Climate effects on the timing and brightness of autumn leaf coloring from alpine to mountain range

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K12268
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 64040:Social-ecological systems-related
• Research Institution: National Institute for Environmental Studies
• Principal Investigator: Koide Dai 国立研究開発法人国立環境研究所, 気候変動適応センター, 研究員 (50761061)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 紅葉の色づき / 生物季節 / マルチスペクトルドローン / 衛星画像 / メカニズム / 定点観察カメラ

Outline of Final Research Achievements

We analyzed satellite images to assess the climatic effects on autumn leaf color brightness in beech forests at a landscape level. We developed a model which describes a relationship between cumulated temperature and color brightness. Spatiotemporal temperature variations impacted the maximum color brightness and the cumulative coldness required for foliage coloring.
Further analysis of the individual-level relationship between autumn leaf color and productivity in beech forests revealed a tendency for stronger coloration in warm lower-elevation sites. However, at the individual scale within the sites, highly productive individuals (i.e., high vegetation index) showed lower color brightness, suggesting that individual variations of stress conditions such as drought would play a role.
In the case of autumn color in alpine regions, the snow-free date was correlated with the color brightness, indicating a potential decrease in color brightness due to future warming.

Free Research Field

植物生態学

Academic Significance and Societal Importance of the Research Achievements

秋の紅葉景観は観光資源としても重要な生態系サービスとして認識されているが、その生態的・生理的な研究はこれまで限られていた。これは特にどれほど強く色づくかという視点において顕著に研究が少ないため、本研究は紅葉景観の重要なKPIと言える色づきの強さに関して、その生態的・生理的なメカニズムに迫った点で高い学術的意義を有している。
また色づきの強さを気候値から予測するモデルを構築し、色づきの将来変化を予測した点などでは、より直接的に紅葉景観の価値とその将来的な気候変動に伴う変化を評価したものであり、高い社会的意義を示した。