Comprehensive best-practice matrix for the quantification of organic soil in forest soils under the REDD+ framework

Abstract

The accurate quantification of soil organic carbon (SOC) is critical for the issuance of soil-based carbon credits within the REDD+ framework. Nonetheless, methodological heterogeneity and systematic errors in the estimation of key parameters such as bulk density and coarse fragment content introduce significant uncertainties that undermine the robustness of SOC stock assessments. This study proposes an integrative evaluation matrix grounded in methodological rigor, statistical robustness, and soil management considerations to enhance the precision and reliability of SOC quantification for carbon credit accounting under REDD+ mechanisms. The framework integrates advanced correction protocols for bulk density estimation, refined procedures for quantifying coarse fragment volume, and optimization of experimental design through statistical replication and power analysis to reduce uncertainty
and improve reproducibility. The application of this matrix supports the standardization of methodological quality across studies and projects, enabling more defensible SOC estimates and reinforcing their credibility in carbon markets and climate change mitigation strategies.