Marina C. Côrtes

Research

Broadly, I am interested in animal-plant interactions and its effects on plant recruitment and evolution. In the past my research activities were focused on understanding patterns of frugivory and seed dispersal in flesh fruited plants in the atlantic rainforest. I have worked intensively with the endangered palm Euterpe edulis mainly studying the seed dispersal effectiveness of the assemblage of frugivorous birds (figure 1) along a forest gradient in a continental island of the Brazilian coast. Currently, I am using molecular markers to assess the effects of forest loss in the fine-scale genetic structure and the contribution of pollination and seed dispersal to the contemporary genetic composition of Heliconia acuminata (figure 2) in a fragmented landscape.

Tropical forests are being consistently modified and converted to various land covers resulting in accelerated rates of deforestation and fragmentation of natural habitats. In general, fragmentation disturbs population and community dynamics by altering ecological and ecosystem processes. One striking consequence of forest fragmentation is the rupture of ecological mutualisms such as those between pollinators, seed dispersers and plants. Pollinators and seed dispersers are the vectors moving plants diaspores within and, eventually, among populations. In this context, I am interested to evaluate how the genetic composition and the spatial distribution of genotypes, as a reflex of gene flow, are affected by habitat loss and isolation. Because fragmentation is an evolving, synergetic and seldom immediate process, I am also interested in investigating how the spatial genetic configuration changes over time.

Heliconia acuminata is a hummingbird pollinated and bird-seed dispersed understory herb common in non-flooded areas in Central Amazon. The plant is subject of an ongoing demographic study headed by Emilio Bruna ( University of Florida, Gainesville, FL) in the Biological Dynamics of Forest Fragments Project (BDFFP), located 70 km from Manaus, Brazil. In collaboration with John Kress (National Museum of Natural History, Washington DC) I am conducting molecular work using microsatellites on samples of Heliconia collected in the late 90’s in permanent plots established in different fragments and areas of continuous forest. I will ultimately return to the same plots to resample and genotype new individuals to assess the temporal variation in the genetic composition of the plant populations. Likewise, I will conduct parentage analyses on newly recruited seedlings to disentangle the two components of gene flow, pollination and seed dispersal.

For more information about this project see the lab'sBrazil project page.

Publications

• Côrtes, M.C., Cazetta, E., Staggemeier, V.G, and Galetti, M. In press. Linking frugivore activity to early recruitment of a bird dispersed tree, Eugenia umbelliflora (Myrtaceae). Austral Ecology.
• Côrtes, M. C. 2006. Variação espacial nas interações entre o palmito Euterpe edulis e as aves frugívoras: implicações para a dispersão de sementes. Masters thesis, Universidade Estadual Paulista Júlio de Mesquita Filho: Rio Claro, SP (Brazil).
• Côrtes, M. C. 2003. Frugivoria e dispersão de sementes de Euterpe edulis (Arecaceae) em três tipos florestais no Parque Estadual da Ilha do Cardoso (SP). Undergraduate thesis, Universidade Estadual Paulista Júlio de Mesquita Filho: Rio Claro, SP (Brazil).