Reforest the Tropics, Inc. An applied research program demonstrating climate change mitigation through sustainable farm forestry

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 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:  info@ReforestTheTropics.org

We frequently receive inquiries regarding how to measure/calculate the carbon sequestered in regrowing forests.  Here is RTT’s approach to addressing this important question:

1) To calculate the carbon being sequestered in a forest, you’ll need a series of permanent sample plots, measured periodically. We use a 1/10-ha plot for each hectare of forest.

2) Measure the green volume of the stems in the plot and add another 50% for the roots.

3) Convert the green volume to dry weight by using the basic density. The literature would have those values for each species in a given plot.

4) About 50% of the dry weight of wood is carbon, C. Use that figure. Multiply the plot value by 10 if you use 1/10-hectare plot sizes.

5) The C content of CO2 is 27.3% based on the respective molecular weights. So divide the weight of carbon, C, in your plot by 0.273 to come up with the amount of CO2 the forest has sequestered.

6) Divide by the age of the forest to get the average annual rate of sequestration.

7) Subtract the calculated total value for last year for the calculated total value from this year and you will have the current annual rate of sequestration.

8) These calculations assume that you started with an open pasture with no trees, i.e., that your baseline was zero carbon on the site when you started.

We’re always willing to address questions about the RTT model for carbon sequestration through tropical forestry.  Email us at info@ReforestTheTropics.org

Oxen hauling logs during a periodic thinning of a RTT carbon-offset forest. Photo taken Feb. 2009.

RTT is developing a model of reforestation that is profitable for the farmer and that sequesters CO2 efficiently for the US sponsor.   The farmer earns money from each forest as RTT carries out periodic thinnings—partial harvests that allow the forest to grow healthier and faster.

RTT always thins the poorer quality trees to leave more room for the remaining trees to grow larger.   Shown here is a team of oxen taking out some logs from a forest we are thinning this month.  The photo was taken last week in Costa Rica.

Many of Reforest the Tropics’ carbon-offset forests implement an innovative “layer cake” design—i.e., a stratified mixture of planted trees which combines fast growth, potential income, strong long-term carbon storage, and ancillary environmental benefits.

A nine-year-old deglupta hybrid tree in the Connecticut College Carbon-Offset Forest. Photo taken Feb. 4, 2009.

The Connecticut College Carbon-Offset Forest is one such forest.  Planted by RTT in 1999, the Connecticut College forest was designed to offset the carbon dioxide emissions associated with the Crozier-Williams Student Center on the college’s campus in New London, Connecticut.

The nine-year-old deglupta hybrid tree shown in this photo is part of the A-layer (above the B- and C-layers) of the specially designed forest, which is located in the the Las Delicias Farm in Costa Rica.

RTT developed the hybrid deglupta tree for its fast growth and other advantageous characteristics.  Tall, straight and widely spaced, the deglupta tree has a light crown that allows light to filter through to the B-layer that contains several species.  Not visible in this photo is the C-layer of Klinkii trees; the C-layer grows underneath the other trees to capture the remainder of the solar energy and increase total production in the forest.

By planting, managing, and monitoring forests such as that sponsored by Connecticut College, RTT continues to improve its innovative designs for tropical carbon-offset forests.

Planting forests to sequester carbon dioxide will work only if the forests are sustainable in the long term—and forests will be sustainable only if they provide an incentive to the farmers on whose land they are planted.  Reforest the Tropics (RTT) is developing an innovative model for sustainability in tropical carbon-offset forests.

Oxen extract a log thinned from a ten-year-old carbon-offset forest in Costa Rica, managed by Reforest the Tropics, Inc. Photo taken Feb. 5, 2009.

The log shown in the picture is one of many thinned last week from a Costa Rican carbon-offset forest.  A thinning is a selective partial harvest to improve the quality of the forest and to allow the remaining trees to grow with less competition.  This site was a farm pasture 10 years ago, prior to its reforestation by RTT in cooperation with Mr. Rojas, a farmer.  The log shown contains about 1 cubic meter of wood, which the farmer can sell for about US$30. Most logs in this first thinning were smaller.  The current thinning began last week and is presently ongoing; dozens of logs will eventually be extracted from this forest.  The extraction of these logs improves the carbon-offset forest by concentrating its growth in the better remaining trees.  This is the first of many planned periodic thinnings to improve this forest and to provide the farmer with income under the RTT model.

This research forest was sponsored by a group of 26 US donors.  RTT manages the forest in a 25-year contract with the farmer.  In general, under the RTT model, US sponsors donate $5,000, a one-time deductible donation, for the rights to the resulting sequestration in a 2 ½-acre forest during those 25 years.  The sequestration rate in this forest is estimated at 25 tonnes of CO2 annually.  Thus, the undiscounted cost per sequestered tonne of CO2, if our estimates of the rate of sequestration are right, is about $8-$10/tonne of CO2.

The RTT model is designed to be a sustainable, win-win model for sequestering carbon dioxide that benefits all participants and the environment.  Contact RTT for additional information or to get involved by sponsoring a new research forest to offset the carbon emissions of an organization or individual.