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Since September 2012 Anaité López (Instituto Nacional de Bosques, Guatemala), Tim Marks (Millennium Seed Bank) and Wolfgang Stuppy (Millennium Seed Bank, do visit his amazing blog) have been working at the Millennium Seed Bank to develop a long-term storage protocol for the seed of the Maya Nut tree (Brosimum alicastrum).

 

This is important because Maya Nut is a significant famine food for the rural poor in northern Central America and is being actively used in reforestation projects as it is fast growing and relatively tolerant of disturbance.  At the moment, however, it is not possible to store the seed for more than a couple of weeks making it very difficult to deploy seed as and when it is needed outside of the fruiting season.

 

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Left: Maya Nut (Brosimum alicastrum) fruit - Fruit as it is when still on the tree

 

Right: Maya Nut (Brosimum alicastrum) seed - Seed once stripped of the fleshy outer layer by bats or birds (left), with both papery coverings removed (centre), with only the outer of the two papery covering removed (right)

 

The work involved collecting about 5,000 seeds from Maya Nut forests in the Peten of north eastern Guatemala. The seed was then shipped to the Millennium Seed Bank by courier where it was unpacked and studied by Anaité who had flown over from Guatemala for six weeks to undertake the work under the supervision of Tim Marks and Hugh Pritchard, specialists in seed research and storage. This was an opportunity for her to take back the skills and knowledge that she had learnt to Guatemala. The work has been funded by Defra through the Darwin Initiative (project 18-010) and is taking place incollaboration with the Maya Nut Institute.

 

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A batch of Maya Nut seeds being germinated following controlled storage. Image courtesy of Anaité López.

 

Our plan was to devise a regime of cooling and drying the seed that would enable it to be cryogenically stored (frozen) and so stored for many years. To do this we needed to identify the best rate at which to drop the temperature and humidity whilst keeping the seed viable. This involved storing the seed at different temperatures and humidities and taking a batch out and germinating it every month.

 

Given that this seed does not survive for long in the wild and that it is protected by two very thin, papery coverings (see above) we expected it to be very prone to dessication and so sensitive to low humidity. In fact we found quite the reverse. Six months later we are still germinating seed that has retained most of its moisture after having being stored in a dessicant for all this time!

 

In order to understand how this could happen we contacted seed morphologist Wolfgang Stuppy, world expert on seed morphology. He made the following images of sections through the seed which show a thin but dense layer of cells that control waterloss from the seed:

 

 

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Section through Maya Nut seed showing the dark outer layer that might reduce water loss. Image courtesy of Wolfgang Stuppy.

 

So we now have a partial explanation as to how the seeds can show such remarkable tolerance to drying out. It does, however beg two questions:

 

  1. Why do seeds not survive under the conditions of the forest floor?
  2. Why would a tropical tree that grows in the humid tropics develop such a remarkable resistance to drying out?

 

To be continued maybe...

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It has been a while since my last post, but here's some news I'd like to announce:

 

Darwin Initiative project 20-021 - Forest Futures: Livelihoods and sustainable forest management in Bolivian Amazon

 

Who we are

We are a team of scientists, development workers and businesses in Bolivia and the UK lead by The Royal Botanic Gardens Kew and comprising the Bolivian NGO, Herencia, the Noel Kempf Mercado Natural History Museum in Santa Cruz, Bolivia and the Edinburgh based company Freeworld Trading, together with a number of subsidiary partners who include brazil nut harvesters, rural communities and regional universities.

 

Where we are working

We are working in the Pando Department of the Bolivian Amazon an area of tropical rain forest that is rich in biodiversity and an important source of brazil nuts:

 

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Project area and communities currently engaged in our project (click images to see the full size version)

 

Why we are working there?

Poverty drives the unsustainable use of forested landscapes as it is difficult and impractical for people to sacrifice their immediate and basic needs for the long-term benefits of sustainable agriculture. 69% of the forest-dependent population of the Pando are unable to satisfy these basic needs and 34% of them live in extreme poverty.

 

This combined with immigration to Amazonia, driven by economic, political and environmental factors, has placed increasing pressure on the tropical forests there. The Pando forests are important as they support a large forest-dependent population, are a significant source of biodiversity and ecosystem services and constitute important buffers for the eastern Andean catchments from predicted impacts of climate-change.

 

Losing these forest will not only lead to a loss of biodiversity and ecosystem services, it will also reduce Bolivia’s ability to meet its Millennium Development Goals and increase vulnerability to climate change among the rural poor. This work is funded by the Darwin Initiative (Award 20-021).

 

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Slash and burn agriculture in the Bolivia Amazon. Image: Bente Klitgaard, 2010

What we plan to do

By September 2016 we plan to mitigate the threats to the tropical forest of the Pando by supporting the development of sustainable practices that reduce forest conversion, coupled with increasing the awareness of how forests reduce poverty and provide ecosystem services amongst the population and government of the Pando.

 

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Ingaagroforest: we are planning to establish similar agricultural systems on abandoned or exhausted pasture in Bolivia. Image from Honduras, courtesy of the Inga foundation.

 

Specifically, we aim to establish Inga tree-based agriculture on degraded cattle pasture, diversify the number of non-timber forest products that can be sustainably extracted from the Pando’s forests and exported, and raise awareness amongst local rural and urban communities and government as to the economic value of their forests and the role that they do and can play in reducing poverty and providing ecosystem services.

 

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