspiration, lysimeter, Shapotou