Research On Key Technology Of Bioremediation In Ore Areas

Ecological restoration and reconstruction in ore areas has currently become a difficult issue for its extremely harsh site conditions.Researches were implemented on the ore area of Mount Yizi located at Luan County,Tangshan City.Fully considering its poor and thin soil,water deficit,high steep rocky slopes and other constraints,the studies focuses on key technologies of bioremediation and ecological reconstruction in the ore area.The concrete proposal was as follows: herbs were planted on terraces,arbors and shrubs on gentle slopes,and cash crop,oil peonies,on reclaimed lands.The results after 3 years indicated that coverage of herbs on terraces reached to 90%;coverage of shrubs on gentle slopes reached to 71%;and the coverage of oil peonies reached to 47%.In addition,plant growth added soil nutrients,increased the activity of soil enzyme,obviously improving the soil environment in the ore area.Variation rules of physiological indicators of vegetation under different drought levels were simulated by using PEG-6000.It found that as drought stress intensified,withered leaves,relative conductivity,relative harmfulness and free proline of the five herbs gradually increased;leaf water volume and chlorophyll a/b gradually decreased;root vitality and POD activity tended to firstly increase and then decrease.Besides,the restoration effects on soil and drought tolerance of various vegetations were evaluated via subordinate function.The Parthenocissus was planted for ecological restoration and all Parthenocissus planted on terraces,floating plate plots and drill holes were monitored in various slope directions.The results indicated that Parthenocissus grew averagely over 6.8 meters after three years,almost covering all bare rocks.The drilling diameter is the key for liana planting technology with drilling.Therefore,under four rooting zone restrictions,the effects on aboveground growth,root growth,photosynthesis and plant physiology of Parthenocissus respectively were studied indoor,combined with engineering cost,showing that 15 centimeter diameter was the optimal choice to plant liana by drilling on rocky slopes.Studies were mainly made from the aspects of phytoremediation,drought stress and plant physiological changes,and vegetation coverage technology on rocky slopes.All efforts were expected to lay a foundation for studies over bioremediation technologies and restoration effects in ore areas under various site conditions.