米老排造林密度试验初报

米老排(Mytilaria laosensis)属金缕梅科半落叶乔木,是中国南亚热带优良速生用材树种,材质优良,经济效益高。60年代在广西大青山试种成功后,已成为主要的造林树种之一。广西已发展到1300ha,幼林普遍生长良好,但某些林分因密度过大而出现生势衰退现象。如何提高经营水平,合理确定其造林密度,是有待解决的问题。为此,1980年我们做了米老排造林密度试验,取得了初步成效。现将试验结果初报如下。

A PRELIMINARY REPORT ON THE DENSITIES OF MYTILARIA LAOSENSIS PLANTATION

Three densities for planting experiment of Mytilaria laosensis plantation have been studied. The result of experiment showed that the planting densities have not significant effect on the tree height growth in the early stage of young plantation, but it has significant difference in the growth of D.B.H (Diameter Breast Heigh). The crown diameter and the root system have highey positive correlation with both D.B.H and tree volume, but highly negative correlation with tree bole of under crown length. Total growing index in different densities in 3×2m>2×2m>1×2m, in the former (i.e. largest spacing) which, uniformity of forest physiognomy, occupied a considerable proportion of trees of larger dimeter classes, higher in available timber. Under the natural prunning, the largest spacing obtained the best effect after five years. It is suggested that the 3×2m is the most suitable density for the Mytilaria laosensis planting.