| Summary: | Permafrost stores large quantities of organic carbon throughout the Arctic tundra. With the warming climate, the permafrost degrades upon thawing. With ice melting, soil subsides, the active layer thickness increases, and the level of the water table depth fluctuates towards dryer or wetter conditions depending on drainage. The thawing of permafrost exposes organic matter to decomposition but also mineral constituents to water. The exposure of a previously frozen reservoir of mineral nutrients may boost biological activity, enhance plant nutrient uptake, and/or influence associations between organic and mineral constituents, thereby modifying the balance between carbon input and output from the permafrost. This study evaluates the impact of warming permafrost on mineral element distribution in soils at the study site of “Carbon in Permafrost Experimental Heating Research†(CiPEHR) in Interior Alaska. The soil mineral element concentrations have been measured in soils before and after 8 years of artificial warming. This study provides evidence for decreasing soil element concentrations upon warming for soluble elements such as Ca. The data also highlight an increase in Fe concentrations in shallow soil horizons from the active layer. It is hypothesized that Fe is mobilized upon reducing conditions induced by changes in the water table depth. This supports that soil warming affects mineral element mobility and therefore likely influences the availability of mineral elements that stabilize organic carbon in soils.
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