Dendrochronological dating of geomorphic processes in the High Arctic

Dendrochronological methods were used to analyze geomorphic processes in the Arctic area. Samples of dwarf shrubs, Salix polaris and Salix reticulata, were collected from different morphodynamic surfaces: talus cones, debris flow tracks and fluvioglacial terraces. Clearly visible, countable and measurable annual growth rings (ranged from relatively wide 0.8 mm in width, to extremely narrow rings less than 0.01 mm in width) and wood anatomical changes (scars, tension wood) allow for using these species in dendrogeomorphological examinations. The age of the dwarf shrubs showed the minimum time during which the surface was disturbed by mass movements (e.g debris flow tracks developed in the early 1950s and 1970s) or the time of plant colonization which indicates disappearance of geomorphic processes (e.g. determining the age of fluvioglacial terraces in the Arie valley). Dwarf shrubs represent problems in synchronization of growth curves (discontinuous rings, missing rings, asymmetric geometry of stem). Samples taking from random surfaces can reflect only local phenomenon, which are limited to microtopography. It is necessary to -analyze material from entire area of geomorphic form.