Warming temperatures accelerate spring leaf flush in Japan

Their analysis found that in 2023, leaf flush began 3 to 7 days earlier than the 2018-2024 average in the Kanto and Chubu regions. In 2024, similar advances occurred in the Hokuriku, Tohoku, and Hokkaido regions, with the Shirakami Mountains area recording SOS nearly 9 days earlier than usual. The study identified spring air temperature (February to April) as a strong driver, showing that each 1 K rise corresponds to an average 4.4-day advancement in leaf flush timing.

Extrapolating these findings to future climate projections, researchers estimate that SOS could occur around 7 days earlier under the low-emissions RCP 2.6 scenario, and up to 21 days earlier under the high-emissions RCP 8.5 scenario. These shifts have potential consequences for biodiversity, ecological synchrony, and forest health.

The study underscores the ecological ramifications of continued global warming and the importance of long-term satellite and field monitoring to understand and respond to such changes.

Research Report:Impact of high temperature in 2023 and 2024 on spring leaf flush phenology in Japan derived by GCOM-C satellite