While performing my initial data collection survey I had no issue implementing my multiple transect line survey. The data collected was somewhat surprising as the amount of observed paper birch along the disturbed open canopy area was much great that expected. After receiving feedback I plan on changing some of the aspects of my study. I plan on incorporating more transects and plots that my initial sampling method. This change should ensure that the data collected is more accurate. Another change I will make in the future is to look at more species than just paper birch in order to determine if it is simply this tree that is observed greater due to open canopy or if there are others that also will see an increase. This change will allow me to determine whether open canopy has a change in overall forest composition or if it simply favours certain growing conditions for some species.
Category: Nancy Elliot
Blog Post 7: Theoretical Perspectives
Blog Post 7: Theoretical Perspectives
From a theoretical perspective, my research touches on competition, the differences between vascular and non-vascular plants, and how the topography of an area affects species composition. Competition is when organisms interfere with each other while trying to access resources. This seems to be apparent in my field research because the ornamental hedges on the side of the field opposite to the slope have grown taller and left the plants at the base of the slope in the shade, therefore outcompeting them for access to sunlight. One of the major differences between vascular and non-vascular plants is the presence of vascular tissue (xylem, phloem, etc.) and therefore the ability to move water in a larger body. In my opinion, this presence of vascular tissue is what allowed the Lodgepole Pine (Pinus contorta) and Paper Birch (Betula papyrifera) found in my study area to grow tall enough to avoid the shade produced by the ornamental hedges and have sufficient access to sunlight. The topography of this area is important because as the elevation increases along the slope there is an apparent shift in the dominant and most plentiful species.
Three keywords that reference my research are elevation gradient, species coverage or percent coverage, and Athyrium filix-femina, one of the dominant species I am studying.
Blog Post 6: Data Collection
Blog Post 6: Data Collection
I have collected data on 10 additional replicates, five at Location 2 and five at Location 3 from my initial field observations. This brings the total number of replicates to 15. Replicate quadrat locations were still chosen using a simple random scheme. I modified quadrat size to 4m2 for quadrats near and around Location 2 (approx. 3 metres from the base of the slope) because the vegetation in that area included Saskatoon berry bushes (Amelanchier alnifolia) dominantly, a larger plant than the ferns sampled using 1m2 quadrats. In addition, at Location 3 (approx. 10 metres from the base of the slope) I modified quadrat size to 25m2 because I was beginning to sample fully grown trees. I would have liked to increase quadrat size to 100m2 but to accommodate 5 replicates within the physical constraints of the lot and slope size, I had to downsize. After quadrats were selected and sectioned off, I took measurements of area of species found within the quadrats, compared that to the total area of the quadrat, and converted this to a percentage of coverage. So far, my results and observations have not led me to reconsider my hypothesis. In fact, they support it. At higher elevations the species composition nearly entirely changes. Non-vascular common ferns (Athyrium filix-femina) were found to be dominant at location 1, whereas at location 3 the dominating species are highly vascularized and developed trees such as Lodgepole Pine (Pinus contorta) and Paper Birch (Betula papyrifera). This supports my hypothesis that the complexity of species found increases at higher elevations along the slope. A possible explanation for this is that plants at lower elevations are shaded from the sun by ornamental cedar hedges, standing at approximately 8 metres high, on the opposite side of the field.
Blog Post 5: Design Reflections
Blog Post 5: Design Reflections
My initial data collection took place July 14/19 at 13:00 hours. I used 5 replicates of 1m2 quadrats with locations chosen using a simple random scheme. The response variable was % coverage of species within the quadrat and the predictor variable is elevation along the slope. To determine the % coverage of each species within each quadrat, area was calculated using measurements from a tape measure, compared to the entire area of the quadrat, and converted to a percentage. The only difficulty I found with this method was that it can sometimes be difficult to get accurate measurements for the irregular shape of plants. My data indicated that less complex plant species (ferns and clover) were more abundant near the base of the slope, and I began to find more complex species (Saskatoon berry) at higher elevations. I was not surprised by these results. I predicted that complexity of species along the elevation gradient would increase. This was because I figured that the hedges on the opposite side of the field would block sunlight from reaching plants at lower elevations, leaving them without enough access to the resource, resulting in stunted development. I will continue to use this method of data collection as I determine % coverage at higher elevations.
Blog Post 4: Sampling Stategies
Blog Post 4: Sampling Strategies
I sampled the Snyder-Middleswarth Natural area using area-based systematic, random, and haphazard methods. The technique with the fastest sampling time was the area-based systematic approach with a sampling time of 12 hours, 5 minutes, while random and haphazard techniques had sampling times of 12 hours 34 minutes, and 12 hours 36 minutes, respectively. The least abundant species showed the most accuracy in results, White Pine had a 0% error for two different methods, random and haphazard sampling strategies. In general, the area-based random sampling technique was the most accurate for each species. Area based systematic sampling showed the least accuracy in results. Below is a list of percent error for the two most rare species, Red Maple and White Pine, as well as the most common, Eastern Hemlock and Sweet Birch, for each sampling strategy.
Area Based Systematic:
Eastern Hemlock-45.4%
Sweet Birch-20.6%
Red Maple-82.5%
White Pine-50.0%
Area Based Random:
Eastern Hemlock-9.1%
Sweet Birch-6.38%
Red Maple-1.85%
White Pine-0%
Area Based Haphzard:
Eastern Hemlock-25.0%
Sweet Birch-6.38%
Red Maple-22.6%
White Pine-0%
Blog Post 3: Ongoing Field Observations
Blog Post 3: Ongoing Field Observations
I returned to my study site for the second time on July 12, 2019 at 19:00 h. The weather was overcast but not raining or windy. For my subject I have chosen to study a biological attribute of the area. I am interested in the change in species composition and species diversity along the elevation gradient of the slope. The response variable is the species diversity. One possible explanatory variable is the amount of sunlight which changes with rising elevation due to cedar hedges across the field from the slope causing shade. This data would be considered both categorical (presence or absence of certain species at specific elevations) and continuous (percent coverage of species at distinct elevations).
Location 1: The first location was at the base of the slope, 0 metres above the flat field. Ferns (Athyrium filix-femina), were the dominant species with approximately 80% coverage. These ferns were similar height, standing at 1 metre tall. These ferns were directly across the field from cedar hedges (Thuja occidentalis) that were around 5 metres tall. Other vegetation includes corn sow thistle, clover, and tall grasses. The clover looked desiccated despite frequent rainfall in the area.
Location 2: The second location was approximately 3 metres up the slope from the base. This area was dominated by Saskatoon berry bushes (Amelanchier alnifolia). There were also 2-3 developing birch (Betula) and maple (Acer). This was the only location where I noticed there was a species of bird present. The height of these plants was approximately the same as the opposing hedges.
Location 3: The final location 10 metres from the base of the slope. Fully developed pine and birch trees were the dominant species. There was a minimal number of ferns but they were shorter than the ferns found at the base of the slope.
In an area with no blockage by the cedar hedges, there were several fully developed pine trees at base level.
My hypothesis is as follows: Plants need sufficient access to resources including nutrients, water, and sunlight. In the absence of any of these resources, plants may not develop into complex organisms. Therefore, the change in species composition and diversity may be attributed to the lack of sunlight to base level plants due to the taller cedar hedge rows.
My prediction is as follows: If the cedar hedges are taller than the developing plants across the field, then they will not have sufficient access to sunlight and will not be as complex or tall as the plants found at higher elevations with greater access to the sunlight.
Blog Post 2: Sources of Scientific Information
Blog Post 2: Sources of Scientific Information
For this post, I chose the article “Influence of repeated fertilization on forage production for native mammalian herbivores in young lodgepole pine forests” written by Pontus M.F. Lindgren and Thomas P. Sullivan, from the Web of Science database. This article is academic, peer-reviewed, research material.
Academic: This article can be considered academic because it includes in-text citations: “Stand thinning and fertilization are silvicultural practices designed to sustain wood and biomass production on a shrinking forest landbase while concurrently creating a diversity of forest habitat conditions to meet the goals of biodiversity conservation (Moore and Allen, 1999; Hartley, 2002; Monkkonen et al., 2014).”, and a list of references. In addition, author Thomas Sullivan belongs to the Applied Biology and Forestry departments at UBC, while Lindgren holds a PhD from the Department of Forestry at UBC.
Peer-reviewed: I determined the article to be peer-reviewed because a search of the publishing journal “Forest Ecology and Management” on the Elsevier database detailed the peer-review process the journal uses for all articles. Also, the article shows a “Revised” date of February 27, 2018, one month before the publishing date of March 20, 2018.
Research material: The article contains both a methods and results section, showing that the authors carried out original research and recorded their findings.
Citation:
Lindgren, P. M., & Sullivan, T. P. (2018). Influence of repeated fertilization on forage production for native mammalian herbivores in young lodgepole pine forests. Forest Ecology and Management, 417, 265-280.
Blog Post 1: Observations
Blog Post 1: Observations
The area I have chosen to study is a flat, grassy field that backs onto a relatively steep mountain slope in a suburban neighbourhood. The area including the entire field and a portion of the slope that I have chosen to study is approximately half of an acre in size. My first visit to the site was July 11, 2019 (considered to be summertime in Terrace, BC), in the early evening (6:00 pm). The weather was overcast, slightly raining, with a cool breeze. Vegetation in the area included ferns, tall grasses, pine and birch trees, clover, low lying plants with broad leaves and a red stem, Saskatoon berry bush.
Along the base of the slope, there looked to be a disproportionately higher number of ferns (Athyrium filix-femina). But at higher elevations, taller trees such as pine and birch appeared to be dominant. This inspired my first question, how and why does the species composition change along the elevation gradient?
I noticed approximately five individuals of a bird species with a brown and white speckled stomach. They could possibly be brown thrashers. The birds seemed to be perching mostly in the Saskatoon berry bushes. This led to my second question, were the birds perched here because they had made nests within the branches, or are the berries a food resource?
Another possible study subject is the berry bushes themselves. I found myself wondering whether the number of berries on each bush was the same, and if not, was this due to a lack of resources (water, sunlight, soil nutrients) on one side of the field compared to another?
Post 7
My project deals with the adaptive traits of western redcedar. Western redcedar is common in our natural forests, but much less abundant in post-harvest stands due to the various challenges with re-establishing it. My hypothesis focuses on the evolutionary fitness of western redcedar. I find this research increasingly important because of the amount of area in British Columbia that has been developed into managed forests. Western redcedar has always been an important ecologically, economically and has significate importance for Aboriginal people. It is ethically important to consider how forest management strategies can adapt in order to maintain redcedars abundance on the landscape. A few key areas that my project will focus on are tolerance, adaptation, and stressors.
Blog Post 2: Sources of Scientific Information
The source of Scientific Information I have chosen for Blog Post 2 is a Journal titled Invasive Predators and Global Biodiversity Loss, written by Tim S. Doherty, Alistair S. Glen, Dale G. Nimmo, Euan G. Ritchie, and Chris R. Dickman.
Journal Article Reference:
Dickman, C.R., Doherty, T., Glen, A.S., Nimmo, D.G., & Ritchie, E.G. (2016). Invasive Predators and Global Biodiversity Loss. PNAS. 113(40). 11261-11265. https://doi.org/10.1073/pnas.1602480113
Based on Module 1 discussions of categorizing information sources into four distinctive groups, this Journal would be categorized as academic peer-reviewed research material. The reasoning for this Journal article to fall under the academic peer-reviewed research material category is based on the information source featuring the following criteria:
- The information source was written by experts, features in text citations, and has a bibliography. Therefore, is not considered to be non-academic material.
- The information states to have been edited by 1 individual, Daniel S. Simberloff from The University of Tennessee, in Knoxville, TN. Therefore, is not considered to be non-peer reviewed academic material.
- The information source does feature Methods, Results, and Discussion sections that offer information collected by the authors of this study. Therefore, this is not considered to be academic peer-reviewed review material.
- By meeting the above criteria the Invasive Predators and Global Biodiversity Loss Journal written by Tim, S. Doherty, Alistair S. Glen, Dale G. Nimmo, Euan G. Ritchie, and Chris R. Dickman is categorized as academic peer-reviewed research material.
