The impact of forest fires on the chemistry of forest soils with emphasis on mercury sequestration-north central US
Woodruff LG and Cannon WF. The impact of forest fires on the chemistry of forest soils with emphasis on mercury sequestration-north central US
A geochemical soil survey in Voyageurs National Park, Minnesota reveals a pattern of variations in many elements that correlates well with the landscape pattern of severe wildfires that burned across the region in 1936, about 65 years prior to the present study. Organic carbon and strongly correlated elements such as Hg, S, Se, Pb, and P are deficient in mineral soils within areas that burned in severe fires in 1936 relative to surrounding areas that have not burned for a considerably longer time. We interpret this pattern to illustrate a long-lived influence of severe fires on the chemical character of soils, an influence which appears to be greater than geological influences in many cases. Of particular interest is an apparent long-lived deficiency in Hg in burned areas relative to adjacent unburned forests, which implies that severe wildfires may have a long-lasting cleansing effect on Hg in these forests. A comparable soil survey of Isle Royale National Park, Michigan shows a similar spatial pattern with higher concentrations of carbon and correlated elements outside of areas that burned in 1936, although in detail this pattern is complicated by variations in geology, vegetation, and climate. Preliminary results from a study on the effect of prescribed fire on soil chemistry within a small watershed in Minnesota define short-term effects of fire on Hg distribution in mineral soils and help clarify the processes that result in the observed long-term changes.
- Type
- Unpublished Report
- Authors
- Woodruff, L; Cannon, W
- Units
- VOYA
- Keywords
- FIRE, Fire Damage, Fire Ecology, Fire Effects, Nitrogen Cycle, Nutrient Recycling, Plants-Fire Effects