关键词: 最小取样面积, 种-面积曲线, 地下水埋深, 离河距离, 塔里木河下游

Abstract: The minimum sampling area with different vegetation species proportion and the relationships between the minimum sampling area and groundwater conditions are analyzed based on the linear, non-linear species-area models and nested sampling investigation of 38 basic quadrats of 64 m×64 m in the lower reaches of the Tarim River. The results show that optimal model can be established by species-area curve, and the minimum sampling areas are 418 m2, 707 m2, 1 138 m2, 1 702 m2 and 2 656 m2 respectively when the proportions of quadrat species to community species are 50%, 60%, 70%, 80% and 90% respectively. The number of vegetation species decreases and the grow vigor of plants drops with the increase of the distance off the Tarim River. When the proportion of quadrat species to community species is 50%, the minimum sampling areas change with the change of the groundwater levels at different distances off the Tarim River, and the groundwater condition is the key factor resulting in the variation of minimum sampling area.

Key words: minimum sampling area, species-area curve, groundwater level, distance off the river, the lower reaches of the Tarim River