In Japan, cherry blossoms are an important tourism resource and provide many cultural ecosystem service benefits. Under future warming conditions, we will require adaptions such as changing the timing of flower festivals to account for changes in the flowering phenology. In this study, we evaluated the coincidence between the flowering phenology of cherry blossoms and the associated festival periods in two Japanese cities under past, recent, and future climate conditions. We examined the situation in Shinhidaka, where the flower festival period changes every year, and Takayama, where the festival period is fixed to coincide with a shrine's annual spring festival. Currently, the average dates of beginning of flowering (more than four or five flowers open in an index tree; ~BBCH60) and full bloom (equal to or more than 80% of flowers open in an index tree; after BBCH65) in Shinhidaka (day of year (DOY) 126 and 130) are later than the long national holiday of Golden Week (DOY 119 to 125). The respective dates in Takayama (DOY 106 and 111, respectively) are later than the local a festival period (DOY 104 and 105). Under a scenario of 1.0 to 2.0 °C warming, the full blooming dates in Shinhidaka will coincide with Golden Week, whereas under 1.0 to 1.5 °C warming, the full blooming dates in Takayama will coincide with the spring festival period. Thus, moderate warming may increase the value of cherry blossoms to the tourism industry. Under more than 3.5 °C warming in Shinhidaka and 2.5 °C warming in Takayama, however, cherry blossoms will have already dropped by Golden Week and the spring festival period, respectively, suggesting that greater warming may decrease the value of this tourism resource.
Keywords: Cherry; Cultural ecosystem service; Flower festival; Global warming; Japan.