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“Permanence” of Carbon in Reforested Tropical Pastures

When it comes to storing carbon in reforested tropical pastures, permanence can be a difficult question.  Traditionally, in our experience, farmers who plant trees on tropical pastures will cut them down when they reach commercial sizes, so there is no permanence other than the 20-30 years the trees needed to grow. After that, you start again if the farmer wants to plant again.

In the RTT Model, we have another idea.  We believe that if pasture reforestation projects are designed and managed correctly, they are capable of producing significant income for the farmer and significant amounts of CO2 sequestered in the live forest.  The basic numbers we seek to show are a) a growth rate of 40 m3/ha/yr during the first 25-year period divided into b) 15 m3/ha/yr given to the farmer from thinnings to sell for profit, and c) 25 m3 (or its equivalent of 25 tonnes of CO2) left in the forest for sequestration.

A 3.5-year-old carbon-offest forest in Costa Rica sponsored by The Superior Nut Company and managed by Reforest the Tropics, Inc.

A three-and-a-half-year-old carbon-offest forest in Costa Rica sponsored by The Superior Nut Company and managed by Reforest the Tropics, Inc.

Our RTT Model posits that if we can show that the farmer can earn $500/ha/yr from thinnings during the initial 25-year contract, then this is competitive with cattle on the same site, opening up thousands of acres of pastures to reforestation using the RTT Model.

Presently, in the RTT Model, the US emitter sponsors each hectare with a donation of $5,000, one-time, up front. The undiscounted cost of one tonne of sequestered CO2 in this Model would be between $8 and $10: 25 tonnes/ha/yr x 25 years = 625 tonnes total sequestered per hectare. 625/$5,000 = $8/tonne.

From the $5,000, the farmer receives $2,000/ha, a contribution towards the costs of establishing a forest (seedlings, weeding, etc.).  The farmer also receives 4 years of intensive management from RTT, an estimated cost of $2,000 or $500/ha/yr.  That’s weekly management of the farmer’s project.  In return, in the 25-year contract signed by RTT with the farmer on behalf of the US sponsor, the farmer agrees to cede the registration of the sequestered carbon solely to RTT in the name of the US sponsor.

At the end of the 25-year period, the forest returns to the farmer.  However, it is still a young forest with a potential of sequestering more CO2.   So, our Model surmises a second contract for the continued management of the forest for both income and sequestration with the sale of the carbon-offsets for the benefit of the farmer.  If the forest continues to follow the same growth rate of 40 m3/ha/yr divided into 15 m3 for sales and 25 m3 for sequestration, sustained income could be substantial.

In fact, certain of our forests have reached over 50 m3 current annual growth in the 5th year, and we believe they may go even higher.  Understanding the annual growth rate of various pasture sites, species plantings, and management schemes is a major focus of RTT’s ongoing research.  Our forests are specially designed using 3 or more tree species. Presently, we are testing 31 different mixtures, different designs.

It our view, permanence depends in large part on giving the farmer a certain minimum level of profitability; in our case, our initial goal is $500/ha/yr.  If the farmer can make as much money as with cattle on the same site, then the farmer has an incentive to preserve the site as a sustainable forest with the carbon in the live stand.

RTT is an applied research program, developing and demonstrating a model for carbon sequestration through tropical forestry.  Feel free to email us with questions: