An assessment of population phenology of Japanese horse chestnut tree (Aesculus turbinata) using flowering and leafing evaluation method

An individual-level phenological evaluation method was developed for grasping changes in the state of inflorescences and leaf buds in 90 Japanese horse chestnuts trees (Aesculus turbinata). From the comparison of the three horse chestnut populations used for collecting the nuts in Ayabe City, Kyoto Prefecture, Japan, this result revealed that the beginning, peak, and late flowering periods of horse chestnut individuals and populations were identified through the evaluation of the inflorescence judged with 10 stages, and that this evaluation method may provide an effective perspective for elucidating the relationship between flowering synchronization and flowering period and their ecological processes. It is expected that the phenological information related to the conservation of the horse chestnut forest will be accumulated through multiple years of evaluation.