Introduction
By Emma Bartlett, Parilee Edison, and Cheryl Sorace
The dependence of molds on moisture and warmth led us to question what was causing the mold populations in Site Four to decrease. Molds, in the fungi kingdom, are primarily made up of water, like humans. They are generally found where there is minimal sunlight to dry them out and reduce that water percentage, but the wetlands of Site Four had statistically fewer molds than the much drier Riparian Flood Zone of Site One. Mold populations are similarly affected by temperature—thriving at 26.7°C. Excessive heat, however, evaporates their moisture, killing off large numbers of them. It might seem that the increased heat, due to increased exposure to the sun, at Site Four, was causing the decreased population, but a team of researchers had already conclusively proven that temperature was not the source of the mold shortages (ESSRE, 2001).
After performing a general biota survey on three microclimates, we discovered many statistically significant differences between sites one, three, and four. There was a distinctive “hill-effect” between the three sites, with site three (a heavily forested area near the stream) at the top, site four (a wetland) a massive drop down, and with site one (a riparian flood zone) a smaller drop below that, incidentally mirroring the height of the sites. The levels of certain chemicals and populations of many microbes all followed the trend of the sites’ altitudes, showing that there was clearly some major factor that was causing a drastic difference between the three sites. More interesting to us were the elements of the environment that defied this model. Out of all of these measured aspects of our microclimates, mold levels were the only one to defy the “hill-effect” completely. Contrary to logic, which would speculate that the most molds would be in the wettest environment, the marshland at site four actually had the lowest level of molds, and in fact was statistically different from sites one and three. We decided to try to discover the cause behind this complete deviant from the remainder of the elements of these microclimates.
Initially we thought that the increased sun exposure in site four might dry out the moisture that the molds thrived on, but one look at the swampy, muddy site quickly disabused us of this notion. We came up with many possible causes of a mold population decline—lack of water, a moisture-evaporating heat wave, too much exposure to ultraviolet radiation—but we kept coming back to the fact that there was plenty of non-evaporating water in site four that should have lead to large groups of molds. Then we realized something else about sunlight—beyond the drying heat that it produced: Sunlight carries with it deadly ultraviolet rays—somewhat hazardous to humans—but killing many microorganisms, in particular, fungi. In the end we decided to test this theory—did exposure to ultraviolet radiation decrease the mold population of site four? We decided to place different covers on the ground to block varying amounts of ultraviolet radiation, wait a few days, and then test the soil under them for mold to determine if a correlation existed between the amount of radiation and the number of molds present in the soil.
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