酸沉降影响下广东陆地生态系统表层土壤特征

Properties of Surface Soil on Selected Forest Ecosystem Affected by Acid Deposition in Guangdong

研究并比较了广东省鼎湖山、鹤山、白云山陆地生态系统表层土壤特征。结果表明， 3个采样点表层土壤酸化都较严重， pH值低。相对于较低的 pH值，三个采样点土壤的有效阳离子交换量 (CECE)介于 59.63— 124.06 mmol· kg－ 1，盐基饱和度（ BS）介于 10.6％— 30.3％，表明表层土壤仍具有一定的酸缓冲能力。 3个采样点表层土壤同时处于阳离子缓冲范围和铝缓冲范围内，活性铝较高，考虑酸沉降对森林生态系统的影响时应重点考虑铝毒的影响。

This paper evaluates the soil properties in surface layer of selected terrestrial ecosystems in Dinghushan, Heshan and Baiyunshan, Guangdong province. The results showed that the surface soil was seriously acidified, characterized by low pH values. The effective cation exchange capacity (CECE) of the surface soil varied with the sample sites taken, ranging from 59.63 to 124.06 mmol· kg－ 1 . The base cation saturation (BS) ranged from 10.6％ to 30.3％ in the surface layers of the three sites, suggesting that the surface soils had a certain buffering capacity. It should be noticed that although the cations had played an important role in buffering of soil acidification, the relatively high concentration of Al 3＋ may be implied that aluminum toxicity would occur, and much more attention be paid.