Impact of spruce deadwood logs on physical properties of a loamy sand Podzol in a steep temperate forest

Abstract

AbstractThinned steep forests are particularly vulnerable to soil physical degradation. Retaining deadwood logs from thinning operations on the forest floor can potentially mitigate soil physical degradation by modifying its physical properties through increased carbon content in steep regions. We aimed to investigate the effect of spruce deadwood logs from thinning operations on the physical properties of a loamy sand Podzol soil in a steep (30°) temperate spruce forest in Bavaria, Germany. The soil organic carbon (SOC) content was 56% higher under deadwood logs compared to the control areas (p‐value = 0.097). Deadwood logs also increased the soil water repellency by 13% (p‐value = 0.269), while decreasing the soil shear strength by 35% (p‐value = 0.001). Shear strength and water repellency strongly correlated with SOC content, with r = −0.87 and r = 0.86, respectively. Although retaining deadwood logs seems a promising carbon sequestration strategy, it can adversely affect soil shear strength and water repellency and potentially lead to soil degradation. Therefore, the choice to keep deadwood logs on the forest floor may align with specific management goals.