酸沉降对森林植物影响过程和机理

The Process and mechanism of rain deposition upon forest plants

文章主要包括如下几方面的内容:(1)概述了酸沉降作用下森林衰退的状况及其相关工作的开展情况;(2)总结了酸沉降对森林植物的影响过程和机理;(3)阐述了酸沉降对森林植物影响研究的模型和临界酸负荷值的确定;(4)探讨了存在的问题和未来值得研究的方向。指出未来的研究方向主要是:酸沉降对森林生态系统的影响机理和森林生态系统对酸沉降的反馈机制;酸沉降对非优势种、稀有种及低等植物的影响;酸沉降与其它环境因子对森林植物的共同影响;酸沉降的监控和预测,建立适合我国实际情况的研究模型;将常规分析手段和分子生物学技术相结合,加强抗性植物和指示植物的筛选工作;加强受损森林植被的恢复和重建工作;开展酸沉降对森林植被的格局动态及森林演替动态变化研究。

Acid deposition has been recognized as a severe environmental problem in the world. However, no valid results have been received with the measures applied to control the emission of SO2 and NOx. And the problem becomes more and more serious in Europe, Northern America and China. Acid deposition inputs to forest ecosystems may influence the receiving forest in direct way by wreaking the structure and function of leaves and cell membrane, destroying the roots, preventing the growth of the plants, reducing the net photosynthesis, decreasing the concentrations and the composition of cholorophyll, increasing the respiration, passivating the activities of some enzymes, and in the indirect way by increasing the soil acidification and leaching of nutrient elements, enhancing the activities of AI and heavy metals, changing the composition and decreasing the plant diversity in forest ecosystems. And the primary cause of the forest decline and death is the deficiency of nutrient elements. The followings, such as the mechanisms between the acid deposition and plants, the impacts of acid deposition on the un-dominated species, rare species and low-plants, the combination impacts with other factors, the valid model for Chinese acid deposition study, the combining and developing traditional technique and molecular biological technique to be used for selecting the resistant plants and indicators, the recovering after the forest decline and the dynamics of plants＇ patterns and forest succession, all should be pay more attention to in the future.