Biostabilization of an active landslide using early colonizing species in the Western Himalayas

Landslides manifest important soil degradation processes in the Western Himalayas. It has been recognized that slopes under vegetation are much more resistant to landslide processes compared to bare soils. Revegetation of such bare and exposed sites by using early successional native colonizing species is, therefore, considered to be a very effective landslide control measure. Three primary successional native plant species were selected for bio-stabilization of landslide damaged sites in Uttarkashi and their growth performance was evaluated for one year. Seedlings of Alnus nepalensis (tree), Mimosa himalayana (shrub) and Woodfordia fruiticosa (shrub) were transplanted on landslide damaged sites from a nearby nursery, where the species were grown and their growth performance was evaluated for one year.

The results reveal that Alnus nepalensis with greater height (36.44 cm), collar diameter (0.69 cm), leaf area (964.80 cm²) and soil volume (0.13 m³) etc. and Woodfordia fruiticosa with higher root volume (72.80 cm³), binding capacity (80.06) and root: shoot ratio (1.03) performed significant better growth than Mimosa himalayana in landslide sites. The successful establishment of these species and their significant above and below ground growth performance on landslide damaged sites indicates that these species can be recommended alone or in suitable combination for the stabilization of such landslides in the region.