Disturbance and Diversity

This experiment was done on October 24, 2014 in Toronto Ontario on York University-Keele campus to test the intermediate disturbance hypothesis. Three separate sampling blocks were designated as high, low, and intermediate levels of disturbance. Data were collected with three other experimenters: Anees, Jamal, and Tarafdar. The weather was sunny and slightly windy. The temperature was approximately 12 degrees Celsius. No precipitation before, so the conditions were dry. Started sampling in the highly disturbed area, south of Vanier College building, at 3pm. Two 20 meter (m) transects were laid on the ground perpendicularly to designate the 400 m2 sampling block. The sampling method used was simple random. A numbered grid system was constructed to divide up the sampling block. Grids were numbered from 1 to 400, with each grid representing 1m by 1m plots. In order to randomly select 25 grids, a random number table was used. Each experimenter then followed the transect length to reach the designated grid to place the 1m by 1m quadrat. A sweep net with a diameter of 35 centimeter (cm) was held 10cm above ground and moved slowly from one edge of the quadrat to the opposite edge. This was done for 77 seconds. Then the experimenter moved to the perpendicular side of the quadrat and continued this sweeping motion for 77 second. At the end of the total sweep time (1.5 minutes), the number of insects in the sweep net was counted, and the different number of RTUS (recognizable taxonomic units) was observed and recorded. Based on morphology of the plant, the number off different plant species was counted (including grass). Any plant near the edge of the quadrat was only counted if the roots were within the quadrat. The percent vegetation cover was observed by standing upright and looking down to make en estimate of the area that was completely covered by vegetation where no soil was visible. The same process was done at Danby grassland for sampling intermediate disturbance level. The sampling block was approximately 60 meters east from the start of the grassland. The same process was repeated for the third time at the grassland near Pond road and Keele street to sample low disturbance.