User: | Open Learning Faculty Member:
When I went into the field to start implementing my field strategy, I didn’t feel as if I had any major difficulties as I had prepared well before going into the field and had the appropriate tools needed. I think where the difficulties have now arisen is in my confusion of understanding the process. I chose to use a distance-based method (as this is used for stationary organisms, such as trees) and to use the simple nearest individual method as mentioned in Module 3 Sampling Techniques Tutorial.
I then used the Vegetation Resources Inventory (VRI) Ground Sampling Procedures from the Ministry of Forests and Range, which was extremely detailed and helpful, to supplement my understanding of the sampling strategy. I ended up implementing an integrated plot centre (IPC) quarter method which is what is now confusing me, as I am unsure if my sampling strategy is correct. My IPC was randomly chosen by splitting the area on the west side of Lost Lake into 16 zones then by using a randomized number generator to choose the zone. From here I used google maps to collect my coordinates to implement my sampling strategy.
I sampled 16 trees in total, four at the IPC and four at each auxiliary plot that are 50 metres north, south, east and west of the IPC. I was unable to sample at the eastern auxiliary plot as this was located in the middle of Lost Lake. At the IPC and the auxiliary points, I quartered the area using cardinal directions, into 4 sections. In each quarter I measured the DBH of the nearest individual (4.0 cm DBH) and measured the distance to the centre point.
Using the VRI ground sampling procedures it actually gets quite complicated for the quarter method as the data that I am trying to collect is tree attributes and the recommended sampling methods are fixed-radius or variable. When I dig further into this, variable plot is a method in which sampling area (plot size) varies with tree diameter and fixed-area, is exactly that, and you need to determine which trees are in or out based a fixed-radius.
To modify my approach, I may need to increase my sample size or alter my methodology. Either way, I plan to use tree attribute cards that have been provided in the VRI ground sampling procedures to help collect data clearly. I also need to document my access point, tie point and reference point. As I am in a municipal park I am unable to leave permanent objects or markings in the forest. Instead, I will look for obvious landmarks or unique trees that can act as these points. I also need to assess if I should replace my dropped auxiliary point, but this also answers if I should increase my sample size. All of these discussed modifications will improve my research to be standardized, repeatable and with little bias as possible.
