Study identifies the factors that favor the recovery of the Atlantic Forest in the São Paulo portion of the Paraíba Valley
AAfter centuries of degradation, the Atlantic Forest shows unequivocal signs of recovery in the Paraíba Valley, on the way between Rio de Janeiro and São Paulo. In the last 50 years, native vegetation has more than doubled. In 1962, the Atlantic Forest area extended to just over 200 thousand hectares. In 1995, this number rose to 350 thousand hectares and, in 2011, to around 450 thousand hectares, equivalent to 30% of São Paulo's Vale do Paraíba territory. The gradual and spontaneous reconstitution of part of the forest appears to be the result of a convergence of social, economic and environmental factors, triggered in the 1950s, as verified by biologist Ramon Felipe Bicudo da Silva, from the University's Center for Environmental Studies and Research. State of Campinas (Nepam-Unicamp), in doctoral research under the guidance of biologist Mateus Batistella, from the Brazilian Agricultural Research Corporation (Embrapa), and anthropologist Emílio Moran, from Michigan State University, in the United States.
“The Atlantic Forest in the Paraíba Valley goes through a process known as forest transition, when there is a change in the characteristics of land use, leaving a period of constant reduction of native vegetation to another of natural expansion of the original forests”, explains Ramon . “There, the transition is related to the abandonment of areas with topography incompatible with mechanized agriculture, environmental preservation projects involving eucalyptus cultivation and the migration of rural populations to large urban centers.” The conclusions are based on images from the Landsat 5 satellite, data on the region's industrial development and interviews with rural producers, university researchers, representatives of non-governmental organizations (NGOs) and government bodies.
Since Portuguese colonization, the Atlantic Forest has been subjected to long periods of intensive and unregulated land use. It was like this at the time of Brazilwood extraction and sugarcane cultivation, between the 1th and 2th centuries, through the gold and coffee cycles and, more recently, livestock farming and urban expansion. Today, the forest area, which once occupied more than 17 million square kilometers (km50) spread across XNUMX Brazilian states, is reduced to simple forest patches of around XNUMX hectares each, according to the latest Atlas of forest remnants of the Atlantic Forest, the SOS Mata Atlântica Foundation and the National Institute for Space Research (Inpe).
The portion of forest in Vale do Paraíba was one of the hardest hit. At the end of the 1920th century, the region became the axis between the two largest metropolitan centers in the country. From the 1950s onwards, it began to undergo an intense process of industrialization, consolidated with the inauguration of the Presidente Dutra highway in the XNUMXs and the creation of the São José dos Campos aerospace technological-industrial complex. By analyzing historical data and statistical surveys carried out by the Brazilian Institute of Geography and Statistics (IBGE), the researchers found that the urbanization of the region, combined with the loss of pasture productivity, triggered an intense flow of inhabitants from rural areas towards economic and industries in the Paraíba Valley, such as the cities of Taubaté and São José dos Campos. “As industrialization and urbanization intensified, changes in social and economic forces encouraged the abandonment of agricultural land, especially in more rugged areas,” explains Ramon. Some inhabitants of the region remained on their properties, but stopped using them for agricultural activities, starting to work in the cities. “This type of phenomenon helped to create the ideal conditions for the natural regeneration of the forest”, comments biologist Ricardo Ribeiro Rodrigues, from the Luiz de Queiroz College of Agriculture at the University of São Paulo (Esalq-USP), a specialist in forest recovery.
Between the 1960s and 1980s, agricultural activity in the Paraíba Valley decreased by 13%, which contributed to the stagnation of deforestation rates in the region. Since then, the Atlantic Forest has begun a spontaneous process of regeneration. Many abandoned lands have been converted into small forests of secondary vegetation, resulting in an increase in forest cover.
For Emilio Moran, the results reinforce studies that verified specific processes of natural regeneration of the Atlantic Forest in other regions of Brazil. One of them is a survey by SOS Mata Atlântica and Inpe that recorded a total of 219 thousand hectares of Atlantic Forest recovering in regions previously occupied by pastures in nine Brazilian states, from 1985 to 2015. This phenomenon was also observed in other countries. In Indiana, in the United States, part of the native vegetation in the south of the state was converted to corn and soybean cultivation at the end of the 5th century, leaving just over XNUMX% of the original forest cover. “Production later migrated to areas more suitable for growing these crops in the north of the state and, over the course of almost a century, the vegetation regenerated, giving rise to what are today state reserves”, explains Moran. More recently, in Medellín, Colombia, it was found that native vegetation in areas previously controlled by drug trafficking and used for coca plantations began to regenerate after the end of armed conflicts in that region of the country.
Eucalyptus production
The researchers also observed that forest regeneration had been more pronounced in areas close to original forest remnants and in land less suitable for agriculture, close to cliffs and cliffs. “The areas previously used as pasture contributed around 75% to the new forest areas in the last decades in the Paraíba Valley”, says Mateus Batistella, from Embrapa. There was also a considerable increase in native vegetation in areas currently used for eucalyptus plantations. The production of this tree is usually associated with environmental degradation, whether due to the drying out of the soil or the decrease in biological diversity in the regions where it is grown. But, in the case of the São Paulo portion of Vale do Paraíba, explains the researcher, there was a positive impact on forest regeneration: to be able to plant eucalyptus, producers need environmental certifications. To obtain them, they were forced to protect fragments of native vegetation, which naturally expanded over time, and to restore areas of riparian forest, which also became forests during this period.
The cultivation of eucalyptus for cellulose production was established in the region in the 1960s, mainly in areas of abandoned or degraded pastures, such as those found in the municipalities of Jambeiro, Natividade da Serra, Paraibuna, Redenção da Serra, Santa Branca and São Luís from Paraitinga. Together, these six cities contributed to 53,8% of the expansion of eucalyptus cultivation in the Paraíba Valley – from 13.115 hectares in 1985 to 38.958 hectares in 2011. During this period, forest coverage expanded by 77%. Today, approximately 89% of the cellulose produced in Vale do Paraíba is sold to markets in China and Europe. The growing global demand for sustainable products is forcing companies to follow specific environmental management standards and practices to obtain environmental certification. “These certifications are fundamental for the cellulose commodities market, contributing to the eucalyptus plantation positively influencing the recovery of native forests in its surroundings”, says Batistella.
Environmental inspection
Based on interviews with representatives of NGOs and more than 90 rural producers in the Paraíba Valley, the researchers identified other elements that contributed to the regeneration of forest plots in the region. One of them is the Atlantic Forest Law of 2006, which introduced financial incentives for environmental restoration projects. The inspection carried out over the last two decades by the Military Environmental Police (PMA) of São Paulo helped to curb deforestation and fires. According to information from the PMA's own database, just over 9.500 occurrences of environmental violations were recorded in the São Paulo portion of Vale do Paraíba between 2003 and 2013, more than half involving the illegal cutting of trees. Even so, the extent of areas affected by deforestation had a considerable reduction in the same period.
Many of the recorded incidents were reported by the population. According to Ramon, governance tools such as legislation, sanctions and distribution of guidance materials favored the development of a notion of environmental citizenship and greater engagement among part of the population of Vale do Paraíba. “The results suggest the establishment of a positive relationship between economic development and environmental conservation in the region, and that the forest transition process can be accelerated by an environmentally conscious society”, says Moran.
The Paraíba Valley phenomenon can guide forest restoration projects in areas where similar historical and economic processes exist. In regions where agricultural mechanization is intense and the few forest remnants that remain are very degraded, it may be necessary to invest in other restoration strategies. “Under these conditions, other initiatives are recommended, such as planting seeds or seedlings of native species”, says Ricardo Rodrigues, from Esalq-USP.
Text published in Pesquisa Fapesp magazine
http://www.revistapesquisa.fapesp.br/