Interaction between knowledge and experience in using wild edible plants in two biosphere reserves in Japan

Local ecological knowledge (LEK) about the sustainable use of wild species is vital for ecosystem management and the preservation of biocultural diversity. However, its decline has accelerated worldwide. Using questionnaire surveys targeting schoolchildren (ages 10–12), their families, and teachers/staff in two mountainous communities designated as biosphere reserves in Japan, we aimed to understand how LEK is maintained among children and their stakeholders. We recorded the number of wild edible plants known to be edible (knowledge richness) and those that had been collected before (experience richness) for each individual. We examined how these measures relate to age, gender, family structure (e.g., living with or near elders), childhood nature experiences, and daily frequencies of collecting or eating wild species. Piecewise structural equation models (SEM) revealed a strong link between knowledge and experience richness, emphasizing the importance of conserving LEK and traditional practices (living knowledge). Among children, proximity to grandparents indirectly increased both knowledge and experience richness by increasing the frequency of eating wild edible plants and playing outdoors. This highlights the vital role of vertical transmission of LEK. Our findings emphasize the significance of experience-based environmental education programs at school for passing on LEK (oblique transmission), especially for children not living with or near their grandparents. Simultaneous assessment of knowledge and experience offers better insights into conserving and restoring LEK and regional ecosystems.