India Education Diary (Índia)

University of São Paulo: Timber production model in forest concessions will run out in 35 years

Publicado em 30 julho 2021

Por Guilherme Gama | Jornal da USP

The forest concessions aim to manage Brazilian public forests, promote sustainable production and stimulate regional economic development, according to the Ministry of Agriculture, Livestock and Supply. However, Edson Vidal, professor at the Luiz de Queiroz School of Agriculture (Esalq) at USP, in Piracicaba, warns that, if not re-evaluated, the timber production model will run out in 35 years, even if the production area is increased in more than 20 times. In a recently published study, the researchers analyzed 27 different production scenarios and only one model is sustainable, but it only meets 31% of the demand in the current wood market. “We need to rethink the management of native forest”, says Vidal.

The forest concession policy has been in effect since 2006, governed by the Public Forest Management Law ( Law 11.284/2006 ), which allows the government to grant legal entities – including companies, cooperatives and associations of local communities – permission to carry out sustainable forest management to extract wood products, as reported by the Brazilian Forest Service (SFB). Sustainable forest management techniques seek to ensure a balance between the exploitation and sustainability of the forest. For this reason, the areas assigned for production go through rotations, or cutting cycles, aimed at recovering the forest and continuing extraction. However, the inability of practices in current models to keep up with market demand worries researchers.

Currently, forest concessions in the Brazilian Amazon cover 1.6 million hectares, a portion that no longer meets the current demand for wood of 11 million cubic meters per year, but experts estimate that the total area of ??potential for concessions is more than 20 times larger, about 35 million hectares. According to Vidal, if extended to 35 million hectares of potential concessions, the current logging rate could meet 91% of demand. However, this level of production would gradually decrease, until complete exhaustion, in 35 years.

The study was developed by the Tropical Forestry Laboratory ( Latrop ) at Esalq at USP, together with international researchers. The article entitled Sustainability of Brazilian forest concessions was published in the journal Forest Ecology and Management , in June this year, and had the support of the Foundation for Research Support of the State of São Paulo (Fapesp) and the National Council for Scientific and Technological Development (CNPq).

To assess the sustainability conditions of current and potential forest concession systems with the annual demand of the timber industry, the researchers relied on an integrated system of simultaneously dependent equations, called Volume Dynamics with Differential Equations (VDDE). The evaluation included data from the Tropical managed Forests Observatory ( TmFO ), through the collaboration of foreign researchers. The calculations estimate the total volume and growth flow of trees, applied over 3,500 hectares of plots monitored for 30 years, in different regions of the Amazon Basin.

Twenty-seven scenarios were tested, combining different variables in three different conditions, such as the proportion of trees of commercial interest – with more than 50 centimeters in diameter – in the areas (20%, 50% and 90%); the cutting intensity (10, 20 and 30 cubic meters per hectare); and the cutting cycle period (20, 35 and 60 years).

The results show that, of the possible combinations, only one scenario is sustainable, but it meets 31% of current demand per year. The researcher explains that, in this scenario, it would be necessary to halve the cutting intensity (10 instead of 20 or 3m3 per hectare/tree), increase the rotation period (65 instead of 35 years) and that 90% of the species’ trees have market value – which, in Vidal’s words, is far from the current situation: “Today, only 20% of tree species are traded and, by current standards, recovery is very slow to recover stocks of wood”, he completes.

Extending the period of logging cycles means increasing forest recovery, but diminishing the short-term financial benefits of legal logging. The author highlights that, in addition, another concern is that restricting logging could lead to an increase in illegal logging and forest conversion – which would require greater efforts in the enforcement of the tenure law. “The new policies must include regional coordination, to avoid illegal trade and its effects, and the economic viability of tropical forest management”, he says. For the researcher, this will increase wood prices, currently considered low compared to production costs and efficiency of processing and processing in the sawmill, currently around 35%.