杉木人工林自疏过程密度变化与环境因子关系的数量分析

收集了１１８块杉木人工样地的林分生长和环境因素资料，用环境因子中１０个定性和４个定量因子对杉木人工林自然稀疏具有较大影响的因子，应用数量化理论Ⅰ建立了杉木要人工林自疏过程密度变化的预防模型。经复相关系数的Ｆ检验表明模型达到极显水平，可应用于杉木人工林自然稀疏预报，并对各环境因子的偏相关系数进行了ｔ检验，结果表明海拔、坡位和林分平均胸径是影响杉木人工林自疏过程密度变化的重要因子（ａ＝０．０１），而

Quantitative Analysis on Environmental Factors and Density Change During Self-thinning of Cunninghamia Lanceolata Plantation

Based on the collected data of stand growth and environmental factors of 118 sample plots, according to the quantitative theory I, the authors set up the predicting model of self-thinning of Cunninghamia lanceolata plantation, using ten qualitative factors and four quantitative factors which have much influence on forest self-thinning of Cunninghamia lanceolata. The F-test for multiple correlation indicates the established model is extremely significant and it can be used to forecast self-thinning of Cunninghamia lanceolata plantation. The results of t-test for partial correlation coefficients show that the altitude,situation of slope and mean diameter at breast height are the most important factors (a=0.01) in the effect on self-thinning of Cunninghamia lanceolata plantation. The soil closeness degree and mean tree height have more influence (a=0.05) on self-thinning of Cunninghaia lanceolata plantation, and aspect of slope, predecessor of forest land, tree age and mean height of dominant tree have also certain effect (a= 0.10 ) on self-thinning of Cunninghamia lanceolata plantation. Regarding the three important factors influencing self-thinning of Cunninghamia lanceolata plantation as control variables, the authors have built the density control model of Cunninghamia lanceolata plantation which can provide reference base for density management and density control of Cunninghamia lanceolata plantation.