O que é o Projeto de Fragmentos Florestais
Silvestre Gorgulho – Texto e fotos
Enquanto os empresários abriam a floresta para criar gado, os cientistas estavam estudando o impacto do desmatamento sobre o ambiente. Assim nasceu o Projeto Dinâmica Biológica de Fragmentos Florestais (PDBFF). É como se os cientistas estivessem pesquisando as “ilhas de floresta” em áreas desmatadas. O PDBFF é um projeto binacional entre o Instituto de Pesquisas da Amazônia (INPA) e o Smithsonian Institution dos EUA, que quantifica as mudanças no ecossistema que ocorrem à medida que a floresta contínua é transformada pelo desenvolvimento humano em um mosaico de habitats.
O PDBFF é um dos únicos estudos integrados a longo prazo sobre efeitos da presença humana na floresta úmida contínua da Amazônia. Iniciado pelo INPA e o WWF-US em 1979, ao norte de Manaus, o projeto mudou-se há 10 anos para a Smithsonian Intitution, onde se tornou um componente crítico do Programa de Biodiversidade, administrado pelo Museu Nacional de História Natural.
Esses fragmentos florestais só estão sendo estudados porque, nos anos 80, um programa do governo brasileiro liberou áreas para ocupações agro-pastoris no Distrito Agropecuário da Suframa. A legislação da época determinava que metade da área de cada fazenda deveria permanecer florestada. Aí os pesquisadores do PDBFF entraram em acordo com os donos das fazendas, o que permitiu a montagem do experimento. Hoje as fazendas não se mostram produtivas, em função da baixa fertilidade dos solos. Muitas estão sendo abandonadas e as pastagens vão se tornando florestas secundárias. Daí a importância histórica, econômica e científica do PDBFF: a ciência mapeia o processo de ocupação da floresta amazônica, sua regeneração e o impacto sobre a biodiversidade.
Science explains consequences of deforestation
Deforestation breaks up the forest and researchers study ” islands” of remaining continuous forests to help in the definition of environmental laws and the use of natural resources
While businessmen opened the forest to create cattle, scientists were studying the impact of deforestation on the environment. This is how the Biological Dynamic of Forest Fragments Project (PDBFF) was born. It is as if the scientists were researching the ” forest islands ” in deforested areas. The PDBFF is a bilateral project, involving the Research Institute of the Amazon (INPA) and the Smithsonian Institution from the U.S.A., which quantifies the changes in the ecosystem that happen at the rate that forests are transformed by human development into mosaics of habitats.
PDBFF is one of the only studies integrated in the long run on effect of human presence in the continuous rainforest of the Amazon. Started by the INPA and the WWF-US in 1979, to the north of Manaus, the project moved 10 years ago to the Smithsonian Institution, where it became an essential component of the Program of Biodiversity, managed by the National Museum of Natural History.
These forest fragments are only being studied because, in the 1980s, a program of the Brazilian government released areas for agriculture and pasture for occupation in the Farming District of Suframa. Legislation at that time determined that half of the area of each farm would have to remain intact. There the researchers of the PDBFF made an agreement with the farmers, which allowed the progress of the experiment. Today the farms do not show to be so productive anymore, as a result of low soil fertility. Many farms are being abandoned and the pastures are becoming secondary forests. Thus the historical, economic and scientific importance of the PDBFF: science shows the occupation process of the Amazonian forest, its regeneration and impact on biodiversity.
The research planned to study communities of plants and animals in the forests, before and after the isolation of forest fragments, originated through the deforestation of areas surrounding farming activities.
For the scientific coordinator of the Project, Heraldo Vasconcelos, ” the twenty years of comments indicates that the forest fragments are ecological entities highly dynamic making it difficult to predict the “capacity of occurrence of the species” only from the size of the fragment. According to Vasconcelos, the relation species/area are insufficient to understand all the processes that determine how many and which species will be present in one specific fragment of a forest.
The results of the research show that:
The specific requirements of habitats of the species and the changes in the structure of the vegetation and the microclimate, along the edge of the forest fragments, are main keys in the determination of the composition of species in the fragmented forests.
The fragmentation of the forest causes a considerable increase in the tree mortality rate, caused by changes in the microclimate and action of wind, especially in the first 100-300 m from the edge of the forest.
The two first effects end up unchaining others, such as: changes in the decomposition rate, in the fecundity rate, the genetic structure of plants and in the composition of animals and plants found in that area in general.
Participation and training
Heraldo Vasconcelos stresses that the participation in the PDBFF is open to all scientists in a competitive base. A Handling Committee composed by members of the INPA and the Smithsonian Institution approves participation.
On student traineeship, Vasconcelos explains that it is a very important aspect of the PDBFF. Pos- Graduate students, Brazilians and foreigners, make up for most of our researchers. Since the creation of this project, more than 200 trainees and Pos-Graduation pupils have worked in the PDBFF in Manaus.