Morphometry and biophysical characteristics of turf-banked lobes and terraces, Kluane Lake, Yukon Territory.

Abstract

The distribution, morphometry and biophysical characteristics of turf-banked lobes and terraces are described from a small subarctic alpine plateau (1300--1900 m a.s.l.) overlooking Kluane Lake in the southwest Yukon Territory, Canada. Observations on the distribution of lobes and terraces at this site indicate that the main controlling factors are the complexity of the topography and the properties of snow cover. Morphometric analysis of 85 lobes subdivided into five different slope orientations indicates a morphogenetic underpinning in which lobe form remains consistent (length-to-width ratio below unity) at different scales and between aspects, however, morpho-biophysical correlations could not provide an explanation for this. Nonparametric and multivariate parametric statistical tests indicate significant inter-aspect differences in the dimensions and biophysical characteristics of the lobes. These appear to be related to differences in site-specific factors. Measurements made along certain transects reveal a definitive downslope trend in the size of lobes. This organization is developed as a result of downslope gradients of various biophysical factors, primarily soil moisture and frost-susceptible soil (silt and clay), which are created by slopewash processes.