Evaluating three methods for estimating soil carbon stocks in forested wetlands

Abstract

Forested wetlands are critical yet understudied carbon pools of the Wabanaki/Acadian Forest region of Canada, requiring practical methods for soil organic carbon (SOC) stock estimation. This study evaluates three methods: Loss on Ignition (LOI), Total Organic Carbon (TOC) analysis, and the Canadian Model for Peatlands (CaMP) for cost, time, and efficacy in eight forested wetlands. CaMP was the fastest and cheapest ($186 investment; 32 minutes/plot) but the least reliable, underestimating SOC stocks by 40.5 ± 106.3 Mg ha-1 relative to TOC. LOI balanced cost and efficacy ($2,770; 128 minutes/plot), averaging 27.5 ± 35.0 Mg ha-1 below TOC, while TOC ($4,042, 128 minutes/plot) served as the reference standard. Results suggest LOI is optimal under budget constraints; CaMP is unreliable, therefore inappropriate for site-scale inventories. This report provides a framework to align SOC stock estimation with resource constraints. Future work should refine procedures for mineral soil wetlands and validate LOI results with minimal TOC.