Widespread synchronous decline of Mediterranean-type forest driven by accelerated aridity

Area of Science:

• Ecology
• Climate Science
• Forestry

Background:

• Large-scale ecosystem shifts due to climate extremes are under-documented.
• Increasing tree mortality suggests some forests approach collapse.
• Mediterranean forests are vulnerable to climate variability.

Purpose of the Study:

• To assess climate and productivity trends in global Mediterranean forest ecosystems (2000-2021).
• To detect and characterize abrupt ecosystem changes in response to climate extremes.
• To evaluate the potential future of Mediterranean forests under projected climate change.

Main Methods:

• Analysis of climatic data and forest productivity trends.
• Identification of abrupt changes in forest health and productivity.
• Comparison of Chilean event with global Mediterranean forest ecosystems.

Main Results:

• A rapid, large-scale forest browning and productivity decline (>90% of forest in <100 days) was detected in Chile.
• This event was driven by sustained, acute drought and extreme warm conditions.
• The Chilean drought conditions are unprecedented in recent Mediterranean ecosystem history.

Conclusions:

• The Chilean forest browning serves as a critical indicator of ecosystem vulnerability to extreme climate events.
• Long-term forest recovery in Chile is uncertain due to declining water balance.
• This event may foreshadow similar abrupt changes in other Mediterranean forest ecosystems globally.