NSF Postdoctoral Fellowship in Biology: Are the Consequences of Wildlife Extirpation in Tropical Forests Reshaping the Drivers of Plant Mortality?

Lamperty, Justine Therese, Seattle WA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Tropical forests hold more species than any other ecosystem. Unfortunately, human activities are reducing the number of large- and medium-sized animals in these forests, a phenomenon called defaunation. Losing these animals eliminates their interactions with plants and other animals, which means that defaunation can trigger a cascade of changes in how tropical forests are functioning. One example of this is that defaunation leads to the loss of many fruit-eating animals that disperse seeds, an important part of forest regeneration. When taken together, changes that are occurring as tropical forests become defaunated may alter factors determining the diversity and survival dynamics of plants in these important and biodiverse ecosystems. This project will investigate if, how, and to what extent defaunation may be doing this through multiple experiments set up in defaunated and intact tropical forests in Ecuador. Further, this project facilitates ecological and conservation education through outreach, training, and mentoring to diverse audiences that include high school and undergraduate students, young scientists, and members of the public. The central mechanism maintaining the unmatched plant diversity in the tropics is thought to be negative density-dependent mortality, by which spatially aggregated plant individuals, particularly conspecific and especially related individuals, face heightened attacks from a suite of plant-enemies (e.g., fungal pathogens, insect and vertebrate herbivores, and seed predators). By triggering multiple ecological cascades, defaunation may directly and indirectly affect the impacts these plant enemies have. For example, one consequence of defaunation is decreased seed dispersal services resulting in lower plant genetic diversity, potentially also reducing the diversity of genes important for mounting defenses against pathogens. This project investigates if defaunation alters the drivers of seed and seedling mortality, thereby reshaping what structures plant diversity in tropical forests. This research compares multiple defaunated and faunally-intact sites and integrates experimental manipulations (e.g., treatments that exclude specific groups of plant enemies) with genomics to mechanistically understand how the relative and overall strengths of different plant enemies change under defaunation. The Fellow will develop several new skills including competence in genomics and bioinformatics. Broader impacts include working with local high school students from minority backgrounds through science internships and workshops. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.