Human-caused ignitions and plant invasion drive fire-regime change in a dryland biodiversity hotspot

Human-caused ignitions account for 95.5% of recorded wildfires since the early 1990s in the Sonoran Desert, concentrating near human infrastructure and peaking in late spring.

• Why it matters: Drylands historically with infrequent fire are being transformed by warming, land-use change, and invasion, but the ignition and fuel mechanisms behind fire-regime change are not well quantified.
• What they did: Using records of more than 73,000 wildland fire events across the Sonoran Desert, the study quantified how ignition source, location relative to roads, and pre-fire vegetation and bare ground relate to fire size and spread.
• The result: Fire spread increased linearly with pre-fire herbaceous cover (detectable effects at 5%), while bare ground reduced fuel connectivity, implying that modest fine-fuel increases can shift fire behavior.

AI summary of the abstract · may contain errors · not medical advice · read the paper.