关键词: 荒漠灌木, 土壤含水率, 发育期, 干鲜重, 孪井滩

Abstract: Based on 25 years (1981-2005) of continuous positioning observation data on desert shrub in Xilingaole area of Alashan league in Inner Mongolia, by M-K trend method and correlation method, the growing periods and yield trends of the 5 main species of desert shrubs, soil moisture trends, and the relationship between them were analyzed. The results showed that the soil moisture, especially that of 10-20cm soil layer decreased obviously（P＜0.05）. Compared with 10-30cm, the soil moisture of 30-50cm soil layer was relatively stable. During 1981-2005, the reviving date, flowering and withering date of the 5 species of desert shrubs all had a ahead trend, especially for withering, reviving on the second, which made the growing length of〖JP〗 the 5 desert shrubs reduced. The fresh weight of the 5 species of desert shrubs was significantly decreased. Compared with dry weight, fresh weight decreased more obvious. Soil water content mainly affected the reviving date of the 5 desert shrubs. The higher soil water content was, the earlier reviving date. The 30-50cm soil layer was the main layer affecting shrubs reviving due to its relatively stable. The 10-20cm soil layer had a significant impact on dry weight and fresh weight of desert shrubs. The correlation of dry weight, fresh weight and average soil moisture of last year was significant than that of the current year, indicating that dry weight and fresh weight of desert shrubs more closely related to pre soil moisture.

Key words: Desert shrub, Soil water content, Growing period, Fresh and dry weight, Luanjingtan