Our Lab currently follows several lines of inquiry yet, we are also moving forward to expand our work into new exciting avenues of research. The following is a list of some of our current work and a few exciting new ideas we are starting to explore. For a more in-depth look at our research, you can visit our ResearchGate page.
Plant Chemical Diversity
Plants are the chemical factories of nature; they produce an amazing diversity of chemical compounds. The current estimation of the total number of plant species on earth is around half a million species. Each of these species produces a plethora of different chemical compounds. Nevertheless, today, one out of every four-plant species faces extinction and, for each plant species that goes extinct, dozens of natural compounds are lost forever. At the Plant Chemical Ecology Lab, we are invested in understanding the processes that forged this diversity and what is the function of this diversity in natural systems. To answer these questions, we work at multiple scales and locations.
At the population level, we are interested in understanding how the variation in plant chemical composition allows plant species to expand their range and confront new challenges as they colonize new territories or habitats. Do plants with a wider geographical range have more diverse or more effective chemical defenses?
At the species level, we investigate the role of chemical composition in the competitive ability of species. Are plants with a more diverse or more effective chemical defense composition better competitors and therefore reach higher local and regional abundances?
We are also interested in understanding how the chemical diversity of plant communities (comprised by the cumulative chemical arsenals from all plants within the community) can affect community assembly and community resilience to biotic and abiotic disturbances. Can plant community chemical diversity explain why some communities are more resilient to invasive species or recover faster after extreme natural events?
Finally, we are also very interested in understanding what forces and mechanisms give rise to the vast diversity of chemical compounds found in plants. What are the roles of environmental factors, phylogenetic constraints, hybridization and polyploidy, and species interactions on the evolution of plant’s chemical diversity?
Plant Chemical Landscapes
The variation within species is the fuel that powers evolutionary mechanisms. At the Lab we are very engaged in understanding how plant secondary metabolite composition varies across multiple biotic and abiotic gradients. We are currently exploring how factors like ontogeny, nutrient, and environmental gradients, and stress can predictably determine a species chemotype (a species chemical composition resulting from the interaction between their genome and the environment).
In close collaboration with Dr. Jay Krishnaswamy’s Lab and the Agroecology program at the Department of Earth and Environment, we explore these questions as part of the FIU’s Industrial Hemp Pilot Program.
Climate Change and Plant Defensive Chemistry
Working with local and rare plant species from the Florida Keys, we are starting to explore how climate change affects the composition of specific defensive secondary metabolites.
Latitudinal Gradient on species interactions
When the German naturalist J. R. Forster and Captain Cook sailed in search of the great southern continent known as “Terra Australis” in 1772, they had the opportunity to sample the local island floras across the Pacific. After the three-year trip, Forester published “A Voyage Round the World”. In that book, he documented that the number of plant species present in a particular island changed as they moved further south; tropical islands had more species than Antarctic islands. This is likely to be the first systematic record of a global pattern known today as the “latitudinal species diversity gradient”, where localities at lower latitudes (tropical) generally have higher species diversity than localities at higher latitudes (temperate). Since then, the latitudinal diversity gradient has fascinated ecologist and has become one of the central themes of ecological research.
Since Forster’s time, it has become clear that animal and plant diversity increases greatly as one goes towards the equator, not only on islands but on all continents as well. This pattern has raised great scientific speculation on the possible ecological and evolutionary causes and consequences of this phenomenon. Among ecologists, it is widely believed that the increase in species diversity characteristic of lower, more tropical latitudes will also increase the intensity of ecological interactions among species. Competition, predation, and parasitism are just a few examples of the biological interactions that are thought to become more intense within tropical latitudes. This increase in species interactions at lower latitudes likely imposes strong evolutionary selective pressures for mechanisms that could reduce the intensity of negative interactions. As a result, species at lower latitudes are expected to have higher levels of specialization to lessen competition, and stronger defenses to reduce predation. However, despite the major advances on documenting the latitudinal species gradient, convincing evidence on the existence of a similar pattern in the intensity of species interactions and mechanisms to alleviate their effect is still scarce.
For plants, in particular, it is expected that plant species at lower latitudes will have a greater and more diverse set of potential herbivores (animals that eat plants) and therefore, higher levels of “herbivore evolutionary pressure”. Similarly, as the herbivore evolutionary pressure increases with lower latitudes, it is also expected that plant species are likely to have evolved greater mechanical and chemical anti-herbivore defenses in response to this greater herbivore pressure. FIU’s Plant Chemical Ecology Lab is driven by the search for such evidence in plant-herbivore interactions.
Other research avenues
Our Lab is always open for collaborations and visiting students and researchers. Here is an exciting list of past and current collaborations:
-With Dr. Alan Chambers (UF): we have investigated how curing techniques affect vanilla’s final chemical composition.
-With Maria Pimeinta (PhD student): we help explore the changes in the flower scent of Guettarda species.
-With Nico Sebesta (PhD student): we help characterize and quantify the sugar composition of the extrafloral nectar sugar found in invasive ferns.