Atmospheric supply of trace elements studied by peat samples from ombrotrophic bogs

Area of Science:

• Environmental Science
• Geochemistry
• Atmospheric Science

Background:

• Ombrotrophic bogs accumulate peat, preserving historical environmental data.
• Understanding atmospheric deposition is crucial for environmental monitoring and pollution control.

Purpose of the Study:

• To assess peat as a medium for estimating temporal and spatial atmospheric deposition of trace elements.
• To identify sources of various elements (e.g., long-range transport, soil dust, marine emissions) in Norwegian peat bogs.

Main Methods:

• Analysis of iron (Fe) and 12 trace elements in peat samples from 21 sites across Norway.
• Consideration of geographical variations in marine influence and air pollution.
• Evaluation of the impact of surface plant cover on element concentrations.

Main Results:

• Surface peat effectively reflects geographical variations in heavy metal deposition.
• Long-range atmospheric transport is the primary source for As, Cd, Pb, Sb, and Zn.
• Co, Cr, Fe, and Ni originate mainly from local soil dust; Se is linked to marine biogenic emissions.
• Manganese (Mn) and zinc (Zn) show surface enrichment due to plant-soil nutrient cycling, while coastal Mn is affected by marine salt deposition.

Conclusions:

• Surface peat is a valuable archive for studying geographical patterns of atmospheric deposition.
• Differentiating between pollution sources (long-range, local, marine) is essential for accurate interpretation.
• Plant-mediated nutrient cycling significantly influences surface peat element concentrations.