I am interested in how ecological communities assemble, maintain, change, and collapse. I use quantitative models, experimental manipulations, and observational experiments to explore how anthropogenic change influences the structure and dynamics of communities at the local scale and how this translates to changes in large-scale biodiversity patterns. My research currently focuses on the following projects:

Pine Rockland Food Web Networks

photo courtesy of Emily SessaThe pine rockland ecosystem of south Florida is one of the most critically imperiled ecosystems on earth. Pine rocklands remain on only 2% of their historic range due to habitat fragmentation, fire suppression, and invasive species. Conservation and restoration of the pine rockland ecosystem requires a modern whole-ecosystem approach that considers not only habitat restoration, endangered species, and invasive species, but relationships between them. Ecological networks, which depict ecological interactions (e.g., predation) as links between species, provide a framework for measuring and tracking linkages between organisms and implementing ecosystem-level conservation. In collaboration with Emily Sessa (University of Florida, Biology Department), Jiri Hulcr (University of Florida, School Forest Resources and Conservation), and the Institute for Regional Conservation, we are using DNA barcoding to develop plant-herbivore food webs for the pine rockland ecosystem. We aim to explore how food web structure changes across pine rockland fragments. This project is funded by the Eppley Foundation for Research.

photo courtesy of Emily Sessaphoto

An integrative approach to quantifying the response of ecological assemblages to anthropogenic stressors

Biodiversity is a multidimensional concept that refers to variation in life forms. While species richness, the number of species in a given location, is commonly used to quantify biodiversity, it does not necessarily reflect the variation in organismal diversity. For example, species may differ in their abundances, ecological function, evolutionary history, and their interaction patterns (e.g., what other species they eat, compete with, or pollinate). Ignoring these differences when assessing the impact of anthropogenic stressors may lead to grossly incorrect conclusions. I am working with Denis Valle (University of Florida, School Forest Resources and Conservation), Tamer Kahveci (University of Florida, Department of Computer and Information Science) and Gordon Burleigh (University of Florida, Department of Biology) to develop new computational approaches that integrate multiple types of biodiversity data to better understand how ecological communities are altered by anthropogenic change. We are utilizing a variety of data sets including data on pitcher plant food webs, island bird communities, and tropical forest tree communities. This project is funded by the National Science Foundation- Advances in Biological Informatics.

Northern Pitcher Plant Food Web

Photo courtesy of Aaron Ellison The northern pitcher plant, Sarracenia purpurea, is a carnivorous plant that inhabits nutrient-poor bogs from northern Florida up the east coast of North America and across Canada. The plant possesses tubular leaves that open during the growing season and fill with water. Upon opening, the leaves capture invertebrate prey that serves as the base of a complex food web containing bacteria, protozoa, and macroinvertebrates. The food web decomposes prey items captured by the plant, releasing essential nutrients to the plant. Due to its tractable nature and geographic range, the aquatic food web found in the leaves of the S. purpurea is a model system in community ecology. The continental distribution of the Sarracenia system provides the opportunity to explore the network structure and functioning of food webs from the local to the continental scale. In addition to field observations and experiments, I culture pitcher plant species and reassemble food webs in greenhouse experiments to study how food web structure effects population dynamics, decomposition, and species invasions.

Using intraspecific trait variation to understand processes structuring continental-scale biodiversity patterns

Understanding variation in the internal and external drivers of community composition across taxa and systems informs both ecological theory and conservation, particularly regarding the resilience and composition of ecological communities in the face of rapid global change. For this project, my collaborators and I use National Ecological Observatory Network (NEON) data on intraspecific trait variation, collect additional measurements from NEON organismal samples, and compile additional data related to NEON sites and samples (e.g., phylogenetic community structure) to determine how assembly processes internal to the community (e.g., biotic interactions, microenvironmental heterogeneity) and large-scale assembly processes external to the community (e.g., climate, land use) combine to affect intraspecific trait variation and community structure at a continental scale. I collaborate with Phoebe Zarnetske (Michigan State University) Angela Strecker (Portland State University) Sydne Record (Bryn Mawr College), Lydia Beaudrot (University of Michigan), Yoni Belmaker (Tel Aviv University), and Mao-Ning Tuanmu (Yale) on this project which is funded by the National Science Foundation- Division of Environmental Biology.