A preliminary checklist for biodiversity conservation in Japanese conifer plantation landscapes

To provide actionable guidance for wildlife-friendly conifer plantation forestry in Japan, we present a preliminary checklist of objectives and quantitative targets organized from landscape to stand levels, together with associated confidence levels based on available evidence. Landscape-level recommendations include maintaining ≥ 40% natural-forest cover within the landscape; designating ≥ 30% of plantations as semi‑natural stands with native broad-leaved trees and developed vertical structure; maintaining remnant natural‑forest patches regardless of size; prioritizing plantation-matrix improvement around natural-forest remnants and reserves; and ensuring ~10% of the production area remains in early‑successional stands (≤10 years old) with a minimum harvest units ≥ 1.0 hectare.

For riverine ecosystems, we recommend retaining riparian buffers ≥ 10 meters on each side and promoting broad‑leaved trees. Stand‑level targets emphasize recruiting and retaining broad‑leaved trees to ≥10% of basal area across subcanopy and canopy strata, conserving understory cover to ≥10%, and implementing dispersed retention of broad-leaved trees together with aggregated retention in riparian forests, ridge-top natural-forest strips, and existing small broad-leaved patches.