不同立地类型的柏木人工林空间结构分析  

Spatial structure analysis of Cupressus funebris plantations of different site types

作　　者：鲁姝月 张小梅 罗可馨 林玉瑄 赖家明[1,3] LU Shuyue;ZHANG Xiaomei;LUO Kexin;LIN Yuxuan;LAI Jiaming(College of Forestry,Sichuan Agricultural University,Chengdu,Sichuan 611130,China;Forestry and Grassland Research Institute of Liangshan Yi Autonomous Prefecture,Xichang,Sichuan 615000,China;National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River,Chengdu,Sichuan 611130,China)

机构地区：[1]四川农业大学林学院,四川成都611130 [2]凉山彝族自治州林业草原科学研究院,四川西昌615000 [3]长江上游森林资源保育与生态安全国家林业与草原局重点实验室,四川成都611130

出　　处：《森林与环境学报》2024年第5期511-520,共10页Journal of Forest and Environment

基　　金：世界银行贷款长江流域上游森林生态系统恢复项目(2019⁃510000⁃02⁃01⁃400761);德国政府贷款四川林业可持续经营项目(G1403083)。

摘　　要：为探究不同立地类型柏木人工林的空间结构特征,以四川省梓潼县七曲山国有林场柏木人工纯林为研究对象,将15个柏木人工林标准地划分为不同的立地类型,并基于Voronoi图构建林分空间结构单元,采用角尺度、大小比数、竞争指数、开敞度和林层指数等5个指数分析不同立地类型柏木人工林的空间结构特征。结果表明:根据对优势木平均高影响显著的立地因子(坡度和土壤厚度)可将柏木人工林标准地划分成立地类型Ⅰ、Ⅱ、Ⅲ;3种立地类型的柏木林分以1株中心木与6株近邻木组成的空间结构单元最为常见;立地类型Ⅰ、Ⅱ、Ⅲ柏木人工林的角尺度平均值分别为0.39、0.37、0.38,林分整体空间分布格局呈均匀分布;大小比数平均值分别为0.49、0.50、0.51,大小分化程度相似,生长态势均为中庸;开敞度平均值分别为0.20、0.32、0.30,林分透光条件较差,生长空间不足;林层指数在3种立地类型间存在显著差异(P<0.05),立地类型Ⅲ柏木人工林在垂直方向分层最明显,立地类型Ⅰ垂直结构最简单;竞争指数在3种立地类型间存在极显著差异(P<0.01),立地类型Ⅲ林分空间竞争最激烈,立地类型Ⅰ林分空间竞争最弱。基于研究区柏木人工林现状,可根据林木生长立地类型的不同进行适当的营林活动。To explore the spatial structure characteristics of different site types of Cupressus funebris plantation,15 standard plots of Cupressus funebris plantation at the Qiqu Mountain State⁃owned Forest Farm in Zitong County,Sichuan Province were divided into different site types.The stand spatial structure unit was constructed based on Voronoi diagram,and the spatial structure characteristics at different site types were analyzed using five indices,namely:uniform angle index,neighborhood comparison,competition index,openness,and storey index of stands.The results showed that according to the site factors(slope and soil thickness)with significant influence on the average height of dominant trees,Cupressus funebris forest comprised three types of site(Ⅰ,Ⅱ,Ⅲ);of which the most common spatial structure unit of Cupressus funebris across all three site types comprised one central tree and six neighboring trees.The average uniform angle index of Cupressus funebris plantation on site typesⅠ,Ⅱ,andⅢwas 0.39,0.37,and 0.38,respectively,and the overall spatial distribution pattern was uniform;average neighborhood comparison values were 0.49,0.50,and 0.51,respectively.The size differentiation degree was similar,and the growth trend was moderate.The average openness was 0.20,0.32,and 0.30,respectively.The light transmission condition of the stands was poor,and growth space was insufficient.There were significant differences in the storey index among the three site types(P<0.05).Vertical stratification of the cypress wood plantations was most obvious at type⁃Ⅲsites and vertical structure was simplest at type⁃Ⅰsites.There were significant differences in competition index among the three site types(P<0.01).Competition for stand space was fiercest at type⁃Ⅲsites and weakest at type⁃Ⅰsites.Based on the present situation of Cupressus funebris plantation in the study area,appropriate forest activities is conducted depending on the different types of tree growth sites.

关 键 词：柏木人工林 VORONOI图 立地类型 林分空间结构 

分 类 号：S757.3[农业科学—森林经理学]