Lab 4: Plant Height Comparison in the Disturbed and Undisturbed Areas of the Grasslands

This dataset was collected by Eman, Azeb, Bava and Saraswatie. The data was collected in the Danby grasslands at York University on October 15th, 2015 and October 22th, 2015 and was divided equally among the participants. Starting time was approximately 3:00pm on both days. On day one, the temperature was approximately 8 degrees with periodic light showers and the temperature on day two was approximately 12 degrees and cloudy with the occasional breakthrough of sunlight. In total, the collection of data took approximately 2 hours to complete on day one and approximately an hour and half on day two. Plant height of 3 individual plant species were recorded (White Aster, Purple Aster and Goldenrod). The height of the 3 plants were recorded in the interior of the grasslands surrounded by extremely dense vegetation and free from environmental disturbances as well as the exterior of the grasslands that was exposed to environmental disturbances such as human interference. Plant height was measured with a tape measurer and was recorded at eye level. Height was measured from the base of the plant to the highest point and this value was recorded in feet. A total sample size of 300 was recorded. 100 trials for each plant, 50 within the interior grassland boundary and 50 within the exterior grass land boundary. All 3 types of plants were measured in the same general area in the exterior of the grasslands, as well as the interior. The purpose of this experiment was to determine if in fact environmental disturbances on the exterior portion of the grasslands played a role in the overall height of the plant species. The question we posed as a group was “Does certain environmental disturbances like human interference have the ability to influence the overall height of the 3 species?” We hypothesized that plant height in the exterior portion of the grasslands would be much shorter compared to the more inland, interior portion of the grassland because it has been exposed to disturbances while the interior had not been. The other purpose of this experiment was to design and test out your own created experiment and use the skills you learned in other experiments to come. On day one, we began by first finding the exterior and interior areas of the grassland and identifying a boundary between the two so as not to stray away. After we found the boundary of the interior and exterior areas of the grasslands, we began to measure the plant height of the purple asters, white asters and goldenrod. We randomly selected the species and confirmed their identity by the use of a plant guide book. Once we identified the plant species to be one of our 3 main plants, we recorded the height. This was done by crouching down and making sure the plant was at eye level first and then using the tape measure to record from the base of the plant to the highest point. Even if the plant in question had multiple branching points, we recorded the highest out of them all. Dead plants were excluded from our recordings. We repeated this process 40 times for each of the 3 plants in the exterior and the interior as well. Recordings for the interior were more difficult as the area was populated by an abundance of plant vegetation that made it challenging to walk. This was not the case for the exterior boundary as the grassland was much less dense and easy to maneuver in. We chose plants evenly around the confinements of our boundaries to provide a more accurate representation of the interior and exterior grasslands. In total, we ended day one with a total of 240 replicates. On day two, we noticed a prominent decline in the amount of live plants making it hard to measure the plant height. Because of the sharp decline in our plant population, we measured the height of 10 plants for each species in both the interior and the exterior. We tried to avoid areas in which we had frequented the week before. In total, we recorded 20 more trails for each plant species with a total of 60 replicates overall leading to the grand total of 300 trials. This data was then complied on a spreadsheet.