Acid Rain Effects on Plants

To understand the acid rain effects on plants, let's understand what is acid rain? During the rainfall, the rain dissolves the chemicals and carries small particles present in the air. When the journey of the rain starts, its pH value is neutral that is, seven. In a clean atmosphere the rain washes down certain particles like dust, CO₂ and other chemicals present in it. The presence of these chemicals in the rain makes it a little acidic and so, the pH valve becomes six.

When the rain carries harmful chemicals like sulfur oxide (SO), nitrogen oxide (NO), hydrochloric acid, phosphoric acid and gases released by industries and vehicles, the acidic nature of the rain increases. This acidic content in the rain reduces the pH value and it ranges between 5.6 to 3.5, and sometimes it even goes below two. Acid rain is very harmful for the flora as well as the fauna. Now let us understand the chemistry of acid rain and its effects.

Chemistry of Acid Rain

In the natural process of bacterial decomposition of sulfur and nitrogen oxides, increase and decrease of gases, volcanic eruptions and forest fires, the atmosphere naturally attains an equilibrium. But the industries, vehicles, burning of coal, power plants and many other appliances have added loads of chemicals in the surroundings and has caused environmental pollution. The various gases like sulfur dioxide and nitrogen dioxide react with water vapors in presence of sunlight and form sulfuric acid and nitric acid mist. The reaction takes place in the following manner.

Chemistry of Acid Rain

SO2 + H2O = H2SO3 (Sulfurous acid) SO2 + O3 (Ozone) = SO3 + O2; SO3 + H2O = H2SO4 (Sulfuric acid) 2NO + O2 = 2NO2; 2NO2 + H2O = HNO3(Nitric acid) + HNO2(Nitrous acid)

The sulfuric acid and nitric acid remain in a vapor state when the temperature is high. The condensation begins with the fall of temperature and it mingles with the rain, fog or snow and this increases its acidity.

The Effects on Plants

The acid rain affects the crops as well as the vegetation. The effect of acid rain on plants is grave. It not only damages the root, but also stops its growth and brings an end to the life of a plant. The nutritive value of the soil is reduced to a great extent as an effect of acid rain. Acid rain effects can be seen on the useful micro organisms which convert the decayed organic matter into essential nutrients for the soil. The consequence is that the micro organisms are killed resulting in reducing the availability of nutrients for the soil and plants. Also, the waxy layer of the leaves is damaged which make the plant more and more susceptible to diseases. On the whole, these ill effects makes it difficult to survive in the extreme climatic conditions like storm, drought, and heavy rainfall. It even effects the productivity and the process germination in the plants. The acidity of the rain has also led to soil erosion by dissolving the soil substrate which are essential for the growth of the plants. Acid rain is also damaging the forests and other vegetation. It takes away the essential nutrients of the soil and releases aluminum, which disables trees from sucking water from the soil.

The direct impact of the acid rain can be seen in the production of carrot, radish, broccoli and beet roots. The yield has reduced to a great extent because of the acid rain which damages the protective layer of the leaves and interrupts in the evaporation process which does not allow the plant to breathe and survive. This stops the process of conversion of nutrients into energy for the plants and thus, the yield is affected.

We all know that this is not the only end; acid rain has not even spared animals, aquatic life, non-living things, and of course, how can we forget the human beings who themselves are responsible for this problem. But nothing is impossible as we can control this problem of acid rain by conserving the energy, reducing the usage, and release of chemicals in the atmosphere and cutting down the use of vehicles by walking, if possible. It has now become essential to concentrate on the acid rain solutions to protect our mother earth and the forth coming generation from the harmful effects of global warming and acid rain.