The Impact of Deforestation on Brazil Nuts
September 03, 2019 Molly Melvin By Molly Melvin Follow

The Impact of Deforestation on Brazil Nuts

These days, everything we eat seems to come with its own ethical price tag. The story behind the Brazil nut, however, offers some respite from this moral minefield. If managed sustainably, the Brazil nut industry presents an unexpected solution to deforestation.

Where are Brazil Nuts Grown?

It may sound obvious, but the Brazil nut comes from the Brazil nut tree or Bertholletia Excelsa. Unconventionally, most of the world’s Brazil nuts are harvested almost exclusively from wild trees which grow throughout the Amazon Basin (find out more about this in ‘The Brazil Nut | How It’s Grown’). So far, efforts to cultivate the Brazil nut tree have failed, largely because it is too difficult to replicate the complex symbiotic relationships the Brazil nut tree depends on to produce fruit.

Brazil Nuts Need Pollinators

Unlike the rest of us, the Brazil nut tree is the most productive between October - December. During this period, it produces large, pale yellow flowers which have the life-span of just one day, with new blooms emerging in daily succession. This presents a small window of opportunity for female orchid bees (‘euglossine’ bees) to work their magic. These feisty little bees are the only insects mighty enough to lift the hood-like structure shielding the stamens at the interior of the flower. Cross-pollination is required for the tree to bear fruit, making these bees a major player in the whole Brazil nut operation.1 

No Bees: No Brazil Nuts

While the female bees are hard at work, males, busy collecting their own pollen, take a trip to epiphytic bucket orchids. During their visit, they daub themselves in the orchid’s pollen, leaving a scent which is irresistible to females – playing the role of cupid in their courtship.

Here's where the plot thickens. Orchid bees tend to live in primary forests where these orchids naturally grow – so without the surrounding forest, orchid bees can’t reproduce, and without reproduction, the Brazil nut tree would produce significantly less fruit. Some theories suggest this love triangle is the principle reason virtually all our Brazil nuts come from wild trees. Cultivating Brazil nuts has been fruitless – quite literally – with farmed trees producing negligible amounts of nuts compared to their wild cousins.2

Bees Under Threat?

Given that orchid bees depend on forest cover, it is easy to imagine how activities such as timber harvesting and slash-and-burn agriculture might affect fruit yield. Recent studies have shown that the last twelve years have seen a decline in forest-dependent bee populations of up to 50% in some Amazon regions – likely due to deforestation and habitat-loss.3

You would think this was sure to have a knock-on effect on fruit numbers, and in turn, the economic security it provides local extractive communities. However, it’s too early in the day to tell – as Manuel Guariguata, CIFOR’s Principal Scientist on tropical forest ecology and management explains, CIFOR are currently undertaking experiments to determine the level to which deforestation may start to influence harvest rates, but until a long term study is made ‘there is no answer yet. What is clear is that when you see Brazil nut trees isolated in pastures, they tend to produce very little fruit, probably due to lack of suitable habitat for pollinators’.

Saving the Rainforest: One Brazil Nut at a Time

Local harvesters are aware of the need to maintain the forest for their livelihood, so Brazil nut collections take place on extractive reserves which protect the forest.4 Which means that – unlike most of what we eat, as long as it’s done sustainably, harvesting Brazil nuts can actually work to conserve rainforests, while also supporting the local communities which depend on it.

The challenge moving forward will be maintaining consumer demand so that harvesters are able to make a better living from Brazil nut sales, lessening their need to turn to other non-forest exploits such as timber harvesting or agriculture.5

Are you more likely to buy Brazil nuts after reading this? Let us know in the comments below!

September 03, 2019 Molly Melvin By Molly Melvin Follow

References

  1. Cavalcante, Oliveira, Maués, Freitas (2012) “Pollination Requirements and the Foraging Behavior of Potential Pollinators of Cultivated Brazil Nut (Bertholletia excelsa Bonpl.) Trees in Central Amazon Rainforest” Accessed 26 July 2019.
  2. Pollination.The Brazil Nut Story: Sustaining the Amazon. Accessed 22 July 2019.
  3. Nemésio (2012) “Are orchid bees at risk? First comparative survey suggests declining populations of forest-dependent species.'' Accessed 26 July 2019.
  4. Salo, Siren, Kalliola (2013) “Collect Locally, Eat Globally – The Journey of the Brazil Nut.” Accessed 24 July 2019.
  5. Guariguata, Cronkleton, Duchelle, Zuidema (2017) “Revisiting the ‘cornerstone of Amazonian conservation: a socio-ecological assessment of Brazil nut exploitation.'' Accessed 23 July 2019.
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