Tiny forests, huge claims: The evidence gap behind the Miyawaki method for forest restoration

Evidence-based methods for restoring ecosystems are essential for successful restoration practices, yet many approaches are adopted without rigorous evaluation. The Miyawaki method, originally developed in the early 1970s, has gained popularity for its purported ability to accelerate biodiversity recovery and ecosystem functioning compared to conventional methods. However, the empirical evidence supporting these claims remains unclear. We conducted a systematic review of scientific literature on the Miyawaki method. Of 51 documents examined, only 41% (n = 21) provided quantitative assessments, and among these, just 33.3% (n = 7) included a control and 14.3% (n = 3) included replication. Reported outcomes offered weak to null evidence for most claimed benefits, including rapid growth, accelerated succession, self-sustainability, cost efficiency, enhanced biodiversity, higher carbon sequestration and increased tree density. Synthesis and applications. To scale up restoration effectively, practitioners and policymakers should prioritize methods supported by robust empirical evidence rather than relying on untested claims. Our findings highlight the urgent need for rigorous experimental designs and transparent reporting to guide evidence-based restoration strategies.