Autumn leaf color brightness of Japanese alpine vegetation is projected to decrease under future climate change.

Area of Science:

• Ecology
• Environmental Science
• Botany

Background:

• Autumn leaf coloring is a vital cultural ecosystem service.
• The mechanisms behind autumn color brightness are poorly understood.
• An 'autumn color crisis' (premature leaf fall without coloring) has been observed in Japanese alpine shrubs.

Purpose of the Study:

• To investigate the relationship between autumn leaf color brightness and environmental conditions.
• To project future changes in autumn color brightness under climate change scenarios.
• To understand the ecological and economic implications of altered autumn coloration.

Main Methods:

• Autumn color brightness was quantified using repeated camera observations at three Japanese alpine sites.
• Environmental factors influencing color brightness were analyzed using linear mixed models.
• Future snowmelt and green-up timing were predicted using degree-day models and climate projections.

Main Results:

• Earlier green-up timing was significantly correlated with reduced autumn leaf color brightness.
• Prolonged leaf duration due to earlier green-up may reduce leaf physiological vitality and anthocyanin biosynthesis.
• Future climate projections indicate earlier snowmelt and green-up, leading to a potential decline in autumn color brightness by up to 15% by the end of the century.

Conclusions:

• Earlier spring green-up due to climate change is a primary driver of decreased autumn color brightness in Japanese alpine shrubs.
• Reduced autumn coloration may negatively impact tourism revenue and alter ecosystem material cycles and productivity.
• Urgent conservation strategies and further research are needed to mitigate the impacts of the autumn color crisis.