芦芽山林线白杄与华北落叶松径向生长特征比较

分别于2007年7月15日—8月7日和9月5日—10月9日，在山西芦芽山林线附近，应用树木径向变化记录仪测量了6株白杄和5株华北落叶松树干的径向生长过程，同步监测环境因子.结果表明：白杄与华北落叶松在7—8月对环境变化的敏感度无显著性差异，在相对低温干旱的9—10月，白杄对环境的敏感度更高;两树种的净生长曲线和累积变化曲线在7—8月呈上升趋势，9—10月则先下降而后基本保持不变，且白杄生长曲线的波动较大;两树种的茎干变化与水分条件显著相关，其中白杄受大气湿度和温度影响较强，而华北落叶松受土壤水分的影响较强.

Stem radius growth of Picea meyeri and Larix principis-rupprechtii nearby the tree-line of Luya Mountain.

The stem radius growth (SRG) of six samples of Picea meyeri and fi ve samples of Larix principis-rupprechtii nearby the tree-line of Luya Mou ntain in North China was measured by the dendrometer in the summer phase from Ju ly 15 to August 7 and the autumn phase from September 5 to October 9, 2007, with the environmental factors measured simultaneously. In the summer phase, there w as no significant difference in the sensitivity of SRG to the environmental fact ors fluctuation between the two species; but in the relatively cold and dry autu mn phase, the SRG of P. meyeri was more sensitive to the fluctuation of envi ronmental factors. The accumulated SRG of the two species increased linearly in summer phase, but decreased first and kept stable then in autumn phase, with the growth increment of P. meyeri fluctuated more than that of L. principis- rupprechtii. The SRG of the two species correlated positively with hydrologica l factors and negatively with thermal factors, and the SRG of P. meyeri was strongly affected by air humidity and temperature, while that of L. principis -rupprechtii was mainly affected by soil moisture.