中文摘要：

分别于7月15日-8月7日（夏季期）和9月5日-10月9日（秋季期），在山西芦芽山林线附近，应用树木径向变化记录仪（Dendrometer）分别测量了3株和4株华北落叶松树干的径向生长过程，并同步监测环境因子. 结果表明：1） 华北落叶松茎干变化在晴好天气呈现出有规律地波动式上升，在阴雨天气下则表现为持续上升，降雨结束后迅速下降；2） 茎干变化在7-8月观测期内与土壤含水量、空气温度正相关，在9-10月观测期内与土壤含水量正相关，与土壤温度、空气温度负相关；3） 径向净生长在夏季期为正，在秋季期为负，在9月初先下降，在9月中期后基本保持为0；4） 在两个观测期内，径向净生长与空气温度负相关，与土壤含水量显著正相关. 图5 表5 参21

英文摘要：

The stem radial growth of 3 sample trees of Larix principis-rupprechtii from July 15 to August 7 （summer phase）, and 4 sample trees from September 5 to October 9 （autumn phase） in 2007, was measured by Dendrometer, combined with synchronized instrumental observation and measurements including habitat temperature and moisture at the treeline of Mt. Luya, Shanxi, China. The results indicated： 1） the diameter of stems varied in sunny days with a daily fluctuation and it steadily widened, while in rainy days it continuously increased during the rain but it shrunk rapidly after the rain; 2） the radial variation of stems at the summer phase was positively correlated with both soil moisture and air temperature, whereas at the autumn phase it was positively with soil moisture but negatively with both air and soil temperatures; 3） the stem radial growth measured by the accumulative increment showed a positive value at the summer phase, whereas in the autumn phase, it was turned out to be a negative figure first in early September but then kept as zero constantly from middle September on; 4） the radial increment of stems showed significant positive correlations with soil moisture, while a significant negative correlation with air temperature was found at the both phases. Fig 5, Tab 5, Ref 21