Increased Wind Erosion from Forest Wildfire: Implications for Contaminant-Related Risks
- Jeffrey J. Whicker *a,
- John E. Pinderb and
- David D. Breshearsc
- a Los Alamos National Laboratory, Health Physics Measurements Group, Mail Stop J573, Los Alamos, NM 87545
b Colorado State University, Department of Environmental and Radiological Health Sciences, 1618 Campus Delivery, Ft. Collins, CO 80523
c University of Arizona, School of Natural Resources and Institute for the Study of Planet Earth and Department of Ecology and Evolutionary Biology, Biological Sciences East 325, P.O. Box 210043, Tucson, AZ 85721-0043
Assessments of contaminant-related human and ecological risk require estimation of transport rates, but few data exist on wind-driven transport rates in nonagricultural systems, particularly in response to ecosystem disturbances such as forest wildfire and also relative to water-driven transport. The Cerro Grande wildfire in May of 2000 burned across ponderosa pine (Pinus ponderosa Douglas ex P.&C. Lawson var. scopulorum Englem.) forest within Los Alamos National Laboratory in northern New Mexico, where contaminant transport and associated post-fire inhalation risks are of concern. In response, the objectives of this study were to measure and compare wind-driven horizontal and vertical dust fluxes, metrics of transport related to wind erosion, for 3 yr for sites differentially affected by the Cerro Grande wildfire: unburned, moderately burned (fire mostly confined to ground vegetation), and severely burned (crown fire). Wind-driven dust flux was significantly greater in both types of burned areas relative to unburned areas, by more than one order of magnitude initially and by two to three times 1 yr after the fire. Unexpectedly, the elevated dust fluxes did not decrease during the second and third years in burned areas, apparently because ongoing drought delayed post-fire recovery. Our estimates enable assessment of amplification in contaminant-related risks following a major type of disturbance-wildfire, which is expected to increase in intensity and frequency due to climate change. More generally, our results highlight the importance of considering wind- as well as water-driven transport and erosion, particularly following disturbance, for ecosystem biogeochemistry in general and human and ecological risk assessment in particular.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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