评估径阶距对天然林空间结构多样性的影响  

Effects of Diameter Size Classe on Stand Spatial Structure of Natural Forests

作　　者：韦丽婷 黎明慧 李远发[1,3] WEI Liting;LI Minghui;LI Yuanfa(Guangxi Key Laboratory of Forest Ecology and Conservation,Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation,College of Forestry,Guangxi University,Nanning 530004,Guangxi,China;Dongmen State-Owned Forest Farm of Guangxi Zhuang Autonomy Region,Chongzuo 532199,Guangxi,China;Laibin Forest Ecosystem Observation and Research Station of Guangxi.Laibin 545700,Guangxi,China)

机构地区：[1]广西大学林学院,广西森林生态与保育重点实验室,广西高校亚热带人工林培育与利用重点实验室,广西南宁530004 [2]广西壮族自治区国有东门林场,广西崇左532199 [3]来宾金秀大瑶山森林生态系统广西野外科学观测研究站,广西来宾545700

出　　处：《西北林学院学报》2025年第2期177-189,共13页Journal of Northwest Forestry University

基　　金：国家自然科学基金(32060340);来宾金秀大瑶山森林生态系统广西野外科学观测研究站科研能力建设项目(桂科22-035-130-01)。

摘　　要：尽管径阶距不像生物或非生物因子参与林分生长过程,但它关乎径阶结构,并可能影响径阶上结构多样性的分析结果。本研究在中国西南地区南盘江流域天然林中建立了3块固定样地,包括次生林[样地A(30 a)、样地B(57 a)]和原始林[样地C(300 a)],以2、3、4 cm和5 cm为径阶距划分树木直径,并分析径阶距与样方水平、径阶水平上树木的分布格局、大小分化和树种混交的关系。结果表明:1)角尺度很少受径阶距影响;2)在样方水平上,混交度的分布受径阶距的影响也很小,但当径阶距为2~4 cm时原始林的混交度与样地B的差异明显(P_(KW)<0.05)。在径阶水平上,原始林的混交度和2块次生林的差异明显;3)样方水平上各径阶距的树木大小分化曲线几乎重叠。当径阶距为2、3 cm时,原始林的大小比数与样地B的差异明显,而原始林和2块次生林的大小分化度则是在2~4 cm径阶距上差异显著。大小分化度在径阶水平上的结果与样方水平相反。研究结果表明,径阶距对林分内空间结构多样性几乎没有影响,但森林演替会加大其影响程度,同时小径阶距能更敏感地反映林分之间的结构差异,对指导异龄林的经营和评估其经营效果具有重要意义。Although diameter size classes may not be as directly involved in the growth process of forest stands as biotic or abiotic factors,they are crucial to diameter structure and may influence the analysis of structural diversity of diameter classes.Three fixed plots were established in natural forests in the Nanpan River Basin,southwest China,including two secondary forests[Plot A(30 a),Plot B(57 a)]and a virgin forest[Plot C(300 a)].Tree diameter distributions were classified by diameter size classes of 2,3,4,and 5 cm,respectively.The relationships between diameter size classes and distribution patterns,size differentiation,and species mixture at the plot and diameter class levels were analyzed.The results were as follows.1)Uniform angle index was less influenced by diameter size class.2)At the plot level,the distribution of species mixture was rarely affected by diameter size class.However,when the diameter size class was in the range of 2-4 cm,there were significant differences in species mixture between the virgin forest and Plot B(P_(KW)<0.05).At the diameter class level,there was a significant difference in species mixture between the virgin forest and two secondary forests.3)The size differentiation curves for trees at various diameter size classes at the plot level almost over lapped.Differences in dominance between the virgin forest and Plot B were significant at diameter size classes of 2 and 3 cm,while size differentiation between the virgin forest and secondary forests were significant at diameter size classes of 2-4 cm.The results at the diameter class level were opposite to those at the plot level.It is concluded that the diameter size class has little impact on spatial structure diversity within forest stands,while its influence could be magnified during the period of forest succession.Smaller diameter size classes are more sensitive to the changes of forest stand structure,which is crucial for guiding the management of uneven-aged forests and evaluating their management effectiveness.

关 键 词：天然林 径阶距 直径分布 大小分化度 角尺度 树种混交 

分 类 号：S718.54[农业科学—林学]