WHY DID WE CHOOSE THIS
IDEA??
The Environmental Science Summer Research Experience for Young Women started off with a Smithsonian Protocol Biota survey of three different sites in the RPCS backwoods. Site 1, "(N 39.35794; W 076.63977) is a riparian seasonal flood plain with numerous large hardwood deciduous trees and relatively sparse undergrowth. It receives not only the runoff from the stream itself but the parking lot overflow of St. Mary's Seminary as well which is located directly above it on the hillside." (ESSRE, 2002). Site 4, "(N 39.35733; W 076.63840) is a wetland meadow that has developed from the filling in of the old farm pond. The stream spreads out across the entire location at this stage in its journey down the hillside, and there are almost no trees and little plant diversity. A broad swath of jewelweed covers it." (ESSRE, 2002). Site 3, "(N 39.35797; W 076.63836) is actually located at the top of the campus hillside near the source of the stream, and its steep, heavily forested sides include a large rhododendron patch, numerous ferns, and dense patches of invasive English ivy. The stream has eroded the soil down to the primary limestone bedrock here." (ESSRE, 2002). The groups spent a week and a ½ surveying the soil texture, chemical nutrients, arthropod and plant life, and microbe population. After organizing the data into readable spreadsheets, performed statistical analysis between sites to find where there was statistical significance. We found that between sites 1 and 4 and sites 4 and 3 there were statistically significant differences between the mold levels and the silt levels.
We then discovered an intriguing pattern: in sites 1 and 3 the average silt levels were approximately the same (around 90 %), but in site 4 the average silt levels dropped to around 70%. We then noticed that a similar drop occured in the mold population as well; the mold levels in sites 1 and 3 were similar while the mold population significantly dropped in site 4. We did some preliminary research and found that mold is defined as a "multi-cellular, microscopic vegetable plant which [develops] especially in the presence of high heat and humidity" (Etherington & Roberts, 2002). It is common knowledge that mold grows best in a moist environment (Jon H. Epsten , Epsten Grinnell & Howell, APC Ralph Szaras and the Szaras Companies, 2002), so it would make the most logical sense that there would be the highest mold levels in site 4 since it is a wetland and is always damp even during the current draught.
Our group decided to pursue the possibility that this drop in mold population was somewhat correlated to the drop in silt levels in site 4. We found that silt "is as smooth as flour when dry and holds water well; [the] particles are smaller than sand but larger than clay." (Britannica, 2002)
Our thoughts evolved into the problem: Do the silt levels in the soil cause a drop in the mold population? We hypothesized that the drop in silt levels did in fact cause the drop in mold levels.
Our independent variable is soil texture. Our dependent variable is mold. Our control variables are sunlight and water. Our negative control is 100% silt in our site. Our positive control is the fact that we took mold from places where we knew it existed.