From observing plant species along the forested Alfred Howe Greenway trail, Port Moody, BC, there was an evident yet gradual shift in general species type and abundance from the south end of the trail to the north end of the trail. More specifically, the most noticeable change occurred in the abundance and characteristics of pine trees, with an evident decline in number and size from the south end of the trail (elevation: 118 m), to the middle of the trail (elevation: 85 m), and all the way down to the north end of the trail (elevation: 50 m).
My field notes consist of the observed distribution, abundance, and character of pine trees at three points along (primarily) an elevation gradient. An urbanisation gradient could also be noted, with the north end of the trail being near Barnet Highway, in addition to observed deforestation and construction near the north end of the trail.
Please Note: My field observations also included plant pathologies noted along the same three points of the trail. Although more plant pathology was notably observed at the end of the trail, pine tree abundance will most likely form the basis of my study, although the notes taken on observed plant pathologies can illustrate the diversity and variation of plants found along the trail.
A copy of the second field journal entry is shown below:
Potential underlying processes that may have caused this particular pine tree distribution along the trail could include:
- Temperature difference (as a result of varying elevation).
- Anthropogenic impact (potential direct, selective, interference that could have disrupted natural species distribution).
- Invasive species/competition (leading to a fewer quantity and smaller size of pine trees at the north point of the trail).
- Soil composition (with academic papers suggesting that pine trees prefer more acidic soils (Kruckeberg, 1969)).
Hypothesis: Relatively colder temperature increases pine tree abundance.
Prediction: The point of the trail with the coldest average temperature will support the greatest abundance of pine trees.
Response Variable: Pine tree abundance (categorical).
Explanatory Variable: Temperature (continuous).
Reference: Kruckeberg, A., R. 1969. Soil diversity and the distribution of plants, with examples from western North America. Madrono 20. https://www.jstor.org/stable/41423658
Hello,
I enjoyed reading your post as it is a similar study design to my own. Your prediction is clearly stated and is very testable in the field. I am wondering though how you will define ‘relatively colder temperature’ when you are analyzing the research and testing your hypothesis. It might be worthwhile saying a specific temperature (e.g. less than 10 degrees Celsius).
On another note, I am second guessing myself now as you have stated that pine tree abundance is categorical. From my understanding of the class readings, abundance would be continuous. I might consider researching this further.
Great work so far and I look forward to seeing your results!
Hello as a followup – abundance can be continuous as 1,2,3,4,5 or it can be expressed as categories, eg 1-4,5-9,10-14, etc. it depends on your goals re analysis ; )