Enhancing Overland Flow Infiltration through Sustainable Well-Managed Thinning: Contour-Aligned Felled Log Placement in a Chamaecyparis obtusa Plantation

Contour felling is a restoration method used to decrease overland flow (OF) and soil erosion in the world. However, impact of thinning placement felled logs on OF remains inconclusive. Low ground cover permeability promote Chamaecyparis obtusa (Siebold et Zucc.) Endl plantations, making for reducing runoff. We examined relationship between C. plantation Japan. Event-based runoff was monitored three plots from 2016 2021, with 40% conducted 2019. In plot T1, were randomly scattered, and, T2, followed contour lines, while control stayed same. After thinning, both treatment showed lower than plot. The ANCOVA test shows significant slope reduction compared pre-thinning post-thinning (T1: 0.67 0.26, T2: 0.66 0.12, p < 0.001, Tukey HSD test). remained stable two years post-thinning, affirming enduring effectiveness contour-aligned log placement. This study backs notion that aligning fallen lines boosts long-term infiltration, supporting sustainable forest management.