酸沉降影响下近20年来衡山土壤酸化研究

对不同时期采自衡山东坡垂直带谱上6个典型土壤剖面Ah层和AB层的样品分析,土壤酸化指标研究结果表明,近2 0年来,由于酸沉降的影响,由花岗岩风化物发育的各类土壤,都有不同程度的酸化,表现在pH值下降,交换性酸,尤其是交换性Al3 增加,交换性盐基总量减少,盐基饱和度下降,特别是土壤酸缓冲性能和土壤酸害容量降低。相比之下,山顶的常湿淋溶土和山麓的湿润富铁土酸化更明显,而山体中部的常湿富铁土酸化进程较慢,山体上部的常湿雏形土酸化进程更慢,表明土壤酸化除了与土壤酸沉降量有关外,还与土壤类型有关

SOIL ACIDIFICATION CAUSED BY ACID PRECIPITATION IN MT. HENGSHAN OVER LAST 20 YEARS

The indicators are analyzed for the samples taken from 6 typical soil profiles, including Ah and AB horizons on the eastern vertical spectrum of soil in Mt. Hengshan. The results show: 1)In the past 20 years, these soils developed on weathering materials of granite have experienced different levels of acidification, which is recognized by such indicators as increase in exchangeable acid, especially exchangeable Al 3 as well as decrease in pH, total of exchangeable base, base saturation percentage, and especially soil acid buffer ability and soil acid damage capacity. 2)By contrast, acidification is more evident for the perudic luvisol at the top of the mountain and the udic ferrisol at the foot of the mountain while the process of acidification is slow for the perrudic ferrisol on the slopes of the mountain and slower for the perudic cambisol at the upper part of the mountain, suggesting that soil acidification is related not only to the amount of acid precipitation to soil but also type of the soil.