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AGUA AZUL

At Agua Azul, sub-commercial mahogany trees were retained after logging in open fields and in closed but heavily disturbed forest.
Pastures
At the Agua Azul field site, sub-commercial mahogany trees were retained after logging in open fields (foreground) and in closed but heavily disturbed forest (background).

The Peracchi Management Project (henceforth ‘Agua Azul’) is an industry-owned reforestation and management project located 9 km southwest of Agua Azul, a small agricultural community midway between Xinguara and Tucumã on unpaved state highway PA-279, approximately 115 km northwest of Marajoara. Topographic relief in this region is more pronounced than at Marajoara, with extensive hilly areas where steeper slopes rise 20–40 m across 200- to 1000-meter distances. Soils grade from gray or white at slope bottoms through yellow and red-yellow to dark red at slope tops. Equally extensive areas at Agua Azul are quite flat, however, with pale to dark gray sandy soils drained by meandering first- and second-order seasonal streams, and it is in these areas where mahogany is (or was, before extraction) found at commercial densities. Mahogany occurs within steeper areas, but at far lower, non-commercial densities.





Heavy thinning of some remaining forest areas in 1997 left many canopy trees exposed to wind in rain-soaked soils. With Miguel Alves de Jesus.
Pastures
Heavy thinning of some remaining forest areas in 1997 left many canopy trees exposed to wind in rain-soaked soils. With Miguel Alves de Jesus.
Dense secondary vegetation (juquira) sprang up where forest was cleared, forcing us to cut tunnel-like trails between surviving mahogany trees. With Manoel Rodrigues Vitorino.
Pastures
Dense secondary vegetation (juquira) sprang up where forest was cleared, forcing us to cut tunnel-like trails between surviving mahogany trees. With Manoel Rodrigues Vitorino.
A trail through juquira to a mahogany tree, the gray stem at center.
Pastures
A trail through juquira to a mahogany tree, the gray stem at center.

Agua Azul consists of adjacent cleared and forested areas covering roughly 1000 and 250 ha, respectively. Nursery-grown mahogany seedlings were outplanted by the managing company from 1994–1997 into bulldozed flats between hedgerows spaced ~100 meters apart in the cleared area. In 1995 approximately 200 hectares remained in heavily thinned forest whose understory had been slashed in a crude shelterwood treatment. All overstory species except mahogany were removed from this area in early 1997, leaving > 75% of the mahogany trees included in the sample exposed to full sunlight in a pasture-like setting. What closed forest survived at Agua Azul was low, highly disturbed, and fire-prone. Original forest composition was similar to that at Marajoara, though with exceptionally high densities of jatobá (Hymenaea courbaril) and caximbeira (Cariniana domestica, Lecythidaceae).

Camp at the Agua Azul field site in 1999. The house on the right was occupied year-round by a family providing site maintenance and protection.
Pastures
Camp at the Agua Azul field site in 1999. The house on the right was occupied year-round by a family providing site maintenance and protection.
Field crew in 1999. From left: Adeilson F. Avelino (Cachorro), Manoel Rodrigues Vitorino, Valdemir Ribeiro da Cruz, Maria Nascimento Rodrigues, Miguel Alves de Jesus, and the caretaker Antonio Pinto Mesquito with his son.
Pastures
Field crew in 1999. From left: Adeilson F. Avelino (Cachorro), Manoel Rodrigues Vitorino, Valdemir Ribeiro da Cruz, Maria Nascimento Rodrigues, Miguel Alves de Jesus, and the caretaker Antonio Pinto Mesquito with his son.
The lively and hospitable Peracchi crew that we encountered at Agua Azul during our first visit in 1995. A few of the names include Negão (center-right, standing), Daniel, Bena, José, Giovani, and Ludimir.
Pastures
The lively and hospitable Peracchi crew that we encountered at Agua Azul during our first visit in 1995. A few of the names include Negão (center-right, standing), Daniel, Bena, José, Giovani, and Ludimir.

We first visited the Agua Azul site in July 1995, and returned to tag and map mahogany trees there in ~600 hectares in June 1996. The sample mahogany trees were all smaller than 65 cm diameter. These were survivors of a first cut in the mid 1980s which removed the population’s larger stems; stumps can be found at varying densities throughout the area. Most sample trees grow in clusters strung along the banks of or adjacent to seasonal streams, mixed by size class. Some trees also grew at the tops of short steep slopes above drainage flats, in rocky gray sands. Similar to Corral Redondo, research objectives at Agua Azul focused on annual diameter growth, fruit production, and reproductive phenology. Access was by dirt track from the PA-279. Peracchi maintained a barraco at the west end of the project area where we camped during each dry season visit. Trails linking mahogany trees were re-opened annually and covered roughly 15 km. To protect trees standing exposed in secondary vegetation from groundfires, aboveground regrowth was removed each dry season to a 3-m radius of surviving trees.

We have been unable to return to the Agua Azul site since landless agriculturists occupied the site in 2002. The fate of mahogany trees there is unknown but we assume that the site has been extensively cleared and burned for crops and pasture.

The Peracchi nursery stocked full of mahogany seedlings in 1995.
Pastures
The Peracchi nursery stocked full of mahogany seedlings in 1995.
Our host family at the Agua Azul camp in 1997 & 1998: Valdisar Anjo Filho, his wife Valdelice Bezerra de Oliveira Filho, and their three sons. Valdisar was a great help to us in the field.
Pastures
Our host family at the Agua Azul camp in 1997 & 1998: Valdisar Anjo Filho, his wife Valdelice Bezerra de Oliveira Filho, and their three sons. Valdisar was a great help to us in the field.
Our hosts from 1999 to 2001 were Antonio Pinto Mesquita (far L) and his family, including sons- & daughters-in-law. Like Valdisar, Antonio and at least one of his sons helped us a great deal with fieldwork.
Pastures
Our hosts from 1999 to 2001 were Antonio Pinto Mesquita (far L) and his family, including sons- & daughters-in-law. Like Valdisar, Antonio and at least one of his sons helped us a great deal with fieldwork.

SELECTED SOURCES

Grogan J (2001) Bigleaf mahogany (Swietenia macrophylla King) in southeast Pará, Brazil: a life history study with management guidelines for sustained production from natural forests. PhD dissertation, Yale University, New Haven, CT, USA. 422 pp.

Grogan J, Schulze M & Galvão J (2010) Survival, growth and reproduction by big-leaf mahogany (Swietenia macrophylla) in open clearing vs. forested conditions in Brazil. New Forests 40: 335-347 (http://www.treesearch.fs.fed.us/pubs/37823).

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