Functional assembly of tropical montane tree islands in the Atlantic Forest is shaped by stress-tolerance, bamboo-presence and facilitation

Aims: Amidst the Campos de Altitude (Highland Grasslands) in the Brazilian Atlantic Forest, woody communities grow either clustered in tree islands or interspersed within the herbaceous matrix. The functional ecology, diversity and biotic processes shaping these plant communities are largely unstudied. We characterised the functional assembly and diversity of these tropical montane woody communities and investigated how they fit within Grime’s CSR (C – competitor, S – stress-tolerant, R – ruderal) scheme, what functional trade-offs they exhibit and how traits and functional diversity vary in response to bamboo presence/absence. Methods: To characterize the functional composition of the community, we sampled five leaf traits and wood density along transects covering the woody communities both inside tree islands and outside (i.e. isolated woody plants in the grasslands community) . Then, we used Mann Whitney test, t-test and variation partitioning to determine the effects of inside vs...研究目的：在巴西大西洋森林的高地草原（Campos de Altitude）生境中，木本植物群落要么以簇状树岛（tree islands）的形式分布，要么散布于草本植被基质内。目前，塑造这类植物群落的功能生态学机制、物种多样性及生物过程仍未得到充分研究。本研究对这些热带山地木本群落的功能组装与多样性进行了系统表征，并探讨了其如何契合格里姆（Grime）的CSR策略分类体系（C代表竞争者、S代表耐胁迫者、R代表杂草型），分析此类群落所展现的功能权衡关系，同时探究功能性状与功能多样性如何响应竹子的存在与否。 研究方法：为表征群落的功能组成，我们沿着覆盖树岛内及树岛外（即草原群落中孤立分布的木本植物）木本群落的样带，采集了5种叶片性状及木材密度数据。随后采用曼-惠特尼U检验（Mann Whitney test）、t检验（t-test）及变异分割分析（variation partitioning），以确定树岛内与树岛外木本群落的差异效应