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.
