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The forest is born again

Natural vegetation of São Paulo recovers 3.8% of the ground lost in the last few decades, and the Atlantic Rain Forest starts growing again, although the Cerrado is almost finished

“Colossal fig trees grow by the banks, their branches bow down to the river, and they put forth multiform roots that dive into the waters (…). Other plant species are also present, and prominent amongst these are, for their profusion, full-crowned ingazeiros, whose white flowers, with multiple stamens, like plumage, attract myriads of insects, which circle around their vast nectaries; imbaubas with a whitish trunk and sparse branches; genipap trees with lustrous leaves and aromatic fruit, which supplied black ink for the Indians? tattoos.”

Mamede da Rocha
In 1905, the physician and naturalist Mamede da Rocha described in this poetic way that appears at heading the vegetation close to the Tietê River in the environs of the city Araçatuba, in the west of São Paulo. Almost a hundred years later, the ingazeiros (Inga uruguensis), the genipap trees and the trees of noble wood Brazilian pepper trees, cabreuvas and jequitibás seen during the expeditions of the Geographical and Geological Commission of São Paulo have disappeared. The trees began to fall with the arrival of agriculture and the railroads, built to facilitate the coffee trade and its expansion at the end of the 19th century. And they kept being felled as the towns were formed since the times of Mamede da Rocha, the population of the state has increased almost 17 times, from 2.2 million inhabitants to the present-day 37 million, while the São Paulo economy has conquered a respectable position, equivalent to 35% of the national Gross Domestic Product (GDP). Today, the consequences of this progress are clear, which gave no importance to bringing down the natural forest, which once occupied 82% of the territory of São Paulo.

According to a recently concluded survey by the São Paulo Forestry Institute, only 13.9% is left of São Paulo’s natural plant cover, which is equivalent to 3.46 million hectares, or 34,600 square kilometers (100 hectares is equal to one square kilometer). Oddly enough, this 13.9% corresponds to the area of natural vegetation destroyed during one of the most intensive periods of devastation, the 60’s, when there was not yet any concern with environmental damage. It is also about the same space occupied today by sugarcane plantations, far and away the farm crop that occupies the largest extension of land in São Paulo.

This new study, the São Paulo Forest Inventory, also brings some good news: in the state of São Paulo, after four decades of periodical surveys, there has been a reversal in the trendtowards deforestation, which can be visualized on the poster that accompanies this issue. Since the Portuguese arrived to begin colonization, it is probably the first time the natural vegetation has increased instead of decreasing. The area preserved today is 3.8% larger than ten years ago, the date of the previous survey carried out by the Forestry Institute, which has been following up the evolution of São Paulo’s ecosystems since 1962. Albeit modest, the growth observed between the two most recent inventories indicates some progress: there are 126,600 hectares more, the same as 1,266 Ibirapuera Parks, the São Paulo capital city’s largest, which on a sunny Sunday is visited by some 30,000 city dwellers.

Even so, it is still early to commemorate. There may indeed have been a consistent regeneration of the natural vegetation in ten years, according to agronomist Francisco Kronka, from the Forestry Institute, one of the coordinators of the inventory. But the increase in plant cover in the state is not due only to the expansion of the areas of the original forest. The use of images from the Landsat 5 and 7 satellites and of photographs taken from planes flying close to the ground has made possible a level of detail at least three times greater than in the previous inventory, carried out at the beginning of the 90’s.

Accordingly, it has been possible to identify stretches of vegetation that were imperceptible before, of up to 4 hectares, in particular those that are in a process of regeneration. Another important point: the increase is an average and represents what has happened overall to the plant cover in São Paulo a mosaic made up of dense forests interspersed with mangrove swamps by the seashore, while on the vast plateau that extends over the hinterland only fragments of vegetation are resisting, with a few twisted trees and some rare compact blocks of forest. The scenario is another one when one assesses each kind of vegetation separately: some have shrunk, drastically, even, and others have managed to recover part of the ground lost in the last few decades.

Gains and losses
First, the good news. The most extensive ecosystem in São Paulo, the Atlantic Rain Forest, a dense and evergreen vegetation, has increased 2.86%, which corresponds to 808 square kilometers. The Atlantic Rain Forest has started growing again mainly in the Paraíba river valley, to the east, with a gain of 27% over the previous decade, and over almost all the coastline, with 12.3% more. It is difficult to determine precisely the causes of this growth. In the first place, the team from the Forestry Institute attributed it to the population becoming aware of the need to preserve the environment, which is added to two other more tangible factors: the stricter environmental legislation, and the adoption of measures against deforestation. Kronka regards as effective initiatives like the Atlantic Rain Forest Preservation Project (PPMA), a partnership between the State Secretariat for the Environment and the German bank KfW (Kreditanstalt für Wiederaufbau).

The PPMA, in which US$ 30 million has now been invested, above all in monitoring and in the consolidation of conservation units, covers an area of 22,000 square kilometers of natural vegetation in 72 municipalities on the coast and in the Paraíba and Ribeira Valleys, precisely where the recovery of the natural vegetation has been more noteworthy. But to the north and northeast of the state, the same land covered by Mamede da Rocha at the beginning of last century, the situation is desolating and aggravates a situation that was already no good at all. “The regions that have least natural vegetation are those that are losing most”, says Kronka, who shares the authorship of the inventory with João Batista Baitello and Marco Nalon, from the Forestry Institute, Hilton Thadeu Zaratte do Couto, from the Luiz de Queiroz College of Agriculture, of the University of São Paulo (USP), and Carlos Alfredo Joly, from the State University of Campinas (Unicamp).

Heading up the devastation are the municipalities of Araçatuba and São José do Rio Preto, which in ten years have lost 16.2% and 12,6% of their forests respectively. In those parts, the Cerrado, now called Savanna, according to the terminology adopted by the researchers, has been progressively replaced by pastures and sugarcane plantations hail the sugarcane seas, as the poet from Pernambuco João Cabral de Melo Neto one day defined them. Today, less than 1% (211,000 hectares) of this kind of vegetation remains, whereas one century ago it used to occupy one fifth of the territory of São Paulo. The remaining stretches appear on the map as spots dispersed over the lower and slightly undulating regions of the state.

Using the satellite images of the whole of the state obtained in the course of 2000 and 2001, the team from the Forestry Institute worked on a scale of 1 to 50,000, in which each centimeter on the map corresponds to 500 meters in the ground. Already like this more detailed than the similar mappings of Rio Grande do Sul, Minas Gerais and Rio de Janeiro, the São Paulo study reached an ever greater level of detail, 1 to 10,000, along the coast, with reinforcement from digital aerial photos. With this magnification, five times greater than used in previous surveys, Kronka’s team detected fragments of native vegetation of only 4 hectares, which previously escaped from the gaze of the satellite.

Considered in June the best work for the Excellence in Public IT Award in two modalities, improvement in in-house management and projects, the map of the green in São Paulo, as this mapping of the vegetation is called, has been extremely useful. On its purely scientific side, it will be the cartographic basis that supports the 38 research projects of Biota-FAPESP, a program for surveying the fauna and flora of São Paulo. “This digital map makes the distribution of plants and animals in the state clearer”, explains botanist Carlos Joly, Biota’s coordinator.

The study by the Forestry Institute has also become an instrument of strategic planning, for indicating the imminent targets for actions of environmental protection. “Mapping is a valuable tool for identifying new regions that may become conservation units”, attests environmentalist Paulo Nogueira-Neto, one of the founders of USP’s General Ecology Department. Even before the conclusion of the inventory, Nogueira-Neto found 109 patches of natural vegetation that are candidates for becoming protected areas. One of them is a farm called Barreiro Rico, in the municipality of Anhembi, between the cities of Botucatu and Piracicaba.

With 2,300 hectares, Barreiro Rico shelters stretches of dense forest in which the researchers found trees typical of the Atlantic Rain Forest like the pau d’arco, glorybushes and cedars of up to 30 meters in height. Living there are four species of monkey threatened with extinction, like the howler monkey and the woolly spider monkey, and some 350 species of birds identified with the assistance of one of the owners of the farm, José Carlos Reis de Magalhães, a hunter converted into a conservationist, who died in August last year.

For having structured a digital foundation, with a database and maps, the inventory of the green in São Paulo may be applied both in extensive areas, like the whole of the state, and in smaller regions, like the river basins in São Paulo and the municipalities themselves. The digital foundation also makes it possible to produce maps containing models of the terrain, with details of altitude, inclination and shape, as well as of the kinds of soil. Accordingly, the survey indicates the best ways of occupying the ground, replacing empiricism with planning founded on information ascertained by scientific method.

This is what was done in the Porto Ferreira State Park, an area with 611 hectares to the northeast of São Paulo, occupied by Atlantic Rain Forest and fragments of Savanna. Using the images of plant cover and information on the local soil, contours and fauna, the researchers defined which areas ought to remain untouched and which would withstand trails and visitors without damaging the environment. At the moment, Kronka’s team is working at an accelerated pace to finish the detailed inventory of the plant cover of São Paulo’s 645 municipalities. “This information will remain at the disposal of the municipal governments that are interested in restoring devastated areas”, he says. Perhaps this is how the municipalities may be able to turn around, at least in part, a long process that on the one hand has lead to the devastation of the green in São Paulo, on the other has transformed São Paulo into the richest state in the country.

The loss of the natural vegetation, started in the 16th century with sugarcane plantations, became more intense with the advance of the coffee plantations. Between 1890 and 1927, the number of coffee shrubs planted in the state leapt up from 330 million to 1.3 billion, according to a study by agronomist Mauro Antonio de Moraes Victor. In those days, good soil for coffee was soil covered by virgin forest, with a thick layer of nutrients. Whenever productivity diminished, the old coffee plantations would be abandoned, and inroads would be made into the forest, in search of more fertile land. With as much as 150,000 hectares being deforested a year, the native plant cover of the state fell by half at the beginning of last century. Nourished by growing profits, the coffee barons supported the construction of railroads that joined the hinterland to the port of Santos, besides facilitating the arrival of immigrants from Europe who helped to fell even more forest and expand the plantations.

And now, what to do about it? The researchers guarantee: it is almost impossible to recover the pristine forest situation of the state. But it is also certain that it is feasible to progress quite a bit beyond today’s 13.9%. According to Kronka, the adoption of measures to foster the regeneration of the remaining native flora and the increase of monitoring to inhibit the fires intended to clear the ground would allow the natural vegetation to reach the levels of the beginning of the 60’s, when they occupied almost one third of the state something close to the minimum required by the environmental legislation, which determines that rural properties should preserve 20% of the native plant cover, besides the vegetation alongside the banks of the rivers and on the tops of the hills.

The restorative role would not just be left to nature. The recovery of the forests and the natural fields could be given some help by means of reforestation. A study by the Forestry Institute that resulted in the expansion of the Assis Ecological Station, in the west of São Paulo, showed that the planting of eucalyptus helped with the resurgence of the native vegetation.

The inventory of the species used in the artificial formation of forests to supply the paper and furniture factories with timber indicates that the area of eucalyptus has remained stable (612,000 hectares), while the area of Pinus has decreased almost one fifth and occupies today 158,000 hectares a result of the commercial interest for trees with short fibers, like eucalyptus, for making paper. Moreover, as another study by the Forestry Institute indicated, this time of the Santana do Parnaíba region, there is a lot of land covered by poorly cared-for pastures, where signs of erosion are already visible. “An initial strategy could be to recover these spots where the soil has been misused”, Kronka suggests.

Even in this critical state, the little that remains of the natural vegetation still surprises. Biologist João Batista Baitello, from the Forestry Institute, has spent the last three years scouring the flora of the Juquery State Park, an area of almost 2,000 hectares, with remnants of what is now called Savanna (the former Cerrado), in the metropolitan region of São Paulo, and he still finds there plants that were thought not to exist any more. Of the 250 or so species that he himself cataloged, six used to be regarded as presumably extinct, and four with a serious risk of extinction in the rest of the country.

This is the case of Camarea hirsuta, with its rounded yellow petals, Passiflora clathrata, a plant that is a relative of the passionflower, with its purple leaves, hidden amongst the bushes, and a species with a whitish flower, Alophia sellowiana, whose petals only open up at night. “From October to November”, says Baitello, “the incredible diversity of shapes, colors and sizes of flowers makes the park look like a beautiful natural garden, where the plants blossom one after the other, particularly after the fires.”