Blog post 3: ongoing observations

When I went back to my chosen site for the field research, I noticed several lawn tractors (i.e., mowing machinery) clearing out large parts of the grasslands where I made my initial observations. The organism that I had previously wanted to study was the pithy-sword sedge and the pattern I had observed was that it seemed to be growing taller and denser around trees. Well, to my disappointment, this was likely largely due to lawn mowing and the tractors avoiding going too close to trees.

All in all, I decided to change gears and focus on another organism: snowberry (Symphoricarpos albus), a deciduous shrub native to British Columbia that produces small white berries. As I was walking around a thick patch of vegetation (trees, shrubs) of about 2400 square meters on the South side of Beacon Hill Park, I noticed that the size and abundance of the berries seemed to be varying significantly depending on the amount of exposure to direct sunlight (and wind? maybe).

1. The organism I plan to study is Snowberry (Symphoricarpos albus), more specifically the size and abundance of its berries along a gradient of incident light.
2. The site can be divided in subsections with different exposures to direct sunlight.
   1. The most shaded area (South-West facing) is about 90% under tree canopy, thus it likely does not receive much incident light during the day. The berries are very small in average (less than 5 mm), the shrubs are closer to the ground compared to other areas, and there seem to be less berries per plant.
   2. The next most shaded area is the South-East portion, with about 60-70% canopy cover. The berries look bigger in general than those facing SW, and they seem more dense (number of berries per plant).
   3. The North and North-West portions of the vegetation patch are the most exposed to incident light, with about 30-40%. This is where I observed the biggest berries (well over 1 cm) and largest abundance, and the shrubs were much taller.
3. A potential underlying process that would be causing the change in snowberries’ size and abundance is the amount of direct sunlight to which they are exposed. My hypothesis is therefore that there is a relationship between snowberry growth and abundance, and exposure to direct sunlight. My prediction is that snowberry grows bigger in size and more abundantly in direct sunlight.
4. A potential response variable is the size of the snowberries (continuous). I am not sure if we are allowed to consider two response variables for the field research, but if so, I would add “abundance” as a second response variable (continuous). A potential predictor variable is the amount of direct sunlight that the shrub is exposed to throughout the day (categorical – for example, on a scale from 1 to 5, 1 being the least access to sunlight).