DISSERTATION RESEARCH: Community trait responses to environmental variation: assessing the roles of species turnover, genetic differentiation, and phenotypic plasticity

气候变化和其他人为影响正在导致世界各地植物群落的结构和组成发生巨大变化。预测这些变化对生态学家来说是一个严峻的挑战。植物如何应对不断变化的环境条件取决于它们的生态特征或性状，如叶和茎的特征和高度。环境的变化可能会有利于具有与当前特定地点不同性状的植物，植物群落可能会以多种方式对这些变化做出反应。第一，具有适应新条件的特性的物种的存在和相对丰度可能增加（物种更替）。第二，已经存在于该地点的物种可能通过其特征的遗传变化（进化）来适应。第三，个体可能能够调整自己的性状以适应新的环境（表型可塑性）。本研究的目标是解开物种周转，进化和表型可塑性的社区对环境变化的反应中的作用，使用北美东部的老田植物群落作为一个研究系统。研究人员将把对从安大略南部到北方佛罗里达北部的旧田社区的联合收割机实地调查与移植实验结合起来，以确定植物性状如何对气候和土壤变化作出反应。通过这项研究获得的知识将提高我们预测生物多样性和生态系统功能变化的能力，以应对未来的气候变化，这些问题对社会具有深远的意义。该项目将为气候-植被模型生成有价值的数据，这些数据将通过在线数据库与世界各地的研究小组共享。该项目还将促进与北美东部研究站和自然保护区的科学家和土地管理人员的合作，并提供生态数据，为这些地点的保护，教育和未来研究提供信息。可利用的老农田生态系统将提供极好的机会，将研究与教育联系起来。调查人员将带领当地中学生在研究地点进行自然漫步，向他们介绍旧田社区的生物多样性，同时教授生态系统概念。该研究还将允许本科生参与实地，实验室和温室的研究，并开发独立的论文项目。

Climate change and other anthropogenic influences are causing dramatic alterations in the structure and composition of plant communities worldwide. Predicting these changes is a critical challenge for ecologists. How plants respond to changing environmental conditions depends on their ecological features or traits, such as leaf and stem characteristics and height. Changes in the environment may favor plants with different traits than the ones currently present in a given site, and plant communities may respond to these changes in multiple ways. First, there may be increasing presence and relative abundance of species with traits adapted to the new conditions (species turnover). Second, species already present in the site may adapt through genetic changes in their traits (evolution). Third, individuals may be able to adjust their traits in order to fit the new environment (phenotypic plasticity). The goal of this research is to disentangle the roles of species turnover, evolution, and phenotypic plasticity in community responses to environmental change, using old-field plant communities of eastern North America as a study system. The investigators will combine field surveys of old-field communities from southern Ontario to northern Florida with transplant experiments to determine how plant traits respond to variation in climate and soils. The knowledge gained through this research will improve our ability to predict changes in biodiversity and ecosystem functioning in response to future climate change, issues of profound importance to society. The project will generate valuable data for climate-vegetation models, which will be shared with research groups worldwide via online databases. The project will also facilitate collaborations with scientists and land managers at research stations and nature preserves across eastern North America and provide ecological data that will inform conservation, education, and future research at these sites. The accessibility of old-field ecosystems will provide excellent opportunities to link research with education. The investigators will lead local middle school students on nature walks through research sites, introducing them to the biodiversity of old-field communities while teaching ecosystem concepts. The study will also allow undergraduate students to participate in research in the field, lab, and greenhouse and develop independent thesis projects.