RESTORATION OF VEGETATIONAL BIODIVERSITY THROUGH REHABILITATION OF DEGRADED MINED LANDS OF UTTARANCHAL HIMALAYA

摘要

The ecosystem in outer Himalayas of Uttaranchal (India) has been greatly disturbed due to limestone mining and other developmental activities. This has resulted in accelerated erosion hazards, poor vegetal cover, increase in per cent slope, decrease in soil depth, poor texture, low moisture retention, environmental degradation and vegetational diversity. The vegetal degradation due to mining-cum-deforestation have resulted in shrinkage of the vegetal cover to 10 per cent or even less at places in Mussoorie hills causing local extinction of many plant species and reduced bio-diversity. The remaining identified species have been categoriesed into endangered, vulnerable, rare, and threatened. To restore the vegetational biodiversity of limestone minedareas, suitable reclamation measures were developed and applied, depending upon soil/ spoil characteristics, site, slope and physio-edaphic conditions. Reclamation techniques developed are combination of mechanical and vegetative measures to arrest minespoil/debris, soil, water and nutrient losses on one hand and combating environmental degradation and restoring vegetational biodiversity on the other; Studies conducted reveal that planned placement of overburden, water and sediment management, top placing and mixing of normal soil with minespoil, soil amendments and mulching, application of organics and fertilizers and revegetation with suitable plant species are the effective rehabilitation measures. In steep slopes, techniques like geotextiles, spraying with seeds slurry prepared with cowdung and hay, planting in holes and pits, contour trenching and wattling etc. proved effective. The plant species found suitable for revegetation are: Eulaliopsis binata, Saccharum spontaneum, Chrysopogon fulvus, Pennisetum purpureum, Eriophorum cosmosum Pueraria hirsuta, Arundo donax Ipomoea earned, Vitex negundo, Agave americana, Leucaena leucecephala, Bauhinia retusa, Acacia catechu, Salix tetrasoperma, Erythrina suberosa, Grewia optiva, Ficus rumphii, Eucalyptus hybrid, Cederela toona etc. Treated minesites have now started generating additional resources of fuel, fodder, fibre, timber and water for irrigation on sustainable basis and have improved the economy and ecology of the area. The species position in the treated sites have started hanging toward succession after regeneration with protection, soil and water conservation and revegetation measures.