Forests acid deposition effects

Discuss acid rain problems in South East Asia. Emphasize your attention on acid deposition effects on biogeochemical cycling in Tropical Rain Forest ecosystems. 

Rasmussen L (1990) Study on acid deposition effects by manipulating forest ecosystems. Commission of the European Communities. Air Pollution Research Report 24. 

Receptors. The receptor can be a person, animal, plant, material, or ecosystem. The criteria and hazardous air pollutants were so designated because, at sufficient concentrations, they can cause adverse health effects to human receptors. Some of the criteria pollutants also cause damage to plant receptors. An Air QuaUty Criteria Document (12) exists for each criteria pollutant and these documents summarize the most current Hterature concerning the effects of criteria pollutants on human health, animals, vegetation, and materials. The receptors which have generated much concern regarding acid deposition are certain aquatic and forest ecosystems, and there is also some concern that acid deposition adversely affects some materials. 

Cronan, C. S. (1984). Biogeochemical responses of forest canopies to acid precipitation. In "Direct and Indirect Effects of Acidic Deposition on Vegetation" (R. A. Linthurst, ed.), pp. 65-79. Butterworth, Boston, MA. 

The effect of acid deposition on forests remains a topic of some dispute among experts. While there is little doubt that sulfur dioxide and other forms of acid deposition do cause damage to trees, a number of other factors may also be responsible for the widespread die-off of trees observed in forests in Europe and North America over the past 50 years. For example, other elements of polluted air, such as ozone or heavy metals, may also contribute to at least some extent to these disasters. 

A second area of concern is that of reduced tree growth in forests. The leaching of nutrients from the soil by acid deposition may cause a reduction in future growth rates or changes in the type of trees to those able to survive in the altered environment. In addition to the change in soil composition, there are the direct effects on the trees from sulfur and nitrogen oxides as well as ozone. 

Effects of Acidic Deposition on Forest Ecosystems in the Northeastern United States An Evaluation of Current Evidence, R.L. Burgess, ed. ESF-84-016, State University of New York, College of Environmental Science and Forestry, Syracuse, NY, January 1984. 

De Vries W., Leeters E. E. J. M., and Hendriks C. M. A. (1995) Effects of acid deposition on Dutch forest ecosystems. Water Air Soil Pollut. 85, 1063-1068. 

Ulrich B. (1983) Soil acidity and its relation to acid deposition. In Effects of Accumulation of Air Pollutants in Forest Ecosystems (eds. B. Ulrich and J. Pankrath). D. Reidel, Dordrecht, pp. 127—146. 

Based on the mineralogy controlling weathering and soil development, sensitivity of ecosystem to acid deposition is assessed with a comprehensive consideration on the effect of temperature, soil texture, land use and precipitation. The results show that the most sensitive area to acid deposition in China is Podzolic soil zone in the Northeast, then followed by Latosol, Dark Brown Forest soil and Black soil zones. The less sensitive area is Ferralsol and Yellow-Brown Earth zone in the Southeast, and the least sensitive areas are mainly referred to as Xerosol zone in the Northwest,... 

Some years ago the first reports appeared on forest die-back in heavily polluted areas. The impact of this information drew the attention on the situation of local forests, which encouraged research on acid deposition in many countries. The quantitative evaluation of damage and the monitoring of forest quality are difficult. Most theories have been based on visual inspections however, trends, actual damage and local effects can only be estimated on the basis of scientific measurements, enabling to make correlations between damage and measured pollutant concentrations. A prerequisite for this evaluation is the availability of representative CRMs. The BCR has hence developed for this purpose two reference materials, namely beech leaves and spruce needles, which have been certified for nutrients (e.g. Ca, Mg, K, P and N) and indicator elements (e.g. S, Cl, A1 and Mn) [17-19],... 

Air pollution sources in the United States and Canada currently emit more than 25 million tons of sulfur dioxide each year. SO2 and wet acidic deposition are believed to cause damage to aquatic life, crops, forests, and materials. The effects on materials include damages to common construction materials including galvanized steel (zinc), paint, copper, building stones and mortar, as well as damages to cultural or historic objects and buildings. 

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