Effects of logging residue mulching on first-year regeneration of Japanese oak following soil scarification

Regeneration techniques for Japanese oak ( Quercus crispula Blume) remain limited, raising concerns about sustainable resource management due to the exponential harvesting of high-quality, large-diameter trees. In the cool-temperate forests of northern Japan, dense dwarf bamboo ( Sasa spp.) often inhibits tree regeneration making soil scarification necessary. However, excessive solar radiation and desiccation created by the treatment may hinder seedling establishment. Therefore, this study investigated whether forest floor mulching with logging residues could enhance Japanese oak regeneration by mitigating them. In a logged stand with partially retained seed trees, logging residues were redistributed beneath the trees and acorns were sown. Seedling emergence, survival, and growth were monitored during the first growing season. Mulching with logging residue significantly increased acorn germination and reduced browsing damage by deer; however, its effect on acorn predation, presumably by rodents, remains unclear. The results suggest that, although some uncertainty remains, mulching logging residues has potential as a supplementary technique to promote early establishment of Japanese oak.