关键词: 全叶马兰, 无性系植物, 分株, 生物量分配, 异速生长, 生长策略

Abstract: Based on the Landsat TM images in July 1986, Landsat ETM images in July 2001, and 1∶50000 DEM data, the landscape pattern change in the mountainous areas along an altitude gradient in the upper reaches of Shule River from 1986 to 2001 was studied by using software ArcView GIS 3.3 and Fragstats 3.3. In the study areas, grassland was the matrix, while shrubs and other landscape types were the mosaic patches. The landscape had simple structure, single composition, regular shape, centralized patch distribution, and a few dispersed residential points. Among the landscape types, sparse grassland had the largest area, followed by naked gravel land. The vegetation coverage was about 52%, and dense grassland only accounted for 5%. In the 15 years, the areas of shrubs, dense grassland, sparse grassland, and swamp meadow decreased due to degradation, while those of mid-density grassland, barren land, bottom land, and cropland increased. The grassland at the altitude 3800-4000 m, the lower limit of permafrost distribution, was undergone most serious degradation. The thickening of active permafrost layer and the decrease of soil moisture content due to climate warming could be the main reasons of grassland degradation.

Key words: Kalimeris integrifolia, Cone plant, Ramet, Bomass allocation, Allometry, Srategy of growth