The Collapse of Solifluction Lobes as a Factor in Vegetating Blockfields


  • Larry W. Price



Active layer, Creep, Frozen ground, Mass wasting, Permafrost, Plant cover, Plant distribution, Plant-soil relationships, Plants (Biology), Slopes, Ruby Range, Yukon


In the Ruby Mt area of southwestern Yukon, tongues and islands of vegetation occur in certain blockfields, which through normal processes develop soil and vegetation only very slowly, due to a lack of near-surface water and great diurnal temperature extremes during summer. The collapse occurs when the lobes move from the meadow onto the steeper slope of the blockfield where composition of vegetation changes and where there is a deeper active layer. Once collapsed, they flow downslope transporting clumps of vegetation which may establish themselves along the mud-flow channel or levee. Thus certain arctic and alpine slopes are vegetated more quickly than would otherwise be possible.