Mistakes to Avoid
Certain errors that may have slightly skewed our results occurred. On cloudy days, significantly fewer UV rays got through. The populations of molds under the coverings should still be relative, but in comparison to the original biota survey information the populations of molds might actually have increased in some instances. For the first two days that we took samples, we were unable to perfectly repeat our experiment. Taking our samples on different days from different quadrats provided replication, but the first day we did not repeat by taking more than one sample from each covering per day. The second day we tried to correct that error-we took multiple samples from under each covering. When plating Quadrat 1, canvas, 10-1 and 10-2, the easygel solution was accidentally placed in normal petri dishes instead of easygel dishes, obviously causing it not to harden. When the mistake was realized, we poured the easygel from the sterile petri dishes into easygel plates. In addition, the saran wrap came off one of the squares (Quadrat 4, Saran). We were able to take a sample (# 1) from under the area that was still covered, but our other sample (# 2) came from the area that would have been covered if the saran wrap had not torn.
Tips for Success:
When cleaning up, fill a plastic bucket 2/3 full of water and 1/6 full of bleach. Submerge Easygel petri dishes completely, and keep them below the surface while opening. Let them sit, open, in the solution for 24 hours.
Make sure to follow the procedure carefully and precisely.
Plan to do the experiment during days when sun has been predicted.
Leave the mold to grow in a dark, fairly cool place (to prevent the molds from drying out).
Wear latex gloves when clearing the plots to avoid poison ivy, poison sumac, and poison oak.
When counting molds, remember that they are the "fuzzy" circles; the other spots are bacteria.
Make sure to record all numbers and mathematical computations.
Make sure to repeat (for precision) and to replicate (for accuracy) the experiment as many times as possible.
Make sure to label the plastic bags and flags before going outside.
No need to plate 100.
Run the entire experiment several times, starting on different days, in order to see if the condition is universal.
Only swirl when mixing the soil-water from the test tube with the Easygel solution during serial dilution.