DISSERTATION RESEARCH: Effects of Genetic Diversity on Invasive Population Success

最近的研究表明，相同物种个体之间的遗传变异是生物多样性的一种重要形式，可以提供生态服务，如增加植物生物量生产和调节营养循环。然而，造成这些影响的机制在很大程度上还没有被探索出来。本研究项目重点研究了遗传多样性影响生态功能的两种机制。首先，它将检验互补性假说，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，基因多样性的增加会增加一个系统包含高功能或多产基因的机会。为了评估这些机制的相对重要性，入侵草地燕麦种群的遗传多样性将被直接操纵并在不同的资源环境中生长。我们将把单一基因型群体与遗传混合群体进行比较，以评估哪些机制推动了积极的多样性效应。这项实验将在多代人中进行，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做出贡献的机制。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开发。此外，这项研究将通过公开演讲和每周高中课堂参与NSF GK-12传播性科学奖学金产生教育影响。本科生研究人员将在相关的独立研究项目中得到积极指导。该项目将加强一名博士生的科研培训。

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.