Fuel availability versus flammability: divergent fire controls across Eurasian drylands

Area of Science:

• Ecology
• Environmental Science
• Geography

Background:

• Fire is crucial for regulating ecosystem cycles, particularly in seasonally dry regions.
• Understanding climate-fuel-fire interactions in Eurasian drylands is limited due to complex vegetation responses to climate.

Purpose of the Study:

• To identify distinct fire regimes (pyromes) in Eurasian drylands.
• To analyze the influence of climate, fuel characteristics, and human activities on these pyromes.
• To improve predictions of fire activity and risk assessment.

Main Methods:

• Identification of eight pyromes based on fire size, expansion, frequency, and duration.
• Analysis of geographical distribution and relationships with climatic factors, fuel load, fuel flammability, and human activities.

Main Results:

• Eight geographically contiguous pyromes with varied responses to environmental factors were identified.
• Fast-spreading fires in the Eurasian Steppe (LFFL, MFIS pyromes) are linked to fuel load and human ignition.
• Slow-spreading, long-lasting fires in high-latitude regions (LSRL, MSIL pyromes) are influenced by fuel flammability changes due to climate stress.

Conclusions:

• Fire regimes in Eurasian drylands are diverse and influenced by a combination of factors.
• Fuel load and human activity are key drivers of rapid fires in steppes.
• Climate stress impacts fuel flammability, controlling fire extent in high-latitude regions.
• Findings offer guidance for enhanced fire activity prediction and risk assessment.