古尔班通古特沙漠羽毛针禾（Stipagrostis pennata）种群种子雨特征

通过布设种子收集器收集种子,对收集的种子以时空差异进行分组分析，探讨羽毛针禾WTBX]（Stipagrostis pennata）WTBZ]种子散布规律以及古尔班通古特沙漠种群的种子雨特征。结果表明：① 羽毛针禾种子雨的积累密度平均达到3 766.30粒·株-1，其中饱满种子占19.56%；② 种子散布的高峰集中在6月25到7月15日，其落种量占整个种子雨的61.96%，其后种子雨密度随时间逐渐减小；③ 种子雨密度与生境之间均不存在显著性差异；④ 种子雨总量与其年龄之间存在显著性差异；⑤ 种子雨的前扩散过程中种子集中降落在背风方向4 m范围和株丛周围1 m内。古尔班通古特沙漠南缘种子雨虽质量不高，但密度大，对种群的自然更新具有一定的意义。

Seed Rain of Stipagrostis pennata in the Gurbantonggut Desert

In this study, some seed collectors were distributed to collect seeds of WTBX]Stipagrostis pennata,WTBZ] and the collected seeds were divided into several groups based on their temporal and spatial differences so as to analyze the characteristics of seed dispersal and seed rain of WTBX]S. pennataWTBZ] in the Gurbantonggut Desert. The results are as follows: ① The average accumulated density of seed rain of WTBX]S. pennataWTBZ] was as high as 3 766.30 seeds under each plant, in which the proportion of full seeds accounted for 19.56%; ② The peak of seed dispersal occurred from June 25 to July 15, the proportion of falling seeds during this period was 61.96% of the whole seed rain, and the seed rain density was decreased gradually with the time; ③ There was no significant difference of seed rain density among the different habitats; ④ There was a significant difference of seed rain amount among the different ages of WTBX]S. pennataWTBZ] plants; ⑤ Seeds fell intensively within a 4 m extent downwind and 1 m extent around the plants at the early stage of seed dispersal of seed rain. In the southern marginal zone of the Gurbantonggut Desert, the quality of seed rain was low, but the density was high and of a certain significance to the natural regeneration of the population.