The Character And Distribution Of The Greenbelt Soil Of Nanjing

With rapid development of urbanization, the influence of urban soils on environment and human health is becoming increasingly concerned. Urban soil that was regarded as the major factor of sustainable development of urban areas is the important part of ecosystem, site for vegetation, nutrition supplier for vegetation, habitat for soil microorganism, energy supplier for soil microorganism, filter and buffer for urban pollution.The greenbelt soil in parks is the important site for the citizen to relax and to get in touch with the natural world. At the same time, many environmental problems are faced, Essential part of the urban environment is urban greenbelt soils, which were seriously affected by human activities in urban areas.Such as the quality of soils is becoming worse, its roles for production and ecology is changing or losing.The study concentrated on parks in Nanjing city ,including 116 samples ,the contents and distributions of pH,total potassium(TK),total phosphorus(TP),Olsen phosphorus (Olsen-P), organic matter(OM) and total nitrogen(TN), heavy metals include Fe, Co, Ni, Mn, Cr, Cu, Pb, Zn, Free-Fe and magnetic susceptibility were analyzed and assessed.The results are summarized as follows:238 topsoil samples from Nanjing including the samples from parks were analyzed. The variant coefficients of pH, TK from Nanjing were 7.6%, 17.4%, indicating that they have strong spatial auto-correlation patterns. They were analyzed with Kriging.The results also showed that the average pH in park soils was 7.9, they were alkalescent.pH from Nanjing parks were influenced by soil parent materials and alkalescent materials from urban constructions.TK were influenced by soil parent materials and landforms in Nanjing (the landform of southwest is flat, while that of northeast is mountainous), so the contents of TK from the southwest were much higher than those from northeast. The variabilitis of TP, Olsen-P, OM and TN were very high, the variant coefficients varied from 63-79%. So they were analyzed with Interverse Distance Weighted(IDW), the results showed that contents of P in parks were very high, they were influenced by the human activities .The contents of OM and TN ere also higher than barren soils, they were influenced by the greenbelts and vetetation types.The pollutants of heavy metals resulted from the exhaust gas and tyre abrasion, and the heavy metals' harm resulted from grain's move.The contents of heavy metals and magnetic susceptibility is comparatively higher, Fe, Co, Ni, Cu, Mn, Cr and magnetic susceptibility have significant correlations. So the measurement of magnetic susceptibility provided a simple, quick means for monitoring pollution status of Fe, Co, Ni, Cu, Mn, Cr in urban...