Rick Scott & Robert Hansen
Mr. Mallett
AP Environmental Science
10/7/11
Effects of Acid Rain on Seed Germination
Acid rain has a wide range of negative effects on the environment as well as on human life. It kills plants and seeds, therefore destroying current ecosystems and preventing others from growing. For example, by lowering the pH of aquatic ecosystems, such as ponds and lakes, the acidity of the water increases, and consequently fish eggs do not survive and frogs can’t tolerate the water. Ecosystems are not the only victims of acid rain; acid rain is an accepted cause of bronchitis and asthma in humans. Acid rain also proves detrimental to statues. Acid rain is produced by the combination of harmful pollutants and water molecules in the atmosphere. These harmful pollutants are made up of emissions such as carbon dioxide, sulfur dioxide, and nitrogen oxides.
While there are many speculations on the harmful effects of acid rain, we question the impact it has on radish seed germination. The purpose of this experiment is to test the ability of radish seed germination under different levels of acidity. By simulating different levels of acidic rain, we will be able to determine in what pH levels, seeds will be able to survive, and therefore prove the harmful effects of acid rain. Therefore, we believe that while the seeds with normal H20 (pH level of 6.0) will survive and succeed, the seeds with the simulated acid rain (pH levels 3.1 & 2.6) will fail and die.
In order to conduct our experiment we first took three petri dishes and labeled them – one for pH 6.0, one for pH 3.1, one for pH 2.6- then we had all three of those solutions nearby in beakers. Next we cut out two layers of filter paper and placed them in the three petri dishes. Then, we placed four “rapid radish” seeds in each dish, and saturated each dishe’s filter paper with its corresponding solution. Finally, we added one drop of each solution to each seed and then covered each dish and placed them by the window in sunlight. Each day throughout the experiment we checked the filter paper to make sure it was still saturated, if it was not, we re-saturated it with its respected solution. *see video of procedure
Our results are displayed on the graph below:
After several days of observations our hypothesis was proved correct. Not only did the radish seeds in pH 6.0 grow immensely, the other two samples had zero growth. As the graph shows, the seeds in the pH 6.0 solution immediately germinated and began to grow at a rapid rate. On the other hand, both acidic solutions inhibited their seeds to grow. It was amazing that in both acidic environments, the seeds experienced absolutely zero growth, thus proving the extremely harmful effects of acid rain. If one can imagine this same effect on a farmers corn crops, one can understand the magnitude of the problem acid rain poses. If a farmer’s crops were hydrated by normal H20, obviously the crops would grow and produce a healthy amount. However, if his crops were hydrated by acidic rain, they would quickly die, leaving the farmer crop-less, without money, and ultimately failing. Acid rain is not just affecting ecosystems where humans are absent from; acid rain is directly affecting the lives of humans by negatively impacting crops and farms. Therefore it is time for humans to take an active role in lowering the levels of acid in the rain. Experiments like this are not only beneficial to the younger generation, but also to today’s adults. This is because the data produced by this experiment prove the harmful affects of acid rain, and therefore encourage ideas to lower the acidity. By enacting the “Clean Air Act Amendments of 1990”, the US government significantly lowered sulfur dioxide and nitrogen oxides from the air, thus reducing the acidity of rain. However, now, twenty years later, more must be done. We believe that coal powered power plants should be forced to utilize “Flue gas desulfurization” or (FGD) techniques, in order to remove sulfur-containing gases. FGD can remove up to 95% of the SO2 in the flue. Acid rain is a problem, however there are solutions. Hopefully, in the near future, techniques such as FGD will be taken advantage of and the levels of acid rain will decrease.
