About 550 hectares of forests were recovered on rural properties in the Doce River basin, between Mariana and Ponte Nova, in Minas Gerais.
Forest restoration in areas where tailings were deposited has been completed, a fundamental activity for the health of watercourses. This initiative involved 202 rural properties located in the Minas Gerais municipalities of Mariana, Barra Longa, Rio Doce, Santa Cruz do Escalvado and Ponte Nova, with participation and authorization from rural producers. The region covers a stretch of about 100 kilometers, where the Gualaxo do Norte and Carmo rivers are located, which suffered the first environmental impact from the Fundao dam collapse in November 2015.
To date, Renova Foundation has allocated R$ 356 million to repair around 550 hectares of forests and Permanent Preservation Areas (PPAs). Approximately 300 thousand seedlings of 96 native species were planted in the affected areas. All hectares were protected by fencing or by the native vegetation existing on the site. Around 526 km of fences were built to protect and delimit the PPAs, with visible results. After the planting actions were carried out, indicators such as vegetation cover above 80%, satisfactory above-ground vegetation mass indexes, exposed soil index compared to the pre-collapse period and increase in regenerating species diversity in the areas were observed.
The next step will be ecological monitoring of the region to assess the effectiveness of the restoration and the methods used. From the data collection, the need for corrective actions will be analyzed. The Renova Foundation will be in charge of maintenance, such as mowing, fertilizing, fighting ants and replanting, if necessary, until 2026. The forecast is that R$ 81 million will be allocated for this phase.
For Giorgio Peixoto, manager of Sustainable Land Use at the Renova Foundation, the actions carried out in the river channel and its tributaries generate an increase in the production of water also in the zone of saturation. “Furthermore, the activities reduced the risk of erosion by preventing sediment from being carried into the river. The actions also made it possible to improve the quality of the water in rivers and increase soil quality from infiltration. It also allowed for faster recovery of permanent preservation areas”, he says.
The beginning
An emergency planting of 800 hectares of fast-growing grasses and legumes to control erosion started environmental recovery actions in 2015 and 2016. At the same time, riverbeds, banks and plains were regularized and revegetated, together with the restoration of riparian vegetation, an activity that contributes to the quality of the water in rivers.
The result of a pilot planting program for forest restoration tests on tailings, in 2017, was the basis for defining the methodology for initial preparation of the affected soil and survival of species. According to Giorgio Peixoto, this action is innovative within the scientific community and in the forest restoration market. “Until then, all activities had to be adapted to this type of area. The size of the hole dug, the fertilization after the soil analysis and even the native seedlings received special care and treatment”, he says.
Researches
From studies on the affected soil, coordinated by researchers from the Federal University of Viçosa (UFV), reforestation became viable in 2018. Maria Catarina Kasuya, specialist in soil microbiology, analyzed samples of seedlings that received substrate based on types of fungi and bacteria to repopulate affected areas and allow for growth with quality and efficiency. The research also indicated that the emergency revegetation process helped in the repopulation of microbial biomass in the soils. With the microorganisms, it was possible to cultivate seedlings resistant to critical soils, such as in sections where there are tailings.
In parallel, studies carried out by the head professor of the Department of Forestry Engineering at UFV, Sebastião Venâncio, showed that the tailings do not impede the process of environmental recovery, if there is the application of management techniques and improvement in soil fertility with adequate nutrients.
Mapping
The Transaction and Conduct Adjustment Agreement (TTAC), an agreement established by the Renova Foundation in 2016, provided for the reforestation of 2,000 hectares. After detailed studies, it was concluded that around 550 hectares of this area could be reforested. The remainder, around 1450 hectares, corresponds to water bodies, civil constructions, rocks, consolidated roads, agricultural areas, steep areas, sand dunes, villages such as Bento Rodrigues and Paracatu de Baixo, cities such as the city hall of Barra Longa, easement strip, passage for animal watering and flooding areas. With the mapping of the regions, it was possible to allocate each of these areas to specific actions of the Renova Foundation’s actions in repair.
Participation of affected rural producers
To engage 202 landowners in environmental restoration, it was necessary to rectify or prepare the Rural Environmental Registry (CAR). The work only began after the land owner signed a term of adhesion to environmental adequacy and the presentation of the property’s specific project. With the authorization, the Renova Foundation began the fencing to protect and delimit the PPA area. Then, with the soil preparation, the team in the field carried out the fight against ants, fertilization and the planting of native seedlings.
The demarcation of the PPA strips to be recovered takes place through the dimensioning required in the forest legislation, in compliance with the guidelines established by federal law no 12.651/2012, and, when applicable, by law no 11.428/2006, until the regulation of the Environmental Regularization Program in the State of Minas Gerais.
In addition to authorizing and adhering to environmental adaptation, some rural landowners carried out implementation activities, such as planting and maintaining what was planted. “In this process, the landowner carries out the activity and gets benefits for it, with the supplies being provided by the Renova Foundation. It is a form of partnership that creates a feeling of ownership of a preserved area and generates additional income for those affected”, says Giorgio Peixoto.
Ater Family Nurseries
About 20,000 seedlings came from affected properties through the Ater Family Nurseries, created by the Renova Foundation. The action is aimed at renovating nursery units and promoting local economic development within rural properties affected by tailings, located in Mariana and Barra Longa.
In 2019, affected producers received technical training and seedlings resistant to soils with tailings cultivated based on UFV research. After months of cultivation and management of seedlings of native species throughout 2020, the new nurserymen sold the seedlings to the Renova Foundation.