重庆酸雨地区森林生态系统土壤、植被与地表水现状分析

酸沉降现象在重庆已成为一个严重的长期环境污染问题，本文根据东亚酸雨监测网土壤、植被监测技术规范的方法-研究了酸沉降对森林生态系统土壤、地表水以及植被的影响和危害。通过对土壤的分析：3个采样点的土壤pH值较低，这可能与大气S和N的输入有关，导致了土壤酸化。而南山采样点的盐基饱和度(BS)均值少于10％，盐基离子交换量(CEC)也较低．土壤中Al^3 浓度相对较高，土壤中C／N较低，南山可能存在土壤酸度增加的危险，以及土壤中Al浓度增高并伴有S或N沉降增加的危险。对地表水分析结果表明，南山采样点地表水的酸中和能力(ANC)较大，但是该采样点土壤剖面的盐基饱和度并不高，由此可推测该地表水可能是经由盐基离子丰富的土壤或岩石径流而来。通过对植被的分析，酸雨可能对杉木和柳杉这两种酸敏感性植物有一定的危害作用。

A Status Report on the Effects Involved with Acid Rain on Vegetation, Soil and Surface Waters of Forest Ecosytstem in Chongqing

Acid rain has been a severe environmental pollution problem in Chongqing,Soil acidification trends have been resultantly obvious.The harm and effect of acid deposition to soil,surface water and vegetation of forest ecosystem were studied in this paper by the guidelines and technical manual for acid deposition monitoring network in East Asia.By soil analysis,it was found that the pH value of soil was low.It was possibly associated with the input of atmospheric S and N,most likely led to the acidification of soil and soil water.The base cation saturation(BS) was less than 10% in all sample layers of the Nan-shan sample sites.The effective cation exchange capacity(ECE) was low.The high content of aluminum in soils of Nan-shan sample sites The C/N ratio was low,and declined with the soil depth,which indicated that the organic matter was well decomposed under warm and rainy subtropical climate.According to surface water analysis,the ANC of Nan-shan sample was high,but the CEC was low.Through thus,it can be speculated that this terra surface water flow by soil or rock with abundance positire ion.According to vegetation analysis,acid deposition might do harm to fir and cryptomeria,both of which are acid sensitive.