Category: Post 5: Design Reflections

Blog Post 5: Design Reflections

TRU Open Learning Leave a comment

Blog Post 5,

After reading the Blair article, which is very similar to my experiment and data collection, I realized how my sampling strategy was correct however, I could have replicated my collection not only in time but also in space by observing from different areas in my sample space. There were no difficulties in implementing my sampling strategy, I chose a place close to my home which was easy to frequent as often as I needed. I also picked a species to observe which is easy to spot and count. The results were also not surprising, as my hypothesis was supported by the data. The squirrels are less abundant in areas with high numbers of predator species like dogs. I will continue to collect data the way I have but I will also enter the park from the other entrance, walking into my sample space from another way.

Post 5: Design Reflections

TRU Open Learning 1 Comment

My experiment takes place over 3 areas which are 10m x 10m in size. I subdivided each area into grids of 25 subplots each measuring 2m x 2m. I gave each grid coordinates of x and y values. To pick the initial subplot in each area, I used the google number generator with n = 5. I rolled it twice, with the first number acting as the x coordinate and the second number acting as the y coordinate. From there I used a systematic sampling method as I found it to be the most accurate in the virtual forest tutorial. From the first subplot, I would increase and decrease the x value until I have x = 1, 2, 3, 4 ,5. Y-values were y and y-1 (where y – 1 = 0, would wrap around back to around to y = 5).

A sample of the data and plot choice method.

I measured the number of individuals, the distance between the each individual to its closest neighbour and the height of each individual. I included averages of the last two measurements.

The soil moisture was previously determined at each area using a simple garden moisture probe in the geographic center of each area. The moisture probe had a scale of 1 (driest) to 10 (wettest). Area 1 (nearest to the man-made water source) measure at 6.0, area 2 ( 2om from the water source) measured at 3.5, and area 3 (farthest from the water source) measured at 1.8.

I found this method extremely easy to carry out in regards to resources and time required. The data did surprise me in that it seems to adhere to my expected results based on my hypothesis. I intend to sample area 1 and area 3 in the same manner.

 

Blog Post 5

TRU Open Learning Leave a comment

The sampling strategy that I chose to measure the density of black spruce at three different elevations is the point centred quarter technique. The hill that I chose to conduct this study on has an elevation of 220m. The three elevations that I chose to measure the density of black spruce is 20m, 110m, and 200m. The hill is not very steep and is very wide. I conducted the point centred quarter technique at 5 points at each elevation, 5 meters apart from each other. Each point was divided into quarters so I measured the distance of the closest black spruce tree to the centre point for each quarter and then took the average of the four distances. I didn’t realize how much labour it would take to measure the distances. At first I went out on my own to get these measurements, however I realized that it would be much more efficient if I had someone to help me out so I had to come back with more individuals to help out. The data that I collected wasn’t surprising since it supported my hypothesis so I will stick with this sampling strategy. I think that the point centred quarter technique is the most accurate for this study since it collects the average of the distances from for quarters compared to other methods such as the neighbour distance method.

Left two comments on others’ posts.

Post 5: Design Reflection

TRU Open Learning Leave a comment

For the initial data collection I used the random sampling strategy in a 1m x 1m area. I chose this technique not only because I thought it would be the most efficient but also, for the soil samples I didn’t want any bias involved as to where they were taken from. The only difficulty I can across was samples in the exact areas where for example a sagebrush plant or fir tree was. In this case I just took the soil sample directly beside the plant or tree. I will continue to use this technique to collect my final data.

Post 5: Design Reflections

TRU Open Learning 2 Comments

I did my initial data collection using the distance haphazard sampling method. I divided the accessible areas at Pipers Lagoon into 6 areas: A through F. I began with only Area A, where I designated five points spread out over the area. I found the sampling technique to be fairly straight forward. Often I found myself confused by my compass which took several seconds to find North. When I indicated the closest tree type in each quadrant, some were of almost equal distance which caused me to refine my guidelines and choose points which created no bias decisions.

The data I collected slightly surprising, as one tree type, the red alder was nowhere in the area, as well as Douglas fir in which a single young tree was recorded. Outside of the data collection I noticed neither of these trees were present. Otherwise, the relative abundances of Garry Oak and Arbutus trees appeared to be representative in which the Garry Oak was slightly dominant.

I believe this sampling method was sufficient in identifying the tree type and relative abundance. Initially, I created a table in which I would write young, mature, very mature, or dead to describe the tree. I believe using a table with a different layout will be easier where I can tick the box which applies rather than having to write down a letter.

By modifying the data collection table I can speed up the sampling process and increase the amount of area covered per hour. Therefore, the research can be done more continuously in a single day rather than requiring several days.

Blog Post 5 – Design Reflections

TRU Open Learning Leave a comment

The sampling strategy was easy to follow. I just divided up the land, counted the trees in each quadrant, and then took a closer look at the moss and whether it was pointing north or not. I wasn’t surprised by the data, due to the sunlight, it seemed likely that the moss would grow quite a bit on the north side. I believe I will continue to collect data in the same way, it was very efficient. My greatest hurdle was to identify the types of moss. I have no background in Botany and very little experience identifying species. So it took me a while but I think (hope) I figured it out.

Blog Post 5: Design Reflections

TRU Open Learning 1 Comment

I did not have any difficulties implementing my sampling strategy.  The data I collected was not surprising as I’ve done a bit of work with Thistle in the past.  I will not be collecting any further data or modifying my approach.  

I have done this type of sampling in the past with work but on a bit of a larger scale so I was comfortable with this and I based everything on what was done for my work sampling.  

Blog Post 5

TRU Open Learning 1 Comment

Did you have any difficulties in implementing your sampling strategy?

I chose to investigate my hypothesis by using the point centered quarter technique. I found this way of collecting data very efficient and straightforward. I did not come across any difficulties.

Was the data that you collected surprising in any way?

I was surprised to observe how sparse Jack Pines are within the forest itself. I thought they would be distributed more evenly amongst the spruce , but they seemed to only appear around forest edges were rocks were present . I also found it interesting how Jack Pines seem to be the dominant species on rock faces. It doesn’t seem like a large tree such as a Jackpine would thrive on a terrain with little to no soil .

 

Do you plan to continue to collect data using the same technique, or do you need to modify your approach?

Point centered quarter sampling is used to gather information on tree density, frequency and coverage. This technique will provide the data that I will need to prove my hypothesis. It can also provide information on how common Jack Pine is relative to others  in the ecosystem. So yes I will continue to use this technique.

Changes to my technique:

  • I may add in more detail to my report relative density, relative frequency and relative basal area.
  • Measuring relative basal area is called relative breast height of the tree and is measure at 4.5 feet from the ground up the trunk. To determine if Jackpine growth is different amongst the different terrains.
  • I will also mark my transect lines using flagging tape, each transect line will be 30m ( 100ft) in a quadrant , instead of haphazardly throwing a ball as my center point , the center point will be the middle of the two transects.
  • I think adding the basal area will add more data to the research that may give a better picture of Jack pine growth in the boreal forest.  I also think using the center point of two 30m transects will give more reliable quantifiable results.

 

 

Blog 5: Design Reflections -Heather Lean

TRU Open Learning Leave a comment

I quickly realized when visiting each of my sample spots on the Goldfinger Potentilla shrub that I did not account for my severe dislike of spiders when crawling in and around the bushes as well as my apparent lack of coordination when measuring the height of my quadrat and attempting to count. It took some practice but I managed to get it done.

I was surprised when I compared the three groups together. I expected there to be much more flowers in each sampling plot in group B then I did in either groups A or C. While overall there was an increase in the number of flowers in group B (which was not surprising) I still anticipated a greater over all difference.

To continue my project I think I will keep up with my initial sampling technique. I found it to be challenging at first but found that it helped me to eliminate any bias towards my three groups.

Post 5: Design Reflections on Leaves

TRU Open Learning 1 Comment

My study design focuses on measuring leaf length of fallen leaves. While this is admittedly easier than climbing trees to collect leaves, fallen leaves bear little loyalty to their parent tree and could blow wherever the wind takes them. Additionally, there is a risk of sampling bias, as more dried leaves take on a dull red colour compared to some of the freshly fallen leaves that have a more vibrant colour. These leaves tend to stand out, which is great but there is some variation in leaf colour, even among freshly fallen leaves. This means those of a duller colour are more likely to be missed. In response to this, I think I will need to use a small quadrat to focus my leaf collection to be exhaustive within a fixed area. That way, all leaves are evaluated to determine if they are freshly fallen enough to be sampled. (Dried leaves are not used because they cannot sustain the manipulation required for measuring and their reduced weight makes them more likely to be dispersed nearby trees by wind from.)