International Research Fellowship Program: Phylogenetic Structure of Sedge Communities in a Quebec Old-Growth Forest

[00:19 . 16]国际研究奖学金计划使美国科学家和工程师能够到国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Kathryn M. Flinn博士与加拿大麦吉尔大学的Martin J. Lechowicz博士进行为期24个月的研究。随着人类活动威胁到世界范围内物种的持续存在，保护生物多样性的努力迫切需要更好地了解其背后的模式和过程。物种丰富的群落是如何形成和维持的？这么多关系密切、生态相似的物种是如何共存的呢？具有相同生态特征的相关生物可能竞争更激烈，共同发生的频率更低（即系统发育过度分散），或者它们可能分类到相似的栖息地（系统发育聚类）。竞争也可能促进近亲之间在栖息地亲缘关系和分布模式上的分化。因此，了解群落的系统发育结构和生态特征的进化可以为研究群落组织提供独特的见解。本项目研究了森林林下植物群落的系统发育和生态结构，以解决这些群落如何聚集和功能的问题。以加拿大魁北克省圣伊莱尔山（Mont St. Hilaire）原生林苔草属苔草（Carex）为研究对象，分析了物种亲缘性和生态相似性之间的关系，包括功能特征和沿环境梯度的分布模式。55种苔属植物生活在山上不同的植物群落中，提供了10平方公里的完整栖息地，这个多样化属的详细、健全的系统发育使得对生态特征进化如何影响群落组织的假设进行有力的测试成为可能。该项目的两个主要目标是评估沿着圣希莱尔山环境梯度的苔属植物组合的系统发育结构，并描述该属内姐妹物种对的栖息地亲和力。收集有关植物群落组成、系统发育关系、环境条件和植物功能性状的信息将有助于检验两组假设。1. 在邻域尺度上，苔草群落表现出比景观尺度更大的系统发育过度分散；在姐妹种之间比在较大的分支之间；在潮湿的低地森林中比在高地森林中；和2。姐妹物种的生态相似性比亲缘关系较远的物种要低，特别是在湿地进化支系中。该项目通过整合系统发育、生态和环境信息，以一种新颖的方法来解决生态学中的一个基本问题，将有助于更好地了解群落结构的进化基础。

0601916FlinnThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Kathryn M. Flinn to work with Dr. Martin J. Lechowicz at McGill University of Canada.As human activities threaten the persistence of species worldwide, efforts to preserve biological diversity urgently need a better understanding of the patterns and processes underlying it. How do species-rich communities originate and maintain themselves? How can so many closely related, ecologically similar species coexist within them? Related organisms that share ecological traits may compete more strongly and co-occur less often (i.e., phylogenetic overdispersion), or they may sort into similar habitats (phylogenetic clustering). Competition may also favor divergence among close relatives in habitat affinities and distribution patterns. Understanding both the phylogenetic structure of communities and the evolution of ecological traits can thus provide unique insights into community organization.This project investigates the phylogenetic and ecological structure of forest understory plant communities in order to address questions about how these communities assemble and function. It assesses the relationships between species' relatedness and their ecological similarity, including both functional traits and distribution patterns along environmental gradients, for the sedge genus Carex in the old-growth forest at Mont St. Hilaire, Quebec. Fifty-five Carex species live within the various plant communities on the mountain, which provides a 10 km2 area of intact habitat, and a detailed, robust phylogeny for this diverse genus makes possible powerful tests of hypotheses about how the evolution of ecological traits affects community organization. The project's two main goals are to assess the phylogenetic structure of Carex assemblages along environmental gradients at Mont St. Hilaire, and to characterize the habitat affinities of sister-species pairs within the genus. Gathering information on plant community composition, phylogenetic relationships, environmental conditions and plant functional traits will allow for testing two sets of hypotheses. 1. Carex communities show greater phylogenetic overdispersion at the neighborhood scale than at the landscape scale; between sister species than among larger clades; and in wet, lowland forests than in upland forests; and 2. Sister species show less ecological similarity than more distantly related species, particularly within the wetland clade. Taking a novel approach to an fundamental problem in ecology by integrating phylogenetic, ecological and environmental information, this project will contribute to a better understanding of the evolutionary basis of community structure.