Exposure To Acid Rain Causes Forest Soils example essay topic

What does acid rain do to trees? The impact of acid rain on trees ranges from minimal to severe, depending on the region of the country and on intensity and type of air pollutant. Acid rain, acid fog and acid vapour damage the surfaces of leaves and needles, reduce a tree's ability to withstand cold, and inhibit plant germination and reproduction. Consequently, tree vitality and regenerative capability are reduced. How else does acid rain affect forests? Prolonged exposure to acid rain causes forest soils to lose valuable nutrients.

It also increases the concentration of aluminum in the soil, which interferes with the uptake of nutrients by the trees. Lack of nutrients causes trees to grow more slowly or to stop growing altogether. More visible damage, such as defoliation, may show up later. Trees exposed to acid rain may also have more difficulty withstanding other stresses, such as drought, disease, insect pests and cold weather. The ability of forests to withstand acidification depends on the ability of the forest soils to neutralize the acids.

This is determined by much the same geological conditions that affect the acidification of lakes. Consequently, the threat to forests is largest in those areas where lakes are also seriously threatened in central Ontario, southern Quebec, and the Atlantic provinces. These areas receive about twice the level of acid rain that forests can tolerate without long-term damage. Are these effects reversible? Acid rain induces irreversible changes to forest soils and their fertility in parts of Ontario, Quebec and the Atlantic provinces, as well as in the northeastern United States. For now, forests in affected areas where acid rain exceeds the critical loads are using the pool of minerals accumulated during pre-industrial times although some monitoring sites are already deficient and visual damage has appeared.

The loss of nutrients in forest soils may threaten the long-term sustainability of forests in areas with sensitive soils. as may also experience damage from acid fog that often forms at higher elevations. Where do sulphur dioxide emissions come from? Sulphur dioxide (SO 2) is generally a byproduct of industrial processes and burning of fossil fuels. Ore smelting, coal-fired power generators, and natural gas processing are the main contributors. SEVERE YELLOWING IN COLOR CAUSED BY ACID RAIN (SHOULD BE HEALTHY GREEN) THE TREE ON THE RIGHT IS SHOWING NORMAL GROWTH THE TREE ON THE LEFT IS SHOWING THE EFFECTS OF ACID RAIN ACID RAIN – A DEFINITION Acidity is measured using a pH scale, with the number 7 being neutral. Consequently, a substance with a pH value of less than 7 is acidic, while one of a value greater than 7 is basic.

It is also worthwhile to note that the pH scale is logarithmic; that is, a substance of pH of 6 is 10 times more acidic than another with a pH of 7. Generally, the pH of 5.6 has been used as the baseline in identifying acid rain, although there has been much debate over the acceptance of this value. Interestingly enough, a pH of 5.6 is the pH value of carbon dioxide in equilibrium with distilled water. Hence, acid ran is defined as any rainfall that has an acidity level beyond what is expected in non-polluted rainfall. In essence, any precipitation that has a pH value of less than 5.6 is considered to be acid precipitation. The following is a visual illustration of the pH scale: WHAT CAUSES ACID RAIN?

One of the main causes of acid rain is sulphur dioxide. Natural sources which emit this gas are volcanoes, sea spray, rotting vegetation and plankton. However, the burning of fossil fuels, such as coal and oil, are largely to be blamed for approximately half of the emissions of this gas in the world. When sulphur dioxide reaches the atmosphere, it oxidizes to first form a sulphate ion. It then becomes sulphuric acid as it joins with hydrogen atoms in the air and falls back down to earth. Oxidation occurs the most in clouds and especially in heavily polluted air where other compounds such as ammonia and ozone help to catalyze the reaction, converting more sulphur dioxide to sulphuric acid.

However, not all of the sulphur dioxide is converted to sulphuric acid. In fact, a substantial amount can float up into the atmosphere, move over to another area and return to earth unconverted EFFECT ON TREES AND SOILS One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulphuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium also present in the soil is freed and this toxic element can be absorbed by the roots of trees.

Thus, the trees are starved to death as they are deprived of their vital nutrients such as calcium and magnesium. Not all of the sulphur dioxide is converted to sulphuric acid. In fact, a substantial amount can float into the atmosphere, move over to another area and return to the soils unconverted. As this gas returns back to earth, it clogs up the stomata in the leaves, thus hindering photosynthesis. Research has been made where red spruce seedlings were sprayed with different combinations of sulphuric and nitric acid of pH ranging from 2.5 to 4.5.

The needles of these seedlings were observed to develop brown lesions. Eventually, the needles fall off. It was also found that new needles grew more slowly at higher concentrations of acid used. Because the rate at which the needles were falling was greater than the rate at which they were replenished, photosynthesis was greatly affected, The actual way in which these needles were killed is still not yet known. However, studies have shown that calcium and magnesium nutrients are washed away from their binding sites when sulphuric acid enters the system. They are replaced by useless hydrogen atoms and this inhibits photosynthesis.

In addition, severe frosts may also further aggravate this situation. With sulphur dioxide, ammonia and ozone present in the air, the frost-hardiness of trees are reduced. Ammonia oxidizes with sulphur dioxide to form ammonium sulphate. This product forms on the surface of the trees. When ammonium sulphate reaches the soils, it reacts to form both sulphuric and nitric acid.

Such conditions also stimulate the growth of fungi and pests like the ambrosia beetle. When trees are under such stress, they release chemicals such as terpenes which attract the ambrosia beetle. Nitrogen oxide and nitric oxide, also components of acid rain, can force trees to grow even though they do not have the necessary nutrients. As well, the trees are sometimes forced to grow well into late autumn when it is actually time for them to prepare for severe frosts in the winter. PLANTS THAT ARE EXPOSED TO ACID RAIN DID NOT PRODUCE AS MUCH FLOWERS OR GROW AS MUCH AS THE PLANTS THAT HAD NORMAL RAINWATER EXPOSURE.

ACID RAIN DID INTER FEAR WITH THE GROWTH RATE OF VEGETATION. THE DIFFERENCE BETWEEN ACID RAIN GROWTH AND NORMAL RAINWATER GROWTH IS VERY NOTICABLE. HYPOTHESIS PLANTS THAT ARE EXPOSED TO ACID RAIN WILL DIFFER IN GROWTH COMPARED TO PLANTS THAT ARE WATERED WITH NORMAL RAINWATER. PROBLEM RAIN, SNOW, FOG, AND MIST POLLUTED BY CARS AND FACTORIES ARE EFFECTING VEGATATION AROUND THE WORLD. ITS CALLED ACID RAIN AND THE MORE POLLUTION PUT IN THE AIR THE WORSE ACID RAIN IS GETTING. ACID RAIN IS SLOWLY WEARING DOWN THE ENVIROMENT EVERYDAY.

POLLUTION IS ALL OVER THE ATMOSPHERE AND WHEN IT REACTS WITH MOISTURE IT FORMS A PERCIPATATION CALLED ACID RAIN. ACID RAIN EFFECTS THE ENVIROMENT AND VEGATATION IN MANY WAYS SUCH AS EATING AWAY AT LEAVES AND NEEDLES OF A TREE. ACID RAIN ALSO EFFECTS THE NUTRIENTS IN THE SOIL. THAT CAUSES PLANTS TO GROW DIFFERENT THEN NORMAL HEALTHY PLANTS. ACIDS CAN STAY IN THE ATMOSPHERE FOR MANY DAYS, AND WITH STRONG WINDS IT CAN TRAVEL MANY HUNDREDS OF MILES ACROSS THE LAND. ALL RAIN HAS A LITTLE BIT OF ACID IN IT FROM A CHEMICAL CALLED CARBON DIOXIDE IT HELPS DISSOLVE MINERALS IN THE SOIL.

WHEN THERE IS TOO MUCH ACID OR CARBON DIOXIDE IN THE RAIN IT STRONGLY EFFECTS THE ENVIROMENT AND EVERYTHING IN IT. THE ACID RAIN BECOMES DESTRUCTIVE AND TAKES MUCH NEEDED NUTRIENTS OUT OF THE SOIL AND BREAKS THE CYCLE OF NUTRIENTS. IT ALSO RELEASES POISONIS METALS WHICH CAN DAMAGE, DECREASE GROWTH, OR EVEN KILL VEGETATION. PROCEDURE THE FOLLOWING CONTROLS WERE IMPLEMENTED: 6 OF THE SAME TYPE AND SIZE PLANTS WERE BOUGHT ALL PLANTS WERE PLACED IN SAME POTTING SOIL 3 PLANTS WERE LABLED ACID RAIN 3 PLANTS WERE LABLED NATURAL RAIN ALL 6 PLANTS WERE PLACED IN THE SAME ENVIRONMENT AND TEMPERATURES PLANTS WERE THEN DIVIDED IN TO 2 GROUPS ACID RAIN NATURAL RAIN NATURAL ACID RAIN RAIN – WATERED – WATER AND AND MISTED MISTED DAILY DAILY WITH WITH A REGULAR WATER COLLECTED LEMON MIX RAIN WATER PH LEVEL PH LEVEL 2.3 2.5 (est.) 5 – 5.5 (est.) A JOURNEL WAS KEPT TO NOTE ANY DIFFERENCES IN SIZE, COLOR, & ANY OTHER CHANGES BETWEEN THE TWO GROUPS ACID RAIN I DID MY PROJECT ON ACID RAIN AND ITS EFFECTS ON PLANT LIFE -RAIN, SNOW, FOG, AND MIST POLLUTED BY CARS AND FACTORIES ARE EFFECTING VEGATATION AROUND THE WORLD. – ITS CALLED ACID RAIN AND THE MORE POLLUTION PUT IN THE AIR THE WORSE ACID RAIN IS GETTING. – ACID RAIN IS SLOWLY WEARING DOWN THE ENVIROMENT EVERYDAY.

– ACID RAIN ALSO EFFECTS THE NUTRIENTS IN THE SOIL. – THAT CAUSES PLANTS TO GROW DIFFERENT THEN A NORMAL HEALTHY PLANTS. – WHEN THERE IS TOO MUCH ACID IN THE RAIN THE ACID BECOMES DESTRUCTIVE AND TAKES MUCH NEEDED NUTRIENTS OUT OF THE SOIL AND BREAKS THE CYCLE OF NUTRIENTS. – IT ALSO RELEASES POISONIS METALS WHICH CAN DAMAGE, DECREASE GROWTH, OR EVEN KILL VEGETATION. – SO FOR MY PROJECT READ PROCEDURE, METER AILS, HYPOTHESIS, JOURNEL, CONCLUSION.