User: | Open Learning Faculty Member:
Kevin Ostapowich
April 1, 2019
My study is looking at the distribution of birch within a mixed forest. Using QGIS, I overlayed a 30m x 30m grid over my study area and haphazardly chose 5 sites to count individual trees. I then went into the field, using GPS to find the sites, and counted trees of all species within the plots. I didn’t have too much trouble implementing this procedure but I noticed that the different tree species tend to be grouped in clusters which may have skewed the results. For example, one of my sample plots was almost entirely composed of pine while the surrounding forest was deciduous. Another plot was almost entirely aspen with no birch but immediately surrounding the sample area was a lot of birch. The plots that I counted may not be entirely representative of the forest composition.
There are two solutions that I can see: choose a larger grid size to encompass a greater diversity of tree species, or sample more locations. For consistency and to keep sampling manageable, I plan on continuing with the method that I have already used and to increase the number of sampling sites.
