Morphometry and Environment of Asymmetric Non-sorted Stripes in Northern Sweden

Because the mechanisms that lie behind the formation and preservation of asymmetric non-sorted stripes have not yet been established, and their particular shape has been given little attention by authors before, this study aims at giving a better understanding of the landforms and the environmental conditions under which they exist, with emphasis on under what circumstances the asymmetry develops. For this purpose, the roles of vegetation and snow were key concerns as well as the wind regime in relation to the vegetation, snow and morphology. The study consists of a thorough description of non-sorted stripes in the valley Gohpasvaggi, near Abisko field station in Northern Sweden. It comprises investigations of the ground thermal regime, soil moisture and other environmental parameters considered likely to have implications for the occurrence and appearance of the landforms. Results showed that the non-sorted stripe continues to the depth of ca 40-50 cm in the form of distortions of the deeper horizons, whereas the asymmetry is limited to the shallower A-horizon. In the stripe ridges there seems to be an upward movement in the soil that is likely physically driven (e.g. frost action). The furrow between the stripe ridges appears to be a quiescent area with normal soil development. The net downward movement here is likely biologically driven. The asymmetry can be related to the wind based on their corresponding direction and on the understanding of how feedback mechanisms involving wind, snow and vegetation works to maintain the micro topography. Differential frost heave and free convection of water in soil are plausible explanations for the origin of the non-sorted stripes in Gohpasvaggi. The current maintenance of the stripes is likely a combination of biological, physical and hydrological mechanisms that interact and depend on each other