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Hydrochemical analysis of characteristics of stream flow in Liangshui National Nature Reserve |
Li Hua,Sheng Houcai,Wu Xiujuan,Di Xueying,Cai Tijiu |
School of Forestry,Northeast Forestry University,150040,Harbin,China |
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Abstract The effects of forest types on hydrochemical characteristics of streams in Liangshui National Nature Reserve were studied by the comparison experiment of watersheds.The results show that the stream flow of each watershed in reserve is weak acidic or neutral.Ca2+ is the most abundant cation followed by Na+ in these streams.In the case of anions,HCO-3 presents the highest concentration and followed by SO2-4.The monthly mean concentrations of TP in stream flow present from 0.031-0.077 mg/L,and that of TN vary from 0.682-0.942 mg/L.The concentration of NO-3-N is higher than that of NH+4-N.The monthly mean concentrations of Fe and Mn are 0.030-0.037 mg/L and 0.010-0.012 mg/L,respectively.The seasonal variation of hydrochemical characteristics of streams indicate the relatively high ion concentrations during snowmelt period(April and May) except for HCO-3,SO2-4,Ca2+,Fe and Mn.Apart from TN,TP,Fe and Mn,the concentrations of other major elements in September are higher than that in rainy season.The streams flowing through the watershed of primitive Pinus koraiensis and broad-leaved climax forest show the best water quality.The expansion of manmade forest and secondary forest in other researched watersheds result in the increase of the soluble matter in the stream flow,however,there are no significant differences except for TP and SO2-4(p<0.05).This results indicate that the influences of artificial disturbances(e.g.forest harvesting or reforestation) on the water quality of the stream flow in Liangshui National Nature Reserve are not significant.
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Received: 26 May 2007
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