Page 26 - 《广西植物》2026年第7期
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1 1 2 2                                广  西  植  物                                         46 卷
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             WANG Xiaoyingꎬ OU Jingyaoꎬ XIAO Zixinꎬ ZHU Qiqiꎬ XIAO Jihongꎬ DENG Chuanyuan
                       ( College of Landscape Architecture and Artꎬ Fujian Agriculture and Forestry Universityꎬ Fuzhou 350002ꎬ China )

                 Abstract: To explore the assembly mechanisms of phylogenetic structures across different synusiae in Pinus massoniana

                 plantations under the unique island habitatꎬ this study focused on P. massoniana forests in the Sandu’ ao Islands of
                 Ningdeꎬ Fujian Provinceꎬ China. Based on community survey dataꎬ we calculated net phylogenetic relatedness index
                 (NRI) and net the nearest taxon index (NTI) for the treeꎬ shrubꎬ and herb layers to characterize their phylogenetic
                 structures. Spatial autocorrelation analysisꎬ regression analysisꎬ spatial lag model (SLM)ꎬ and structural equation model
                 (SEM) were comprehensively employed to parse the influence pathways and spatial effects of climaticꎬ edaphicꎬ and
                 light factors on the phylogenetic structure of each synusia. The results were as follows: (1) Significant differences in
                 phylogenetic structure were observed among synusiae: the tree layer was predominantly characterized by phylogenetic
                 overdispersionꎬ indicating weak habitat filtering and suggesting that competitive exclusion dominated its construction
                 processꎻ the shrub layer tended towards phylogenetic clusteringꎬ reflecting a strong effect of environmental filteringꎻ the
                 herb layer exhibited weak overdispersionꎬ implying more complex construction mechanisms. (2) Soil pH was the
                 dominant environmental factor regulating community phylogenetic structureꎻ alkali ̄hydrolyzable nitrogen not only had a
                 direct positive effect on the phylogenetic indices of the tree and herb layers but also served as a mediating variable for the
                 indirect effect of soil pHꎻ canopy closure exerted a significant regulatory effect on the phylogenetic structure of the tree
                 layerꎬ highlighting the critical role of light conditions in its construction. (3) The NTI of the herb layer displayed a
                 significant spatial lag effect under the environmental distance weighted matrixꎬ meaning its phylogenetic structure was
                 significantly influenced by the community composition of neighboring plotsꎻ canopy closureꎬ soil pHꎬ and wind speed
                 were the core driving factors of this spatial effectꎬ exhibiting the most significant comprehensive positive effectꎬ revealing
                 the synergistic roles of habitat heterogeneity and wind disturbance in shaping the community phylogenetic construction of
                 the herb layer. This study reveals the differentiated driving mechanisms of phylogenetic structure across different synusiae
                 of island P. massoniana plantationsꎬ and clarifies the relative contributions of environmental filtering and spatial effects
                 on island plant community constructionꎬ and provides a scientific basis for vegetation restoration and ecosystem protection
                 of P. massoniana plantations in island areas.
                 Key words: islandꎬ Pinus massoniana plantationꎬ synusiaeꎬ phylogenetic structureꎬ environmental factorsꎬ
                 spatial effect


                群落构建是生态学研究的核心问题ꎬ通常由                            增加异质性增强ꎬ物种组成相似度降低ꎻ二是空间
            竞争排斥、环境过滤和中性过程等多种机制共同                              依赖性ꎬ即群落特征受邻近单元溢出效应影响ꎬ表
            驱动(郭邵华等ꎬ2025)ꎮ 基于谱系结构的分析为                          现为空间滞后效应或空间误差效应ꎮ 空间滞后效
            揭示这些机制提供了重要视角:竞争排斥理论认                              应指群落特征本身受邻近单元特征直接溢出影响
            为ꎬ亲缘关系相近的物种因生态位相似ꎬ对有限资                             (如种子传播、化感作用)ꎻ空间误差效应则反映遗
            源的竞争更为激烈ꎬ导致近缘种难以共存ꎬ群落谱                             漏变量或随机因素导致残差的空间自相关( 刘瑜
            系结构呈发散格局ꎻ而环境过滤理论则认为ꎬ特定                             等ꎬ2023)ꎮ 国内研究证实森林群落存在显著空间
            生境筛选出具有相似适应策略的物种ꎬ这些物种                              效应ꎬ如粤北植被固碳特征的空间依赖性( 潘森源
            往往亲缘关系较近ꎬ因而群落谱系结构呈聚集格                              等ꎬ2025)ꎬ草本群落因种子传播距离短而空间自
            局(Webb et al.ꎬ 2002)ꎮ 因此ꎬ分析群落谱系结构                  相关性更强( Peng et al.ꎬ 2024)ꎮ 海岛生境中ꎬ地

            的聚集或发散特征ꎬ是推断群落构建的关键手段ꎮ                             理隔离与强风限制物种扩散ꎬ但空间效应的表现
                 植物群落作为地理空间的核心生态单元ꎬ其                           形式、驱动因子及其与谱系格局的关联尚未在海
            物种组成与结构特征是物种与环境、种间相互作                              岛马尾松林研究中被系统阐释ꎮ 因此ꎬ将谱系结
            用在空间上的综合体现ꎮ 空间效应主要包括两大                             构分析与空间效应探究相结合ꎬ是深入理解海岛
            机制:一是距离衰减效应ꎬ即环境因子随空间距离                             群落构建机制的关键途径ꎮ
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