森林土壤-植物系统铝毒害及防治研究进展

Research progress on aluminum toxicity and its control in forest soil-plant system

铝是地壳中含量最丰富的金属元素。由于林地土壤酸化等环境因素的影响,使本来固定在森林土壤中的铝溶出而成为活性铝,对森林植物的潜在毒性增加。酸性土壤中活性铝对陆地生态系统的潜在毒性是20世纪70年代蔓延中欧的森林退化的主要因素之一,从而引起了各国的高度重视。开展森林土壤-植物系统铝毒害的研究,对森林资源保护和铝毒的评估及防治具有重要意义。本文综述了森林土壤中铝的化学形态及其分布、铝在森林植物中的积累和存在形态以及对森林植物的生长、生理生化进程、遗传因子的影响等方面的研究进展。此外,还从控制酸化进程、添加盐基离子、控制根际有机酸、接种菌根真菌、选择适当的植物类型和混交种植等方面介绍了减缓森林铝毒害的措施。在此基础上,本文从铝危害的阈值研究和铝毒风险评估、铝的亚细胞分布和化学形态与铝毒关系研究、减缓铝毒的新措施等方面提出了需进一步开展研究的方向。

Aluminum is the most abundant metal in the crust. More and more aluminum originally fixed in the forest soils has been transferred into active forms due to the environmental problems such as soil acidification, which led to the increase in its potential toxicity in forest plants. The potential toxicity of active aluminum in terrestrial ecosystems was a major factor leading to the for- est degradation overspreading along Central Europe in the 1970s. This problem aroused concern in various countries. Studies on aluminum toxicity in forest soil-plant system are very important for the protection of forest resource, the evaluation of aluminum toxicity in forest ecosystems and its control. This paper summarized researches on the chemical forms and distribution of aluminum in forest soils, the accumulation and chemical forms of aluminum in forest plants, the effects of alu- minum on the growth, physiological processes and genetic factors of forest plants. Furthermore, the alleviation measures, including the control of soil acidity, addition of base cations, control of organic acid in rhizosphere soil, inoculation of mycorrhizal fungi, selection of suitable plants and mixed plantation, were also described. Accordingly, some suggestions for further research in this field were proposed： the threshold value of aluminum toxicity and risk assessment of aluminum toxicity, the subcellular distribution and chemical forms of aluminum and their relationship with aluminum phytotoxicity, and new alleviation measures.