A Study on the Biomass Production of Populus,Salix,Ulmus and Robinia on the Reclaimed Arca by Coal Ash

Coal ash from thermal power factory was filled in the collapsed area formed by coal-digging,and then 30 cm of soil is covered onto the coal ash.The result was that four tree species grew normally under proper fertilization and irrigation condition.Their biomass are:4-year-old poplar 51.95 kg,5-year-old Robinia 76.56kg,5-year-old Salix 44.15 kg,5-year-old Ulmus 38.98 kg.Biomass distribution of the inside tree was:trunk 46.3%～63.0%,branches 17.4%～23.4%, roots 14.3%～25.9% and leaves 2.5%～4.6%.The conclusion was that the planting of alkaline resistant tree species or shrubs on the reclaimed coal ash is an effective way in the improvement of ecological environment and soil utilization.