Abstract and subjects
Disturbances in forest ecosystems are common and vary in frequency and severity. For forests that contain chemical or radiological contamination, these disturbances have the potential to increase contaminant transport rates and elevate human and ecological risk through increased soil erosion. However, most risk assessments, even those that project risks out for tens of thousands of years, generally do not consider major disturbances in risk predictions, nor are there much data on the magnitude of what these impacts might be. This article summarizes the relationships between ecosystem disturbance, dust production, and environmental health. The key points are that wind transport of dust would be increased in disturbed forested areas and, if the area contained chemical or radiological contaminated soil, this increase could result in higher levels of airborne contamination with increased risk to neighboring residents. These relationships are illustrated from several studies in forests impacted by wildfire and tree thinning. Previous studies show that wildfire and tree thinning each raise wind transport of dust (independently) and that the level of the increase and the recovery trajectory of the ecosystem, as measured by dust flux, depended on the severity of the disturbance. The combination of fire and thinning resulted in additive increases in wind transport of dust. In addition, previous studies suggest that concentrations of uranium increased in a neighboring community, following the fire and thinning, although the concentrations were low. A conceptual model is presented that illustrates the relationship between the magnitude and frequency of ecosystem disturbances and the recovery trajectory of the ecosystem, soil erosion, and health risk.