Soils and frost boil ecosystems across the North AmericanArctic Transect

摘要

We studied soil properties of frost boils at nine zonal-vegetation locations across theNorth American Arctic Transect (NAAT) in order to better understand arctic soils and theirinteraction with other biogeophysical components of frost boil ecosystems. Soil genetichorizons were analyzed for particle size, pH, electrical conductivity, total organic carbon(OC) and nitrogen (N), bulk density and volumetric water content. Surface soils (0-5 cm)across frost boil patterns were analyzed for of pH, OC, water content, extractable N and P,and exchangeable K, Ca and Na. Our results revealed that soil texture, pH, EC, P, Na and Ca contents are strongly influenced by local parent materials. Soil pH was acidic inthe north going to alkaline in the midtransect and then again back to acidic in the south.Simple correlations between soil analytical data and observed frost boil properties acrossthe NAAT support and are consistent with the laboratory and theoretical-conceptual models of pattern ground dynamics that have been developed by others. Soil water relatedwell to texture. Soil horizon %0C and profile OC stocks under the pattern correspondedwell to biomass and frost heave, respectively. Also soil water was closely related tobiomass and heave. Nutrients in surface soils at sites corresponded to OC stocks. Aninteraction between soil water and segregation of Na and Ca between the pattern andinterpattern was found for locations with high cation availability. At these sites, chemicalas well as physical disruption of the pattern area could affect plant establishment. Overallthere was a good linkage between properties relating to frost boil pattern dynamics andsoil biogeochemical properties. Our study offers insight into the important process ofcryoturbation for carbon sequestration in Gelisols across the Arctic.