Tomas Navratil, Institute of Geology, Academy of Sciences of the Czech Republic (Czech Republic)
Maria Hojdova, Institute of Geology, Academy of Sciences of the Czech Republic (Czech Republic)
Jan Rohovec, Institute of Geology, Academy of Sciences of the Czech Republic (Czech Republic)
Vit Penizek, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague (Czech Republic)
Zuzana Varilova, Bohemian Switzerland National Park Administration (Czech Republic)
Mercury is a toxic trace metal with the potential to bioaccumulate. Therefore it is important to understand Hg cycling, determine pools of Hg in ecosystems as well as its natural and anthropogenic sources. Major anthropogenic sources of Hg to the atmosphere were studied, monitored and quantified but the natural sources of Hg emissions to the atmosphere were not as well characterized. Recent studies indicate that wildfires may provide a significant flux of Hg from terrestrial ecosystems to the atmosphere. During the forest fires previously deposited Hg is released primarily from the biomass and organic-rich soil horizons to the atmosphere.
This study investigated effect of forest fire on soil Hg pools in mixed forest located in central Europe, Czech Republic. Large forest fire burned the standing biomass and vast majority of organic soil horizons on area of 17.9 ha at the Bohemian Switzerland National Park in July of 2006. The fire resisted in a hardly accessible area for one week. The soils in area affected by forest fire were Albic Podzols developed on quartz sandstone bedrock. The pool of Hg in soil profiles of unburned forest ranging from 134 to 179 g of Hg ha-1 was decreased to ranges from 13 to 81 g of Hg ha-1 as a result of forest fire in the burned part of forest. The emissions from one hectare of the burned forest would then range from 53 to 166 g of Hg ha-1. Comparison of data from unburned and burned area demonstrated that litter and possibly vegetation are important sources for Hg emitted during fire.