Canopy buffering of different forest types under acid rain in Tianmu Mountain.

Canopy buffering of different forest types under acid rain was investigated by comparison of acid precipitation pH at open land and under six forest types canopy by field measurement in Tianmu Mountain National Nature Reserve,Zhejiang province.The results indicated that tested forest canopy had buffering effect of acid rain,but varied with seasons and forest canopy.pH value in the spring was 5.7 at the open land and 5.9 under forest canopy,that was 5.3 in the summer at the open land and 5.6 under forest canopy,and 5.1 in autumn at the open land and 5.3 under forest canopy,and 4.4 in winter at the open land and 4.8 under forest canopy.The result showed that it had the best buffering effect of forest canopy of acid rain in winter.