Community assembly
Environmental filtering and species interactions are two key processes that govern the assembly of ecological communities, each acting as agents of selection on functional traits. Traits are heritable properties of plants that impact their performance and fitness. We study how traits differ among and within species, how they influence demographic rates and drive species sorting along environmental gradients, and how they determine the outcome of species interactions.

Restoration ecology
The restoration of degraded ecosystem structure, function, and composition is one of the most important applied challenges for ecology. The science of restoration ecology strives to develop general principles to guide the practice of restoring ecosystems. We have worked to restore wetlands in Michigan, dry prairies in Pennsylvania, ponderosa pine and mixed conifer forests in Arizona, and temperate rainforests of New Zealand. Our long term goal is to develop empirically-sound trait-based methods to the restore urban and wild landscapes.

Ecological modeling
Mathematics is the language of science. We cannot advance our understanding of Nature without quantifying evidence and testing hypotheses. Models allow us to make predictions, and evaluating our models in light of empirical data permits us to test what we believe to be true. We develop predictive models of community assembly so that we can predict how species will respond to environmental change and react to novel species interactions in a rapidly changing world.