The Project ‘Sustainable Forest Management of Mahogany (Swietenia macrophylla): a pilot initiative by the State Government of Acre’ had as its overall objective the design and testing of management protocols for sustained-yield production of mahogany and associated high-value timber species in the state of Acre. The Project had basic research, applied, and technical training components. Research objectives were to improve biological understanding of mahogany and associated species in a region where relatively little was known about forest and species ecology. Applied objectives were to develop and implement sustainable logging practices for these species, especially promoting seedling regeneration to provide future harvests. Technical training objectives included training local logging crews in reduced-impact logging and silvicultural practices necessary to ensure sustainable production. The Project was initiated in the field in October 2001 within an 8000-hectare privately owned tract of primary forest located 125 km northwest of Rio Branco.
Partner institutions included the Instituto do Homem e Meio Ambiente da Amazônia (IMAZON), responsible for research and coordination of field activities; the site owner AFG Oliveira Madeireira, responsible for supplying logging manpower and infrastructure maintenance; the state government of Acre’s Secretário Executivo de Floresta e Extrativismo (SEFE), responsible for securing site access and providing logistical support; and the Fundação de Tecnologia do Estado do Acre (FUNTAC) and Instituto Floresta Tropical (IFT), responsible for training harvest crews in reduced-impact logging techniques. Project funding was provided by the US Forest Service’s International Institute of Tropical Forestry (USFS-IITF) and International Programs (USFS-IP), USAID Brazil, WWF Brasil, and Brazil’s Ministério do Meio Ambiente (MMA).
The Acre field site is located 45 km south of Sena Madureira on the Rio Iaco at 9°25' S, 68°38' W. The project’s base camp was situated at the edge of a large pasture clearing beside an aseasonal stream 1.5 km north of the field site. Living facilities included open-sided thatch-roof barracos and an enclosed kitchen with adjacent dining space. Steep topographic relief on this landscape combined with dense clay soils creates difficult conditions for overland transport during the rainy season, which typically extends from September to June. Thus even small four-wheel-drive trucks could not navigate the rudimentary road between camp and the field site during wet periods, forcing us to walk back and forth during most of the year.
The 8000-hectare project area extends in a large rectangle to and beyond the Rio Iaco on the west side. Five 100-hectare logging divisions (talhões) were demarcated along the north border of the project area and gridded for planned, reduced-impact logging (RIL) operations. This entailed cutting parallel trails at 50-meter intervals and locating, identifying and mapping all trees larger than 20 cm diameter of commercial timber species within this area. Two additional divisions were opened and inventoried in this manner south of the first 5 divisions in 2002. The first division, which actually only covered 85 hectares, was logged in 2002 by a professional logging crew provided by IFT, supported by local crew members-in-training.
Mahogany typically occurs at low densities in western Amazonia compared to densities in southeast Pará; only 12 trees per 100 hectares (0.12 per hectare) > 20 cm diameter occurred within the project area, and commercial densities (trees larger than 60 cm diameter) were even lower.
Bauch SC, Rodriguez LCE, Vidal E & Grogan J (2002) Manejo florestal de impacto reduzido no Acre: custos e competividade em relação ao desmatamento. IMAZON, Belém, PA, Brazil.
Grogan J, Jennings SB, Landis RM, Schulze M, Baima AMV, Lopes JCA, Norghauer JM, Oliveira LR, Pantoja F, Pinto D, Silva JNM, Vidal E & Zimmerman BL (2008) What loggers leave behind: impacts on big-leaf mahogany (Swietenia macrophylla) commercial populations and potential for post-logging recovery in the Brazilian Amazon. Forest Ecology and Management 255: 269-281 (http://www.treesearch.fs.fed.us/pubs/29979).
Grogan J, Schulze M, Pantoja F, Vidal E, Lentini M, Valle D (in review) Enrichment planting of big-leaf mahogany in logging gaps in Acre, Brazil. Forest Ecology and Management.
Valle DR, Couto HTZ, Vidal E & Grogan J (2003) Equações de volume para uma floresta em Sena Madureira, AC. IMAZON, Belém, PA, Brazil.