西南桦树冠与胸径生长关系研究

A Study of the Relationship Between the Crown Width and Diameter Growth of Betula alnoides

以普洱和西双版纳不同海拔自然生长的西南桦(Betula alnoides)为研究对象,选择生长良好、周围无干扰的西南桦单株,研究西南桦胸径与冠幅间的关系,结果发现,西南桦在胸径长到45 cm^50 cm之前,其冠径比值为22.4~71.3倍,且有随着胸径增大,冠径比逐渐减小的趋势,而胸径生长到45 cm^50 cm以后时,其冠径比处于较为稳定的状态,冠径比值约为19.1~22.6倍。

The relationship between DBH and crown width were investigated for independent and well-growing trees without disturbance in the natural stand of Betula alnoides in Xishuangbanna.It was found that the crown diameter ratio was about 22.4~71.3 times （the ratio of crown diameter to DBH） before DBH reached about 45 cm^50 cm.With the increase of DBH,the number of stands should be reduced accordingly.When the DBH reached above 45~50cm,the crown diameter ratio was basically stable,and the crown diameter ratio was about 19.1~22.6 times.