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Reinvigorated forest

Study identifies factors aiding recovery of the Atlantic Forest in the São Paulo part of the Paraíba Valley

After centuries of degradation, the Atlantic Forest is now showing unequivocal signs of recovery in the Paraíba Valley, in the area between the states of Rio de Janeiro and São Paulo. The native vegetation there has more than doubled over the past 50 years. In 1962, the Atlantic Forest spanned a little more than 200,000 hectares. In 1995, the forest cover had increased to 350,000 hectares, and in 2011 to 450,000 hectares—equivalent to 30% of São Paulo State territory in the Paraíba Valley. This gradual, spontaneous regeneration of part of the forest appears to be the result of a convergence of social, economic and environmental factors, set in motion beginning in the 1950s, according to biologist Ramon Felipe Bicudo da Silva of the Center for Environmental Studies and Research at the University of Campinas (NEPAM-Unicamp). Silva’s findings appear in a doctoral research study carried out under advisors 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 is undergoing a process known as forest transition, when there is a change in the characteristics of land use, moving from a period of constant reduction of native vegetation to a period of natural expansion of the original forests,” Silva explains. “There, the transition is related to the abandonment of areas whose topography is incompatible with mechanized farming, in favor of environmental conservation projects involving eucalyptus cultivation and the migration of rural populations to large urban centers.” The conclusions were based on images from the Landsat 5 satellite, data on industrial development in the region, and interviews with farmers, university researchers, and representatives of nongovernmental organizations (NGOs) and government agencies.

Ever since the colonization by the Portuguese, the Atlantic Forest has been subjected to long periods of intensive and unregulated land use. This was true during the era marked by Brazil-wood extraction and sugarcane cultivation from the 16th to the 18th century, and it continued through the gold and coffee cycles, and into the more recent era of cattle ranching and urban expansion. Now, the forest, which once covered more than a million square kilometers spanning 17 Brazilian states, has been reduced to lone patches of about 50 hectares each, according to the latest Atlas de remanescentes florestais da Mata Atlântica [Atlas of Atlantic Forest Remains], published by the SOS Atlantic Forest Foundation and the National Institute for Space Research (INPE).

The section of forest in the Paraíba Valley has been one of the most heavily affected. In the late 19th century, the region became the corridor between the country’s two largest metropolitan centers. Starting in the 1920s, it began to undergo an intensive industrialization process, solidified by the opening of the Presidente Dutra Highway in the 1950s and the establishment of the São José dos Campos aerospace technological/industrial complex. In their analysis of historical data and statistical surveys conducted by the Brazilian Institute of Geography and Statistics (IBGE), the researchers found that urbanization in the region, combined with loss of pastureland productivity, had triggered a massive flow of rural inhabitants to the economic and industrial centers of the Paraíba Valley, such as the cities of Taubaté and São José dos Campos. “As industrialization and urbanization intensified, changes in the social and economic forces prompted the abandonment of farmland, particularly in areas featuring rougher terrain,” Silva explains. Some of the region’s residents remained on their property but ceased to use it for agriculture and went to work in the cities. “This kind of phenomenon helped create the ideal conditions for natural forest regeneration,” comments biologist Ricardo Ribeiro Rodrigues of the Luiz de Queiroz College of Agriculture at the University of São Paulo (ESALQ-USP), a specialist in forest recovery.

From the 1960s to the 1980s, agricultural activity in the Paraíba Valley decreased 13%, a factor that contributed to stagnating deforestation rates in the region. Since then, the Atlantic Forest has begun a process of spontaneous regeneration. Many abandoned lands have been converted into small groves of secondary vegetation, resulting in increased forest cover.

As Emilio Moran sees it, the findings substantiate studies that have confirmed the occurrence of localized processes of natural regeneration of the Atlantic Forest in other regions of Brazil. One such study is a survey, conducted by SOS Atlantic Forest and INPE, that recorded a total of 219,000 hectares of Atlantic Forest in recovery in areas formerly occupied by pasturelands in nine Brazilian states, between 1985 and 2015. This phenomenon has also been observed in other countries. In the U.S. state of Indiana, some of the native vegetation in the southern part of the state was turned over to corn and soybean production in the late 19th century, leaving only slightly more than 5% of the original forest cover. “Production then migrated to areas in the northern part of the state more suitable for growing those crops and, over nearly a century, the vegetation regenerated and gave rise to what are now state reserves,” Moran explains. More recently, in Medellín, Colombia, it was noted that the native vegetation in areas once controlled by drug traffickers and used for coca crops had begun to regenerate after the armed conflicts in that part of the country ceased.

Eucalyptus production
The researchers also observed that forest regeneration was more pronounced in areas adjacent to remnants of original forest and on land less suitable for agriculture, near escarpments and ravines. “The areas formerly used as pastureland accounted for about 75% of the new forest areas in the Paraíba Valley in recent decades,” notes Mateus Batistella, from Embrapa. There was also a considerable increase in native vegetation in areas now used for growing eucalyptus. The production of these trees is usually associated with degradation of the environment, either by drying of the soil or by diminishing the biodiversity in regions where they are grown. But in the case of the part of the Paraíba Valley that lies within São Paulo State, the researcher explains, there was a positive impact on forest regeneration: to be able to plant eucalyptus, producers need environmental certifications. To obtain the certifications, they were required to protect fragments of native vegetation, which expanded naturally over time, and to restore areas of riparian forest, which also became forests during this period.

The cultivation of eucalyptus for cellulose production became established in the region in the 1960s, mainly in areas with abandoned or degraded pasturelands, such as those found in the municipalities of Jambeiro, Natividade da Serra, Paraibuna, Redenção da Serra, Santa Branca and São Luís do Paraitinga. Together, these six cities accounted for 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 that period, the forest cover expanded by 77%. Today, approximately 89% of the cellulose produced in the Paraíba Valley is sold to markets in China and Europe. The growing worldwide demand for sustainable products is forcing companies to follow specific environmental management rules and practices in order to obtain an environmental certification. “These certifications are critical for the cellulose commodities market, helping the planting of eucalyptus to have a positive influence on the recovery of native forests in the surrounding areas,” Batistella says.

Environmental monitoring
On the basis of interviews with representatives of NGOs and more than 90 farmers in the Paraíba Valley, the researchers identified other elements that have contributed to the regeneration of parcels of forest in the region. One such factor is the Atlantic Forest Act of 2006, which introduced financial incentives for environmental restoration projects. In addition, monitoring by the Environmental Military Police (PMA) of São Paulo over the past two decades has helped to curb deforestation and land-clearance fires. According to information from the PMA’s own database, a little more than 9,500 occurrences of environmental violations were recorded in the São Paulo portion of the Paraíba Valley between 2003 and 2013, more than half involving illegal tree cutting. Even so, the extent of areas affected by deforestation was considerably reduced during that same period.

Many of the incidents recorded were reported by members of the public. According to Silva, tools of governance such as laws, sanctions and distribution of guidance materials promoted the development of a notion of environmental citizenship and greater engagement on the part of the people of the Paraíba Valley. “The findings suggest that a positive relationship has been established between economic development and environmental conservation in the region, and that the process of forest transition can be accelerated by an environmentally conscious society,” Moran says.

The phenomenon of the Paraíba Valley could provide guidelines for forest restoration projects in areas where similar historical and economic processes exist. However, in regions where agricultural mechanization is intensively practiced and the few forest remnants left are heavily degraded, it may be necessary to invest in other restoration strategies. “Under those conditions, other initiatives are recommended, such as planting seeds or seedlings of native species,” says Ricardo Rodrigues of ESALQ-USP.

Planted forests and Atlantic Forest: analysis of land use and land cover and their environmental, political and socioeconomic connections (No. 11/13568-0); Grant Mechanism Doctoral Research Grant; Principal Investigator Mateus Batistella (Embrapa); Grant Recipient Ramon Felipe Bicudo da Silva (Unicamp); Investment  R$125,430.79 + R$38,768.56 (Research Internships Abroad – BEPE).

Scientific articles
SILVA, R. F. B. et al. Socioeconomic changes and environmental policies as dimensions of regional land transitions in the Atlantic Forest, Brazil. Environmental Science & Policy. V. 74, pp. 14-22. 2017.
SILVA, R. F. B. et al. Drivers of land change: Human-environment interactions and the Atlantic Forest transition in the Paraíba Valley, Brazil. Land Use Policy. V. 58, pp. 133-44. 2016.
SILVA, R. F. B. et al. Land changes fostering Atlantic Forest transition in Brazil: Evidence from the Paraíba Valley. The Professional Geographer. 2016.