广东鹤山主要森林生态系统酸沉降影响现状研究

Status and Effects of Acid Deposition on Major Forest Ecosystems at Heshan, Guangdong Province

通过野外现场采样及室内分析方法,对广东鹤山主要森林生态系统酸沉降影响现状进行了研究。结果表明,鹤山森林生态系统林内降水、地表水和土壤酸化比较严重。林内降水pH值较低(<4.8)。通过降水析出的阳离子总量大于阴离子总量,林冠层负电荷相对较多,易吸附H+。地表水较之大气降水pH值有所升高,然而阳离子含量高,大量的营养离子流往林外。不管是针叶林还是阔叶林0～10cm层土壤都表现出很强的酸化现状,盐提pH值在4.0以下,土壤交换性酸含量高,而盐基饱和度却较低。酸沉降对鹤山森林生态系统影响较严重。

This paper studied the effects of acid deposition on major forest ecosystems at Heshan, Guangdong province. It indicted that the canopy through fall, stem flow, runoff and soil had been seriously acidified at Heshan. The canopy through fall and stem flow had the low pH value, under 4.8. The amount of cations was more than that of anion in both canopy through fall and stem flow, which suggested that the canopies had more negative charge and could easily adsorb H+. Compared with the atmospheric rainfall, the runoff had higher pH value, but it had a lot of exchangeable ions leaching out of forests. The soil in 0～10 cm layer was also seriously acidified, with the pH value under 4.0 when the soil was extracted by 1 mol·L-1 KCl. The content of exchangeable acid was high in soil, but the base cation saturation (BS) was low. The results above suggested that the effects of acid deposition on major forest ecosystems at Heshan were serious.