Andy Jarvis writes:
We’ve long known that climate change is shifting the seasons, and plants appear to be flowering earlier in spring. But a recent study of flowering in 17 species and varieties of cherry trees in Japan had some interesting results that highlight the value of agricultural biodiversity. ((Abraham J. Miller-Rushing et al. (2007), Impact of global warming on a group of related species and their hybrids: cherry tree (Rosaceae) flowering at Mt. Takao, Japan. American Journal of Botany 94:1470-1478.)) The authors have observed that cherry trees on average flower 5.5 days earlier today compared with 25 years ago, and attribute this to an increase in temperature of 1.8°C in February-March. Another example of changing phenology. But what is most interesting is the divergent response between varieties and species – some are flowering 3-5 days earlier per 1°C temperature change, while others as many as 9 days earlier per degree change. Interestingly, these are traits that required climate change to express themselves, and must have impacts on production in addition to the aesthetics of the entire mountain no longer flowering at once.
There must be other places where blossom is important that have long term records like this.