文献类型：期刊文献

英文题名：Responses of the Crown Shape of Larix kaempferi Plantations to Site Index in Subtropical Areas of China

作者：Gao, Huilin[1] Chen, Dongsheng[2] Sun, Xiaomei[2] Zhang, Shougong[2]

第一作者：Gao, Huilin

机构：[1] College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; [2] State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China

年份：2023

卷号：14

期号：11

外文期刊名：Forests

收录：EI(收录号：20234815125998);Scopus(收录号：2-s2.0-85178096796)

语种：英文

外文关键词：Climate models - Nonlinear equations - Polynomials - Regression analysis

摘要：This study addresses how site index may affect crown shape by developing a crown shape regression model for the planted L. kaempferi at high altitudes in the subtropical climate of China. A total of 9241 branches from 78 trees, including 39 dominant trees and 39 intermediate trees, were measured in Hubei Province, southern China. The branch characteristics, including branch length, branch angle, and branch chord length of all living branches, were measured by felling trees. The models that showed good performance in crown shape modeling were used and compared in the present study. The goodness of fit statistics and stability of parameter estimation of the modified Kozak equation were better than those of the segmented polynomial equation. A nonlinear mixed-effect crown shape model was developed based on the modified Kozak equation. In addition to the tree level variables of diameter at the breast height (DBH), crown ratio (CR), and tree height-to-DBH ratio, an attempt was made to incorporate the site index into the crown shape model for the planted L. kaempferi. However, the site index was not a significant variable in the crown shape model. The purpose of our study was to lay the foundation for further study of the growth of the trees and the effects of crown morphology on stem growth in the future. ? 2023 by the authors.