1. By:Zuzanna Maria Joanna Wieczorek, 9J

2. A broad termreferring to amixture of wet anddry depositedmaterial from theatmosphere, whichcontains higherthan normalamounts of nitricand sulphuric acids. 3. Acid rain formationresults from bothnatural sources, suchas volcanoes anddecayingvegetation, and man-madesources, primarilyemissions of sulphurdioxide and nitrogenoxides resulting fromfossil fuelcombustion. 4. Acid rain occurswhen these gasesreact in theatmosphere withwater, oxygen, andother chemicals andform various acidiccompounds. A mildsolution of sulphuricacid and nitric acid iscreated as a result. 5. Wet deposition refers to acidic rain, fog, andsnow. If the acid chemicals in the air are blowninto areas where the weather is wet, the acidscan fall to the ground in the form of eitherrain, snow, fog, or mist. When this acidic waterflows over and through the ground, it affects avariety of plants and animals. The strength ofthe effects depends on severalfactors, including how acidic the water is; thechemistry and buffering capacity of the soilsinvolved; and the types of fish, trees, and otherliving things that rely on the water. 6. In areas where the weather is dry, the acidchemicals may become incorporated into dustor smoke and fall to the ground through drydeposition. They stick to theground, buildings, homes, cars, and trees. Drydeposited gases and particles can be washedfrom these surfaces by rainstorms, which leadto increased runoff. This runoff water makesthe resulting mixture more acidic. Around halfof the acidity in the atmosphere falls back toearth through dry deposition. 7. In the forest, a springshower falls throughthe trees to the forestfloor below. Sometrickles over theground and runs intostreams, rivers, orlakes, and some of thewater soaks into thesoil. That soil mayneutralise some or allof the acidity in acidrainwater. This isknown as bufferingcapacity. 8. Differences in soil bufferingcapacity are an importantreason why some areas thatreceive acid rain show a lotof damage, while otherareas that receive about thesame amount of acid raindo not appear to be harmedat all. The ability of forestsoils to resist, orbuffer, acidity depends onthe thickness andcomposition of the soil, aswell as the type of bedrockbeneath the forest floor. 9. Acid rain doesnt killtrees directly. Insteadit damages theirleaves, limits thenutrients available tothem, or exposes themto toxic substancesslowly released fromthe soil. Quiteoften, injury or deathof trees is a result ofthese effects of acidrain in combinationwith one or moreadditional threats. 10. Scientists know thatacidic water dissolvesnutrients and helpfulminerals in the soil andwashes them awaybefore trees and plantscan use them to grow.Acid rain causes therelease of substancesthat are toxic to treesand plants, such asaluminium, into thesoil. 11. Scientists believe thatthis combination ofloss of soil nutrientsand increase of toxicaluminium may beone way that acidrain harms trees.Such substances alsowash away in therunoff and are alsoreleased from thesoil when the rainfallis more acidic. 12. However, trees canbe damaged by acidrain even if the soil iswell buffered. Forestsin high mountainregions are oftenexposed to greatamounts of acidbecause they tend tobe surrounded byacidic clouds and fogthat are more acidicthan rainfall. 13. Scientists believe thatwhen leaves arefrequently bathed inthis acidfog, nutrients in theirleaves and needlesare stripped away.This loss makes treesmore likely to bedamaged by otherenvironmentalfactors, particularlycold winter weather. 14. Acid rain can harmother plants in thesame way it harmstrees. Food crops arenot usually affectedby acid rain becausefarmers frequentlyadd fertilisers to thesoil and by doingthis, they replace thenutrients that havewashed away. 15. In 1983, a survey in Forests at highWest Germany showed altitudes may bethat 34 % of theenshrouded by cloudscountrys total forest is or fog for much of thedamaged by airtime. The pH of lowerpollution. This cloud droplets mayincluded about oneaverage 3.6, which is ahalf of the famousmuch lower pH thanBlack Forest. the final rain of pH 4.2. Switzerland has Some of the mostrecorded damage to 14 dramatic effects on% of her forest trees.forests have beenobserved in Europe. 16. By:Zuzanna Maria Joanna Wieczorek, 9J