Flowering shift due to climate warming in cool temperate Japan

Abstract

Biological processes can be disrupted by global climate warming, causing phenological mismatching and mistiming. On Hokkaido Island (Japan), which has a cool temperate climate, warmer and shorter winters affect plant flowering phenology. Rapid changes in flowering phenology suggest that shorter winters will result in earlier flowering. Flowering phenology patterns were recorded for nine years (2013–2021), and nine species were selected for analysis. I analyzed climate variables that affect plant flowering phenology, including annual changes in aerial temperature, snow depth, and snowmelt timing. The results indicated that winters are getting shorter and that the accumulated degree hours of aerial temperature have not significantly changed over nine years for these plant species except one species. Plant responses to these changes differed between species, with the first flowering day occurring earlier (1.5–1.8 days per year) for two species, although that of the other seven not. If climate warming continues, it will have diverse, complex, and unpredictable effects on various individual organisms and biological relationships among species. Detailed studies are needed to link climate change predictions to the predicted degree of mismatch in species interactions and networks.