Genetic differentiation in the timing of budburst in Fagus crenata in relation to temperature and photoperiod.

Climate change is expected to influence plant productivity particularly through changes in the timing of budburst. Nonetheless, knowledge about the intraspecific variation of the timing of budburst and its relationship with climate is insufficient for most tree species. Based on the common garden experiments of Fagus crenata, we investigated the interrelationships between the day of budburst, cumulative degree-days (temperature sum), chilling duration, and photoperiod at the timing of budburst for the trees of different combinations of 11 sites of seed origin and seven experimental sites in Japan.