Flowering of cherry blossom and warming in winter in recent years

Abstract

In this paper, relationship between flowering of cherry blossom and warming was investigated including effects of dormancy breaking in winter in recent years. Before 1990, the main factor of cherry blossom flowering was able to be explained only mean temperature in March, at most of the weather stations. However after 1991, the necessity of adding the winter minimum temperature to it was suggested. It was clarified that after 1991, the region which flowering of cherry blossom delayed due to increase of winter temperature extended from Kyushu to some points of Honshu. In Choshi, there were many warm winter that mean minimum temperature were more than 5 degrees and delay of the flowering dates were remarkable after 1991. Therefore it is concluded that winter warming have delayed the dormancy breaking of cherry blossom, and finally delay of the flowering dates occurred in larger area in recent years.