Imprimir Republish

Environmental preservation

One road, many forests

The construction of a ring road around Greater São Paulo triggers an operation to replant forest

LUIS FERNANDO DO REGO / DERSAThe road crossing one the water reservoirs in the São Paulo state capitalLUIS FERNANDO DO REGO / DERSA

At least once a week, Paulo Ortiz, a biologist from the State of Mato Grosso do Sul, arrives around seven a.m., an hour and a half before the usual time, at the Botanical Institute, next door to the São Paulo zoo. He puts on his black boots and soon goes out with other biologists to visit the outskirts of the state capital and neighboring towns, in order to check on the growth of the forests that have been planted to recover the native vegetation lost through the construction of the southern stretch of the Mario Covas ring road, a 57 km road that goes around the São Paulo state capital and another six towns in the Greater São Paulo area, linking the inner-state roads to the coast.

The work of recovering the Atlantic rainforest, though it is not very visible to those who move about the streets of the metropolis, is important in order to reduce heat and flooding. It is the largest experience of forest restoration undertaken jointly by government bodies, research institutes and private-sector enterprises in the history of São Paulo state. The 1,016 hectares (each hectare equals 10 thousand square meters) that are being replanted with native Atlantic rainforest species are spread over 147 public areas of various sizes, ranging from 70 square meters (the size of an apartment) to 100 hectares (or 100 soccer fields put together) in São Paulo and in another 13 neighboring towns (Biritiba Mirim, Cotia, Embu das Artes, Itapecerica da Serra, Mairiporã, Mauá, Mogi das Cruzes, Nazaré Paulista, Ribeirão Pires, Salesópolis, Santo André, São Bernardo do Campo and Piracaia; see the exact replanting sites).

This experience bears witness to the ability of the researchers from different institutions to work together. They have undertaken to face up to urgent problems and natural or human resistance to the growth of urban forests. In one third of the planted area, or some 300 hectares, the trees have died or failed to grow, as expected, due to unforeseen events such as flooding, arson, frost, cattle invasions, and opposition from the inhabitants of neighboring areas, who would rather continue to use public land as clandestine pasture for their cattle. The team from Esalq, the Luiz de Queiroz School of Agriculture of the University of São Paulo (USP) helped to restore 8,500 hectares, an area far greater than that of the southern stretch of the ring road. However, it involved fewer conflicts because the new woods grew on privately-owned land, whose owners sought environmental certification for sugar and alcohol production (see Pesquisa FAPESP nº 144 of February 2008).

As it progresses, occupation with native vegetation of an area equal to 25% of the Tijuca forest in the city of Rio de Janeiro shows the capacity of botanists and agronomical and forestry engineers to make an effective contribution to the formulation and implementation of public policies. Evidence of this is that fact that thanks to the results of research that became arguments for improving the environmental laws of São Paulo state, each hectare must contain about 2 thousand trees of at least 80 different species. In this way, it should be possible to produce lasting new forests, and at the very least ones that are similar to those that were removed in order to build the road.

There was no reforestation offset for the preceding, western stretch of the ring road, but the laws and methods used to restore the Atlantic rainforest near the southern stretch should be put to use in the construction of the upcoming northern and eastern stretches, to offset the loss of native vegetation near the Serra da Cantareira park, the largest urban forest in the world, with 7,900 hectares, twice the size of the Tijuca forest. Another environmental requirement for the southern stretch that should be adopted in the upcoming segments is the system that monitors the demographic dynamics and the transformation of the use of soil and of native vegetation, developed and managed jointly by the teams from Seade (the Foundation for the State System of Data Analysis), Emplasa (the São Paulo State Company of Metropolitan Planning) and the Forestry Institute.

The call
In 2007, as a condition for the approval of the project to construct the southern stretch of the São Paulo ring road, environmental bodies at the state and federal level decided that Desenvolvimento Rodoviário S.A. (Dersa), the public company responsible for the road’s construction, should replant 1,016 hectares of forest in areas close to the future highway, to offset the loss of 200 hectares of the Atlantic rainforest that surrounds the Greater São Paulo area.

The first problem emerged when Luiz Mauro Barbosa, at the time the director of the Botanical Institute, found out that his institution had been appointed to oversee the recovery of living plants and the compensatory reforestation of native species: “We hardly knew anything about that area, from a botanical point of view”, recalls Barbosa, who is currently director of one of the institute’s research centers. He was one of the leaders of a team of 80 researchers who soon afterwards went into the woods to identify the plants and remove them as soon as possible, before the tractors arrived and began to rip up the forest in order to make way for the road.

Eduardo CesarOne of the new Atlantic rainforest areas in Parelheiros, at the southern tip of São Paulo: the diversity of trees is already visibleEduardo Cesar

The researchers were concerned about the fact that they did not have much time to do the job and about the size of the forest area that they would have to cover. The forest to be cut down to build the new highway covered an area four times greater than the other pioneering experiment that the institute had participated in back in 1985: the recovery of native vegetation on the hillsides of the Serra do Mar mountain range, eroded by the pollution from chemical companies in the city of Cubatão, which at that time was unchecked. Looking back, Barbosa feels that, notwithstanding the pressures, they saved about 80% of the herbaceous and epiphyte plants from the deforestation required to build the southern stretch of the ring road.

In total, 22 thousand plants were rescued (mainly ferns, palm trees, bromeliads and orchids). These were transferred to the city of São Paulo Botanical Garden and to public squares in the Greater São Paulo area, or replanted near the area from which they were taken or in reforestation zones. In the Atlantic rainforest surrounding the Guarapiranga reservoir, one of the main sources of water for the residents of Greater São Paulo, the botanists found rarities such as a bromeliad with lilac colored flowers, the Tillandsia linearis, thought to have become extinct, and the Zygopetalum maxillare, an orchid that was under threat of extinction.

Trampling and religious orders
Two years later, the southern stretch of the ring road is in operation, being linked to the preceding (western) stretch, and many areas already look like young forest, with good growth prospects, particularly when surrounded by areas of remaining native forest.

In one of the new fragments of forest in Parelheiros, on the outskirts of the city of São Paulo’s south side, things are going well. “Look, the forest is beginning to function,” notes the agricultural engineer Maycon de Oliveira, from Verdycon, one of the three companies hired by Dersa to undertake replanting trees in the 147 areas selected.

Oliveira shows one of the trees, a fumo-bravo that he and his team planted in November 2009. It has since grown and is now almost 2.5 meters high; it has flowered, produced fruit and released seeds that have germinated and formed descendents that are already 30 cm high, near the main tree. The fumo-bravo, the ingá tree and the timburi tree that thrive in this parcel of land are species of pioneer trees, which grow quickly, providing shade for those species that grow more slowly but live longer. Beside it, a dedaleiro, a tree that should live there for many years, is already 1.5 meters high and is in flower.

There, as they did two years ago in the 147 areas selected for reforestation, Paulo Ortiz and another biologist, Carlos Yoshiyuki Agena, examine the emerging forest – whenever they can the biologist Regina Tomoko Shirasuna and the engineer Renata Ruiz Silva also participate in the inspections. There is a visible diversity of species and there are no creepers competing for nutrients. Here, the mortality rate of the trees is just 12%. Their assessment is that this is a good result, given that at onset of replanting, this area was invaded by horses that trampled on the newly planted seeds.

Now surrounded by fences to keep animals from getting in, the trees are growing on land formerly occupied by a vegetable garden that was expropriated by the city administration. The trees that stand around this piece of land are older and taller. Karina Cavalheiro Barbosa, a biologist at Dersa who is accompanying the teams that are overseeing or carrying out the planting, points out that the group of parcels of land that were planted in Parelheiros are part of four conservation units that are to be handed over to the municipal government in the next few months.

In Piracaia and Mairiporã, two towns with areas earmarked for replanting, the problems are worse. The belief is that some of the local residents cut down the fences around the selected areas to put back the oxen and cattle that had been expelled. There have also been fires possibly of a criminal nature in the forests that are growing; fuel tanks found on lands that have been torched reinforce this possibility. Karina and her team persist, replanting what has been lost and putting up signs informing that this is a public area that is not to be invaded. “Don’t leave macumba [Afro-Brazilian religion] offerings,” pleads an anonymous sign staked into the ground of a reforestation area in Mairiporã. It is of way trying to avoid the fires caused by candles used in religious rituals.

Sometimes the neighboring residents of areas selected for reforestation are more direct, announcing to the first ones who arrive that they do not want any change of this type in the area, because an area of woodland would reduce the visibility of their homes and make the community more isolated. And they make threats: if reforestation is carried out, there will be reprisals. What should be done? Sometimes the decision is taken to redo the planning in order not to waste work: replanting forests is expensive, costing R$ 20 thousand to R$ 25 thousand per hectare.

Nobody foresaw these opposing reactions, just as nobody foresaw the frost that in a single night in July 2011 destroyed almost half of the trees planted in the town of Cotia by the teams from Verdycon and from the Jardiplan/Biotech consortium. In areas where the soil is poor – one of them, right next to the ring road, used to be a truck yard and building waste dump – the mortality rate of the trees is about 40%, but solutions are arising. Oliveira, from Verdycon, is assessing the effectiveness of using a waste product from sugar and ethanol mills to improve soil quality. The team from Corpus, another company hired for planting, covered the poor soil with waste from mushroom production and found that the trees are growing better.

Short-lived forests
Barbosa, from the Botanical Institute, believes that he contributed a great deal to the legal definition of the reforestation criteria adopted, reinforcing the need to use the wide range of native species to increase the likelihood of restoration success. Thanks to two public policy projects financed by FAPESP in 2001 and 2003, he assessed 98 areas that were reforested throughout the entire state of São Paulo over the preceding 10 years.

Eduardo CesarIndicators of success: a Lafoensia pacari “thimble” plant in flower and Ortiz recording a tree mortality rate of only 12%Eduardo Cesar

“When I saw the result, I got a shock,” he tells us. In most of the areas, there were at most 30 species of tree per hectare, well below what is found in the original Atlantic rainforest. Out of these 30 species, pioneer trees, which have a short lifespan and die within the space of a few years, were predominant. “In two years there was a small forest,” he states, “but after 10 years there was almost nothing left.” Only 2 out of the 98 areas examined had an acceptable density of trees and  diversity of species.

Barbosa kicked up a real fuss. He contacted the people in charge of the State’s Bureau of the Environment and the ensuing conversations resulted in Resolution SMA-21, published in 2001, which determined the compulsory minimum planting of between 30 and 80 species per hectare, depending on the size of the area (the larger the area, the greater the number of different species that should be planted) and on the proximity to leftover forest areas, which could boost the diversity of species. Another resolution, SMA-47, published in 2003, determined that each hectare should contain at least 80 different native species, at least 40% of which should be of pioneer trees, short life, while 40% should be of non-pioneer trees, long life.

This legislation meant that the seedling nurseries increased their number of species along with the production of seedlings of native tree species. Once again, Barbosa went in search of the numbers and discovered that 55 registered seedling nurseries produced 13 million seedlings of 277 species of native tree in 2001. The survey he carried out indicates that today 208 seedling nurseries produce 41 million seedlings of more than 600 species that are native to the State of São Paulo (the institute’s site,, provides the registered seedling nurseries and a list of 700 tree species acknowledged as native to the state). Thanks to this progress, he believes that the task of reforestation of the state’s 1.3 million hectares should now take 63 years, rather than the 200 estimated 10 years ago.

This led to the creation of legislation and a structure for the support of seedling production that puts the State of São Paulo ahead of the others. “My biologist friends in the State of Mato Grosso do Sul cannot believe that here in São Paulo we are doing restoration work with such a wide range of species, which at least for the time being is not feasible there,” comments Ortiz.

The concepts have matured substantially. In 1985, one of the strategies used to replenish the hillsides of the Serra do Mar mountain range with native vegetation was to throw seeds that were inside gelatin capsules out of helicopters; afterwards it was confirmed that only 30% of these seeds germinated. Brachiaria, an exotic species of fast growing grass, was used to fix the soil on the hillsides. “Today we wouldn’t go about it like this,” declares Barbosa. If necessary, he says, they would use orelha-de-onça (Tibouchina clavata), a native shrub, for the same purpose. Previously it was believed that that the seeds could only be kept for weeks, but it is now known that they can last for years. Moreover, there are now various forest restoration techniques that can be combined if necessary.

In addition to trees
There are still problems, of course. A study carried out by Esalq indicated that creepers, epiphytes such as the bromeliads and orchids make up 42% of the biomass of a forest and are extremely important for environment reconstruction, whereas the trees account for a 35% share of the biomass.

IF / EMPLASA / SEADEThree years later: the forest grows in one of the parks created by DersaIF / EMPLASA / SEADE

“Trees alone are not the solution,” reiterated Paulo Kageyama, a professor at Esalq, at a symposium on ecological restoration held in November 2011 at the Botanical Institute. The problem is that at present, nurseries only supply tree seedlings. A regulation recently issued by the Bureau of the Environment recommends, but does not yet make it compulsory, that not only trees should be planted.

Restoration techniques for the Atlantic Rainforest are relatively mature, but are less clear concerning the State of São Paulo’s other natural environments, such as scrubland, mangroves and salt marshes. “New research will indicate new pathways,” believes Kageyama.

The new woods growing around the ring road are already serving as a base for research that compares plant growth in different areas or under different types of natural or urban pressure. One of the questions that will only be answered many years hence is whether the fragments of forest that are built into the urban environment will behave like the fragments of forest in the middle of pastures in the Amazon region, for example.

Furthermore, forest replacement is yet to exceed forest loss. Between 1995 and 2003, the National Research Institute of the Amazon Region (Inpa) fostered restoration of the Amazon Forest, but not to the point of replacing what was continuously being lost. Reports about this work, which included financing from Japan, indicate that the restoration of natural landscapes only advances significantly if undertaken in conjunction with broader public sector policies. In a study the journal PNAS in 2008, American researchers estimated that between 2000 and 2005 Brazil lost 2.6 million hectares a year due to the deforestation of rainforest, whereas in Indonesia, the country with the second largest loss of native vegetation, estimates indicate deforestation of 700 thousand hectares a year.

Finally, to the discomfort of those residents of the State of São Paulo who are in a hurry, the results are slow in coming. “Restoration takes time,” acknowledges Ortiz. “We’ll only find out 10 to 20 years from now if these forests around the ring road will really take hold.”

The projects
1. Models of vegetation replacement for the protection of water systems in degraded areas of the State of São Paulo various biomes (nº 2000/02020-9); Modality Public Policies Program; Coordinator Luiz Mauro Barbosa – IBt; Investment R$ 144,214.61 (FAPESP)
2. Establishment of assessment and monitoring parameters for induced reforestation with a view to environmental licensing (nº 2003/06423-9); Modality Public Policies Program; Coordinator Luiz Mauro Barbosa – IBt; Investment  R$ 173,793.33 (FAPESP)