PROJECT SUMMARY

1995-96

Introduction

Around the world, growing human populations and economic pressures are inexorably leading to widespread conversion of tropical rainforests into a mosaic of human-altered habitat and isolated remnants. The Biological Dynamics of Forest Fragments Project (BDFFP), a bi-national research effort of the Brazil's National Institute for Amazonian Research (INPA) and the Smithsonian Institution, measures ecosystem changes that occur as continuous rainforest is transformed by human development into a habitat mosaic.

The BDFFP is the one of the few long-term, integrated studies of the interface between continuous Amazonian rainforest and human encroachment. Initiated by INPA and WWF-US in 1979 north of the city of Manaus in Brazil's Amazon rainforest, the Project has since moved to the Smithsonian Institution, where it has become a critical component of the Institution's Biodiversity Programs, administered by the National Museum of Natural History.

Manaus

3°S latitude; 60°W longitude, 80-110m above sea level
26°C mean temperature (maximum=35-39°C, minimum=19-21°C)
1900-2300mm annual rainfall (Dec.-Apr., rainy; May-Nov., dry)
Distance (by road) to nearest reserve=92 km or 1.5-2.5 hours
Distance (by road) to farthest reserve=121 km or 2.5-3.5 hours

History and Design

The BDFFP began as the Minimum Critical Size of Ecosystems Project, with an original research goal of identifying a minimum size of tropical forest habitat that would maintain most of the biotic diversity represented in an intact ecosystem. The research design entails studies of plant and animal communities in forest plots before and after their isolation by cattle ranchers opening new pastures. Additionally, post-isolation communities in the plots are compared to control studies in adjacent continuous forest through time.

By isolating a replicated series of 1-, 10-, and 100-ha forest patches and studying the presence and absence patterns of biota before and after isolation, predictions could be generated on what size forest patches are needed to maintain given percentages of the original diversity. One of the specific predictions, which would allow correlating the size of a forest fragment with retention of diversity, was that the rate of extinction of isolated fragments would be area dependent -- extinction would proceed faster in smaller fragments.

From 1980 to 1984, ten 1-, 10-, and 100-ha fragments were isolated. In 1990 a second 100-ha reserve was isolated, and an approximately 200-ha remnant, isolated on a neighboring ranch on 1979, was included in the sampling regime. Fifteen years of observations by BDFFP researchers indicate that the forest reserves are highly dynamic ecological entities and that it is an oversimplification to expect to be able to predict "species carrying capacity" from the size of the reserve alone. Species/area relations are insufficient to understand all of the processes that determine how many and which species will be present in a given reserve. Rather, species-specific habitat requirements, structural changes in the reserves originating from the creation of a forest edge, and changes in the vegetation of the forest fragment are key elements in determining ecosystem structure in the habitat fragments.

Results

The following constitute a highlight of the major results of 15 years of research:

Fragmentation and edges

• Decrease in species richness of birds, some insects, primates, bees, and termites.
• Increase in species richness of small mammals, amphibians, and butterflies
• Changes in composition of communities of butterflies and small mammals
• Within taxonomic groups there is a predictable size effect of fragmentation on community evolution
• Serious structural changes in forest
• Changes in resource distribution (fruits, and insects)
• Changes in microclimatic conditions associated with edges
• Negative effects on tree survival and leaf fall
• Animal response to edge is variable
• Animal response to barrier created by pasture is also variable
• Importance of matrix habitat for understanding the dynamics of populations and communities in fragments
• Discovery of second-order effects of isolation: ecological processes (decomposition and pollination) are affected by fragmentation
• Demonstration of non-applicability of Theory of Island Biogeography to reserve design for amphibians

Forest Regeneration

• Land-use history after forest clearing has deterministic effect on forest regeneration trajectory
• Herbivores have strong negative impact on regeneration of degraded lands
• Controlled clearings in second growth forests enhance survival of commercially important trees

Early results demonstrating a complex suite of factors affecting habitat fragments led to an expansion of the research activities supported by the BDFFP. While we continue to study the relationships of forest fragment size and species number, the dynamics of the forest edges, both biotic and physical, as well as the interaction between the forest islands and the matrix habitat around them are now central issues in the Project's mission.

The BDFFP provides unique research opportunities to study the processes involved in forest regeneration. Because we know the history of forest clearing and secondary growth in the pasture surrounding the BDFFP isolates, researchers have a perhaps unparalleled laboratory in which to investigate through observation and manipulation the basic biology of succession. For example, what will be the role of forest remnants as seed sources for surrounding fallow lands? We also are addressing applied questions of how manipulation of abandoned pastures might turn them into landscapes capable of supporting colonists.

As the Project moves through the second decade of operation, we stand ready to make major contributions to the relatively new field of conservation science, providing data vital to integrating the preservation of biodiversity with human development.

Participation

Participation is open to all scientists on a peer-reviewed basis. Participation is approved by the standing Management Committee.

Student training is a very important aspect of the BDFFP. Graduate students, both Brazilian nationals as well as non-Brazilians, constitute a major portion of our researchers. Since the inception of the project, over 175 student interns and graduate students have worked with us in Manaus. Funding for projects is available through a highly competitive, yearly application process for fellowships and grants.

Projects in Progress

Remote sensing

Dalton de M. Valeriano, INPE
Detection of forest phenological change in Manaus region using RADARSAT

Botany

Roger Hutchings, INPA
Francisco Dallmeier, Smithsonian Institution
Jim Comiskey, Smithsonian Institution
Leandro Valle Fereira, INPA-SI
William Laurance, INPA-SI
Susan Laurance, INPA-SI
PDBFF Phytodemographic inventory data

Maria A. de Freitas, INPA
Factors affecting colonization and establishment of arboreal species in rainforest clearings.

Aldicir Scariot, University of California
Ecological and genetic consequences of fragmentation of tropical rainforest on a palm community.

Renato Cintra, INPA
Maria E. de A. Elias, INPA
The effects of fragmentation on growth and survival of Copaifera multijuga.

Manoel Pacheco, University of Illinois.
Factors controlling survival and the distribution of 2 species of tropical trees.

David Chivers, Cambridge University
Wilson Spironello, Cambridge University
Sapotaceae community ecology in a central Amazon forest: effects of seed dispersal and seed predation.

Nadja M. L. Cunha. University of Sao Paulo.
Genetic variation of a rare tree species with aims towards its conservation.

Chris Dick, Harvard University
The effect of habitat fragmentation on the genetic structure of tropical forest trees.

Jeffrey Chambers, University of California
Dynamics of dead wood debris of tropical forests

Matthew Hamilton, Smithsonian Institution
Robert Fleischer, Smithsonian Institution
The influence of forest size on paternity pool genetic diversity in two tropical forest plants

John Kress, Smithsonian Institution
William Hahn, Smithsonian Institution
Molecular population genetics of palms in fragmented forest in Amazonia

Ellen Andrensen, University of Florida
The fate of mammal dispersed seeds in a tropical rain forest in Central Amazonia

Forest regeneration

Maria Miriti, University of Illinois.
Seed dispersal and forest regeneration.

Rita Mesquita, University of Georgia
Bruce Williamson, Louisiana State University
Strategies of pioneer tree species in central Amazonia

Gislene Ganade, Imperial College.
Effects of insects and nutrients in the establishment of seedlings during forest succession.

Ed Tanner, Cambridge University
Simon Lewis, Cambridge University
Treefall gaps and regeneration: a comparisons of continuous forest and fragments in central Amazonia.

Limnology

Bruce Forsberg, INPA
Domatila Pascoaloto, INPA.
Distribution, seasonal variation, and taxonomy of macro-algae in streams of the Manaus region

Invertebrates

Christopher Martius, INPA
Joana D'Arc Ribeiro, INPA.
The ecology of Labiotermes labralis in terra firme forest of central Amazonia.

Carlos Roberto Fonseca, Oxford University
The growth and reproduction of ants living in sympatry with myrmecophytes of Amazonia.

Jacques Delabie, CEPLAC
Heraldo Vasconcelos, INPA
Paulo Moutinho, UFPa
Ants as bioindicators of forest regeneration at forest edge in central Amazonia

Jos‚ A. Rafael, INPA
Luis E.F.R. Silva, INPA.
Biotaxonomic studies of Tachinideae associated with army ants.

Roger Hutchings, INPA
Keith Brown, UNICAMP
James B. Sullivan, Duke University Marine Laboratory
Community structure and dynamics of Lepidoptera in continuous forest and fragments in the Manaus area

Harold Fowler, UNESP
Eduardo Venticinque, UNESP
Forest fragments and metapopulation theory

Vertebrates

Claude Gascon, INPA
Claudia Ramos, UFPa
James Bogart, University of Guelph
The ecological and genetic responses of amphibians to forest fragmentation in the Manaus area

Mandy Tocher, University of Canterburry.
The effects of fragmentation on populations of frogs.

Larissa Barreto, INPA
The effects of fragmentation on the dynamics and structure of tadpole communities in central Amazonia.

Marcelo Gordo, INPA
Habitat choice by adult frogs

Renato Cintra, INPA
Andrea Araujo, UNICAMP
The effects of fragmentation on the interaction between hummingbirds and plants

Miguel Rodrigues, USP
Flora Acuna, University of Sao Paulo
Reproductive success of Colostethus stepheni.

Charles Handley, Smithsonian Institution
Elizabeth Kalko, University of Tuebingen
Erica Sampaio, University of Tuebingen
Effects of forest fragmentation on the structure and diversity of bat communities in Amazonian tropical forest

Kellen Gilbert, Rutgers University
Primate diversity and density in fragments and continuous forest in central Amazonia.

Phillip Stouffer, Univ. of Southwest Louisiana
The effects of fragmentation of bird vocalization.

Mark Lomolino, University of Oklahoma.
The importance of immigration for small mammal communities in forest fragments.

For more information contact:

In Brazil
Dr. Claude Gascon, PDBFF
Scientific Coordinator
Ecologia/INPA
CP 478
69011-970 Manaus, AM
Brazil
Tel: (55-92-642-1148)
Fax: (55-92-642-2050)
E-Mail: pdbff@inpa.gov.br

In DC:
BDFFP
c/o Marsha Sitnik
Biodiversity Programs, NMNH MRC 180
Smithsonian Institution
Washington, DC, 20560
Tel : 202-357-2670
Fax: 202-786-2934

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