毛乌素沙地北沙柳形态特征与花序分布习性研究

Morphological Characters and Inflorescence Distribution Habits of Salix psammophila in Mu Us Sandland

采用随机抽样法，对毛乌素沙地鄂尔多斯市乌审旗图克乡境内的北沙柳株丛的形态特征和花序数量进行了调查分析，以明确北沙柳的形态特征及其花序分布习性。结果显示：北沙柳树冠最大横截面积在5～10m^2的株丛最多，占总株丛数的40％，频率呈现偏左正态分布。北沙柳株高、近地直径和枝条长度频率均呈现正态分布；80％以上的株丛其花序数量小于3万个，频率呈现偏左正态分布；株丛树冠最大截面积与花序数量的相关系数为0．588（P〈0．05）；着生花序枝段长度与花序数量间的相关系数为0．355（P〈0．05）；2年和3年生萌蘖枝数平均花序数量分别为92个和138个。研究表明，花序数量主要取决于株丛最大横截面积、2年和3年生萌蘖枝数量以及着生花序枝段长度；生产中平茬周期以4年为宜，雌雄树比例应为1：0．75。

The morphological characters and the number of inflorescence Salix psarnrnophila in Tuke town of Wushen Banner Erdos were researched by random sampling method for realizing its characters of inflo- rescence distribution and promoting its fruit. The results showed that the number of the crown section area of Salix psammophila at the range of 5~10 m2 was at most,which was 40% of sum. The frequency of the most section area of crown was normal distribution but to the left of center. The frequency of high,branch diameter near ground and length of branch were normal distribution. Inflorescence number of above 80% plants were smaller than 30 000, the frequency of which was normal distribution but to the left of center too. The coefficient of correlation between the number of inflorescence and the most section area of crown was 0. 588 （P〈0.05）. The coefficient of correlation between the number of inflorescence and length of branch inserted inflorescence was 0. 355 （P（0.05）. Average inflorescence number of 2 and 3 years old branches were 92 and 138 respectively. The most section area of crown, the number of 2 and 3 yesrs old branches and the length of branch inserted inflorescence had the most effect on the number of inflorescence on a plant. Salix psammophila should be stubbed every 4 years. Proportion of female and male was 1.34.