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