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The biological attributes that I intend to study are the species richness and abundance of forbs between the riparian, transitional, and upland zones of eastern bank of the South Saskatchewan River.
On June 13, 2020, I chose four locations adjacent to an overgrown pathway leading down, from the upland region (at the coordinates of 52.1384, -106.6400), towards the South Saskatchewan River. Based upon preliminary observations, each of the four locations (A, B, C, and D) (Fig. 1) have their own distinct vegetation structure. I have chosen to focus in on forb species because of the striking difference between species and abundance at each location. In addition, forbs appear to be present in each location; the same cannot be said for shrubs and trees (with shrubs occurring in high abundance in the upland and trees occurring in moderate abundance towards the river. Furthermore, based on these observations, species richness of forbs appears to be highest in the middle of the riparian zone, and lowest along the river and in the upland.
Therefore, I hypothesize that the distance between the river and the uplands influences the community structure of forb species. Along those lines, I predict that the richness and abundance of forbs will increase approaching the centre of the riparian zone. A potential response variable is the species richness and a potential explanatory variable is elevation. Both species richness and elevation are continuous variables.
Hey mremenda,
I like the study area you have chosen and your decision to measure forb richness and abundance along a gradient. Perhaps an idea to make your hypothesis stronger and more falsifiable, you should clarify what you mean by distance. Based on your observations of the vegetation community do you believe it is specifically distance from the riparian zone that influences the forb community or elevation gain? Perhaps both?
I bring this up because I wonder if in a similar riparian zone that has more uniform slope you would still find the same forb distribution as you move along the gradient. In this case, soil moisture could also be an explanatory variable.
Does the river regularly flood the low riparian zone where forb species are lower? I wish I could read your field notes but they are too small, looks like some detailed and interesting drawings!
Good luck!
Caleb
Hello Caleb,
Thank you for your comments. Originally, I was thinking that “distance” would serve as a good correlate to altitude. Granted, this would have forced me to make the assumption that the slope is uniform throughout the study area. My initial thoughts were along the same line as in those of Kimmerer and Allen (1982) in the paper that we evaluated in module 6 (if you haven’t had a chance to check it out yet). This was because I had some concerns (initially) about accurately reporting altitude from an app. However, having collected all of my field samples, I found collecting altitude data to be reasonably okay.
Furthermore, since making this post, I have refined my hypothesis to include some of the underlying processes involved in producing a gradient in forb community structure along the riparian zone. Chief among them are soil type and moisture.
Finally, great question about the flooding. My study site is located very close (and upriver) to a weir that was built to help the river maintain a (relatively) consistent level as it moves through the city of Saskatoon. In addition, by pure coincidence, a monitoring station is present on the opposite side of the river from my study site. I had no idea about this until I was deeply into my data collection. The monitoring station collects data on the river level, daily, and it is all available to the public. I am still working out how to use this data; but it indicates that the river depth has only fluctuated by, about, 3 meters throughout the last year. This low level of flooding would only have submerged the locations of my lowest quadrats, while leaving the vast majority of them intact.
Thanks, again, for the comments! If you are interested in seeing how my project has developed: check out my Blog 6 post.
Good luck to you as well,
Matt