华北落叶松二年生苗地上部分生长规律研究

The Aboveground Part's Growth Law of Biennial Larix principis-rupprechtii Mayr Seedling

通过对华北落叶松二年生苗地上部分生长规律的研究，结果表明，在实验地条件下，华北落叶松3月下旬芽萌动，4月初展叶，6月初叶已完全展开，6月底叶数增长最快。平均苗高与平均地径生长量最大峰值分别出现在6月20日和6月30日。整个生长期分两阶段，第1阶段生长量随旬平均温度和旬积温值升高而增加，第2阶段随旬积温值的升高而减少。

The study on the aboveground part's growth law of biennial larix seedlings on the experimental site show that larix seedlings begin to sprout in the last ten days of March, unfold their leaves in early April and fully open them up in the eary part of June. The number of leaves increases most rapidly at the end of June, and the increment peak value appeare respectively at June 20 and June 30. The wholly growth period can be devided into two stages: in the first stage, the increment increases with the rising of average and accumulated temperature mere than 10℃ in ten days; in the second, the increment decreases with the rising of accumulated temperature more than 10℃. Both of the stages show the specific growth law of the Larix.