Flowering phenology under climate warming

Owing to global climate warming, biological processes will be disrupted, causing phenological mismatches and mistimings. In Japan's cool temperate region of Hokkaido Island, warmer and shorter winters will affect plant flowering phenology. Rapid change in the flowering phenology led to the hypothesis that shorter winters would result in earlier flowering. The flowering phenology of 611 species was recorded for nine years (2013–2021), and 9 species were selected for analysis. The accumulated degree hour, which is the total value of the hourly aerial temperature above zero, was calculated as the effective aerial temperature for plant flowering phenology. The results indicated that winters are getting shorter, and the first flowering day of two plant species occurred earlier. However, the accumulated degree hours for the plant species have not significantly changed over the nine years. 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.