在秦岭南坡天然林分布地带选择火地塘典型林区,测定区内雨季降雨和流域出口径流水样pH值及水化学成分,探讨秦岭林区径流水化学对雨水酸化的响应。结果表明: 长期雨水酸化可导致林区径流pH值降低,Ca2+和Mg2+浓度降低,K+和Na+浓度变化与雨水酸化关系不大; 径流Zn,Pb和Cd浓度对雨水酸化响应不明显,酸化雨水未导致森林土壤富集的重金属释放。
This study was conducted in the Huoditang naturally-regenerated forest, which is located at the center of the natural forest region across the southern-slope of the Qinling Mountains. Rainwater and stream water samples were collected mainly in rainy seasons in the area. The sample pH values and chemical concentrations were measured. The response of stream water chemistry to rainwater acidification in the region was studied. The results showed that long time rainwater acidification could result in reduction of pH value, Ca2+ and Mg2+ concentration in the strean water. The changes of K+, Na+ concentration of stream water were not correlated with the rainwater acidification. There was no response of Zn, Pb and Cd concentration of the stream water to rainwater acidification. The acidified rainwater did not result in the release of the heavy metals enriched in the forest soil.