六盘山北侧华北落叶松树干直径生长变化及其对环境因子的响应

Stem Diameter Growth of Larix principis-rupprechtii and Its Response to Meteorological Factors in the North of Liupan Mountain

2005年5—11月在宁夏六盘山北侧的叠叠沟林场,应用带状树木径向变化记录仪研究9株华北落叶松树干的直径生长变化过程及其对环境因子的响应。结果表明:树干直径的日最大值出现在6:00—9:00,最小值则在16:00—20:00;直径生长的季节变化表现为前期快后期慢,8月下旬以后基本停止生长;林分内优势度大的林木生长较快;树干直径生长过程随时间的变化符合幂函数曲线,方程的确定系数为0.78～0.92。对影响直径生长变化的环境因子进行主成分分析,结果表明温度和水分是主要影响因子;结合偏相关分析,筛选出日最高温、空气相对湿度、日平均太阳辐射通量和土壤含水量作为影响树干直径生长变化的主要因子。建立线性回归模型。

The growth pattern in stem diameter of nine sample trees of Lar/x principis-rupprechtii was measured by dendrometer and the response of which to the meteorological factors was researched from May to November in 2005 in the north of Liupan Mountain, Ningxia. The results showed ： The maximum of stem diameter was distributed from 6 ： 00.to 9 ： 00 and the minimum one was distributed from 16：00 to 20：00. The stem grows more quickly in former days than in after days of growth period. The stem growth stopped from the last ten days of August. And the higher dominance degree of the sample trees the faster stem of which grows. The pattern in cumulative stem diameter growth could be fitted by the power function satisfactorily. And the correlation coefficient was between 0.78 and 0.92. Principle component analysis to meteorological factors showed that the temperature and moisture were the main effect factors to the stem diameter growth. Combine with the partial correlation analysis, the maximum daily temperature, the air relative humidity, average daily solar radiation and the soil water content could be selected to establish the linear model.