不同林分密度对杉木生长的影响

Effects of Different Forest Density on Chinese Fir Growth

林分密度的研究在人工林集约化发展的进程中是非常重要的。本文调查了黟县洪星山场的3种杉木人工林,其林分密度分别为8 m×8 m、6 m×6 m、5 m×5 m,在10余年连续跟踪监测的基础上,研究了不同密度杉木人工林对其林木生长的影响,研究结果如下:(1)3种林分密度对杉木树高的生长差异不明显,但是不同的林分密度对胸径、冠幅、枝下高、材积和蓄积量的生长均具有显著差异。(2)在密度为8 m×8 m时杉木的胸径为24.61 cm,冠幅为7.87 m,枝下高为5.68 m,单株材积为0.3401 m^(3),此时杉木的生长状况最好,最利于培育杉木大径材。(3)在密度为5 m×5 m时杉木的单位面积蓄积量为102.9 m^(3),单位面积净增蓄积量也最大为18.61 m^(3),即随着林分密度的增加,单位面积蓄积量也在不断增加,且差异显著。

The study of stand density is very important in the process of intensive development of plantations.In this paper,three kinds of chinese fir plantations in Hongxing Mountain Farm in Yixian county were investigated,and their stand densities were 8 m×8 m,6 m×6 m,5 m×5 m,respectively,and the effects of fir plantations of different densities on their forest growth were studied on the basis of more than 10 years of continuous follow-up monitoring,and the results were as follows:(1)The difference between the three forest stand densities on the growth of chinese fir tree height was not significant differences,but the different stand densities had significant differences in the growth of breast diameter,crown width,sub-branch height,tim⁃ber volume and volume.(2)At a density of 8 m×8 m,the girth of Cedar wood is 24.61 cm,the crown width is 7.87 m,the height under the branches is 5.68 m,and the timber volume of a single plant is 0.3401 m3,the growth of chinese fir is the best,which is the most conducive to cultivating large-diameter fir lumber.(3)The unit volume of storage of Cedar wood at a density of 5 m × 5 m is 102.9 m^(3),and the net increase per unit area was also the largest 18.61 m3,with the increase of stand density,the unit area volume was also increasing,and the difference was significant.