Frost heaves in the cold arid Leh-Ladakh region: observations on their morphological variability and patterns as indicators of pastureland degradation

This study analysed frost heave lands in the cold arid Leh-Ladakh region of the Himalaya, India through semi-detail field survey and remote sensing. Most of these sites are highland grasslands occurring along the alluvial plains of rivers in the Leh and Nubra valleys. The study identified the occurrence of some unique frost heave patterns whose morphometry varied from simple, isolated to complex ones with elongated, coalesced and superimposed bedforms. These lands can be further subdivided into vegetated and degraded types. The degraded forms exhibited several cracks, dry, collapsed and slump structures. Invasion of Cirsium arvense over native grass species, soil salinity and feeding pressure by livestock have been identified as major land degradation factors. C. arvense has replaced the native vegetation on frost heaves and has allowed Carex species to grow, which is known to degrade and deplete the pasture ecology.