《酸雨对中国南方地区的影响》魔法香蕉nanb

3、Literature review

　　In recent decades, with global urbanization, rapid industrial development, increasing energy demand and increasing emissions of acid gases such as sulfur dioxide, acid rain has become a global environmental problem (Liu et al., 2019). Acid rain may lead to acidification of soil and water, forest decline, crop yield reduction, corrosion of buildings, monuments, statues, etc. (Singh and Agrawal, 2008).
　　As the most serious acid rain disaster area in China, many domestic and foreign scholars have made various researches on the phenomenon of acid rain eroding ecological environment in southern China. In terms of plants, studies have shown that acid rain first causes hidden physiological damage to leaves, and then develops into explicit damage. pH3.5 is the threshold value of physiological damage caused by acid rain to plant leaves, and pH3.0 is the threshold value of visible damage (Zhang et al.2020). In terms of terrestrial ecosystems, studies have shown that acid rain, on the one hand, inhibits soil from providing carbon sources to plants by reducing soil pH; on the other hand, it inhibits soil from providing nutrients to plants by dissolving metal ions in the soil (Liu et al.2022). In terms of buildings, studies have shown that concrete bridges, dams, roads, high-voltage wire steel frames and other civil construction infrastructure in acid rain areas are directly exposed to the atmosphere, resulting in corrosion of metals, denudation of cement concrete, erosion of mineral and rock surfaces, erosion of plastics and coatings. (Niu et al. 2008).
　　The destruction of the ecological environment not only causes great economic losses in China, but also seriously hinders the sustainable development of the ecological environment. However, most of the studies on the acid rain phenomenon in South China are focused on some aspects of the impact of acid rain on people. Therefore, it is of great significance to systematically analyze how acid rain affects all aspects of people\'s lives and how to improve the ecological environment erosion caused by acid rain.