5 Contamination in Peatlands

With increasing resource extraction activities such as: peat harvesting, mining, and associated transportation corridors in boreal areas; and with forest harvesting and agricultural development in tropical environs; there is increased risk of anthropogenic contaminant release in peatlands. In many cases, contaminants alter the ability of peatlands to provide important ecosystem services such as carbon sequestration. These alterations are driven by shifts in the cycling of nutrients and carbon or by direct disruption of biotic systems (i.e., by toxic metals) that are integral to peatland function. Sources of contamination range from direct aqueous inputs to long-range atmospheric deposition. The type of peatland, specific contaminant, and mode of input govern the contaminant mobility and changes of peatland functions. For example, in some peatlands, a chemical will be a mobile contaminant but in others it will be sequestered. Understanding the feedbacks between specific contaminants, delivery methods, and peatland function is critical to properly mitigating adverse human and environmental health impacts.