Reducing logging intensity in north temperate rainforests for climate and economic benefits

Interior temperate rainforest’s role as a global carbon sink conflicts with lucrative logging revenues. Yet, the relationship between the proportion of trees harvested and whole-ecosystem carbon flux is still unclear. In a large, replicated trial in western Canada, we monitored carbon in the ecosystem and wood products in response to logging of varying intensity: clearcuts, light and heavy partial-cuts, and no harvest. Averaged over the 26 years, net-CO₂e yr⁻¹ emissions increased linearly with logging intensity (R²=0.80 for mature stands). Unharvested stands were sinks (2.2 ± 1.9 MgCO₂e ha⁻¹ yr⁻¹; mean ± standard deviation) and clearcuts were sources (-21 ± 11 MgCO₂e ha⁻¹ yr⁻¹), whereas light partial-cuts almost recovered their pre-harvest carbon (-2.9 ± 2.7 MgCO₂e ha⁻¹ yr⁻¹). An economic exercise suggests that partially or fully retaining mature trees in interior temperate rainforests can help meet 2050 ‘net-zero’ targets while still providing economic benefits greater than logging if emissions are priced above ∼CAD65 $ MgCO₂e⁻¹.