和田河流域胡杨、灰叶胡杨种群结构特征的比较研究

在和田河流域设置胡杨、灰叶胡杨样地14块，应用相邻格子法进行每木调查，对胡杨、灰叶胡杨种群结构及空间分布格局进行比较分析，结果表明：（1）和田河流域胡杨、灰叶胡杨的种群结构均呈纺锤形，以Ⅲ一Ⅵ径级的植株数量最多，幼苗严重不足，种群有衰退趋势；（2）胡杨、灰叶胡杨种群存活曲线均接近于DeeveylI型，但灰叶胡杨种群死亡率曲线呈双峰型，胡杨种群随径级增加呈递增趋势。（3）在生长发育过程中，胡杨、灰叶胡杨种群空间分布格局在I一Ⅵ龄级呈聚集分布，Ⅶ一Ⅷ龄级呈均匀分布。（4）在不同尺度上，胡杨、灰叶胡杨种群均呈聚集分布，但聚集强度在1S～6S尺度上胡杨种群大于灰叶胡杨种群，而在9S-25S尺度上，胡杨种群小于灰叶胡杨种群。

Comparative Study on Population Structure Characteristics of Populus Euphratica and Populus Pruinosa in Hotan River Basin

14 sample plots of Populus euphratica and Populus pruinosa were established in the Hotan River Basin for the obtaining of sampling data by tally in the contiguous quadrats. Through the comparative analysis of P. euphratica and P. pruinosa population struc- ture and spatial distribution pattern, the result showed that ： （ 1 ） the population structures of P. euphratica and P. pruinosa were a spindle type in Hotan River Basin. The trees number of I ~ VI diameter class were most, and P. euphratiea and P. pruinosa popula- tion is declining due to lack of seelding ; （2） survival curves of P. euphratica and P. pruinosa population belonged to Deevey ]1 type. But, the mortality curves of them were different. The mortality curve of P. pruinosa population had two peaks, that of P. euphratica population was increased along with increasing diameter class. （ 3 ） in the process of development and growth, spatial distribution pat- tern of P. euphratica and P. pruinosa population in I - VI age class belonged to aggressive distribution, and that of them in VII ~ V~ age class belonged to uniform distribution. （4） In different scale, spatial distribution pattern of P. euphratica and P. pruinosa popula- tion showed aggregation distribution, but the aggregation intensity ofP. euphratica population was higher than P. pruinosa populations in 1 S - 6 S scale, and which was less than P. pruinosa population in 9 S-25 S scale.