Brazil nuts reproduction ecological report


Dr. Alan Rizzo
IB Biology SL Y1
January 13, 2014

Brazil nuts reproduction ecological report

Brazil nuts contain exceptional nutritious elements and can only be harvested in the Amazon forest of Brazil. Each Brazil nut tree towers high up to 200 feet; its branches provide habitat and food for other animals. Despite the fact in which only those Brazil nut trees that grow in undisturbed forests bear fruit, their reproduction has high dependency on other organisms of the forest. In accordance to my research, there are two main organisms that every Brazil nut tree depends on for its own reproduction: the orchid Coryanthes vasquezii and the agouti of genus Dasyprocta.

Only an insect strong enough to lift the coiled hood on the flower can pollinate Brazil nuts and with a tongue long enough to reach the complex flower spiral. Nut production depends on the presence of Coryanthes vasquezii, an orchid that attracts long-tongued male orchid bees of genus Euglossa, with its scent that male bees need to attract females. The large female long-tongued orchid bees then pollinate the Brazil nut trees. If there is no orchid, the bees will not mate, and the lack of bees means that Brazil nut trees will not get pollinated. Brazil nut fruits will take 14 months to mature after the pollination. Each fruit has a diameter of 10 to 15 cm and weighs up to 2 kg, which is called “Ouriço”. Its shell, similar to wood, is 8 to 12 mm of thickness, and it has about 8 to 24 seeds, which are the Brazil nuts, inside.

The agoutis, South American rodents that appear similarly to large guinea pigs, possess the ability to penetrate the hard-rock case of Brazil nut fruits. Their small and chiseled teeth crack open Brazil nut pods. They eat some of the nuts before burying them for future meals. When those nuts are forgotten, they stay dormant for years in nature before finding optimal conditions to germinate, and grow into a new Brazil nut tree.