Category: Post 3: Ongoing Field Observations

Post 3 – Ongoing Field Observations

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Organism– Western Red Cedar (Thuja plicata)

Environmental Gradient– Slope position of the organism (Upper, Mid, Lower/Toe)

Hypothesis

The recent logging has intensified the environmental stressors (drought and intense sun exposure) causing the existing Cedar to thrive under their new conditions.  I predict that, if BC experiences another heat wave, the onsite Cedar trees will weaken or die completely.

The Cedar on the lower slopes that have adjacent mature trees along their southern boundary will have the highest probability of maintaining their established presence.

Response Variable– Stress indicators expressed in

the tree (Continuous).

Explanatory Variable– Weather (Temperature, cloud cover) (Continuous).

It was this small patch of Cedar trees that caught my attention. The Cedar appeared to be healthier and more abundant, in this particular area, than the Douglas fir or western larch trees.  This area has high exposure to the sun with shallow soils, which makes it prone to drought. This patch of Cedar appeared to have been outperforming the fir and larch prior to the harvesting of the adjacent stand that occurred in the fall of 2018.

Blog Post 3: Ongoing field Observations

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The biological attribute I am going to study is the number of birds in the yard. I am defining “in the yard” as: landing in the trees, bushes, on the fence, on the shed, or in the grass; not including birds that fly over without stopping.

The Environmental gradient I am using is the amount of precipitation: rain/no rain/length of rain. I have decided to use precipitation as a predictor of the number of birds because the termperature in Swift Current is fairly constant while during this season the rain is variable and will provide more variance throughout the test.

I have learned in biology classes that most small birds will wait out rain in some sort of shelter. Rain poses a risk of hypothermia. But smaller birds have smaller energy reserves and therefore can withstand less cold (and less rain) than larger birds can. But one problem of having a small energy reserve is that they can’t go too long without eating and therefore if it rains for a long period of time, the smaller birds will come out of their hiding places for some food. Therefore I predict that if I count birds in my yard immediately after it starts raining, that there will be very few to no small ones, but if it continues to rain then the numbers will eventually start to rise again. I will therefore need to establish the average number of birds that frequent the yard when it is not raining in order to compare the numbers in the variable conditions.

My response variable is number of birds in the yard. The predictor variable is if it is raining or not and how long it has been raining for and how much rain (heavy vs. light).

Blog Post 3: Ongoing Field Observations

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I have selected to study the pattern of trees adjacent to and away from pathways in Stanley Park. Three locations along the environmental gradient include survey plots with a diameter of 3m located adjacent to a pathway, 10m away from the pathway, and 20m away from the pathway.

I observed a more diverse mix of trees immediately adjacent to paths as well as an abundance and rich diversity of herbaceous plants including shrubs, ferns and grasses. Ten meters away from the pathway I observed less deciduous tree species and reduced incidence of shrubs and other understory plants. At 20m away I observed mostly mature evergreen species with a limited understory.

My hypothesis is that increasing distance from a site of forest disturbance, such as a pathway, is correlated with lower tree species diversity, lower tree density, and larger tree size. Based on this hypothesis I would expect to see larger cedar and hemlock trees further from a pathway due to the lack of disturbance. The disturbance of a pathway would allow for new species of plants to establish due to the availability of sun, runoff from pathways, and additional space. Further, the clearing of the edges of pathways would allow for continual colonization of new plants.

The response variable is the number (continuous), type (categorical) and size (categorical due to slotting trees into size brackets) of trees in a plot. The predictor variable is distance from a pathway (categorical due to 3 distance measurements being used).

10m From Trail
Adjacent to Trail
Notes1
Notes2
Notes3
20m From Trail

Blog Post 3: Ongoing Field Observations

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I have been observing backyard birds in my observation area including robins, blue jays and cardinals. I’ve noticed that the distribution of birds in the backyard is inconsistent on certain days. On some days there are many birds that can be heard singing in the trees, there is a lot of activity and they can be seen throughout the backyard grazing/foraging. There does appear to be more activity on days when the weather is warmer. On cool/rainy days bird activity is less.

I hypothesize that bird activity is busier on days when the temperatures are between 10-15 degrees celcius. Bird activity will be decreased when temperatures are above or below this temperature gradient.

The response variable in this study is bird activity/presence in the backyard. This variable is classified as categorical. One potential explanatory variable is temperature. Another potential explanatory variable is rain. Both of these variables are classified as continuous.

O’Connor, R. and Hicks, R. (1980). The Influence of Weather Conditions on the Detection of Birds During Common Birds Census Fieldwork. Bird Study. 27:3, pp. 137-151, doi: 10.1080/00063658009476672. Retrieved from https://www.tandfonline.com/doi/pdf/10.1080/00063658009476672

Post 3: Ongoing Field Observations

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I have selected the western redcedar tree (Thuja plicata) as the organism that I plan to study. The three locations along the environmental gradient in my research area are divided by the kind of soil the plants are growing in, namely sandy, silty and loamy soil (see field notes attached)

If a large population of cedar trees are observed thriving in silty soil but are entirely absent from areas with only sand, then western redcedars must need the moisture and nutrients that silty soil contains to populate an area successfully when in competition with pines and firs.

My hypothesis is that western redcedar trees grow in low elevation areas that collect moisture in silty soil. Therefore, because the distribution of western redcedar trees changes along the length of the research area, I predict that the composition of the soil varies as well, in a way that is either detrimental or beneficial to the growth of the tree in relation to the amount of water it can retain.

The response variable is the number of western redcedar trees observed in an area (density), which is a continuous variable. Some predictor variables are the slope, elevation, and soil that the trees grow in, all of which are related to the amount of moisture and nutrients available to the plant. Slope and elevation are continuous variables, but soil can be separated into sandy, silty or loamy soil, and is therefore categorical.

Post 3: Ongoing Field Observations

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The organism I’m interested in studying is moss and its abundance in different levels of canopy cover. On April 12, 2019, I noticed that a majority of the moss in the area was in areas of shade or less canopy cover. In areas where canopy cover was more than 50%, there was moss on the trees, but little to none on the ground. In areas with less canopy cover, but still shade present, moss covered the ground. In open field, where there was 0% canopy cover, moss was present but slight.

high level of canopy cover, moss on trees, leaf debris on ground
high level canopy cover, no moss evident
treeline edge (less canopy cover), moss more abundant

I want to examine the abundance of moss covering the ground in three different areas where there are gradients of tree cover. Areas are divided into three different levels of canopy: greater than 50% canopy cover, less than 50% canopy cover (edge of treeline, open canopy), and areas with 0% canopy cover (open field). These ares provide a gradient of sun exposure to the moss. The underlying processes would be the balance between shade/canopy cover, and sunlight exposure. Moss need sun to photosynthesize, however, they prefer being out of direct sunlight. Too much sunlight can be drying to moss.

Nelson Bar Ranch

Hypothesis: The area with equal amounts of canopy cover/sunlight exposure, will support a higher abundance of moss. .

I predict moss will be the most abundant in areas with less than 50% canopy cover, compared to areas with more than 50% canopy cover, or 0% canopy cover.

A potential response variable would be the abundance of moss (% coverage/m^2) in each area, which would be a continuous variable. A potential predictor variable is the amount of canopy cover present which would be a continuous variable, however, I’ll be using it as a categorical variable.

Blog Post 3 – Ongoing Field Observations

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For the research project I will be looking at which species of birds are most common on the Thompson Rivers University campus.

When observing the different birds on campus I have noticed that there are quite a large number of larger scavenger type birds (ex magpies). These birds are not just seen in the central part of campus which I had discussed in previous forum posts but all over campus (from House 9 all the way to the Ken Leppin Building).

Since the TRU campus is not a natural environment (like marsh land or forest) there is a greater amount of human traffic. My hypothesis therefore is that, due to the increase in human presence, there will be more scavenger type birds, such as magpies, crows, pigeons, etc.

Post 3: Ongoing Field Observations: Courtenay Estuary/ K’Omosks Estuary

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Posted on April 22, 2019, by caudia

Cathy Audia

April 16, 2019

 

Upon my first visit to the Courtenay Estuary I noticed the reed type plants in the tidal flats appeared to be dead.  Moving upwards toward the shoreline the percentage of the healthy reeds increased in number. As my first visit was early spring, I began to wonder if the reeds die off and grow back seasonally, or if there was another factor.  Perhaps too much moisture had caused the reeds to parish.   For this natural experiment the biological attribute I will study are the reed type plants. I went back to the estuary one week later and found no change to report.  The weather was overcast, the temperature was 12 degrees Celsius and the time was 14:20.

I divided the estuary into 3 zones.

Zone 1: Tidal flats consisting mostly of muddy sand, seagrass, seaweed, and reeds, would be completely covered in water with each high-tide.

Zone 2:  Marshy area between the tidal flats and the bank, this area consists of more of the same vegetation as the tidal flats as well as some other types of plants, rocks, and logs. This area would be covered by the water during some high-tides.

Zone 3: The sloped sandy bank consists of some the same types of plants found in zone 2 but the plants appear much healthier. This area would rarely be covered in water.

Hypothesis: The reeds will grow back as spring progresses with the greatest abundance of healthy reeds located in zone 2.

Prediction: The reeds will not thrive in zone 1 due to too much moisture, conversely, they will not thrive in zone 3 due to too little moisture. The slope of the gradient is the factor that reduces each zone’s contact with water.

The reed-like plants are the response variable and the amount of moisture in the sand is the predictor variable.  The response variable will be measured with a continuous scale as the sliding scale will allow me to be more specific conveying the health of the plants.

Blog post 3: ongoing field observations

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By using the observations made on the field and the online plant database of the website https://www.wildflower.org/, I was able to identify the four plants of the site as the following:

 

Crotalaria Juncea L. or Sun hemp, the two-lobed yellow flowers.

Helianthus debilis or Beach sunflower, the flowers with yellow petals and a black or yellow center of stamens.

Hepatica nobilis acuta sharp-lobed hepatica, the small white flowers with three-lobed green leaves.

Richardia brasiliensis small 6 petal purple flowers. They have long pointy green leaves.

 

During my observations on the field, the concept of ecotone or transitional zone is what really hit me first. The abundance of flowers seemed to be proportional to the distance a certain patch of grass was from the beach. In other words, it seemed like the farther away I walked from the beach, the more flowers were scattered on the ground around me. It also seemed like the two types of yellow flowers were much less abundant all throughout the field. Though surprisingly, those bigger flowers appeared much closer to the beach than the majority of the smaller white or purple flowers.

My hypothesis for this study will be that the natural step-cline creates a gradient in flower abundance that increases proportionally to its distance from the beach. The effect of the natural step-cline that is the beach, in this case, could be on nutrients in the soil or dryness of the soil. As observed, the soil in the area is very sandy, which is probably a result of its proximity to the beach. Very sandy and dry soil cannot support much plant life. Hence why the beach is one of the only places in the world where grass can not grow. So, my prediction for this research is that more flowers will appear as I walk away from the beach with my quadrat. No flowers should be observed in the first few meters from the beach as the soil will still be too dry and sandy. But, as I move towards the mainland, I predict that a few flowers will first appear and that abundance will increase after.

The hypothesis I will test will be evaluated by the effect of the predictor variable (the distance of the quadrat from the beach) on the response variable (the abundance or number of flowers in the quadrat). By repeatedly gathering data on those two variables along the gradient, I’m hoping I will discover a trend in abundance variation. Considering that both the response and predictor variables will be continuous data, a regression design study will be used.

Post Three: Ongoing Field Observations: Cates Park

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The organism I would like to study is Tsuga heterophyllum and their growth distribution associated with nurse logs, a biological attribute.

After observing nurse logs throughout Cates Park / Whey-Ah-Wichen during previous visits, noting that Tsuga heterophyllum are the predominate trees to grow out of long-ago logged Thuja plicata, I grew curious to their habits, growing regions, need for sunlight or idea soil conditions to thrive. Because Cates Park is situated on a point that has varying degrees of sunlight and wind, I chose four gradients to observe distribution and abundance of local species: the west and east sides of the park, and both through the canopy on trail, and on the beach for the marine-terrestrial interface.

  1. Southest side of Cates Park, from west path to pier, along beach
  2. Northest side of park, from west path to pier, along trail
  3. Southeast side of Cates Park, from stairs to small point, along beach
  4. Northeast side of park, from stairs to small point, along trail

Southwest

Northwest

Southeast

Northeast
Tsuga heterophyllum

(Western hemlock)

4

19

2 on nurse log

4

21

3 on nurse log
Thuja plicata

(Western red cedar)

18

21

6

5

1 on nurse log
Picea sitchensis

(Sitka spruce)

1

0

0

0
Pseudotsuga menziesii

(Douglas fir)

0

3

0

1
Unidentified deciduous tree (either Alnus rubra (Red alder), Populus trichocarpa (Black cottonwood) or Acer macrophyllum (Broadleaf maple))

10

0

37

35

Hypothesis: Western Hemlock (Tsuga heterophyllum) are more common in cleared forest areas because they are better suited to such disturbances.

Prediction: If Tsuga heterophyllum trees are better suited to take advantage of open forest canopy following a disturbance, they will grow more frequently in areas that have experienced harvesting

The predictor variable is are the amount of canopy cover and the type of substrate, either nurse log or forest floor. These are both categorical variabilities.  The response variable is also categorical, as the relative abundance of hemlocks on nurse logs compared with forest plots.

This natural experimental design is a Tabular study. Sample units will be an equal number of haphazardly selected nurse logs, in order to reach their location, and simple randomly selected forest plots. Nurse logs and forest plots will analyzed in each region of the park: both east and west of the park’s central point, and north and south to account for the gradient away from the ocean.