My research interests fall within two broad themes, range limits and species interactions.
What determines species’ range boundaries?
Every species does not occur everywhere – though at first glance simplistic, this observation forms the foundation of the fields of ecology and evolution. But even after centuries of investigation, there is still not a single species for which we have identified completely all the environmental components that restrict that organism to its particular geographic location. This is due to the complex suite of factors involved in structuring the distribution of species, including abiotic conditions, dispersal limitation, adaptive potential, and interspecific interactions.
Of particular interest are those processes limiting range boundaries – why do we see some species’ ranges expanding rapidly while others stand remarkably still? Explanations for static range limits fall into two broad categories: a failure to disperse outside the range boundary or a failure to adapt to novel conditions existing therein. These novel environments have been explored primarily in the context of climatic variables such as temperature and precipitation, but environments are complex and comprised of multiple abiotic and biotic factors that often covary across space. It is increasingly acknowledged that we need to look beyond climate to gain insight into factors driving the formation of range boundaries.
I’m currently exploring these questions with Clarkia xantiana (Onagraceae), an endemic Southern California wildflower. The species is comprised of two parapatric subspecies (ssp. xantiana and ssp. parviflora) whose range limits have remained stable for many generations. Through a combination of range-wide environmental sampling, field transplants, and greenhouse experiments I’m investigating how biotic and abiotic factors may interact to constrain range expansion in the species.
Pollination Ecology of Lyonia lucida
Fetterbush (Lyonia lucida) is a common coastal plain shrub of the Southeastern U.S. I first became interested in its pollination ecology while interning in the Plant Ecology Lab at Archbold Biological Station in Central Florida. Although L. lucida has showy floral displays, pollinator visits were extremely rare, even though its two congeners at Archbold receive plenty of visits from a diverse suite of Hymenoptera. I began my work with fetterbush by testing the hypothesis that thrips could be contributing to pollination, which has been found for some tropical trees and even another ericad with similar floral morphology. It ends up that thrips probably aren’t contributing significantly to seed set in fetterbush, but what I did find was even more surprising — nocturnal pollination by moths! This is strange given the floral morphology of the species and the rareness of this pollination mode in the Ericaceae. I followed this observation with a series of experimental manipulations and specimen collections, the results of which are reported in
Future work in this system will involve range-wide sampling of floral variation and pollinator assemblages, combined with experimental studies on selective pressures that might lead to pollinator switching in fetterbush.
Market Science is science outreach initiative run by a group of graduate students and post-docs at the University of Minnesota. Every Saturday during the spring, summer, and fall, we set up a “science discovery” booth at public venues across Minnesota, introducing kids and adults to a wide range of topics in the natural sciences. We mostly work at farmers markets, but also take Market Science to street fairs, county fairs, and other informal, public settings. Themes run the gamut from geology to water quality to entomology, and we always welcome new volunteers! We hope that by providing this fun, informal setting for researchers to interact with the public, we can work to narrow some of the wide achievement gaps in STEM fields, garner more public support for science, and introduce the amazing world of scientific inquiry to our broader Twin Cities communities.