How do so many types of organisms persist on a small number of shared resources?
Organisms compete with their neighbors–both individuals of the same and different species–-for resources. Through recent theoretical and empirical advances, we’ve come to understand the mechanisms that maintain the incredible diversity of species that we observe in competitive communities. However, these competitor species are themselves resources for consumers, and many hypotheses for the origin of diversity depend. Modern coexistence theory has shown that consumers can be a potent force in both the maintenence and erosion of diversity, yet the empirical literature has substantially lagged these advances. Though consumers have been implicated in the origin of species diversity for more than a half-century, their role in the maintenance of diversity remains an open question.
The primary focus of my postdoctoral research is to understand how variation in interactions with consumers affects species diversity in competitive communities. To do this, I work with a well-studied community of competing winter annual plant species and their seed-consumers at the University of California’s http://sedgwick.nrs.ucsb.edu/. I am developing new mathematical models of plant population dynamics and collecting field data to parameterize them. By casting the dynamics of plant populations in a multi-trophic community context, I account for the effects of both direct consumer-prey interactions and indirect interactions between prey competitors through shared consumers (i.e., apparent competition and apparent facilitation). This work respresents one of the first formal empirical tests of coexistence theory in a multi-trophic context.
Collaborators:
- Jonathan Levine, ETH Zurich
- Nathan Kraft, UCLA
- Oscar Godoy, Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS-CSIC)
- Gaurav Kandlikar, UCLA