I strongly believe in the importance of long-term datasets for identifying long-term trends and relationships in natural populations. During my tenure at UC Davis, I amassed a large mark-recapture dataset on two neighboring populations of California tiger salamanders at the Jepson Prairie Preserve. The California tiger salamander is an endangered species endemic to California. Due to its large habitat requirements and high land prices in California, conservation of this species is controversial. I am currently working on turning the dataset of over 30,000 capture events into an integral projection model that can be used to both understand the life history factors that allow this species to persist in its highly stochastic environment and for population viability analyses examining different scenarios for habitat management and climate change. I am also collaborating with Michelle Afkhami and Aaron David (post-doc) to turn other long-term datasets into integral projection models that examine the effects of microbes on plant population persistence. These include projects in California (Bromus laevipes) and the Florida Scrub (Hypericum cumulicola).
Niche models are a powerful tool since they take advantage of two large pools of data – georeferenced museum localities and interpolated climate layers for GIS – to inform us about species’ ecology. However, there needs to be more work ground-truthing how these models are made and which of their outputs are informative based on comparisons to independently derived field data. I have previously conducted projects that evaluate the utility of different model building refinements to both uncover new localities of a cryptic endangered species and to accurately identify the climatic variables that are most important in determining a species’ niche. I am currently working with Caitlin Mothes (graduate student) to examine whether niche models can accurately predict the relative success of invasive species among Miami-Dade County’s incredibly diverse community of non-native lizards. I am also collaborating with Aaron David (post-doc) and Michelle Afkhami to evaluate the relationship between predicted habitat suitability from niche models and population growth rates.
Applied Community Ecology
I have previously used a mesocom approach to examine the effect of different tiger salamander genotypes on vernal pool communities. This data has been used to make recommendations on how hybrid tiger salamanders should be managed under the Endangered Species Act and in general how taxon substitutes should be evaluated. I have recently initiated a project looking at the effects of proposed Everglades restoration measures (e.g., tree island creation, hydrological manipulations, invasive species removal) on the reptile and amphibian community (with graduate student Hunter Howell). Stephanie Clements (graduate student) and I have also begun a project on the ability of preserved Pine Rockland fragments to maintain the native herpetofaunal community in urban Miami-Dade. My entire lab group just completed a project investigating the effects of cattle grazing on the pond-breeding amphibian community of Central Florida.
My research in the McCauley lab at the University of Toronto focused on a set of 36 experimental ponds that we constructed at the Koffler Scientific Reserve. We built these ponds in a geographically structured array so that they are different distances from existing ponds on the landscape that serve as the source of colonizers. Since their construction, we have monitored the colonization process to determine the relative contributions of determinacy and contingency in community assembly and whether this varies based on landscape context. Preliminary data on one of the colonizing species (green frogs) shows that larger frogs are more likely to disperse farther from the source ponds, indicating that dispersers are not random draws from the population as is often assumed.