Post 6 – Data Collection

On May 23, 2023, I returned to Glenbrooke Ravine to complete the field data collection for my study. I collected another 20 samples (10 from the north aspect and 10 from the south aspect). The ground cover had changed quite a bit from the time of my original sample collection. The deciduous perennial under story which was predominately himalayan blackberry on the north slope and salmonberry on the south slope, have begun their new growth and their leaves had returned. This made the challenge of access I had experienced during the first round of sampling even more difficult. During the first round of sampling, the thickets of these shrubs lay close to the ground and had less prickles on the stems. The new conditions made it extremely difficult to sample on the transect set on the north and south aspects of the ravine and to place my 2 metre diameter sample unit. Due to this, I made changes to my sampling design. Instead of collecting 10 samples along 2 transects, I decided that I would collect 2 samples along 10 transects and limit the number of paces in the random number generator. I divided the study area approximately 10 sections and then collected a sample from the north and south slope at the distance from the trail chosen from the random number generator. Because I could no longer lay down my sample unit, I cut a 1 metre length of the tubing and used it at arm’s reach to count the number of sword ferns. In order for a plant to be included in the sample count it was required to have the majority of the plant within the sample unit (i.e. > 50%). Where it appeared to be around 50%, the plant was included in the data. I chose to make this the thresh hold to offset the error that was introduced into the data from not having a fixed sample unit. Given that my objective was not to determine density, the precise area of each sample unit is not important to my analysis.