Page 91 - 《广西植物》2023年第7期
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7 期 李大标等: 浙江遂昌马尾松林物种和谱系 β 多样性驱动因子分析 1 2 5 9
( 1. Natural Resources and Planning Bureau of Suichangꎬ Lishui 323300ꎬ Zhejiang ꎬ Chinaꎻ 2. College of Life Sciencesꎬ Zhejiang Universityꎬ
Hangzhou 310058ꎬ Chinaꎻ 3. Suichang Ecological Forestry Development Centerꎬ Lishui 323300ꎬ Zhejiangꎬ Chinaꎻ 4. Wuyanling National
Nature Reserve Administration of Zhejiangꎬ Wenzhou 325500ꎬ Zhejiang ꎬ Chinaꎻ 5. Zhejiang Academy of Forestryꎬ Hangzhou 310023ꎬ
Chinaꎻ 6. College of Life and Environmental Scienceꎬ Wenzhou Universityꎬ Wenzhou 325035ꎬ Zhejiang ꎬ China )
Abstract: Habitat filtering and dispersal limitation are the main ecological processes affecting species composition
variation ( β diversity) in forest communitiesꎬ but their relative importance in subtropical Masson pine ( Pinus
massoniana) forests remains unclear. Jointly analysis of how phylogenetic and species β diversity varies with habitat
factors and geographic distance is critical to understand the roles played by historical and current ecological processes in
shaping the regional biodiversity. In this studyꎬ 37 Masson pine forest plots in Suichang Countyꎬ Zhejiang Province were
selected to analyze the species and phylogenetic β diversitiesꎬ and the main ecological mechanisms driving the
differences of species composition among communities were explored. Species β diversity index ( Bray ̄Curtis) and
phylogenetic β diversity index (the mean phylogenetic dissimilarityꎬ Dnnꎻ the mean nearest taxon distanceꎬ Dpw) were
calculatedꎬ and their correlation with habitat factors including soil and topographyꎬ as well as geographical distance were
analyzed. The relative importance of habitat factors and geographical distance on species and phylogenetic β diversity was
analyzed by variance partitioning. In additionꎬ two life stages (divided by diameter class) and growth form were for the
same analyses. The results were as follows: (1) Bray ̄Curtis index significantly correlated with soil factorsꎬ topographic
factors and geographical distance. Dnn correlated with geographical distance only. Dpw correlated with soil factors and
geographical distance. (2) The explanatory degree of habitat factors to Bray ̄Curtis and Dpw was higher than that of
geographical distance. (3) For species diversityꎬ habitat factors could better explain Bray ̄Curtis of both life stages than
geographical distance. For phylogenetic diversityꎬ geographical distance could better explain Dnn and Dpw of sapling
stageꎬ while habitat factors were more likely to explain Dpw of adult stage. To concludeꎬ The results show that habitat
filtering is the main ecological mechanism driving species and phylogenetic β diversity of Masson pine forests in this
region. Dispersal limitation plays a dominant role in the β diversity of Masson pine forests only at the sapling stage. The
most important finding of this research is that the main mechanism drives for species and phylogenetic β diversity in
Masson pine forests are differentꎬ which highlights the necessity of joint analysis of species and phylogenetic β
diversity. This research also suggests that the main ecological mechanism drives β diversity may change as plants shift
across different growth stages.
Key words: Masson pine forestꎬ dispersal limitationꎬ beta diversityꎬ phylogenetic structureꎬ species composition
β 多样性是指沿着某一环境梯度的物种替代程 是由二者共同驱动形成( Qianꎬ et al.ꎬ 2013ꎻShi et
度ꎬ反映了群落物种组成的周转情况ꎬ它连接了局 alꎬ 2021)ꎮ 只不过ꎬ随着群落和尺度的变化ꎬ两种
域(α 多样性) 和区域(γ 多样性) 尺度上的物种多 生态机制对群落 β 多样性形成和维持的相对重要
样性ꎬ对其形成和维持机制进行分析可以揭示推动 性存在差异ꎮ 因地理距离而造成的扩散限制和生
群落构建的生态过程(Whittakerꎬ 2019)ꎮ 当前ꎬ主 境因子塑造的生态位稳定性共同影响了物种分化
要有两种理论解释群落 β 多样性形成和维持机制: 和形成 的 过 程ꎬ 进 而 塑 造 了 群 落 的 多 样 性 格 局
一种认为某种生境对具有适应该生境性状相似的 ( Swenson et al.ꎬ 2007ꎻ Graham & Fineꎬ 2008ꎻ
一类物种进行了选择ꎬ即生境因子在空间上的变异 Swensonꎬ 2013)ꎮ 因此ꎬ通过分解各种因子的贡献ꎬ
驱动ꎬ这一过程被称为生境过滤ꎻ另一种则认为物 可以阐明生境过滤和扩散限制两种机制在群落构
种本身ꎬ尤其是扩散限制的作用驱动了群落 β 多样 建过程中的相对影响(Shi et al.ꎬ 2021)ꎮ
性格局ꎮ 扩散限制即种子在离开母体后ꎬ因传播距 群落的物种组成实际上是长期进化与短期生
离有限等原因而无法到达合适的萌发地点的过程 态过程 共 同 作 用 的 结 果 ( Whittaker et al.ꎬ 2001ꎻ
(李宁等ꎬ2011)ꎮ 然而ꎬ最近的研究表明ꎬ群落 β 多 Ricklefsꎬ 2004)ꎮ 以往许多关于群落 β 多样性的研
样性格局不是由生境过滤或扩散限制单独解释ꎬ而 究往往基于物种分类数据ꎬ但不同物种之间在进化