A map analysis of patterned-ground along a North AmericanArctic Transect

摘要

Arctic patterned-ground features have been described individually, but neverexamined as parts of integrated landscape/ecosystems that vary along the Arctic climategradient. Here we examine the complex interrelationships between patterned ground,climate, vegetation and soil along a north-south transect through all five bioclimatesubzones of the North American Arctic. We mapped the vegetation, biomass,end-of-summer thaw depths, and snow cover on twenty 10 x 10-m grids. The vegetationmaps illustrate the transition of vegetation types and patterns from north to south.Biomass maps showed lower biomass in the centers of patterned-ground features than inareas between features, and increasing biomass from north to south. Thaw-depth mapsshowed deeper thaw in the centers of features than between features, and shallow thaw onthe north and south ends of the transect. Snow depth maps showed less snow onpatterned-ground features subject to differential frost heave compared to areas betweenfeatures which did not heave, and a north-south gradient of increasing snow depth.The maps also documented the change from small nonsorted polygons to larger nonsortedcircles from north to south, and increasing pattern size with moisture. Principalcomponents analysis revealed underlying relationships between patterned-groundlandscapes and measured vegetation and environmental variables. Climate in combinationwith the vegetation was the most important factor affecting patterned ground on zonalsites, but soil moisture, texture and chemistry were also important.