摘要
在不同pH值 (2 .0、3.5、5 .0、6 .0及蒸馏水 )的模拟酸雨作用下 ,对福建四种类型山地土壤进行了为期 12 0d的淋溶试验。结果表明 ,盐基离子的淋溶量随模拟酸雨pH值的降低而增加 ,尤其当pH≤ 3.5时 ,增加最明显。 4种类型土壤中各离子淋失量大小均为 :Ca2 + >Mg2 + >K+ >Na+ ,这与原土壤中交换性盐基含量一致。在pH≥ 3.5的酸雨作用下 ,土壤中铝的淋失较少 ,而当酸雨pH =2 .0时 ,铝的淋失骤然升高。pH2 .0的模拟酸雨不仅增加了土壤铝离子的释放 ,而且加速了矿物的风化。在pH2 .0的模拟酸雨淋溶下 ,红壤、黄壤、山地草甸土和紫色土中由矿物风化输入的 5种阳离子总量分别为 2 .94、4 .33、4 .35和 6 .0 4 (cmol kg)土 ,显著大于其它酸雨处理。土壤对酸沉降的缓冲作用由阳离子交换、氢氧化铝水解以及原生矿物风化缓冲作用三部分组成 ,其相对重要性不仅决定于土壤酸度、盐基饱和度和矿物组成 。
Four types of mountain soils with 60 cm deep profiles were collected from Fujian and subjected to a simulated acid rain adjusted to pH values of 2.0, 3.5, 5.0, 6.0, and to distilled water (the control). The 120 day experiment revealed that leaching of base cations increased with increasing rain acidity, especially when acid rain pH≤3.5. Leached nutrients from the lysimeters decreased in the order: Ca 2+ >Mg 2+ >K +>Na +, which is consistent with the contents in the original soils. The released quantities of aluminium were low at pH≥3.5 levels, but increased remarkably at pH2.0.The pH2.0 treatment not only accelerated aluminium release, but also promoted weathering of the soil minerals. At pH 2.0, the estimated weathering inputs of the total 5 cations in red soil, yellow soil, meadow soil and purplish soil were 2.94, 4.33, 4.35, and 6.04 cmol/kg soil, respectively, which is significantly greater than other treatments. The buffering system of the soils to acidic deposition is supposed to consist of cation exchangeable capacity, hydrolysis of aluminium, and mineral weathering, and their relative importance is not only dependent on acidity, base saturation, and mineral composition of the soils, but also relevant to pH values of the rain.
出处
《山地学报》
CSCD
2002年第5期570-577,共8页
Mountain Research
基金
日本国际绿化推进中心 (JapanInternationalForestryPromotionandCooperationCenter)
福建省自然科学基金(B9910 0 19)联合资助项目
