水曲柳的生长规律

水曲柳是我国东北林区的珍贵阔叶树种之一，由于长期的不合理采伐，这一资源已近枯竭。为了恢复和发展水曲柳资源，在长白山地区通过实验，对水曲柳的生长规律进行了研究。结果显示：水曲柳的高生长期与径生长期不同步，表现出先高生长，后径生长的现象。林隙自由生长木的高生长量和胸径生长量都远远大于林内丛生木的高生长量和胸径生长量。林隙木在后期的生长策略上表现为径生长占主导；相反，林内丛生木在后期的生长策略上表现为高生长占主导。对林分进行人工抚育，改善树木的生长条件，水曲柳的平均胸径达到24cm和32cm时的培育期可以分别比自然条件下(未抚育)的林分缩短15a和20a。

The Growth Rule of Fraxinus mandshurica

Fraxinus mandshurica is one of the valuable bradleaved trees in the northeast forest region,because of long-term cutting that is unscientific,the resource of Fraxinus mandshurica is drying up.The growgh rule of Fraxinus mandshurica in Changbai Mountain was studied to resume and develop it .The results showed that the dates of height growth and diameter growth are saynchronous,the height growth begins firstly,and then the diameter growth. Both the height increment and the diameter increment of the gap trees are higher than those of the fascicular trees.The diameter increment of the gap rtee is the uppermmost in the upper date,contrarily,the height increment of the fascicular tree is the uppermost in the upper date.If the forest is tended,the period of cultivation can be shorten by 15 years and 20 years when the diameter at breast height reach 24cm and 32cm.