基于TLS的长白落叶松人工林树冠体积模型  

Crown volume model for Larix olgensis plantation based on TLS

作　　者：沈玉曦 田栋元 姜立春[1,2] SHEN Yuxi;TIAN Dongyuan;JIANG Lichun(College of Forestry,Ministry of Education,Northeast Forestry University,Harbin 150040,Heilongjiang,China;Key Laboratory of Sustainable Management of Forest Ecosystem,Ministry of Education,Northeast Forestry University,Harbin 150040,Heilongjiang,China)

机构地区：[1]东北林业大学林学院,黑龙江哈尔滨150040 [2]东北林业大学森林生态系统可持续经营教育部重点实验室,黑龙江哈尔滨150040

出　　处：《中南林业科技大学学报》2025年第4期65-75,共11页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金项目(32271866)。

摘　　要：【目的】树冠是衡量树木活力的重要指标,开发树冠体积模型可为林分冠层结构的管理和优化提供理论依据。【方法】以长白落叶松Larix olgensis人工近成熟林为研究对象,使用地基激光扫描技术(Terrestrial laser scanning,TLS)获取的点云数据提取单木信息,包括胸径、树高、冠幅、冠长和树冠体积,使用K-means聚类分析将样地内林木划分为优势木、平均木和被压木3个等级并将其设置为哑变量引入树冠体积预测模型中,通过再参数化方法纳入协变量,构建广义树冠体积模型,并模拟树冠体积随树冠尺寸、竞争强度和结构多样性梯度变化的响应。【结果】K-means聚类分析法能够客观地描述不同生长优势的林层间树冠体积的差异;十折交叉检验的结果表明以林木分级作为哑变量,包含单木和林分变量的落叶松树冠体积模型具有稳健的预测能力,精度满足林业工作适用标准;落叶松的树冠体积随着冠幅和冠长的增加而增加,随着林分密度和基尼系数的增加而减小。【结论】通过建立树冠体积模型,揭示了树木大小、树冠因子、林分结构多样性和种内竞争与树冠体积之间的关系,可为人工林冠层优化管理提供参考。【Objective】Tree crown is an important indicator to measure tree vitality,and the development of a crown volume model can provide a theoretical basis for the management and optimization of the crown structure of stands.【Method】Based on the point cloud data obtained by the terrestrial laser scanner(TLS),individual tree information was extracted,including DBH,tree height,crown width,crown length,and crown volume,from the point cloud data obtained by Larix olgensis plantation.K-means cluster analysis was used to divide the trees into three grades:dominant trees,average trees,and pressed trees,and set them as dummy variables into the crown volume prediction model.The generalized crown volume model was constructed by incorporating covariates by the reparameterization method,and the response of crown volume to the gradient of crown size,competition intensity and structural diversity was simulated.【Result】The K-means cluster analysis method could objectively describe the differences in crown volume between different growth dominances.The results of the ten-fold cross-test show that the larch crown volume model,including tree classification,individual tree,and stand variables,has robust prediction ability,and its accuracy meets the applicable standards of forestry work.The crown volume of larch increased with the increase in crown width,crown length,and tree height and decreased with the increase in stand mean DBH and Gini coefficient of DBH.【Conclusion】This study revealed the relationship between tree size,crown factor,stand structure diversity,intraspecific competition and canopy volume by establishing a canopy volume model,which provided a reference for the optimal management of plantation crown.

关 键 词：长白落叶松人工林 树冠体积模型 哑变量 林木分级 林分结构多样性 地基激光扫描 

分 类 号：S791.229[农业科学—林木遗传育种]