March 10, 2016 (1:00pm)
Sunny, 10 degrees Celcius
I plan to study invasive plant species around Thetis Lake Regional Park
Location 1: Park Entrance
- Site conditions: a lot of pedestrian and dog traffic; lower lying (20 m elevation); some paved road; dry; mostly rocky; small wet ditch running parallel to road.
- Invasive plant species observed: Scotch broom (Cytisus scoparius), Himalayan blackberry (Rubus armeniacus), English ivy (Hedera helix), carpet burweed (Soliva sessilis), spurge laurel/daphne (Daphne laureola)
- Notes: area heavily dominated by invasive plant species, mostly along the ground.
Location 2: Higher elevation along Lower Thetis Lake trail
- Site conditions: less busy, fewer people and dogs; higher elevation (90 m elevation); gravel path; very dry; very rocky; mostly exposed bedrock.
- Invasive plant species observed: Scotch broom (Cytisus scoparius), carpet burweed (Soliva sessilis)
- Notes: this area is a Garry Oak meadow and was dominated by native plant species.
Location 3: Lakeside trail between Upper and Lower Thetis Lakes
- Site conditions: some pedestrians and dogs observed; lower elevation (10 m elevation); muddy path; forested; wet soil.
- Invasive plant species observed: English holly (Ilex aquifolium), carpet burweed (Soliva sessilis), spurge laurel/daphne (Daphne laureola)
- Notes: this area is densely forested with mostly Douglas fir trees and western red cedars present. A moderate density of invasive plants were observed at this location.
Hypothesis: invasive plant species are most densely populated in areas of high foot traffic (people and dogs).
Prediction: the farther from the park entrance, the fewer and less dense the invasive plant species.
Response variable: six invasive plant species observed. This will be continuous as I’d like to observe density.
Predictor variable: presence or absence of pedestrians/dogs. This will be categorical (presence/absence).
Your project looks very interesting – I’m familiar with the Thetis Lake Park from time spent in Victoria and know it is a good study site to look at the variables of human and animal disturbance on an ecological zone.
My project is similar; I want to measure abundance and distribution of invasives according to Riparian Zone disturbance, which I plan to identify as percent Riparian canopy cover.
I spent a lot of time trying to determine an appropriate sampling strategy to measure a range of vegetation from grasses to bushes, and finally decided on a 5 x 5 m quadrant on a transect. I’m wondering what your method will be, and how you plan to count or measure the density of your response variable? Also, have you decided on sites, and if so, how did you decide where to place your plots? I found it difficult to find a common unit of measurement for the range of vegetation I want to count (grasses are too abundant to count by stem, and bushes are too spread out to count accurately in smaller quadrants) so I’m hoping the larger quadrat size will help me with this.
I’m interested in seeing how your project develops!