Organic Carbon Contents of Permafrost Soils Along the Yukon Coastal Plain, Canada

The response of Arctic coasts to climate change can effect changes to the global carbon cycle. This is because degrading permafrost and eroding shorelines have the potential to release not only carbon dioxide and methane directly to the atmosphere, but soil organic carbon into the nearshore zone as well. This feedback has implications for carbon system dynamics and future climate change. In this regard shorelines containing ice-rich permafrost and backshore areas with extensive wetlands are the most sensitive. The Yukon Coastal Plain along Canada's Beaufort Sea represents potentially one of the most sensitive coastal climate systems. This study details the methodology for quantifying the amount of soil organic carbon along the Yukon coast. A morphological method developed to estimate the relative percentages of sediment and ground ice is applied to various terrain units in different geomorphic settings, with the resulting values being calibrated by field data. Published values for soil carbon are then used to calculate the organic carbon contents of the coastal soils. The potential contribution of organic carbon to the nearshore zone caused by climate change-induced thawing of permafrost and increased wave erosion along the Beaufort Sea coast is discussed.