Harvest residue retention or removal can influence soil carbon (C) sequestration during forest management. Many studies have explored the factors that affect the direction and extent of changes in soil C after different harvest residue management practices. However, the effect of soil properties, especially soil texture, on the difference in mineral soil C storage between harvest residue retention and removal treatment are still not fully understood. Using a meta-analysis approach, we investigated the factors that influence the change in mineral soil C stocks following stem-only harvest (SOH), when compared to whole-tree harvest (WTH). We found that the retention of harvest residues associated with the SOH treatment led to 8.2% greater soil C storage in 0–20 cm mineral soils, compared to the WTH treatment. Soil properties (soil clay content and C concentrations) were the most important factors mediating soil C response to residue retention. Relative to the WTH treatment, the SOH treatment showed smaller mineral soil C pools in some high clay content soils, possibly by increasing the mineralization of existing soil organic matter stocks via a priming mechanism. Climate was a poor predictor of differences in treatment effects, with no significant difference between temperate and tropical forests. There were no significant relationships between the treatment effect on mineral soil C and mean annual temperature or precipitation. Both coniferous and broadleaf forests exhibited a significantly higher mineral soil C storage in the 0–20 cm soil layer with the SOH relative to the WTH treatment. Compared to WTH treatment, the higher soil C contents in upper mineral soils after the SOH treatment appeared to last about one decade after harvesting. The findings of this analysis suggest that soil texture and C concentrations in mineral soils should be considered when assessing the impact of forest harvest residue management on soil C pools.
