Effects of Acid Rain on Plant Growth and Development

Abstract

Acid rain is a rain or any other form of precipitation that is unusually acidic and possesses elevated levels of hydrogen ions (low pH). Acid rain is caused by emissions of Sulfur dioxide and Nitrogen oxide, which react with the atomospheric water and water vapours to produce acids. Vegetation and soil are the prime receptor of acid deposition and function as sink. Monocotyledons are reported to be relatively less affected by acid rain as compared to dicotyledons and young rootlets, leaves and shoots are typically more sensitive to low pH conditions. It also affects the compositions/makeup of soil water which is the main medium of nutrient supply for the plants and soil microflora. Acidic rain solutions make their entry into the leaf tissue through the cuticle and produce marked effects on plants. Acid rain generally retards the growth of plants by stimulating abnormalities in metabolism of the plants, like photosynthesis, nitrogen and sulphur metabolism, however, there are exceptional cases of promoting growth as well. Present articles reviews studies conducted worldwide on the exposure of various crop plants to acid rain and its ultimate effects on plant growth and reproduction and draws attention for development of plant types suited to acid rain affected lands.