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BRAZIL NUTS. The Brazil Nut. The Brazil Nut Bertholletia excelsa. Bertholletia excelsa belongs to a pantropical family of trees (Lecythidaceae) that includes approximately 200 species in the Neotropics, distributed from southern Mexico into southern Brazil.
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TheBrazil NutBertholletia excelsa Bertholletia excelsa belongs to a pantropical family of trees (Lecythidaceae) that includes approximately 200 species in the Neotropics, distributed from southern Mexico into southern Brazil.
A Brazil Nut barge on the Rio Madre de Dios. The Brazil Nut is one of the most important economic plants of the Amazon. The edible seeds of this species, along with the latex of rubber trees, Hevea brasiliensis, are often cited as the most important products of extractive reserves in Amazonia. Approximately 2.5 tons of Brazil Nuts are exported each year from the Department of Madre de Dios in Peru, and approximately 20% of the population of the department works in the industry on at least a seasonal basis.
Mature Brazil Nut trees are very large, usually among the largest trees in the forest. The largest ones are 40-50 meters tall.
Unlike many large trees in the rainforest, Brazil Nut trees lack a buttressed trunk.
This individual, the largest-trunked Brazil Nut we have seen, was along the Rio Cristalino in northern Mato Grosso, Brazil.
Teresa in a Brazil Nut tree, Rio Cristalino, Brazil - Even high above the ground the trunks of Brazil Nut trees are very large.
Brazil Nut trees are not uniformly spread through the forest, but are concentrated on areas of higher, better-drained land. In Madre de Dios they are usually concentrated in strips or patches. There is also some evidence that they are dependent on tree-fall gaps.
Flowering of Bertholletia excelsa occurs during the dry season and into the wet season. In fact, Brazil Nuts grow naturally only in regions with a three-to-five-month dry season. In the eastern part of Amazonian Brazil, flowering begins at the end of the rainy season in September and extends to February. Peak flowering occurs in October, November, and December
Brazil Nut flowers are pollinated in November. For the most part, cross-pollination is needed for seed set in Neotropical Lecythidaceae. Therefore, the bees, and to a lesser extent bats, are essential for the pollination and subsequent fruit and seed development of Brazil Nuts and other members of the Lecythidaceae.
The flowers can only be entered by large-bodied bees with enough strength to pry open the androecial hood to obtain the pollinator reward that is thought to be nectar produced at the apex of the coiled androecial hood. Bees of the genera Bombus, Centris, Epicharis, Eulaema, and Xylocopa have been captured visiting Brazil Nut trees.
Beginning Brazil Nut fruits. The fruits take 13-15 months to develop.
A slightly more mature Brazil Nut fruit with the tiny developing nuts visible.
Brazil Nut fruits do not begin to fall until late December or January, 13-15 months after being pollinated. The majority of the fruits fall in January and February.
The fruits, which weigh from 0.5 to 2.5 kilograms and contain somewhere between 9 and 32 seeds, though 18-24 seeds is more normal.
Brown Agouti Dasyprocta variegata - The Agouti is an important element in the dispersal of Brazil Nut seeds. Agoutis and squirrels may be the only animals able to efficiently gnaw through the extremely hard, woody outer shell of the Brazil Nut fruits. These rodents eat some of the seeds and cache others for future consumption. Inevitably, some seeds are left in a forgotten cache where they may eventually germinate 12 to 18 months later.
The fruits are gathered immediately after they fall in order to minimize insect and fungal attack of the seeds, and to control the number of seeds carried away by animals. An experienced worker can open 1500 fruits in a day. Most collectors in the region believe that the harvest is steadily declining. The reasons for this are unclear, but decreasing rainfall may be the cause.
The Brazil Nut industry is often claimed to be sustainable, but Brazil Nut gatherers often rely on hunting wild game to provide food for the months they are in the forest. With a large group of people eating wild game every day for two months, the impact on the populations of game animals can be quite severe. Populations of animals such as large monkeys, deer, peccary, tapirs and curassows are greatly reduced by this hunting pressure and negate the claim of sistainability. Red Howler Monkey
Additionally, there is also good scientific evidence that intensive harvesting of Brazil Nuts has adversely affected the number of Brazil Nut seedlings in the forest. Over time the composition of the forest will change as there will not be enough young trees to replace old trees when they fall and die.
Brazil Nut seedling Published in the 19 December 2003 edition of the journal Science, a report by Dr Rob Freckleton of Oxford and others states: “The clear message is that current Brazil Nut harvesting practices at many Amazonian forest sites are not sustainable in the long term.....The harvest of Brazil Nuts from natural forests has led to an ageing of populations, because few seeds survive to produce seedlings, and the few seedlings that make it are fed on by large herbivores. If this process is left unchecked, then the harvest of Brazil Nuts would be unsustainable.'
A Harpy Eagle nest in a Bertholletia excelsa at Heath River Wildlife Center. As Brazil Nuts are among the largest trees in the forest, they are used as nest sites by Harpy Eagle and other species of eagle.
Scarlet Macaws along the Rio Tambopata in Peru. Large macaws like these and Amazona parrots feed on the unripe Brazil Nuts.
Red & Green Macaws at the Blanquillo ccolpa. Unripe Brazil Nuts are among the foods that macaws need to detoxify.
There is a species of Bufo toad and many insects that utilize the water that collects in Brazil Nut shells as a place to breed.
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