The Humidity Shift of the Acidified Nature Jennifer Liu and Alice Li Moscrop Secondary Floor Location : J 122 V

Starting from the 1970s, the beginning of global warming?industrial pollution began to appear as a big concern to environmentalist of many nations. When many harmful gases mixed together with water vapour, they become sulphuric acid (H2SO4) and nitric acid (HNO3) and travel for thousands of miles from the polluted area before coming down in the form of acid rain. It seeps through the dirt and reduces the capacity of the tree roots capability to carry water to the leaves. The lack of nutrients causes the trees to grow slowly. In a more serious situation, they can stop growing altogether. Therefore, our hypothesis is that the grass that is watered with the higher pH will produce less humidity than those with lower pH.

For the experiment, we prepared four pairs of boxes that had the pH rate of 2, 3, 4, and 5.6 (rainwater) with two boxes in each pair. For each pair, there is one box with plain soil and the other planted with grass. After watering 400 ml of water to each box on the first day, we waited for one week before the trial. During the trial we sealed each box and recorded the humidity using eight hygrometers every five minutes for one hour. In order to get the humidity produced by the grass alone, we subtracted the humidity of the four boxes with grass off the humidity of the boxes with plain soil.

The result turned out to be that the grass, which was watered with pH 2 had produced the humidity rate of 3.645, was the lowest of all. As the pH rate got lower, the humidity increased. This applies to our hypothesis due to the fact that when the acid rain reduces the growth rate of the grass, it also limits the capacity of the grass. Therefore, less humidity is produced.