重庆南山马尾松衰亡与土壤铝活化的关系

研究了重庆南山马尾松衰亡与铝中毒的关系.发现南山土壤中活性铝含量相当高,而活性钙含量很低,轻灾区和重灾区的Al/Ca比都已超过伤害植物的阈值.试验结果表明,铝活化是土壤严重酸化的后果.溶液培养试验结果表明,铝对马尾松幼苗生长有明显毒害作用,且毒性最大的形态是Al~(3+),铝中毒是南山酸雨危害马尾松的主要原因.

RELATIONSHIP BETWEEN DECLINE OF A MASSON PINE FOREST AND ALUMINUM ACTIVATION IN NANSHAN, CHONGQING

The relationship between the decline of a masson pine forest in Nanshan mountain and aluminum phytotoxicity was studied. The results showed that active aluminum content in Nanshan's soil was several times higher than that of normal, while active Ca content was very low. The Al/Ca ratios in light and heavy decline areas exceeded injury threshold to plant. Al content in masson pine in heavy decline area was four to five times as large as that of normal. More than 90% of aluminum was in fixed state. It was found that aluminum activation was caused by soil acidification. The current degree of soil acidity in Nanshan mountain was easy to result in Al toxicity to aluminum activation (pH<4. 0) It was demonstrated that alminum was the masson pine and Al3+ was the most toxic form in solution. Based on these conclusions,it was suggested that aluminum toxicity was the main reason for the damage of acid rain to the masson pine forest.