My research aims to understand the ecology of plant communities, with a particular interest in plant-pollinator interactions and the development of novel quantitative methods.
Effects of within-species variation in plants on associated communities and ecosystem processes
Not all individuals of a species are exactly the same; this is an obvious statement, but for many years, within-species variation was under-appreciated. Spurred on by the now-established field of community genetics, within-species genetic variation is recognized as a driver of community structure and ecosystem processes (Genung et al. Functional Ecology 2011). My PhD focused on indirect genetic effects (IGEs), which occur when the expression of genes in one individual affects the phenotype of an interacting individual. To my knowledge, my co-authors and I were the first to apply IGEs, which were well-established in behavioral ecology, to plant-plant interactions. We showed that IGEs between interacting plants could impact above- and below-ground biomass (Ecology Letters 2012, Ecology and Evolution 2013), herbivory (Oecologia 2012), pollinator visitation (Ecology Letters 2012, PLoS ONE 2010), decomposition rates (PLoS ONE 2013), and nutrient cycling (PLoS ONE 2013). Following the publication of this research, I was invited to write an article for The Scientist describing the many ways IGEs can manifest themselves in a range of biological disciplines (The Scientist 2014).
Effects of plant genotypic diversity on plant-pollinator interactions
Plant genotypic diversity (the number of unique genotypes in an area) can affect the number of pollinator visits received by a focal plant. This may be due to the overall increased productivity of plants growing in genotype mixtures, as plant in mixtures can produce more floral biomass and thus attract more visitors (PLoS ONE 2010). However, pollinator visitation is sometimes increased due to interactions between particular plant genotypes even in the absence of increases in floral biomass (Ecology Letters 2012). This may be due to synchrony in flowering time between neighboring plants, as plants with prolific floral displays may attract visitors when benefit neighboring plants. These genotype interactions have the potential to alter the coevolutionary dynamics of the interacting plants (Functional Ecology 2011), if the differences in pollinator visitation have consequences for plant fitness.
Application of the Price equation to ecological questions
Many experiments have examined the relationship between biodiversity and ecosystem function and have greatly expanded our understanding of the importance of biodiversity. But ecosystem services are delivered in real ecological systems, in which community composition, abundance, and evenness vary considerably and unpredictably across sites. The Price equation is a promising approach for disentangling the drivers of ecosystem services in real-world systems, because it is applicable to any ecosystem service regardless of the structure of the community that provides the service, and does not require experimental monocultures. However, the method is not as widely-used as it could be.
I have four specific goals in this area: 1) apply existing Price equation methods to large real-world data sets to demonstrate the value of the approach, 2) develop new, focused methods that use the Price equation to understand specific mechanisms underlying the biodiversity-ecosystem services relationship. For the first two goals, I am working with Rachael Winfree and Jeremy Fox to develop a new partition of the Price Equation that can examine differences in the temporal variance of pollination services across different sites, and determine the ecological processes (e.g., random species loss, non-random species loss, context-dependent differences in abundance across sites) or particular species responsible for stable ecosystem service delivery.
In the future, I hope to 3) clarify the relationship between the output data generated by the Price equation and established ecological concepts, and 4) provide a step-by-step guide that allows ecologists to understand the type of data required to use the Price equation, the decision-making process the is necessary for setting up and interpreting the analysis, and different options for combining and/or simplifying the Price equation output to better address particular ecological questions.
Do genetic and species-level differences affect plant range shifts caused by climate change?
Predicting the responses to species and communities to climate change is critically important. Along with Joe Bailey, I helped organize a special feature for Functional Ecology that included papers on the genetic mechanisms and evolutionary consequences of plant range shifts that are induced by climate change. In our contribution (Bailey et al. 2014, Functional Ecology), we suggested that indirect genetic effects (effects of the phenotype of one individual due to the expression of genes in a different individual), which can drive plant-soil feedbacks, local adaptation and genotypic diversity effects, just to name a few, will be important to understanding the consequences of climate change.