Category: Robyn Reudink

Blog Post 5: Design Reflections

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Initial data was collected at Mission Creek Regional Park on March 21, 2021. Systematic plots (400m^2) were used spanning from the mission creek riparian bank to the uplands crest, 100m total distance with plots alternating 20m along the transect. The number of pine and total number of trees were counted in each plot, with pine diameters measured and the average recorded.

Several difficulties were noted when implementing the sampling strategy. The first being physical constraints due to the terrain and floor vegetation, the transect was difficult to pace and plots challenging to confine. Another difficulty arose with plot size; counting and measuring individual trees became tedious. The collected data was surprising, with the number of Ponderosa pine remaining consistent along the transect though a gradient was suspected.

Moving forward I plan to collect data using plots of a smaller area to ease sampling constraints and modifying my approach to include adjacent area(s) of similar site characteristics to the study. I think this modification will improve research by increasing the data pool and providing a method of comparison.

Blog Post 7: Theoretical Perspectives

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The hypothesis of my research involves determining whether the presence of other plant species growing near an individual bean (Phaseolus vulgaris) plant contributes to its growth and abundance. I want to understand whether greater diversity in garden plots reduce the intraspecific competitions; thus, resulting in larger bean plants. The ecological processes that my hypothesis might touch on include the biotic factor such as competition, mainly the intraspecific, but also interspecific competitions. Other ecological processes to be explored include the abiotic factors such as soil moisture, water balance and nitrogen fixation. The species richness in biodiversity will also be relevant to this topic.

Exploring all these different processes could lead to significant findings that could lead to further research, which could potentially improve current beans cultivation practices, and other plant species in a more sustainable and productive way.

The keywords that I would use to describe my research project are intra-specific competition, sustainable development, and nitrogen fixation.

 

 

Blog Post 7: Theoretical Perspectives

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For my research project, I’m studying how soil moisture affects the distribution of western redcedar trees (Thuja plicata). This touches on how abiotic factors, such as soil moisture, can affect organisms. Water is a fundamental resource required for life, so it follows that it would play a significant role in the ecosystem. If water is scarce, the more tolerant organisms will be better competitors and have a better chance at survival.

I have found that Douglas-fir trees (Pseudotsuga menziesii) are the most common tree in both sites with cedars and without. Douglas-firs require more well-drained soil compared to western redcedar, indicating that Douglas-firs are likely to be more tolerant of water scarcity. Therefore, Douglas-firs can be found in the sites with less soil moisture, where western redcedars can not survive.

The keywords that I would use to describe this project are soil moisture, tolerance, and western redcedar.

Blog Post 6: Data Collection

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As previously discussed in Blog post 5, and small assignment 2, I collected data to help me understand the factors that influence the growth of bean plants specifically as observed at Duggan Community Garden. The hypothesis of my research is to determine whether the presence of other plants growing near an individual bean plant influences its growth and abundance; and therefore, due to greater plant diversity in garden plots reducing intra-specific competitions which would result in larger bean plants.

In this module, I completed all my data collection. I gathered data was from two different locations, which represents two different garden beds. Each garden bed area was about 5.56m2, 3.81 length, and 1.50m width. For both locations, I did 10 sample replicates. Each of the 10 sample units was 30cm away from the others to allow for independence of every single one of them.

One of the problems I faced, was that I was unable to collect data from the third location, as I had initially planned to do so. This was because of the inaccessible fence around this garden bed, I could not reach individual beans without making damage. Therefore, I decided to avoid any damage, and thus just collected data from only two locations.

The patterns observed have made me reflect on my hypothesis. I would not say that there is significance between the abundance of bean plants and the number of other types of plants growing nearby, but the data show a potential correlation. Also, I think my data is not sufficient to determine the significance of this relationship. However, I believe that I will be able to come up with a more developed conclusion once I analyze my data on a more detailed and deeper level, and when I read more literature about similar research.

Blog Post 8: Tables and Graphs

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My research project is examining the expansion of a stand of Trembling Aspen Populus tremuloides into a field at Campbell Valley Park in southwestern BC. I chose to use the point quarter method to determine the density of 2 size categories of aspen trees along a transect, so I had a lot of measurements documented as part of my field data.  I took all of the measurements and followed the point quarter method directions from an article (Mitchell, 2007) I found describing how to sample as well as analyse the data. For the graph that I submitted I calculated the average distance to each of the sampling points along the transect and then squared that number and the inverse of that number equaled the trees per m2. I decided to graph these values as I thought they would show the density of the different size Aspen trees from the field, into the forest. When I originally started my project, the trees had full leaves and the forest was lush and full and the soil was drier compared to the winter with wet soil and no foliage. Reviewing my original hypothesis, the data I collected does not appear so far to support that the Aspen stand is expanding into the field as there were smaller trees dispersed along the transect. I did notice that the soil was absolutely saturated in some sections and I want to explore if the data show anything when compared to that.

References:

Mitchell, K. (2007). Quantitative Analysis by the Point-Centered Quarter Method (pp. 1–34). Hobart and William Smith Colleges. http://faculty.wwu.edu/wallin/envr442/pdf_files/PCQM.pdf

Blog Post 6: Data Collection

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For my research project, I am collecting data on soil moisture to see how it affects the distribution of Cedar trees. I am also collecting extra data on moss biomass. To do this, I am using 0.5 m2 quadrats randomly placed in both sites with Cedar trees and sites that have other trees but no Cedar trees. My data collection is ongoing at this point. I have so far collected nine moss samples from sites without Cedar trees, eight moss samples from sites with Cedar trees. My goal is to collect ten samples from each site type. Moss sampling has been going on without any problems since I fixed the GPS problem discussed in blog post five.

My biggest problem implementing the soil sample portion of my project so far has been finding the time to do it. I am aware that soil moisture varies on a day to day basis, especially with the intermittent rain that comes with spring in Nanaimo, so I must collect all my samples in one go. My plan is to collect 20 soil samples (10 for each type of site) so I know I will have to block off an entire day to do this. I will spend a day this weekend to get it done.

Since my hypothesis has changed to the effects of soil moisture on Cedar tree distribution, moss biomass has become my ancillary pattern. It seems that there is more moss in areas where I predict there will be less soil moisture. This doesn’t make sense to me, as moss tends to grow best in moist areas. This may mean there are other influences here that I am missing.

Update: I have now taken all my soil samples. The only problem I ran into was that I couldn’t dig very far down, as there were too many rocks, so all of my samples are from the surface. Other than that, I successfully collected all my samples before it began to rain!

Post 9: Field Research Reflections

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It has been a whirlwind of effort to design and implement a field experiment in a few weeks. One of the main issues that arose during implementation was that there were far more fern fronds per plant than I expected. To manage this issue, I limited the number of fronds I measured to ten per fern as that is what I could fit into my notebook, and that would hopefully have the power of statistical analysis. As I wanted to maintain consistency across all the treatments and samples, I decided that I would start with the frond closest to me at the top of the fern and move in a clockwise direction until I came back to the first fern at which point I would move to the next level down. I had also intended to look at whether the fern had fern neighbors as a way to look at density, but these results did not show any significant patterns. I think the better alternative would be to put down quadrats to determine the number of ferns in the area. Additionally, my lack of botanical knowledge was certainly a detriment to my experiment as I could not determine diversity or species richness around the ferns or even among the ferns. If I had the knowledge, I would have examined the other species around the ferns to get a better idea of the competition. Lastly, if I had the tools, I would also have measured the soil for moisture and Nitrogen content in each of the locations.

This field experiment has altered my appreciation for how ecological theory is developed. I appreciate how much effort and time goes into all the studies which help build ecological theory.

Post 8: Tables and Graphs

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The graph was relatively painless to create as I had set up the data with clear predictor and response variables and had produced a graph predicting the results when I was developing the methods and determining the hypothesis. The most difficult part of creating the graph was coming up with a descriptive title for the graph and labels for the variables.

The outcome of the graph was as predicted and supported my hypothesis. In general, the data did not reveal anything unexpected with the exception of an insignificant result from four data points where the fern frond was eaten by something. When I was averaging my data, I removed these data points as they added factors that were outside the experimental design. It is interesting, however, that the eaten fronds were only found in the partial shade and shaded conditions, which leads me to think that maybe the organism that ate them only lives in shaded forest areas. To investigate further I would need to look at more fern samples and see there were more ferns eaten as well as look for the organisms that eat ferns.

Post 7: Theoretical Perspectives

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Based on my research so far the theoretical basis of my research is competition, niches, and succession. The areas I am researching have at one point been logged and so I am observing different levels of succession where the forest on the west side of the ridge has recovered from the logging event whereas the east side of the ridge has not recovered and is currently impeded by urbanization. The ferns are dealing with various levels of competition and different communities and so fill different niches in each treatment condition and have evolved to thrive in each niche to compete with the other plants. In addition, there is likely a difference in diversity between the three treatments since old-growth forests may have more diversity than areas that have had a more recent disturbance. This means that high diversity would be expected on the west side of the ridge as opposed to the east side where the logging has been more recent. Furthermore, the ferns may have evolved so that ferns in the forest have bigger leaves in order to collect more sun versus the ferns in the sunlight condition, which have smaller leaves as they can easily collect sufficient sun for photosynthesis. 

Some keywords that summarize this project are as follows: ferns; Tracheophyta; vascular plants; competition; niche; community; succession; Pacific Northwest; ridge; Galbraith Mountain; sunlight; shade; logging; new growth forest; urbanization; diversity; disturbance. These words were chosen based on the research I have conducted so far for this study as well as descriptors of the subject and its locations.

Post 6: Data Collection

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Field data was completed today. In total there are 30 replicates with 10 replicates of each condition. One of the issues that arose was that a few of the fronds sampled were eaten by insects or animals and so were shorter than expected. When processing data, these frond measurements will be excluded as they were shorter due to factors other than the amount of sunlight. Another problem I encountered was that it was exceedingly difficult to balance my lab notebook and measuring tape and so I acquired the help of a friend to record the measurements as I read them aloud. A third issue I encountered was trying to avoid stepping on other flora when walking towards and measuring the ferns. Otherwise, the data collection went relatively as indicated in my experimental design. The refinement made during the initial sampling was very helpful in making this process smooth.

One trend I noticed was that the eaten ferns tended to be in the shade treatment. While this does not change my hypothesis or alter it in any way, it is interesting and likely a result of the fact that the plants prefer the dense forest to sunlit urban backyards. Another factor I noticed is that the temperature is cooler in the woods than in the sunlight and I wondered if this was a factor in fern growth. Lastly, I noticed that in the shaded area there are a lot of plants and fungus including ferns, moss, trees, lichen, and other plants whereas in the semi-shaded area there was less variety of plant life as much of it lives on the edge of human activities. The sun area appeared to have a greater variety of grasses and other leafy green plants as opposed to the trees, moss, ferns, and lichen of the shaded forest. This does not change my hypothesis, but could potentially be a factor in accounting for the differences between the treatments.