How do agroforestry credits turn tree measurements into tonnes of carbon?

Through allometric equations that link a simple measurement, such as trunk diameter, to biomass. Isometric's protocol allows only published equations, chosen in order: local peer-reviewed ones, then Chave et al. 2014 for the tropics, then national forest inventories, then IPCC generalised equations. A global default carbon fraction is a last resort.

The order of equations

Equations vary by species, age and site, and not every species has a well-established one. The protocol restricts the choice to those published in reputable literature.

1. Local peer-reviewed equations.
2. Chave et al. (2014) for tropical regions.
3. National forest inventories.
4. IPCC generalised equations.

The carbon fraction of dry biomass

The methodology permits a conservative global default only when more specific factors are unavailable. Preferred are regional or species-specific values, or genus-specific or national average values, supported by scientific literature. ICVCM notes the default is an average, specific data is mandatory where it exists, and verifiers and the program oversee this.

What it means in the field

• Record species, planting date and trunk measurements for sampled trees.
• Ask the developer which equation it will use for each of your species and why.

What Senseible does here

Senseible does not issue or verify carbon credits and is not a registry. It gives carbon credit eligibility signals from your own records and keeps those records in order for a verifier. Verified here means rule checks passed against the evidence, not third-party assurance.

• Shade trees and carbon removals on tea and coffee estates
• Coffee agroforestry carbon credits
• Carbon credits

Sources: ICVCM, Observations on category assessment: afforestation, reforestation and revegetation, agroforestry (August 2026)

Last reviewed 2026-11-04.