Bruna Lab - Ongoing Projects

Ant-plant mutualisms in natural and human-modified habitats

Ants that establish colonies inside of plants and in return defend their host-plants from herbivores are one of the defining features of tropical rainforests, yet they have remained conspicuously overlooked by conservation biologists. My collaborators and I are investigating 1) the factors structuring ant communities associated with these plants and 2) how fragmentation-related changes in the density and diversity of ants, host-plants, and herbivores influence mutualism dynamics.

This work is supported by a grant from the National Science Foundation.

Collaborators & Graduate Students: Heraldo Vasconcelos (Universidade Federal de Uberlandia), Brian Inouye (Florida State University)

Plant population dynamics in fragmented landscapes

Plants in fragmented habitats are hypothesized to be at increased risk of extinction, yet the effects of fragmentation on plant population dynamics are for the most part unexplored. Our lab is doing so, using a combination of demographic surveys, manipulative experiments, and models. Our model system is populations of the Amazonian understory herb Heliconia acuminata in 13 permanent plots at the Biological Dynamics of Forest Fragments Project.

This work is supported by a grant from the National Science Foundation.

Collaborators & Graduate Students: Maria Uriarte (Columbia University), Ana Andrade (BDFFP), W. John Kress (Smithsonian), Alexandre Oliveira (USP)

Plant demography in Neotropical Savannas

Decades of research have demonstrated plant communities in African and Asian savannas are regulated by a combination of pervasive top-down and bottom-up effects. In contrast, studies investigating the dynamics of plants in the Neotropical savannas known as The Cerrado have focused almost exclusively on fire, soil chemistry, and other bottom-up drivers. In collaboration with colleagues from Brazil's Universidade Federal de Uberlandia I am investigating how herbivores (leaf-cutter ants) and granivores (small mammals) influence the diversity and demography of Cerrado plants. In collaboration with Micheel Mack (UF Botany) we are expanding by experimentally manipulating soil nutrients.

This work is supported by grants from the National Science Foundation.

Collaborators & Graduate Students: Heraldo Vasconcelos, Glein Monteiro de Araujo, Alana Vaz Ferreira (Universidade Federal de Uberlandia), Michelle Mack (UF Botany)

Other Projects

While most of our lab's research focuses on the areas above, we are involved in a variety of other collaborative projects related to plant ecology, population dynamics, and tropical conservation. Previous and ongoing projects include:

Stochastic demography (Link to the NCEAS Stochastic Demography Working Group).
Development and application of matrix models.
Plant-herbivore interactions and invasive plants (with Nora Underwood (FSU) and Stacey Halpern (Pacific U.)).
Ecology of Non-timber forest products (with Erika Nakazono (UFPA), and Simone Athayde (UF)).