For the surveys, the scientists recorded every tree with a trunk diameter of at least 10 centimeters, or about 4 inches. To learn how each stand was harvested, they examined records, interviewed nut gatherers and, in some cases, counted the number of opened or harvested Brazil fruits on the ground. The stands ranged in size from about 22 acres to about 3,336 acres, and some of the historical harvest data dated back to 1900.
The result of the research was unambiguous, the authors wrote.
New trees "were most common in unharvested and lightly harvested stands, uncommon to rare in moderately harvested stands and virtually absent where seeds had been persistently collected in the 20th century," the paper says. "The clear message from this study is that current Brazil nut harvesting practices at many Amazonian forest sites are not sustainable in the long term."
Kainer said Brazil nuts have long been considered a model "nontimber forest product" because they enable local populations to earn cash without engaging in more destructive practices, such as timbering or clearing the land for farming. In fact, because Brazil nut trees flourish only in the wild, they provide an economic incentive to preserve the rainforest. While the research does not indicate any short-term threat to this ecologically sustainable industry, it does suggest managers should plan for the future now, she said. Options include limiting harvests, restricting harvest seasons, or nurturing and planting more Brazil nut trees, she said.
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Contact: Karen Kainer
kkainer@latam.ufl.edu
352-846-0833
University of Florida
18-Dec-2003