| Summary: | Existing methods of restoring vegetation to abandoned coalmine wasteland are inapplicable to the harsh Qinghai-Tibet Plateau because it faces several unique challenges, including a perennially low temperature, strong winds and solar radiation, the presence of permafrost, and the lack of suitable topsoil, all of which are absent from low-altitude regions. It remains unknown which restoration measures could be successful in this particular environmental setting. In this case study we demonstrated that these challenges can be overcome via four proposed measures, each targeting a unique challenge. Namely, the surface morphology of the mining waste must be reshaped into a pyramid-resembling terrace comprising flat strips interspersed with slopes < 25 degrees to prevent permafrost-thawing triggered debris slippage. Instead of expensive topsoil replacement, locally sourced and quickly weathered mixture of permafrost and coal gangue can be used to reconstruct the topsoil after its fertility has been enriched with fertilizers. A mixture of grass seeds suitable for the frigid environment must be sowed at a higher dosage (e.g., 300 kg.ha(-1)) than the usual 20-30 kg.ha(-1). Covering the sowed fields using a mesh made from fibers considerably boosted seed germination and grass growth. Field experiments demonstrate that a combined use of the adapted measures enables vegetation to be established. Both plant height and aboveground biomass reach the peak value of 40.6 cm and 71.0 g.m(-2), respectively, after three years of restoration, but decreases by year five. Plant cover and the quantity of new seeds increase with time, peaking at 57.3% and 682.9 seeds.m(-2) at the end of year five, respectively. These vegetation properties are consistently better on sunny slopes than on shady ones. Thus, surface covering and the dosage of seeds sowed on these slopes need to be increased accordingly. It is concluded that the adapted measures are suitable for the study area and other plateau areas sharing similar environmental settings.
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