Ph.D. (candidate) Vanderbilt University, Earth and Environmental Sciences
M.S. University of California, Santa Barbara, Earth Science
B.S. College of Charleston, Geology
Contact: jennifer.l.bradham at vanderbilt.edu
Tropical ecosystems regulate global climate, act as carbon sinks, and contain some of the highest levels of biodiversity in the world (Clement et al., 2001, Gaston, 2000). Yet, they are also among the most threatened ecosystems on the planet (Achard et al., 2002). Thus, knowledge of their evolution and response to changing conditions is of critical importance. Large mammals provide an interesting angle through which to evaluate changing tropical ecosystems, as they have unique top-down effects and can directly moderate ecosystem services, plant diversity and abundance, and amount of available habitat for other organisms (Desbiez, et al., 2009, Beck et al., 2016, Bello et al., 2015). My research combines techniques from conservation biology, computer modeling, landscape ecology, stable isotope geochemistry, and movement ecology to understand how large mammals access and utilize their environments and how aspects of their biology, including diet and habitat use patterns, vary in fragmented and agricultural ecosystems. Using these data, I aim to find solutions for preserving native species and ecosystems in the face of increasing anthropogenic pressures.
Specifically, I ask:
- How do large mammals influence tropical ecosystems?
- How do large mammal interactions and influences on the ecosystem vary as a result of human alteration to the landscape?
- How do fluctuations in these interactions and influences affect the long-term sustainability of tropical ecosystems?
Current research projects evaluate the ecosystem roles of large mammals in South America, specifically those of white-lipped peccaries (Tayassu pecari) in central Brazil. As ecosystem engineers, keystone species, and apex seed predators and consumers, white-lipped peccaries directly and indirectly shape the ecosystems they inhabit. Prior studies have documented reductions in biodiversity, lack of seed dispersal, and changes to forest structure in areas where they have gone locally extinct as a result of landscape fragmentation (e.g. Kiltie, 1981; Keuroghlian et al., 2004, 2009, Beck, 2005, 2006; Beck et al., 2010; Altrichter et al., 2012), making peccaries a model species for investigating links between large mammal habitat use and human-driven land use changes.
Current projects are driven by the following questions:
- How do large mammals utilize agricultural landscapes?
- What habitat fragmentation parameters (e.g. percent forest cover, number of forest fragments, etc) impact large mammal habitat use?
- What are the consequences of land use change on large mammal habitat-use patterns and how do changes in these patterns influence forest dynamics?
- To what degree do large mammals alter diets spatially and in response to landscape fragmentation and climate change?
These research projects are currently being evaluated in the Brazilian Pantanal, Cerrado, and Atlantic Forest biomes with amazing colleagues from Vanderbilt University , Universidade Estadual Paulista -- LEEC , Universidade Estadual Paulista -- LaBiC, the USDA, and local grass-roots organizations including the IUCN/SSC Peccary Specialist group.