基于混合效应法的急尖长苞冷杉林单木冠幅预测模型  

Prediction Model of Single Tree Canopy of Abies georgei var.Smithii Forest Based on Mixed Effect Method

作　　者：姚慧芳 卢杰[1,2,3] 王超 张萌 YAO Huifang;LU Jie;WANG Chao;ZHANG Meng(Reseach Institute of Tibet Plateau Ecology,Tibet Agriculture&Animal Husbandry University;Key Laboratory of Forest Ecology of Tibet plateau,Ministry of Education;National Key Station of Field Scientific Observation&Experiment of Alpine Forest Ecology System in Nyingchi Tibet,Nyingchi Tibet,860000,China)

机构地区：[1]西藏农牧学院高原生态研究所 [2]西藏高原森林生态教育部重点实验室 [3]西藏林芝高山森林生态系统国家野外科学观测研究站,西藏林芝860000

出　　处：《高原农业》2021年第6期572-580,共9页Journal of Plateau Agriculture

基　　金：科技部国家野外科学研究观测站(生态系统)运行补助项目(西藏林芝高山森林生态系统国家野外科学观测研究2015-2020);西藏农牧学院研究生创新计划项目(YJS2020-29)。

摘　　要：冠幅作为林木生长发育的重要因子,加强对其研究对于林业发展有重要意义。本研究以藏东南色季拉山急尖长苞冷杉林为研究对象,对4761株急尖长苞冷杉进行每木检尺,基于混合效应法对3809株急尖长苞冷杉建立冠幅预测模型,并用952株对其进行精度检验,选出最优模型。结果表明:(1)急尖长苞冷杉的胸径、树高与冠径呈正相关关系。(2)每个模型的显著性水平都达到极显著(Sig<0.001),该树种胸径—冠径的最佳拟合模型为幂函数模型,树高—冠径的最优模型为二次多项式模型。(3)急尖长苞冷杉的理论冠径值和理论冠幅值随胸径的增加而不断增大,相反冠径比、理论密度、最大密度则随之减小,并以径级Ⅴ(20~25 cm)为界限,超过第Ⅴ径级的冠径比和林分密度的下降速度变缓。(4)当林分的实际密度接近最大密度时,需要采取人工间伐措施保证林木健康生长。本研究所建模型的精度检验具有一定的统计学意义,为藏东南大面积森林调查和林分参数预测提供理论参考。Crown width as an important factor in the growth and development of trees is of great significance to strengthen the research on canopy for forestry development. In this study, 4761 trees of Abies georgei var. Smithii in Sejila Mountain, southeastern Tibet were examined. The crown width prediction model for 3809 A. georgei var. Smithii was established based on the mixed effect method, and the accuracy of 952 trees was tested to select the optimal model. The results showed that:(1) DBH, tree height and crown width of A. georgei var.Smithii were positively correlated.(2) The significance level of each model reached extremely significant(Sig<0.001).The best fitting model of DBH-crown width was power function model, and the best model of tree height-crown width was two degree polynomial model.(3) The theoretical crown diameter value and theoretical crown amplitude of A. georgei var.Smithii increased with the increase of DBH. On the contrary, the crown diameter ratio, theoretical density and maximum density decreased. Taking diameter class V(20~25 cm) as the limit, the decline rate of crown diameter ratio and stand density beyond the V diameter class slowed down.(4) When the actual stand density was close to the maximum density, artificial thinning measures were needed to ensure the healthy growth of trees.The accuracy test of the model established in this study had certain statistical significance, which provided a theoretical reference for large-scale forest survey and forest parameter prediction in Southeast Tibet.

关 键 词：藏东南 色季拉山 急尖长苞冷杉 混合效应法 冠幅 

分 类 号：S758[农业科学—森林经理学]