Liu Juxiu, Zhang Deqiang, Zhou Guoyi, Wen Dazhi, Zhang Qianmei
South China Institute of Botany, Chinese Academy of Sciences, Guangzhou 510650, China.
Ying Yong Sheng Tai Xue Bao. 2003 Aug;14(8):1223-8.
Studies on the chemical properties of precipitation, throughfall, stemflow and surface run-off in major forest types at Dinghushan under acid deposition showed that the pH value of precipitation was about 4.90, and the frequency of acid rain was over 62%. In broad-leaved forest, the pH value of precipitation was lower than that of throughfall, but higher than that of stemflow and especially the surface run-off, indicating that the soil was naturally acidified. In mixed forest, both throughfall and surface run-off had a higher pH value, but stemflow had a lower pH value than precipitation. The throughfall and stemflow were more acidified than precipitation in coniferous pine forest, but the surface run-off had a higher pH value than precipitation. These results suggested that among the three major forest types at Dinghushan, the canopy of broad-leaved forest had the highest buffering ability, whereas for the soil, the coniferous forest had the highest soil buffering capacity. The concentrations of nutrient elements, such as P, K, Ca, Na and Mg in the throughfall, stemflow and surface run-off were higher than those in bulk precipitation in all forests at Dinghushan, some even 10 times higher, indicating that a large amount of nutrients were leached from the canopy. The concentrations of nutrient elements in stemflow were higher than those in throughfall in all forests, and the concentration of nutrient elements in surface water was higher than those in atmospheric rainfall. Coniferous forest had a higher concentration of nutrients in the throughfall and stemflow and a lower nutrient concentration in the surface run-off than other forest types, which implied that nutrient loss was more serious in broad-leaved and mixed forests than in coniferous forests.
对鼎湖山主要森林类型在酸沉降条件下降水、穿透水、树干流和地表径流化学性质的研究表明，降水的pH值约为4.90，酸雨频率超过62%。在阔叶林里，降水的pH值低于穿透水，但高于树干流，尤其是地表径流，这表明土壤已自然酸化。在混交林里，穿透水和地表径流的pH值较高，但树干流的pH值低于降水。在马尾松林里，穿透水和树干流比降水酸化程度更高，但地表径流的pH值高于降水。这些结果表明，在鼎湖山的三种主要森林类型中，阔叶林冠层的缓冲能力最强，而对于土壤来说，针叶林的土壤缓冲能力最强。鼎湖山所有森林中，穿透水、树干流和地表径流中P、K、Ca、Na和Mg等营养元素的浓度均高于大气降水，有些甚至高出10倍，这表明大量养分从林冠层淋溶下来。所有森林中树干流的营养元素浓度均高于穿透水，地表水的营养元素浓度高于大气降雨。针叶林穿透水和树干流中的养分浓度高于其他森林类型，地表径流中的养分浓度低于其他森林类型，这意味着阔叶林和混交林的养分流失比针叶林更严重。
