Scholarly record

COMPARATIVE ANALYSIS OF VAN BEMMELEN FACTORS FOR SOIL ORGANIC CARBON IN PARAMO ECOSYSTEMS

Freddy Armijos-Arcos, Luis Pati o, Andris Beltran-Davalos

Abstract

Accurate estimation of soil organic carbon (SOC) is critical for carbon accounting in high-altitude ecosystems, where variability in soil properties challenges the use of standardized conversion factors. This study assesses the validity of the Van Bemmelen conversion factor (1.724) for estimating SOC from soil organic matter (SOM) across contrasting Andean ecosystems within the upper Pastaza River watershed in Ecuador, with a primary focus on paramo. A total of 109 soil samples were collected at 30 cm depth using a modified GLORIA methodology. SOC was determined via DUMAS dry combustion, while SOM was assessed by the Loss on Ignition (LOI) method. Conversion factors were calculated for four ecosystem types: paramo grasslands, montane forests, anthropogenic grasslands, and subnival zones. Results showed that in paramo grasslands, the empirical conversion factor (1.729) was statistically indistinguishable from the theoretical value, supporting its continued use in this ecosystem. However, significant deviations were found in montane forests (1.656) and subnival areas (1.866), emphasizing the need for ecosystem-specific adjustments. One-sample t-tests and ANOVA confirmed these variations, and the high correlation between SOM and SOC (R- = 0.93) suggests potential for local calibration to refine estimates. Despite variations among ecosystems, the Van Bemmelen factor remains a practical tool for estimating organic matter from SOC when its limitations are considered. This research contributes to improving SOC quantification practices in complex mountain environments and highlights the need for caution when applying global constants to heterogeneous landscapes. The findings support the partial validity of the Van Bemmelen factor in paramo systems, while encouraging the adoption of calibrated factors elsewhere to enhance carbon monitoring precision.

Publication Impact Profile

• Captures
• Mendeley - Readers: 1

PLUMX see details

Dimensions ID: pub.1195348489

DOI resolver: doi.org/10.5593/sgem2025/3.1/s12.30

Publication details

Back to publication list