Four sites were chosen for field studies during a reconnaissance tour of the region in June–July 1995. Of these the principal site is the Marajoara Management Project (‘Marajoara’), where a camp presence was established in October 1995. Logistical constraints limited research activities at the other sites to descriptive studies of distribution and demographic patterns, growth, fruit production, and reproductive phenology by mahogany trees > 10 cm diameter.
Marajoara is a 4100-ha tract of forest located at 7°50' S, 50°16' W, 34 km on a straight line northwest of Redenção. It was designated a management area for selective extraction of mahogany by the Serraria Marajoara Ltda (SEMASA) logging company (Sr. Honorato Babinski, owner). The management plan’s implementation was supervised by the Brazilian federal environmental agency (IBAMA). The property was acquired in 1998 by Sr. Claudiomar Vicente Kehrnvald of Juary Madeireira.
Marajoara lies 35 kilometers by unpaved road west-southwest of a sawmill hamlet by the same name, which in turn lies 35 km north of Redenção on the PA-150 (Marabá-Belém) highway. Access is by pick-up truck, motorcycle, and bicycle. Motorized travel time from Redenção is two to four hours depending on the season. Living facilities include an open-sided wooden house built by Sr. Babinski for the Mahogany Project on high ground with a deep (10 m) well, and a barraco (thatched-roof shelter) located 300 m from the permanent house on the banks of a third-order seasonal stream called the Grota Vermelha (Red Stream). Seedling nurseries were installed in open areas adjacent to both camps.
Marajoara is gridded by roadtracks into 12 divisions (talhões) 1.08 km wide and 3.15 km deep, encompassing an area roughly 13 km x 3.15 km oriented north-south along its long axis; each division is oriented east-west along its long axis. Criss-crossing forest trails spaced at 200-m intervals sub-divide each division into sixteen ~22-hectare areas. The original management plan called for annual extraction in successive divisions from 1992, with mahogany matrizes (seed trees) designated for retention prior to extraction, but the entire site was logged during 1992–1994. Research activities were restricted to divisions one to six on the north end of the project grid. Logging records show that, with 175 seed trees retained in the first six divisions, a total of 815 pre-harvest trees > 20 cm diameter grew in 2040 ha. In fact, actual densities proved higher due to trees missed by company mateiros (woodsmen) during the first round of exploration.
Topographic relief at Marajoara is slight, with high ground rising only 5–20 m above low areas across horizontal distances of hundreds to thousands of meters. An aseasonal stream averaging 4–8 m wide during the rainy season—the Rio Capybara—bisects Marajoara from west to east in division seven. A complex network of seasonal streams drain the rest of the project area, also generally flowing west to east. Divisions two to four, an area covering 1035 ha within which we concentrated efforts examining spatial aspects of population dynamics, are drained by the Grota Vermelha, which fills 2–4 m wide during the rainy season and is fed by first- and second-order tributaries originating both within and upstream from the Project area.
Most of the landscape surrounding Marajoara has been converted to pasture. Marajoara is bordered to the north and west by degraded pastures, on its south side by the Pau d’Arco River, and to the east by logged forest and pasture that was established in 2000.
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