酸雨引起森林生态系统钙流失研究进展

酸雨作为一个全球性环境问题,随着我国经济的快速发展,其危害也日益严重。诸多长期观测研究认为酸雨导致森林生态系统营养流失,特别是Ca的流失是酸雨导致森林衰退的一个重要原因。长期酸雨影响下,土壤中的Ca大量流失,在红壤等酸性土壤中表现得尤为严重;此外酸雨也会直接淋溶出植物叶片中的Ca,造成林冠中Ca不同程度的淋溶流失,并可能造成叶片Ca含量下降。且酸雨会导致叶片细胞内Ca稳态的失衡,影响植物的正常生理响应。对于整个森林生态系统而言,酸雨改变了生态系统中Ca生物地球化学循环的特征,大量的Ca从森林生态系统中以地表径流的形式流出系统,导致可利用Ca库的下降和周转速率的上升。酸雨对森林土壤、植物及生态系统各层面中的Ca均造成了长期广泛的影响,深入研究其影响程度与植物的应对机制,对我国酸雨危害区的酸雨防治和森林保育具有重大意义。

Calcuim depletion in forest ecosystem induced by acid rain: a review

Acid rain is a global environmental problem that has become a very serious issue in China coupled with the rapid economic growth. The loss of nutrients in forest ecosystems, especially calcium, as shown in a lot of references done over long-term observation and research, is one of the key factors which indicate that acid rain caused the decline of forest ecosystems. Calcium has been markedly leached from the soils by acid rain, mostly in acidic soils such as red soils. Acid rain has also leached calcium from the canopy of forest resulting in a decrease of the folia calcium content sometimes, imbalance of calcium homeostasis at the cellular level, impair of physiological responses. From the ecosystem aspect, acid rain changed the characteristics of calcium biogeochemical cycle, brought calcium to be depleted from the ecosystem in the surface runoff, reduced the bioavailable calcium pool and increased the turnover rate. Because acid rain influenced calcium at different levels of the ecosystem, it is important that we focus on studying the calcium depletion and responses of plants under long-term acid rain, which can help us in the progressive prevention and treatment of acid rain and the conservation of forest ecosystems.