Effects of Canopy of Natural Forest on Water Quality

The indicators of water quality,such as pH and so on,of rainfall and throughfall of natural forest in Huoditang region,Qinling mountain,were measured from collected samples,and then analyzed through comparing and contrasting.The result shows that the canopy of natural forest has several effects on water quality.Firstly,the canopy has a notable ability of buffering the pH of acidicrain,reducing the degree of acidity of rain to be medium when rain becomes throughfll.It is foliage that plays an important role in buffering the pH.Secondly,the canopy can reduce NO~-_3 to some degree in rain.Thirdly,the canopy enriches NH~+_4,K,PO~(3-)_4,Na,Mg and Fe in throughfall,especially K.It was enriched greatly.At the same time,the canopy adjusts NH~+_4,Na,Ca and Mg in water when rain becomes throughfall.The concentrations of K,Na,Ca and Mg in throughfall are higher in leave-falling time.Fourthly,the canopy can absorb toxic elements Cr,Pb and heavy mentals Mn,Zn in rain,especially Pb and Zn.The capability of absorbing Cd in rain is about 0.8 μg/L.In addition to absorbing Pb and Zn significantly,it still stabilizes and regulates them when rain becomes throughfall.