Plant neighborhoods & herbivory
Plants grow in complex communities. Not only are they attacked by a variety of insects - caterpillars, beetles, aphids, you name it - but their risk of attack can change just based on who their next-door neighbor is. A weedy plant that produces potent toxins in its leaves might not just protect itself, but also adjacent, less toxic hosts. These "neighbor" effects are ubiquitous -from terrestrial to marine ecosystems, from forests to fields of corn. This has led to a focus on understanding the mechanisms underlying neighbor effects, as well as the consequences for communities and the evolution of plant traits.
As a graduate student at Cornell, I combined observational and empirical methods to study neighbor effects. After documenting a pattern of neighbor effects across wetlands in upstate New York, I investigated the role of defense plasticity and competition in plant susceptibility to herbivores. You can find more details of my work in Ecosphere. |
Landscape fragmentation & population stability
How do animal movement and population connectivity change with habitat loss and fragmentation? This has been a challenging question for landscape ecologists to answer. To tackle it, we have to manipulate the amount of habitat available to animals, and how many fragments they can occupy. That is a tricky task for any scientist, and impossible to do ethically for organisms of conservation concern.
Cactus bugs to the rescue! After I graduated from college, I worked with Rob Fletcher, Brian Reichert, and a team of undergraduate students at the University of Florida to perform an ambitious field manipulation of Opuntia cactus patches in multiple landscapes. We removed patches in either random patterns (as often assumed in models) or aggregated patterns (as often occurs in the real world) and at different amounts of loss (up to 80%). Not surprisingly, habitat loss had negative effects on populations of the cactus bug Chelinidea vittiger. But even more interestingly, we could predict those negative effects best when we used habitat connectivity measures that were calculated at the scale of insect dispersal. Our results demonstrate the importance of using the natural history of your animal when assessing the impacts of fragmentation, and anticipating that habitat connectivity will mean different things for organisms that disperse at different spatial scales. |