杉木风景游憩林冠径与胸径关系研究

为研究杉木风景游憩林标准林分密度（立木株数），确定合理抚育间伐强度提供科学依据。本文在福建将乐国有林场通过设置杉木人工林39块标准地和2 906株每木检尺实测数据，建立了福建将乐杉木人工林树冠径与胸径以及冠径与胸径比值(cd/D)关系，并分析了冠径与胸径比值在风景游憩林树木空间、林分密度和间伐强度中的应用。研究表明:胸径在2~43 cm之间时，相关系数(R²)达0.919 5，呈显著线性相关，其中2~35 cm模型精度较高，35~43 cm误差较大。通过对不同大小的杉木(cd/D)比值进行分析，得出随着胸径增大比值是逐渐减小的，并且减小的趋势随着胸径的增大趋于平稳，最后趋于一个常数。

Relationship between Crown Diameter and Diameter at Breast Height of Cunninghamia lanceolata Scenery and Recreation Forest

The aim of this study is to provide scientific basis for intermediate cutting by determining standard density (stem number) of Chinese fir scenery and recreation forest. Thirty nine sample plots and 2 906 trees of Chinese fir plantation in Jiangle national forest in Fujian province were measured to build crown diameter and diameter at breast height (DBH) and their relationship and analyze the application of the relationship in the forest space, stand density and thinning intensity. The results showed that: the correlation coefficient (R²) is 0.919 5 among 2-43 cm DBH, which was significantly linear. The simulation accuracy among 2-35 cm DBH was high, but among 35-43 cm DBH was low. The analytical result of cd/D in firs of various sizes showed that cd/D decreased gradually with the increase of DBH, and it would finally tend to be a constant.