Category: Nancy Elliot

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For my field study, I’ve narrowed down my sampling unit down to 7 locations. These 7 locations were determined by observing the number of people and anthropogenic sources in Cates Park. I’ve categorized my anthropogenic sources from no disturbance which is the forested area in Cates Park all the way to a high disturbance which is a kids playground. My point counts of foraging crows have been conducted before 10 am and the survey plot is 50 meters. These points were selected from the 22-hectare park and each point was greater than 100 meters away from the previous point. So far I have visited the park four times and I plan on visiting it one more time.

So far I have implemented many changes to my study such as: categorizing the anthropogenic effect, focused more on foraging birds, and narrowed my sampling point down to 7 locations. I also made a change to my hypothesis which was too specific so with these changes my experiment has become a lot more manageable. With the gradient moving from no disturbances to disturbed areas there has been a trend emerging that supports my hypothesis.

Blog Post 7

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The theoretical basis of my field project is that the response variable (stand density of maple trees) is influenced by a mature western cedar tree that dominates the site where observations are taking place. Ecological processes I may touch on include light availability, soil composition on western facing slopes in an ICH zone, influence of invasive groundcover that is present on the site, influence of litter as there is a thick blanket of maple leaves present on the site, impacts on the site from the rocks and boulders that are present, and the response of the maple trees to changes in canopy density as determined by the large cedar.

3 keywords or phrases that could be used to describe my project are: Acer glabrum, stand density, and forest ecology.

Blog 6

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November 20, 2017

In an effort to measure bird species presence and abundance along an urbanized gradient, surveys were completed within the Stanley park around the Lost Lagoon.

Site 1 – West side of Lost Lagoon, Site 2- South Side of Lost Lagoon, Site 3 – East Side of Lost Lagoon

4 replicate point count surveys in each of three areas listed above (2 replicate locations per area, on 2 different dates). I will complete at least one more day of data collection, with 2 more replicate point count surveys in each of the three areas over the next week. In addition, limiting the number of point count surveys to two per habitat has also made the surveys manageable as it still takes about 1 hour to complete all 6-point count surveys across the three areas on any given sampling day.

I calculated my explanatory variables for each area (approximately 300m x 300m area) as a whole using aerial photography to determine the percent cover of natural habitat (forest, wetland, etc…) and urbanized areas (buildings, roads, trails, etc…). I used a systematic sampling strategy to place my point count survey sites within each survey area randomly along the road or trail that runs through them. A random number generator provided the first survey point location in each site, while the second survey point was systematically placed 200m away to maintain the minimum distance required for independence between sites. At each point count survey, all birds seen and heard within a 50m radius of the observation point were recorded during a 5-minute period.

Bird abundance has been quite highest in site 2, site 1, and then site 3; in that order. Site 1 does have large flocks of Canadian geese swimming through it which will definitely elevate the overall abundance numbers for that site, whereas the other two sites have smaller abundances by individual species but more species overall.

blog 5

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My time collecting data at Lost Lagoon, Stanley Park, I had no difficulties in implementing my systematic sampling strategy. I focus the study on examining bird species presence and record other species that I have observed.  I’ve noticed a pattern of abundance at three different sites along an urbanized gradient.

Revised hypothesis: Bird species presence and abundance is impacted on how close their natural habitat is located near an urbanized city.

Revised predications are:

  1. Bird species richness will be highest in areas closer to the city (south side of lagoon)
  2. Bird species evenness will be highest in areas with the highest percent cover of natural habitat (west side of lagoon).
  3. Bird species richness/evenness will be lowest in areas near the main highway/road because of lack of food (east side of lagoon).

My response variable will remain as bird species presence and abundance (continuous variable), and my explanatory variable of percent cover (categorical variable) of natural habitat vs. urbanized areas (roads, buildings, trails) at each site as a whole will also remain the same.

In addition, the followings changes will be made in the experimental design in regards to the way data is collected:

  1. Initial sampling took place around 1:00pm and overall lots of activity and species present.
  2. My new sampling strategy includes two survey sites (point count surveys) in each of the three habitats along the gradient. During the replicate exercise, I expanded the number of point count surveys in one of the sites to five. While it would be ideal to maintain this type of replication it is too time consuming to perform five replicate surveys in each of the three sites. As a result, I will perform two replicates per site, and will conduct surveys at each site on at least three different days.

During the next blog I will go into more detail on the sampling strategy, sample unit, how these changes have impacted the data collection, and any ancillary patterns that appear in the data to support the new hypothesis and predictions.

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Blog Post 4: Sampling Strategies

  • Three sampling techniques that were used in the Virtual forest tutorial are Systematic, Random and Haphazard with 30 samples taken from each.
  • The results show that systematic has the fastest estimated sampling time by over an hour and haphazard had the slowest sampling time.
  • From the data below, the accuracy did in fact change with species abundance. Overall, the systematic sampling strategy was the fastest and the most accurate.  The comparison % errors are low across the different samples with the samples spreading out over a large area to allow for more accurate comparisons.

Systematic: 5 hrs, 5 min

Random: 6 hrs, 21 min

Haphazard: 13 hrs, 35 min

Comparison of % error between 2 common & 2 rare tree species:

Eastern Hemlock (Common), Sweet Birch (Common), Striped Maple (Rare), White Pine (Rare);

Systematic: 2.2%, 13%, 27%, 12%

Random: 19%, 7%, 11%, 12%

Haphazard: 15.9%, 4.8%, 51.9%, 49.7%

 

 

Blog 3

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  • Nov. 5, 2017
  • Weather: Partly Clear Skies, 14C, 1:28pm
  • I’m planning to study Canadian geese (Branta canadensis) and how different gradient sites affect their habitat
  • I’ve taken a few pictures of the different gradient sites around the lost lagoon in Stanley park. The 3 sites that I have observed are west, south, and east side of the lagoon.   I’ve noticed that there is an abundance of birds on the south side of the lagoon where it’s closest to the city and residential neighbourhood. The east side of the lagoon that is near a major road has not many abundances of animals. The west side of the lagoon which is more “inside” the park, has a more diverse species abundance in comparison to the west side.
  • I believe there is an impact of human interactions with certain bird species such as the Canadian geese, crows, and seagulls as there were abundance of them flocking the south side of the lagoon. It’s a possibility that the birds are conditioned to flock near humans in finding food as there maybe people feeding them while sitting on the bench.
  • After observing all 3 different sites, my hypothesis is that a large number of bird species are drawn to the south side of the lagoon where the residential areas are located because of abundance of food from humans.
  • Response Variable: Presence of humans, Explanatory Variable: Abundance of bird Species

I find they would be categorical variables because it takes on values that are numerical such that an “population of birds” depends on “population of humans” in a given area.

field drawing: 09091601 east

south 

west

Blog Post 6

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My data collection is proceeding smoothly. I have settled on a strategic sampling design that involves 15 replicates located along 5 bearings. I have not had any problems implementing my sampling design as it is a fairly simple method of standing at the base of a tree, taking 3 separate bearings, and establishing plots along each of the bearings. More specifically, each bearing consists of a transect that is 15 m long and has a plot located at 5m, 10m, and 15m. Each plot is a 1m2 square with the middle located at the predetermined point on the transect.

I had to look up the word ancillary and now that I know that it means providing support or serving as an aid, I have noticed some additional variables within my site that may be contributing to the stand density that my hypothesis is based on. For instance, the plots that have the most saplings present are also located close to large rocks (warmer microclimates for germination?) and all are leaning in a similar direction, towards the area that has the most solar impact.

Blog Post 7: Theoretical Perspectives

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The theoretical basis of my research project will focus on plant species (specifically grasses, shrubs & forbs) within one habitat compared to another, each habitat has different features & limitations, and I would like to explore what makes the plants grow in such diversity & abundance in one site, & not in the other. I will explore the limiting factors, such as sunlight exposure, moisture, exposure to the elements, as well as anthropogenic factors that could adversely affect the plant species within the measured sites.

The ideas that underpin my research are rooted in simple observation of the plant diversity and richness from one habitat to another. I would like to know why many of the plants I observe in one site have the ability to propogate, reproduce, survive & (seemingly) thrive in a certain habitat, but not in the other.

Key phrases: plant species diversity, environmental limitations, reproductive fitness.

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For my sampling, I witnessed a lady feeding crows bread which I never thought of as a treatment level for my experiment. At this point, the number of crows was much great than any other point confirming that as the anthropogenic sources increase the number of crows does as well. I will add anthropogenic sources to certain points for the rest of my field study. The point counts that I observed were as predicted for my experiment that as the anthropogenic sources in the area increased so did the density of the crows. With these added treatment levels I feel that it will present clear evidence that anthropogenic sources allow for a greater density of crows.

Blog post 2

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Blog Post 2

I’ll be using this article in relation to my previous question in Blog 1:

  • If the Vancouver park board decides for some reason to turn the Lost Lagoon to a salt marsh, what potential impact can that cause on the current wild life habiting the Lost Lagoon?

Bibliography:

Herbert, E. R., Boon, P., Burgin, A. J., Neubauer, S. C., Franklin, R. B., Ardón, M., … Gell, P. (2015). A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands. Ecosphere, 6(10), 1–43. https://doi.org/10.1890/ES14-00534.1

This is a peer-reviewed, academic, article.

It is academic as the authors are professionals in the field and the paper has in-text citations and a bibliography. Furthermore, the journals website states it is a peer-reviewed journal.