Increased wind erosion from forest wildfire: implications for contaminant-related risks.

Area of Science:

• Environmental Science
• Ecology
• Geochemistry

Background:

• Estimating contaminant transport rates is crucial for human and ecological risk assessments.
• Data on wind-driven transport in non-agricultural systems, especially after disturbances like wildfire, are limited.
• Wildfire events, like the Cerro Grande fire, can alter ecosystem properties and influence contaminant dispersal.

Purpose of the Study:

• To measure and compare wind-driven horizontal and vertical dust fluxes in areas affected by the Cerro Grande wildfire.
• To assess the impact of wildfire severity (unburned, moderately burned, severely burned) on dust transport rates.
• To compare post-fire dust transport with pre-fire conditions and water-driven transport.

Main Methods:

• Field measurements of dust fluxes over three years at sites with varying fire impacts.
• Utilized metrics related to wind erosion to quantify dust transport.
• Compared dust flux data between unburned, moderately burned, and severely burned ponderosa pine forest sites.

Main Results:

• Wind-driven dust flux was significantly higher (over an order of magnitude initially) in burned areas compared to unburned areas.
• Elevated dust fluxes persisted for at least three years post-fire, with a two to three times increase one year after the fire.
• Ongoing drought conditions appeared to delay ecosystem recovery, contributing to sustained high dust fluxes in burned areas.

Conclusions:

• Wildfire significantly amplifies wind-driven dust transport and associated contaminant risks.
• The persistence of elevated dust fluxes underscores the long-term impact of wildfire and drought on ecosystem stability.
• Integrating wind-driven transport into risk assessments is essential, particularly in disturbed landscapes and in the context of climate change.