Kikuchi Ryunosuke
Department of Basic Science and Environment, ESAC--Polytechnic Institute of Coimbra, Bencanta, 3040-316 Coimbra, Portugal.
Chemosphere. 2004 Feb;54(8):1163-9. doi: 10.1016/j.chemosphere.2003.10.025.
The forest soil ecosystem can buffer and neutralize acidic airborne pollutants to some extent, but extensive acidification degrades the soil ecosystem. Several investigations have shown that surface flows often show particularly low pH values in rivers and lakes during snowmelt and that this acidification phenomenon takes place in a short time frame. Acid water from snowmelt first makes contact with the litter layer in the soil ecosystem. Therefore, a laboratory experiment was performed to study the impact of forest litter on the chemical composition of the water solution. The experiment presented in this paper confirmed that deacidification with a little leachate of organic matter is caused by cation exchange not only in upper mineral soil but also in the litter layer and that leachate of labile Al is restrained in the presence of litter. An attempt was made to incorporate these factors into the biogeochemical module of the model (ILWAS) to accurately estimate damage by acidification.
森林土壤生态系统能够在一定程度上缓冲和中和空气中的酸性污染物，但广泛的酸化会使土壤生态系统退化。多项调查表明，在融雪期间，河流和湖泊中的地表径流pH值往往特别低，且这种酸化现象在短时间内就会发生。融雪产生的酸性水首先与土壤生态系统中的枯枝落叶层接触。因此，进行了一项实验室实验来研究森林凋落物对水溶液化学成分的影响。本文所展示的实验证实，不仅在上层矿质土壤中，而且在枯枝落叶层中，少量有机物质渗滤液的脱酸作用是由阳离子交换引起的，并且在有凋落物存在的情况下，不稳定铝的渗滤液受到抑制。人们试图将这些因素纳入模型（ILWAS）的生物地球化学模块中，以准确估算酸化造成的损害。
