Category: Nancy Elliot

Post 3: Ongoing Field Observations

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On my second visit to Pat Bay it was unfortunately quite rainy and dreary to be outside. The time was at 10:00am and no one was around.

I have decided to study a relationship between the honey bees (Apis) and the blackberry bushes (Rubus) that line the bank and up by the hill. The gradient starts at the road and goes to the paved path that people walk along. From there the gradient turns to grass, with no blackberry bushes in sight, and then down to another path near the water bank. The bushes habitat that area around the water bank and end at the rocks down to the water edge. I have come up with two questions for a hypothesis:

  1. Would temperature/weather conditions affect the productivity of honey bees?
  2. Would blackberry bushes near the busy road not be as successful as the bushes closer to the water’s edge farther away from the road (humans)?

For my hypothesis I decided to go with:

Temperature and weather conditions affect the productivity of bees  on blackberry bushes, ultimately affecting the final product (production of berries).

I predict that weather and temperature will affect the bees as they do not go out in colder weather and stigma’s on flowers do not stay receptive for long.

I have come up with a couple options for variables too that I have yet to decide which would be the best and most efficient to observe.

Response variable- # of bees in a time frame that are pollinating or amount of blackberries produced over the duration of the summer.

Predictor- weather/temperatures

Both variables are continuous.

 

Final Reflection

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I was fortunate in that the implementation of my project went very well. I think that due to making a few visits to my location prior to beginning data collection I was able to design a feasible experiment and refine my methodology in order to prevent disappointment after my initial data collection.

As I begin to write up my paper, especially considering the limitations to my study, I have such a great appreciation for the thought process and time that has to go into ecological research and its experimental design. What I have really noticed is there are so many variables to consider, making it harder to fully trust your results, as there may be more at play than you are able to measure (given time and resources). However, even conducting a “simple” project, I can see the benefit my results could make to the field of ecology.

Theoretical perspectives and underlying processes

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The man-made staircase that forms the foundation of my hypotheses is an abiotic factor that may influence the growth potential of creeping juniper. More specifically, because the staircase is embedded in the sand, and creeping juniper typically grows along sand, the absence of availability of a favourable environment may decrease plant size. Because my two conditions differ in the amount of sand present for creeping juniper to grow in/along, I am able to statistically test for this abiotic influence.

Keywords for this project would include: creeping juniper; abiotic environmental influences; growth limiters

Data Collection at Cranberry Flats

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I sampled 10 replicates on each side of the staircase. My sampling strategy was straight forward and easy to implement. One difficulty I had was that I intended to randomly measure three projections at each sampling site; however, at nine of 20 sampling sites, no projections met my inclusion criteria (at least 30cm in length). This means that I have no data for these sites. This is relevant for my hypothesis that there are more projections on one side of the stairs compared to the other. Unfortunately, this also means that I am not able to calculate an average length of projections for these sampling sites, decreasing the amount of data I have to analyze. This means that I am less likely to find a difference between conditions as differences are difficult to detect in small samples, unless the difference is large. I believe that my hypotheses are sound, although there are other variables that could explain any potential differences in groups (e.g., amount of sunlight received, ground moisture and run-off) which I will have to address in my study limitations. Patterns in these variables may be of interest; however, I am unable to measure them.

Implementation of sampling strategy

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I am hypothesizing that the number and length of projections of Creeping juniper will vary based on their distance from a man-made staircase at Cranberry Flats, Saskatoon. Specifically, along the South-East side of the stair case, where creeping juniper runs immediately perpendicular to the stairs, there will be fewer and shorter projections of Creeping juniper compared to the NW side where the Creeping juniper sits at least a meter from the stair case.

Implementation of my sampling strategy went fairly well. I chose to sample 10 random sites of Creeping juniper on either side of the stair case at Cranberry Flats. At each site I counted and measured the number of projections extending from the main plant body in a 1m span. I intended to randomly measure the length of three of the projections in each 1m span; however, in all cases, there were no more than two projections, at times even zero.

I used a random number generator to determine which projections I would measure at each site. As stated above, I was not able to implement this randomization in the first five replicates. However, to counter this issue in the remaining replicates, if there are 4 projections in the 1m span and I am supposed to measure projections 1, 2 and 5, I will adjust my procedure and measure projections 1, 2, and 4 in order to maximize observations. This will increase the amount of data I have at each replicate site. Although I will still only have ten data points per side of the staircase (mean length of projections), if I am able to measure three instead of two projections, my data will be more representative of what is found in the environment.

Sampling Strategies

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I chose to sample by area. Please refer to Table 1 for estimated values and percentage error.

Systematic sampling was the fasted technique, taking 12 hours and 41 minutes (compared to 13 hours and 13 hours and 9 minutes for haphazard and random, respectively).

 

In the case of common species (Eastern Hemlock and Sweet Birch), the simple random technique had the highest percentage error, while the haphazard technique had the lowest. When sampling rare species (Striped Maple and White Pine), percentage error was highest when using the systematic technique and lowest using the simple random technique.

 

There was a significant decrease in accuracy based on species abundance. When sampling common species, the average sampling error was 13% compared to that of rare species, which was 104.1%.

 

Overall, the most accurate sampling strategy was haphazard.

 

 

Blog Post 8: Tables and Graphs

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In order to summarize my data, I have created one table and two graphs. I did have to put some thoughts into how to organize my data. I had to keep my hypothesis in mind to make sure that my table and graphs would reflect it.

I created two graphs. Figure 1 contains all the data of my experiment. For Figure 2, I excluded one set of data, which is the value for the number of other birds at low tide for survey one. On that particular day, the beach was covered with crows (about 200). I observed this phenomenon only once. Since that value is very high, it changes the mean result and the way the graph looks drastically. I also want to do two the statistical analysis, one with and one without that value.

The results of my data collection are mainly as I expected. The number of gulls (Larus spp.) in the intertidal zone varies with the tides and the number of birds of other genus does not. However, I don’t know yet if these results are statistically significant yet. Furthermore, my data show that the number of gulls in the intertidal zone at low tide is higher especially in the late afternoon and evening.  I did not expect that the number of gulls in the intertidal zone at low tide would vary in function of the time of the day. Factors other than the time of the day might have influenced this result, such a weather or wind.

 

Table 1

Comparison of the number of Gulls (Larus spp.) at low and high tide and the number of birds of other genus at low and high tide in an intertidal zone.

   

Gulls (Larus spp.)

  

Other birds genus
  Low Tide High Tide Low Tide High Tide
Survey 1 80 1 200 0
Survey 2 281 0 1 2
Survey 3 2 0 6 0
Survey 4 23 1 0 0
Survey 5 43 0 1 1
Survey 6 79 0 0 1
Survey 7 0 2 2 1
Survey 8 0 0 2 0
Survey 9 0 0 0 0
Survey 10 14 0 5 5
Mean 52.2 0.4 21.7 1
Mean* 52.2 0.4 1.89* 1

*Mean value excluding the value for Other birds genus at low tide for Survey 1.

 

Figure 1. Comparison of the mean number of gulls (Larus spp.) at low and high tide and the mean number of birds of other genus at low and high tide in an intertidal zone.

 

Figure 2. Comparison of the mean number of gulls (Larus spp.) at low and high tide and the mean number of birds of other genus at low and high tide in an intertidal zone. The mean value for other birds genus at low tide excludes the value of survey 1.

Post 4: Sampling Strategies

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Hello everyone,

The sampling techniques I used in the field were a bit different from the ones listed in the tutorial. The areas I chose to study were located in lentic and lotic ecosystems. The benthic invertebrates and periphyton were mainly collected during the fall. The water samples were collected on a bi-weekly basis (if accessible) for water quality analysis.

Study components:

Water and tissue chemistry: to analyze selenium concentrations in samples of surface water, invertebrates and periphyton.

Field Sampling:

Sampling approach – systematic sampling

Surface water – all the surface water samples that were collected from the stream were based on BC Field Manual. The samples collected were submitted to a CALA certified lab in the lower mainland.

Physical habitat assessment – CABIN field protocols.

Benthic invertebrate samples – kicknet (stream) and sediment grab sampler (wetland). After collecting the benthos, they were sieved from debris, then rinsed, patted dry and put into a freezer. The samples were submitted to a lab for analysis.

Periphyton – collected from hard substrates using a clean scraper (stream), glove hand or 400-µm dip net. After collecting the periphyton, the sample was patted dry, placed in sample packages and put into a freezer.

Cheers,

CQ

Blog Post 7: Theoretical Perspectives

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While collecting my data, I have observed that the number of gulls (Larus spp.) present on the beach is much greater at low tide. I have also observed that there are more gulls on the beach when the low tide occurs in the late afternoon and early evening as opposed to in the morning. These observations are true only for one of the three zones of the beach where I collected my data. Gulls were numerous mainly in the rocky intertidal middle zone, in contrast to the two sandy zones of the beach. I have also observed that the number of birds of other genus or species does not seem to vary in function of tides.

The main ecological process underlying the presence of gulls in a rocky intertidal zone at low tide is foraging. Gulls are known to forage for invertebrates in rocky intertidal zones. Their main preys are mussels, chitons, limpets, urchins, sea stars, sea cucumbers, crabs and barnacles. They also prey on small fishes in the shallow water adjacent to the intertidal zone. Gulls are often seen foraging within one hour of the lowest tide since a greater area of the intertidal zone is exposed at that time. Gulls are also known to display other behaviors while in the rocky intertidal zone, such as resting. Some of the others birds that I have observed while conducting my study are buffleheads, common merganser, eagle and common goldeneye. These birds are known to dive in order to forage for their food (invertebrates and fishes). This foraging behavior explains the reason why these birds were not seen in higher number foraging in the rocky intertidal zone at low tide.

Another aspect of my study is the presence of the creek that flows into the ocean right over the rocky intertidal zone. I have been trying to find a link between the presence of the creek and that of a rocky intertidal zone. I would like to find out if the creek is responsible for the presence of the rocky zone. I have also been trying to determine if the creek influences the presence of preys in the intertidal zone through an increase in the amount of nutrients available. I am still searching answers to these questions.

The three key words that I could use to describe my research project are gulls’ (Larus spp.) foraging behaviors, rocky intertidal zone and invertebrate predators.

Cranberry Flats Saskatchewan in the Spring

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Creeping juniper “crawling” across the stair case.
Mixed grass prairie.
One type of berry observed – others were red or deep purple.

I have chosen the conservation area Cranberry Flats (incidentally also chosen by another student) which is under the control of the Meewasin Valley Authority near Saskatoon, Saskatchewan. It is described as a “mixed grass prairie” comprised of grasses, wildflowers and hardy plants. The hardiness was clear with some plants still having berries despite the snow recently melting and frost occurring on most nights prior to my visit. Also, the diameter of small trees and thick shrubs was small, however, they stood upright despite strong winds over the winter and little protection by large trees or hills. There is a 1km trail which ends at the South Saskatchewan River. The trail is mostly dirt with the last third covered by a man-made wooden boardwalk. Up until this boardwalk the land is mostly flat with some dips and small hills. However, 100-150m from the river there is a slope down to the river.

I visited Cranberry Flats on 01-04-2017 from 11:58 – 12:31. The temperature was 12 degrees Celsius, mostly cloudy with a light breeze and beginning of Spring. Some birds were heard in the distance but there were no observable animals. There is diversity in flora with both long and short grasses, creeping juniper (Juniperus horizontalis), berry-bearing shrubs, stalky trees, and white birch trees (Betula papyrifera). There was a clear gradient in plant diversity, with diversity being higher away from the river.

Three questions that come from this initial survey of the area are:

  1. What exactly is the change in plant diversity as you move closer to the river from the beginning of the flats?
  2. How does the creeping juniper interact with the abiotic factors such as the boardwalk and stair case?
  3. What berries can be found within a certain distance of each other and how does this change over the spatial gradient?