Our lab focuses on a wide range of chemically mediated ecological interactions. We are particularly interested in the role of plant chemistry in structuring diverse ecological communities. We utilize a multidisciplinary approach that combines field and laboratory approaches with the latest spectroscopic tools in organic chemistry to address basic ecological questions.
Phytochemical diversity and species diversity - Plants produce a diverse mixture of chemical defenses to reduce biomass loss to herbivores. By producing multiple secondary compounds plants create a complex chemical profile, which is more difficult for herbivores to adapt to, hence escaping herbivore pressure.
Our research focuses on understanding the causes and consequences of phytochemical diversity on ecological interactions. Compounds within these diverse mixtures are often found to act synergistically, meaning that the combined effects of multiple compounds are greater than the sum of effects for the individual compounds. The synergistic effects of multiple plant secondary metabolites on upper trophic levels constitute an underexplored but potentially widespread component of coevolution and ecological interactions. We are interested in quantifying these synergistic effects on generalist and specialist herbivores (lepidopteran larvae) and the effects the third trophic level.
Our research focuses on understanding the causes and consequences of phytochemical diversity on ecological interactions. Compounds within these diverse mixtures are often found to act synergistically, meaning that the combined effects of multiple compounds are greater than the sum of effects for the individual compounds. The synergistic effects of multiple plant secondary metabolites on upper trophic levels constitute an underexplored but potentially widespread component of coevolution and ecological interactions. We are interested in quantifying these synergistic effects on generalist and specialist herbivores (lepidopteran larvae) and the effects the third trophic level.
Diet specialization in woodrats - The overall goal of the woodrat project is to identify how the differences in the genetic and metabolomic pathways associated with detoxification of plant secondary metabolites maintains two species of woodrats across a hybrid zone.
A network visualizing relationship between plant diet, woodrat species (one that live on the hills "H" and one that live on the flats "F") and fecal chemical profiles.
Fire and interaction diversity - Longleaf pine (Pinus palustris) forests are classic fire adapted systems in that they are dependent on fire to maintain forest structure, interactions, and levels of diversity that define these forests. While role of fire in maintaining plant diversity in these ecosystems is well documented, less is known about the impacts of fire on arthropods in any fire adapted system. Working within prescribed burns in the longleaf pine forests at Eglin Air Force Base in the Florida panhandle we investigated the effects of fire on arthropod communities.
Metabolomics -
Since Ehrlich and Raven’s (1964) influential paper on the coevolution between plant and herbivore, many studies have focused on understanding the causes and consequences of phytochemical mixtures on ecological interactions. However the challenge remains in deciphering the ecologically and biologically important compounds from diverse phytochemical mixtures. Using a network based approach, we analyzed binned proton NMR data from 200 artificial mixtures of commonly studied secondary metabolites including, alkaloids, amides, terpenes, iridoid glycosides, saponins, phenylpropene, flanvanoids and phytosterols. Within these mixtures we manipulated multiple dimensions of chemical diversity, including molecular complexity, mixture complexity and differences in the relative concentrations of each compound. This approach was then applied to crude extracts of 20 species in the phytochemically diverse tropical plant genus Piper. Using these extracts in multiple organism bioassays enabled us to identify a prenylated benzoic acid from these mixtures that exhibits antifungal properties. In addition, we identified small structural changes that had a large effect in the bioactivity. In sum, this approach allowed us to combine chemical and ecological datasets and identify potentially important biologically important compounds from crude extracts.
Since Ehrlich and Raven’s (1964) influential paper on the coevolution between plant and herbivore, many studies have focused on understanding the causes and consequences of phytochemical mixtures on ecological interactions. However the challenge remains in deciphering the ecologically and biologically important compounds from diverse phytochemical mixtures. Using a network based approach, we analyzed binned proton NMR data from 200 artificial mixtures of commonly studied secondary metabolites including, alkaloids, amides, terpenes, iridoid glycosides, saponins, phenylpropene, flanvanoids and phytosterols. Within these mixtures we manipulated multiple dimensions of chemical diversity, including molecular complexity, mixture complexity and differences in the relative concentrations of each compound. This approach was then applied to crude extracts of 20 species in the phytochemically diverse tropical plant genus Piper. Using these extracts in multiple organism bioassays enabled us to identify a prenylated benzoic acid from these mixtures that exhibits antifungal properties. In addition, we identified small structural changes that had a large effect in the bioactivity. In sum, this approach allowed us to combine chemical and ecological datasets and identify potentially important biologically important compounds from crude extracts.
