Higher carbon storage in primary than secondary boreal forests in Sweden

Overview

This study quantifies carbon storage differences between primary and managed secondary boreal forests in Sweden through extensive mapping and field inventories. The research examines total ecosystem carbon pools across vegetation, deadwood, soils, and harvested wood products to assess the implications of forest management for global carbon cycling.

Methods and approach

The investigation employed extensive spatial mapping combined with field inventory data from primary forests in Sweden. Multiple independent methodological approaches were applied to estimate carbon storage across all major ecosystem compartments, including aboveground and belowground vegetation, deadwood, soil organic matter, and long-lived harvested wood products. Cross-validation across methods provided robustness to estimates.

Key Findings

Primary forests store approximately 72% more total carbon than managed secondary forests, with this estimate consistent across multiple methodological approaches (70-74% range). Soil carbon comprises both the largest absolute carbon reservoir and the largest differential between forest types. The quantified difference in total carbon storage between primary and managed secondary forests ranges from 2.7 to 8.0 times greater than previously reported estimates in the literature.

Implications

These findings substantially revise previous assessments of boreal forest carbon dynamics and the carbon consequences of conversion from primary to managed secondary forests. The considerably larger storage differential implies that past estimates of boreal forest management contributions to atmospheric carbon dioxide concentrations may be substantially underestimated. Current and projected future carbon balance estimates for boreal forest regions require recalibration in light of these empirically-derived storage differentials.