DISSERTATION RESEARCH: Effects of Genetic Diversity on Invasive Population Success

最近的研究表明，同一物种个体之间的遗传变异是生物多样性的一种重要形式，可以提供诸如增加植物生物量生产和调节营养循环等生态服务。然而，造成这些影响的机制在很大程度上尚未被探索。本研究项目主要探讨遗传多样性影响生态功能的两种机制。首先，它将检验互补假说，该假说预测个体基因型之间的性状差异将减少竞争，增加资源分配。其次，它将检验抽样效应假说，该假说预测遗传多样性的增加会增加系统包含高功能或高产基因型的机会。为了评估这些机制的相对重要性，将直接操纵入侵草Avena barbata种群的遗传多样性并在不同的资源环境中生长。将单一基因型种群与遗传混合物进行比较，以评估哪种机制驱动积极的多样性效应。该实验将进行多代，以评估这些生态机制如何随着时间的推移与进化选择相互作用。这项研究将有助于更广泛地研究遗传多样性在生态和进化时间尺度上对种群表现和功能的影响机制。它还将阐明驱动和维持物种入侵的过程，加强预防潜在物种入侵和管理现有入侵种群的方法的发展。此外，本研究将通过公开讲座和每周高中课堂参与NSF GK-12传播科学奖学金产生教育影响。本科研究人员将在相关的独立研究项目中得到积极指导。本项目将加强博士生的研究训练。

Recent research suggests that genetic variation among individuals of the same species is an important form of biodiversity that can provide ecological services such as increasing plant biomass production and regulating nutrient cycles. However, the mechanisms responsible for these effects have been largely unexplored. This research project focuses on two mechanisms by which genetic diversity can affect ecological functions. First, it will test the complementarity hypothesis, which predicts that trait differences among individual genotypes will decrease competition and increase resource partitioning. Second, it will test the sampling effects hypothesis, which predicts that increased genetic diversity increases the chance a system contains a highly functioning or productive genotype. To assess the relative importance of these mechanisms, the genetic diversity of populations of the invasive grass, Avena barbata, will be directly manipulated and grown in differing resource environments. Single genotype populations will be compared to genetic mixtures to assess which mechanisms drive positive diversity effects. The experiment will be conducted for multiple generations to assess how these ecological mechanisms interact with evolutionary selection over time. This research will contribute to a broader literature on mechanisms by which genetic diversity can contribute to population performance and function over both ecological and evolutionary timescales. It will also elucidate processes driving and maintaining species invasions, enhancing the development of methods to prevent potential species invasions and manage existing invasive populations. Furthermore, this research will have educational impacts through public talks and weekly high school classroom involvement in a NSF GK-12 Communicating Science Fellowship. Undergraduate researchers will be actively mentored in associated independent research projects. This project will enhance the research training of a doctoral student.