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Ecology

Re-planting the Forest

With the support of research centers and because of pressure from government authorities, farmers and local administrations are bringing forests back to life

A wide strip of the Mata Atlântica rainforest at the edge of the Iracemápolis reservoir in the State of São Paulo is a good example of the ups and downs in the challenge to regenerate forests. The sugarcane fields belonging to a sugar and ethanol mill had been slowly creeping up to the edge of the reservoir until 1985, when a severe drought revealed the extent of the silting: there was much less water than expected in the reservoir, which was almost entirely covered in earth. The mayor and the city councilmen realized at that time that the edges of the reservoirs should never have been invaded by the sugarcane, because of a law that had been enacted twenty years before. The local authorities confronted the mill owners, retrieved the land and got to work regenerating the forest to avoid water scarcity again. Nowadays, the locals can go fishing in the reservoir, go on picnics and stroll in the shade of the tangled branches of native trees such as jequitibás, cabreúvas and pau-marfim, which grow up to a height of eight and even ten meters. The entrance to the forest is garden-like, planted with mango and guava trees, orchids and bromeliads that people have brought to the forest.

The regeneration of the native plants followed a strict plan, which established sites where 120 species of trees were to be planted in an attempt to reproduce the structure of a native forest on the banks of a nearby river. “This is not how we would proceed nowadays,” says biologist Ricardo Ribeiro Rodrigues, a professor at the Esalq agricultural college of the University of São Paulo (USP), one of the institutions that took part in the reforestation of the region from 1988 to 1992. In 2003, a tornado destroyed the taller trees and the notions on which the effort to regenerate a forest that imitated another forest had been based. “We do not need to previously redefine the final structure of the forests; instead, we need to restore the biological processes that lead to the creation of a forest,” says Rodrigues. Many years before, Rodrigues and his team had attempted to restore a swampy forest without draining the terrain first. Nearly all of the one thousand seedlings that had been planted perished under the water.

Persistence did away with disappointment and quickened the development of an approach that still values planning, accepts uncertainty and defines things, without the previous excesses of what, how and where to plant. The ensuing methodology spread its roots throughout Brazil and gained credibility to the point of becoming one of the references used in the drawing up of the Pact to Restore the Mata Atlântica rainforest. This pact was prepared by a group of NGOs and presented in November 2007 in Vitória, State of Espírito Santo.

Reports on the work of this group from Esalq describe the regeneration of forests on lands owned by pulp and paper companies in the states of Rio Grande do Sul, Bahia and Paraná, in sugarcane fields in the state of São Paulo, on coffee plantations in the state of Minas Gerais, on soy fields in the state of Pará and on pasturelands in the states of São Paulo, Mato Grosso and Mato Grosso do Sul. In the last 15 years, teams from Esalq’s Forest Restoration and Ecology Laboratory reforested 3,500 hectares (1 hectare equals 10 thousand square meters) of vegetation on river banks, an area equal to one and a half times the size of Israel, but that is still very small when compared to the vastness of rural properties that are 400 times bigger.

Biologists, agronomists and forestry engineers that are part of this group act together with NGOs and government authorities, especially public prosecutors, to put pressure on landowners to comply with the law. Pursuant to the law, all rural landowners have to maintain native vegetation on strips of land that are at least 30 meters wide; these strips of land are called permanent protection areas; they are essential to prevent rivers from drying up and river banks from being destroyed. The law also establishes that 20% (or up to 80% in some of the Northern states) of rural property has to be covered with native vegetation – these are the so-called legal reserves. “This is the law,” says Gandolfi, a professor at Esalq, “but farmers are unwilling to lose this area, which is good for crop planting, especially the more fertile lands that lie on the banks of rivers.”

But the law has to be complied with, so twice a year public prosecutor Daniel José de Angelis flies over the 22 municipalities along the basin of the Pardo River. Then, when he is in his office located in the courthouses of Ribeirão Preto and São Joaquim da Barra, he takes a look at the photographs and maps of the rural properties before he summons the landowners, who own the plantations or the pasturelands and who have not complied with the law, for a chat. “I’m pleased with the results,” says Angelis, who has motivated rural landowners by showing them that regenerating the native vegetation is neither impossible, nor as expensive nor time-consuming as they had imagined. Angelis is acquainted with the work of the group from USP, and is therefore prepared to provide solutions that make reaching agreements with the farmers easier, which goes beyond demanding that they comply with the law.

The motivation of the landowners is not the result of being afraid of the law nor a love of nature. It stems from the need to obtain environmental certification, which is necessary for them to be able to sell their products to other countries, and is of interest to those who want to ensure that the path to money is kept open. “Before approving loans,” says Angelis, “the banks demand that companies are in regular status with the Public Prosecutor’s Office”. Another motivation is the possibility of making money by planting trees and selling firewood, or using timber for carpentry and furniture after 30 or 40 years. In the midst of initiatives taken mainly by companies who have announced their plans to tackle global warming by planting millions of trees, local governments such as the city of Potin administration stand out. Ten years ago, the local authorities of Potin started to re-forest the banks of the rivers that run through the municipal region. Last year, this was mentioned in the book “BenchMais: As 85 melhores práticas em gestão ambiental do Brasil” (Benchmais: the 85 best environmental management practices in Brazil). The book was compiled by Adalberto Marcondes, Marilena Lavorato and Rogerio Ruschel.

The sale of seeds of trees used to regenerate forests can also be good business. One kilogram of seeds can cost as much as R$ 1,000, depending on the size of the seed and how difficult it is to collect, says agronomist André Gustavo Nave. While doing his doctorate, he studied strategies for the recovery of native vegetation in Capão Bonito and found that many inhabitants of rural areas made more money selling seeds than planting tomatoes. “Someone who gathers seeds is not going to let the native forests be destroyed,” he says.

Toucans and song-thrushes
And so dark green canopies of thick forests are beginning to spring up above the endless fields of sugarcane and soy bean plantations. “Six years ago, sugarcane reached all the way down here,” says Edson Pinto de Azevedo, pointing at the banks of a stream that crosses one of the 45 farms owned by the Vale do Rosário sugar mill in Morro Agudo, not far from Ribeirão Preto. A former supervisor of sugarcane cutters, he is now one of the people who look after the seedlings and the trees that are already two meters tall and that adapt to the sunlight before being planted in their permanent places. A native of Brazil’s Northeast, Azevedo had never planted a tree nor seen toucans, which are sometimes seen in the forest. He had never seen monkeys, song-thrushes or boa constrictors, either. “All the animals come back once the trees have been planted.”

Or most of them do. Alexander Lees and Carlos Peres, from Great Britain’s University of East Anglia, studied the diversity of bird and mammal species in 32 areas where native vegetation remained, (24 areas were inter-connected and 8 areas were isolated) and in 5 areas along river banks located in large forest-control areas in the region of Alta Floresta, the state of Mato Grosso. In this study, to be published in Conservation Biology, they found that narrow tracts of land (less than 20 meters wide) or tracts disconnected from forest fragments retained very few animal species, whereas the wider tracts, especially those which have been well preserved, sheltered all of the region’s 365 bird species and 28 of the mammal species. In addition to emphasizing the value of extensive tracts of land with the remains of native vegetation to maintain biodiversity and the waterways, Lees and Peres recommended that these tracts of land be widened to 200 meters of forested land on each side of the rivers. In addition, they state that restricting the access of cattle to the banks of rivers and preventing this land from being used for farming would allow the native vegetation to regenerate and make it easier to reestablish connections.

The work of transforming an arid and empty area into an oasis begins with the mapping and isolation of the terrain to be repopulated, according to the current approach taken by the group from USP. The next step is to identify the kind of forest and native trees in the region that will survive in the fragments of vegetation located nearby and that will provide the seeds. Grown in greenhouses, the seedlings that sprout from these seeds are planted in sunny parts of the area to be regenerated, along two parallel and interspersed rows, perpendicular to the river, at a distance of two meters from one another. Each seedling should be three meters away from the next seedling.

One of the rows, which acts as the filler, is sown with 15 to 20 fast-growing species (the ones that grow a few meters a year) that provide a lot of shade. These trees die within five to ten years, and some examples are the capixingui, the mutambo and the monjoleiro trees. These trees provide the shade which controls the grass on the abandoned land, shape the initial structure of the forest, and protect the plants in the second row, which provide the diversity. This row is sown with three to four different tree species. The trees grow at a slower pace, a few centimeters a year, but they will be the keepers of long stories throughout their 80 to 100-year life spans. The species include the jatobá, the ipê, the jenipapo and the jequitibá trees. In addition, these rows contain species such as the imbaúba, which grow quickly and do not provide much shade, but attract the birds and insects that transport pollen and seeds. In addition, they speed up the work of the forest when they die and clearings open up. In two to three years, this initial organization disappears in the midst of the thick trees that blend and cover the ground with shade and moisture.

“We have helped change some of the concepts of the environment, conservation and regeneration of the forest,” says Gandolfi. He adds that in the last 20 years, specialists in this field no longer consider only the isolated remains of native vegetation when they observe the landscape and the interaction between environments such as pastures and cities with tracts of native vegetation. Natural disasters such as tornados are beginning to be viewed as normal, because they regulate the structure and the composition of the vegetation. “Any vegetation is a mosaic of plants that re-organize themselves as a result of natural or human disturbances,” says Gandolfi. “It is no longer a single balanced situation.”

Entrepreneurs
Results in this field, however, can only be verified in the long term – even in São Paulo, which has even older regenerated forests, such as the one on the land of the Usina Ester sugar mill in the city of Cosmópolis. The forest started being regenerated 50 years ago by José Carlos Bolinger, a researcher from the Instituto Florestal forestry institute; another example is found in the city of Assis, also started by the Florestal 35 years ago. Both forests have a much higher diversity of species than had originally existed. There are other approaches to bring back shade to parched lands. The group headed by Ademir Reis and Fernando Bechara from the Federal University of Santa Catarina/UFSC prefers to leave more space for unexpected events. They adopt the nucleated approach – artificial perches and shelters made of branches and rocks spread throughout the area to be regenerated – to attract animals and re-establish biological processes such as decomposition and seed dispersion.

There is no lack of proposals to regenerate Brazilian forests. It is very unlikely that any kind of consensus will be reached soon in terms of the best method, but at present the experts agree on two points: the use of native species, because non-native species are at a high risk of dying sooner, and the greatest diversity possible in terms of the species. The problems that existed formerly seem to have been solved. Many years ago, Ludmila Pugliese de Siqueira and Carlos Alberto Mesquita, biologists from the BioAtlântica Institute, did field work to identify and encourage the initiatives to regenerate native vegetation in the states of Espírito Santo and Bahia. They identified 65 areas for forest regeneration on eight properties and found that there were many doubts as to how and what to plant: most of the five thousand trees that had been planted were of the fast-growth/short life span kind.

Although the owners of those lands had little or no technical advice and the loss of randomly planted seedlings was quite significant, “these entrepreneurs and their families have produced admirable results,” acknowledged Ludmila and Mesquita in their book “Meu pé de Mata Atlântica“, launched last year. Michel Frey, a French engineer and environmentalist owned a piece of land in Conceição do Castelo, state of Espírito Santo, on which he had planted 300 thousand trees. “The older trees are 15 years old and have formed a forest that is wonderful to look at,” he reported “When we started , there were only some guans in the surroundings. Now these guans multiplied so much that sometimes I see about one hundred of them around the house.” But not everything is about birds. In 2001, a severe drought killed one third of the seedlings he had planted. Frey passed away in 2006. Before his death, he founded an institute that purchased more land and that today protects the springs of a stream that flows into a river which then flows into the Itapemirim River, one of the main rivers in the state of Espírito Santo.

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