Global buffering of temperatures under forest canopies

Area of Science:

• Ecology
• Forestry
• Climate Science

Background:

• Macroclimate warming trends are widely documented.
• Forest microclimates are often assumed to mirror ambient warming.
• Tree canopies possess the potential to significantly modify local thermal environments.

Purpose of the Study:

• To investigate the thermal buffering capacity of forest canopies.
• To compare understory temperatures with open-air temperatures across diverse global sites.
• To quantify the impact of forest cover on microclimate moderation.

Main Methods:

• Paired temperature measurements were collected under forest canopies and in adjacent open areas.
• Data were gathered from 98 distinct study sites spanning five continents.
• Statistical analysis was employed to compare thermal offsets.

Main Results:

• Forest canopies significantly moderate understory temperatures, providing cooling during heat and warming during cold.
• The magnitude of this thermal offset increases with temperature extremes.
• The observed buffering effect surpasses the rate of global land temperature warming over the last century.

Conclusions:

• Forests act as critical thermal insulators, moderating microclimates.
• Tree canopies can substantially reduce the negative impacts of extreme temperatures on forest biodiversity.
• Forests play a vital role in ecosystem resilience to climate change.