摘要
为量化采伐对林木生长的影响,以北京郊区侧柏人工幼龄林为研究对象,以竞争指数、采伐指数作为自变量,伐后5 a胸高断面积生长量为因变量,构建侧柏人工幼龄林竞争效应模型,采用判断系数(R^2)、剩余标准差(R_(MSE))、赤池信息准则(A_(IC))对模型进行评价。结果表明:断面积比竞争指数(C_(I2))、采伐指数(R_(I2))优于其余4种指数;得到了以5种竞争指数和采伐指数为自变量的竞争效应模型,根据模型R^2、R_(MSE)、A_(IC)值,推断出侧柏人工幼龄林的最佳竞争范围的半径为4 m;以C_(I2r_4)、R_(I2r_4)为自变量的模型比只有C_(I2r_4)的模型R^2提高了33.8%,说明采伐对侧柏单木生长的影响显著。
Platycladus orientalis young plantation were selected to quantify the cutting influence on tree growth in Beijing suburb. We used the competition index, cutting index and 5-year basal area growth after cutting as dependent variables to construct P. orientalis young plantation competition effect model. The model was evaluated by the judgment coefficient （ R2 ） , the re- sidual standard deviation （RMSE ） and the Akaike Information Criterion （AIC）. The basal area ratio competition index C12, cutting index R1= were superior to the other four indexes. Then the competition effect model with five kinds of competition index and cutting index were got as independent variables. According to the R2, RMSE, AIC, the best competition range of semi diameter of P. orientalis young plantation was 4 m. The R2 of the model, which used C12r4 and R12r4 as the independent variables, was increased by 33.8%, indicating that cutting has a significant influence on individual tree growth.
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2016年第9期9-13,共5页
Journal of Northeast Forestry University
基金
国家林业局"948"引进项目(2013-4-66)
关键词
侧柏人工幼龄林
竞争范围
采伐
竞争指数
采伐指数
P. orientalis young plantation
Competition limits
Cutting
Competition index： Cuttinz index
