Collaborative Research: Modeling Successional Vegetation Dynamics in Wet Tropical Forests at Multiple Scales: Integrating Neighborhood Effects, Functional Traits, and Phylogeny

人们提出了几种机制来解释热带森林中物种数量之多。这些过程的结果，其中可能包括随机或非随机因素，可能反映在进化历史和功能性状（植物大小，叶片大小，开花模式等）的分布。在一个社区里。由于它们反映了“社区集会的行动”，演替热带森林（在干扰后发展）提供了一个理想的自然实验室，以测试社区集会的综合多方面方法的力量。利用在哥斯达黎加和波多黎各的次生林和成熟林中收集的数据，拟议的研究将开发一种新的方法来理解社区集会，将整合详细的森林清查数据。这种方法将被用来评估相对重要性的生境差异，生态位差异，并缺乏幼苗在不同的空间尺度和生命史阶段驱动热带森林群落组装。本研究的主要目的是：（1）比较物种水平的系统发育模式，（2）比较物种水平的系统发育模式，（3）比较物种水平的系统发育模式，（4）比较物种水平的系统发育模式演替和成熟森林群落之间植物的（进化）关系和功能相似性;（2）通过复杂的树木死亡和生长模型，将功能性状和系统发育结构与种群和群落动态联系起来，和（3）评估募集限制的作用以及功能和系统发育相关性在预测物种和阶段中的相对重要性在许多热带国家，次生林现在的覆盖面积超过了现存的原始森林，是保护生物多样性和提供生态系统服务的热带景观中越来越重要的组成部分。迫切需要对这些森林群落是如何组装的机械理解。作为该项目的一部分，将发现植物之间的进化关系，这将有助于加深对被子植物进化历史的理解。将培养两名博士研究生、一名博士后研究员，以及来自美国联邦系统最大的拉美裔机构波多黎各大学的本科生。

Several mechanisms have been proposed to explain the high number of species present in tropical forests. The outcome of these processes, which could include random or non-random elements, may be reflected in the evolutionary history and distribution of functional traits (plant size, leaf size, flowering pattern, etc.) in a community. Because they reflect "community assembly in action", successional tropical forests (developing after a disturbance) provide an ideal natural laboratory for testing the power of an integrated multi-faceted approach to community assembly. Using data collected in secondary and mature forests in Costa Rica and Puerto Rico, the proposed research will develop a novel approach to understanding community assembly that will integrate detailed forest inventory data. This approach will be used to assess the relative importance of habitat differences, niche differences, and lack of seedlings in driving tropical forest community assembly at different spatial scales and across life history stages. Coordinated data collection will allow for comparisons of functional traits across successional stages within a context of the plants' evolutionary history, which will be reconstructed using DNA bar-coding technology.The major objectives of this research are to (1) compare patterns of species-level phylogenetic (evolutionary) relationships and functional similarity of plants between successional and mature forest communities; (2) link functional traits and phylogenetic structure with population and community dynamics through sophisticated models of tree mortality and growth, and (3) assess the role of recruitment limitation and the relative importance of functional and phylogenetic relatedness in predicting species- and stage-specific population dynamics during succession.Secondary forests now cover more area than remaining old-growth forests in many tropical countries and are increasingly important components of tropical landscapes for biodiversity conservation and provision of ecosystem services. A mechanistic understanding of how these forest communities are assembled is urgently needed. The evolutionary relationships among plants that will be discovered as part of this project will contribute to a deepening understanding of the angiosperm evolutionary history. Two doctoral graduate students, one postdoctoral researcher, and undergraduate students from the University of Puerto Rico, the largest Hispanic institution in the US federal system, will be trained.