基于结构方程模型的城郊森林公园林分空间结构评价
Evaluation on Stand Spatial Structure of Suburban Forest Park Based on Structural Equation Model
杜锦瑞 1冯雨萌 1杨露露 1马瑞皓 1武小钢 1杨秀云1
作者信息
- 1. 山西农业大学 林学院,山西晋中 030800
- 折叠
摘要
为探索优化林分空间结构的有效措施,以太原森林公园为研究对象,以水平空间结构、垂直空间结构和竞争空间结构为一阶因子,以林分空间结构为二阶因子,依据传导机制建立结构方程模型,对指标赋权,并基于样地实测数据,对太原森林公园林分空间结构进行综合评价.结果表明,林分空间结构评价结构方程模型的平均适配度指数(χ2/df)为1.285,近似误差均方根(RMSEA)为0.046,增值适配度指数CFI、TLI和NFI分别为0.986、0.973和0.941,各拟合指数均符合适配度参考值,可满足研究需要.林分空间结构评价体系中,3个准则层因子,即水平、垂直和竞争空间结构的权重分别为0.352、0.347和0.301,水平和垂直空间结构为影响林分空间结构的关键因素.研究区各样地林分空间结构综合得分为0.31～0.78,集中在Ⅱ、Ⅲ和Ⅳ等级;处于不同等级的样地数量表现为Ⅳ等级(7块)>Ⅲ等级(6块)>Ⅱ等级(1块).林分空间结构主要受水平和垂直空间结构影响;为改善整体林分空间结构,应采取单株采伐抚育、抚育间伐和多树种补植等措施.
Abstract
In order to explore effective measures to optimize stand spatial structure,taking Taiyuan Forest Park as study object,structural equation model was established based on conduction mechanism by taking horizontal spatial structure,vertical spatial structure and competitive spatial structure as first-order factors,stand spatial structure as second-order factor,and indexes were assigned with weights.Based on measured data of sample plots,stand spatial structure of Taiyuan Forest Park was evaluated comprehensively.Results showed that aver-age fitness index(χ2/df)of structural equation model for stand spatial structure evaluation was 1.285,root mean square error of approximation(RMSEA)was 0.046,and value-added fitness indexes including CFI,TLI and NFI were 0.986,0.973 and 0.941 respectively,which were in line with reference values of fitness and could sat-isfy research needs.Weights of three factors in criterion layer in stand spatial structure evaluation system,which were horizontal,vertical and competitive spatial structures,were 0.352,0.347 and 0.301 respectively,with horizontal and vertical spatial structures being key factors affecting stand spatial structure.Comprehensive scores of stand spatial structures in sample plots of study area ranged from 0.31 to 0.78,concentrating on gradesⅡ,ⅢandⅣ.Number of sample plots in different grades followed order of gradeⅣ(7 plots)>gradeⅢ(6 plots)>grade Ⅱ(1 plot).Stand spatial structure was mainly affected by horizontal and vertical spatial structures.In order to improve overall stand spatial structure,measures such as single-tree harvesting,thinning and multi-species replanting should be taken.
关键词
林分空间结构/结构方程模型/综合评价/城郊森林公园Key words
stand spatial structure/structural equation model/comprehensive evaluation/suburban forest park引用本文复制引用
基金项目
山西省基础研究计划项目(202103021224142)
山西省基础研究计划项目(202103021224144)
山西省太原市植物园横向项目(2022HX095)
&&(2024QT002)
出版年
2024
国家科技期刊平台
NSTL
万方数据