杉木造林密度试验阶段报告

以南方１４省（区）杉木栽培科研协作组划分的杉木带、区为基础，于１９８１年分别在广西、江西、福建、四川及河南各省设置５种密度的杉木造林试验林。经过１０年试验结果，研究了密度对主要测树因子和木材质量的影响，还根据出材量和经济效益分析，确定了各带主要指数级的最佳初植密度。即南带。中带１４—１６指数级和北带１２－１４指数级每公顷以栽植５０００株为宜；中带１８指数级以上者，每公顷以栽植３３３３株为宜。

STAGE REPORT ON THE EXPERIMENT OF PLANTING DENSITY FOR CUNNINGHAMIA LANCEOLATA

Based on the Cunninghamia lanceolata zone and region,which are divided in 14 southern provinces(regions)accordiog to the Chinese fir research coordinated groups,in 1981 the experimental plantations of Cunninghamia lanceolata were established in Guangxi,Jiangxi,Fujian, Sichuan and Henan Provinces,which consisted of 5 different densities.The measurements of 10 years showed that densities influenced the main growth parameters of trees and wood quality. According to the analysis of timber yield and economic benefit,the optimum initial planting densities for various index classes are determined,i.e.5000 trees per hectare are optimum for the index class of 14-16 in the south and middle zone, and for the index classes of 12-14 in the north zone, 3333 trees for those over 18 classes in the mid zone.