中文摘要：

以民勤绿洲边缘丘间低地和固定沙丘（退化梭梭固沙林）两种生境下红砂种群为研究对象,采取空间替代时间和O-ring空间点格局方法研究了红砂种群的结构特征、空间分布以及空间关联性,结果表明：（1）红砂种群在丘间低地生境下,主要集中在龄级1;在固定沙丘生境下,主要集中在龄级3,表明种群的更新受到很大的限制。（2）两种生境下红砂种群的空间格局分布和不同龄级间空间关联性差异很大。丘间低地的红砂种群及龄级1和2在小尺度范围内呈聚集分布,之后随着尺度的增加趋于均匀分布（龄级1和红砂整个种群）或随机分布（龄级2）,而龄级3在整个研究尺度范围内为随机分布;固定沙丘生境下的红砂植株只有龄级2和整个种群在小尺度内为聚集分布,其余均为随机分布。（3）在丘间低地生境下,龄级1和龄级2、3在小尺度上显著负相关,其余各龄级在0-5 m尺度上基本无关联;固定沙丘生境下,各个龄级之间均为无关联。这种差异与生境的异质性（地下水位、结皮的类型和盖度等）以及群落结构等有关。该研究对于民勤绿洲边缘红砂种群的保护和利用以及退化梭梭固沙林的人工修复有一定的指导意义。

英文摘要：

Minqin oasis fringe is located between Tengger desert and Badain Juran desert, China, which has a great ecological strategic significance. Although the windbreak and sand-fixation plantation has appeared different degree of degradation, Reaumuria soongorica has successfully settled in the degenerated Haloxylon ammodendron woodland. In order to explore the structural characteristics, spatial patterns and spatial relevancy of Reaumuria soongorica population under the interdunal depression and fixed dunes habitats in Minqin oasis fi＇inge, the O-ring statistic of point pattern analysis and space instead of time were used in this paper. The results showed as follows： （ 1 ） the majority ofReaumuria soongorica individuals were in age 1 under the interdunal depression, being growth population; under the fixed dunes, most of the Reaumuria soongorica individuals were in age 3 which were recession populations, indicating that the update of Reaumuria soongorica population had been greatly restricted. （2） The spatial distribution pattern and spatial relevancy between different age class individuals of Reaumuria soongorica population were very different in the two habitats. Under interdunal depression, Reaumuria soongorica population and the individuals in age 1 and age 2 showed aggregated distribution at small scales, and then as the scale extending, it tended to be uniform distribution in Reaumuria soongorica population and individuals in age 1 or random distribution in the individuals of age 2; Individuals in age 3 showed random distribution at all scales. In fixed dunes, only Reaumuria soongorica population and individuals in age 2 showed aggregated distribution at small scales, and the rest populations and individuals all presented random distribution. （3） Under the interdunal depression, there existed significant negative correlation between individuals of age 1 and age 2,3 at small scales, and no correlation among the rest age classes at zero to five meters scale; under the fixed dunes, there were no cor