Global patterns of drought recovery.

Area of Science:

• Ecology
• Climate Science
• Carbon Cycle Research

Background:

• Droughts are a major climatic extreme impacting global ecosystems and the land carbon sink.
• Understanding ecosystem recovery time after drought is critical for predicting future land carbon dynamics.
• Global trends in drought regimes are uncertain, but increased frequency and severity are projected for the 21st century.

Observation:

• Analysis of three independent gross primary productivity datasets reveals key factors influencing drought recovery.
• Drought recovery time is strongly linked to climate variables and carbon cycle processes.
• Biodiversity and carbon dioxide (CO2) fertilization play secondary roles in ecosystem drought recovery.

Findings:

• Drought recovery is longest in tropical and high northern latitude ecosystems, areas particularly vulnerable to climate change.
• Ecosystem drought impacts, measured by recovery area and time, have demonstrably increased throughout the 20th century.
• Global spatiotemporal patterns of drought recovery are strongly associated with climate and carbon cycle dynamics.

Implications:

• Projected increases in drought frequency may shorten the intervals between drought events, potentially exceeding ecosystem recovery times.
• This could lead to irreversible ecosystem damage and significant degradation of the vital land carbon sink.
• Urgent research and mitigation strategies are needed to address the growing threat of prolonged drought impacts on global ecosystems.