Molecular Ecology, Evolution and Genetics

The fundamental goal of the Molecular Ecology, Evolution, and Genetics (MEEG) subgroup is to create a dynamic, competitively funded research program that applies molecular genetic techniques to focal questions about the ecology, evolution, and conservation of tropical organisms.

The MEEG group is concentrating on three core research projects. These projects include work on:

1. reproductive and population biology of hawksbill turtles,
2. territoriality and reproductive behavior of the Mona rock iguana, and
3. population persistence,reproductive success, and gene flow in a riparian orchid metapopulation.

Each project is designed to unite extensive field research with molecular genetic estimation of relatedness. Study species are either currently endangered (the Mona iguana and hawksbill turtles) or exist in highly fragmented populations (orchids).

For further information, contact W.Owen McMillan at wmcmilla@rrpac.upr.clu.edu. or verify your website http://zephyr.hpcf.upr.edu/~mcmi-lab/

Population Ecology Group

Focuses on the impact of exotic species on the native flora and fauna of Caribbean islands. The key projects focus on biological introductions of global relevance: introduced feral ungulates in Mona Island and Africanized bees as pollinators of endemic plant species.

Mona Island Project

One of the most serious ecological problems facing insular biotas is caused by the accidental or else intentional introduction of mammalian herbivores such as pigs, goats and cats. The introduction of wild goats (Capra hircus) and pigs (Sus scrofa) by Spaniard settlers was common throughout the islands of the Commonwealth of Puerto Rico 4 centuries ago.

The Department of Natural Resources of Puerto Rico (DNR) has been engaged in intense management efforts to control these animal populations in Mona Island first through its seasonal hunting program and more recently through the intensification of the use of enclosures to fence out goats and pigs in particular areas. The recent interest by DNR to intensify the use of enclosures provided a unique opportunity to study the potential effects of current browsing levels on plant communities in this dry forest reserve in terms of their responses to the exclusion of introduced herbivores.

We studied vegetation responses to the experimental exclusion of feral herbivore (but allowing activity of native herbivores) in two depression forests in the Reserve. Our results showed, strong initial growth vegetation responses to the exclusion of herbivores. However, these responses were not uniform across depression forest location. These results may be a consequences of interacting factors such as temporal and spatial changes in microenvironment as well as indirect effects of ungulate removal.

Funding by the CREST program will be used to study how these factors may alter plant community responses to the removal of introduced goats and pigs.

For further information, contact Elvia Melendez at elmelend@upracd.upr.clu.edu. verify your website http://www.ites.upr.edu/~elvia/

Many studies have examined impact of invasive Africanized bees on beekeeping and pollination in agriculture (Guzman-Novoa and Page 1994). In contrast, to date only a few studies examined ecological impact of Africanized bees (e.g. Rogel Villanueva 1999).

In Puerto Rico, Africanized bees were officially first found in 1994 (Cox 1994). The estimated number of feral Africanized bee colonies in Puerto Rico is know over 150 000 (Daniel Pesante, personal communication). Africanized bees represent a threat to other Caribbean islands as well, for instance they are also established in Trinidad. It would be important to determine the impact of this apparently permanent introduced species on the biota of Puerto Rico. We propose to start this effort by studying influence of Africanized bees on reproductive biology of the endemic endangered plant , Goetzea elegans.

Goetzea elegans is an excellent model system to address conservation issues for rare Caribbean trees because it is similar in many ways to other rare species.

First, despite having perfect flowers, Goetzea elegans requires outcrossing for pollination, a condition shared with many trees of tropical regions (Bawa and Ashton, 1991).

Second, the historical range of the species is fragmented, and the population densities are low.

Third, the species exhibit multiple flower visitors, including native elements and invasive species, e.g. Africanized bees.

For further information, contact Tugrul Giray at tgiray2@yahoo.com.

Landscape Ecology Group

Investigates the differential responses of species to landscape variation. Key projects focus on Caribbean frogs and Andean birds, in order to examine how body size reflects spatial and temporal discontinuities in ecosystem at large-scales. LEG has six long-term goals.

First, foster cross-scale thinking among members of the Center for Tropical Applied Ecology and Conservation and the Department of Biology at UPR-RP.

Second, encourage communication among landscape ecologists and macroecologists interested in tropical ecosystems.

Third, contribute tools and techniques to study tropical landscapes.

Fourth, contribute to the theoretical foundations of the recently developed field of Landscape Ecology.

Fifth, apply knowledge to the conservation,management, and restoration of tropical landscapes.

Sixth, disseminate results to a broad audience.

The transformation of tropical landscapes due to land-use change has influenced plant and animal assemblages in different ways. Whereas some species have been favored, others have become vulnerable to population declines and extinction; still others have experienced no change. Here we propose that the differential response of species to land-use change results from complex interactions between landscape structure, body size, and developmental stability (textural discontinuity hypothesis).

For further information, contact Carla Restrepo at crestre@goliath.cnnet.clu.edu.

Ecosystem Ecology Group

Research is carried out in three main areas: effects of plant biodiversity on ecosystem functioning, past and present climatic changes in tropical ecosystems and metabolism of rivers and streams as affected by human disturbance in island ecosystems. This group is being established with the addition of new Center faculty fellows.

For further information, contact Elvira Cuevas at ecuevas@goliath.cnnet.clu.edu.