Category: Percy Hebert

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.

Post 4: Sampling Strategies

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Kevin Ostapowich

March 27, 2019

The sampling methods I chose were distance-based.  See the table below for a summary of the results:

Sampling techniques results

The method with the least amount of error is the Haphazard method.  The Random method takes the longest to sample and the Systematic takes the shortest amount of time to sample.

The error is lower for the most common species (eastern hemlock, sweet birch, red maple) across all methods compared to the two rarest species (white pine and striped maple) which have very high errors across all methods.  The more abundant the species, the more accurate any sampling method is.  Given the results from this trial I would probably choose the Haphazard method as it has the lowest errors (in this study) and enables the user more flexibility in choosing sample sites.

Post 3: Ongoing Field Observations

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The species that I plan to study is Paper Birch (Betula papyrifera) and its distribution across elevation, aspect, and slope changes in the study area.

Site 1 – Lowest site in study area, located at toe of slope.  Elevation is 570m above sea level.  Slope is 0-5%.  This site is the only site in the study area that I have observed large cottonwood trees.  The forest composition is roughly 50% poplar, 30% birch, and 20% coniferous.  There are a few willows.

Site 2 – Mid slope in study area.  Elevation is 600m above sea level. Slope is 25-30%.  The forest composition is roughly 65% poplar, 30% birch, 5% coniferous.  There are more willows and low shrubs on this site than the other two sites.

Site 3 – Upper extents of study area.  Elevation is 640m above sea level.  Slope is 20-25%.  The forest composition is roughly 60% poplar, 20% Birch, 20% coniferous.  The forest is more widely spaced than the other two sites.  There are shrubs/willows in the openings.

All forest compositions are quick, visual estimates of the immediate surrounding forest.

There is snow on the ground in all locations, varying from 30 to 60cm in depth.

Observation sites in study area

My hypothesis is that birch tree populations will vary with changes in elevation, slope, and aspect.  My prediction is that the most populated sites will be the lowest in elevation, most northerly aspects, and low to moderately sloped hillsides.

The response variable is the density of paper birch.  This is a continuous variable.

The predictor variables are the slope, elevation, and aspect and are also continuous variables.  These are likely linked to water availability for the birch.  I am not able to measure the soil moisture content directly so I will rely on slope, elevation, and aspect as proxies to infer the soil moisture content of the soils.  I will also record the other types of vegetation that are growing in the sample sites to infer moisture conditions.  This is a categorical variable.

Field notes

Post 3: Ongoing Field Observations

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After doing some initial observations at General Brock Park, I have decided to study the dandelions (Taraxacum) growing there. I noticed that the dandelions tended to grow more abundantly and in greater density towards the perimeter of the field, especially towards the north and east sides. Although the dandelions can be observed to be growing throughout the field, it is sparser towards the centre of the field as well as on the south and west sides where a playground, benches, and street hockey court can be found nearby. I also noticed that the dandelions in this field were shorter compared to ones found on the lawns of nearby residents.

Dandelion growth on northwest perimeter of General Brock Park

 

From these observations, a hypothesis I have come up with is:
The abundance of dandelions found at General Brock Park is influenced by the proximity to areas of the park frequented by humans.

One response variable is the abundance of dandelions while one explanatory (predictor) variable is the frequency of human presence in certain areas of the park. The response variable is continuous while the explanatory (predictor) variable is categorical.

Post 2: Sources of Scientific Information

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Kevin Ostapowich

March 23, 2019

Article:
Comeau, P.G., and Heineman, J.L. 2003. Predicting understory light microclimate from stand parameters in young paper birch (Betula papyrifera Marsh.) stands. Forest Ecology and Management 180(1–3): 303–315. Elsevier BV. doi:10.1016/s0378-1127(02)00581-9.

This article is:  Academic, peer-reviewed research material.

  1. It is academic:
    1. The lead author (Comeau) is associated with the department of Earth Sciences at the University of Alberta so can be considered an expert.
    2. There are in-text citations.
    3. The article contains a bibliography.
  2. It is peer reviewed:
    1. The journal is Forest Ecology and Management which states that it uses: “A peer-review process ensures the quality and international interest of the manuscripts accepted for publication.”
    2. The article also notes when it was received and received again in revised form, indicating that it had been reviewed and re-submitted after revision.
  3. It is research material:
    1. The article contains results from a field study.
    2. It has “Methods” and “Results” sections.

Post 1: Observations

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Kevin Ostapowich

March 23, 2019

The study area is approximately 15 acres of crown land behind my house located approximately 10 km south of Smithers, B.C.  It is on the slope of a hillside facing east to slightly north of east.  The slope ranges from 0% grade at the bottom to approximately 30% grade at the upper end of the study area.  It is a wooded area of mostly deciduous with a minor amount of coniferous tree species.  There is no evidence of anthropogenic disturbances such as logging or road building.  Up-slope and higher in elevation from the site is a dominantly pine forest.

Study Area

The most recent site visit was on March 21st, 2019 around 1500 hours.  The weather was sunny, warm (10 degrees centigrade), with snow cover on the ground and no wind.  The tree types I observed in the forest includes paper birch, cottonwood at the base of the slope, aspen, spruce, and pine.  I plan on more thoroughly identifying the species later on in the study.  I roughly estimate the forest composition to be approximately 60% poplar, 25% birch, and 15% coniferous.  The undergrowth includes willows, devils club, and thimbleberry.  There is abundant ungulate (moose) sign throughout the area including tracks, beds, and droppings.

Moose bed, tracks, and droppings
Typical forest mid slope

This site is interesting because there seems to be (through my own other observations and talking with other locals) an abundance of birch on this site compared to other sites around the Bulkley Valley.  It is also a widely spaced deciduous forest in an area where much of the forests are primarily coniferous.  This leads me to believe that there may have been a disturbance, perhaps fire, that lead to the deciduous community coming up in succession.  Questions I have about this site are:

  1. Is this a site of a natural disturbance?
  2. Are the majority of tree species in this forest typical to disturbance-succession environments?
  3. Is the distribution and abundance of birch trees at this site consistent with other sites around the Bulkley Valley region?
Field Notes

 

Blog post 5

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The collection of data for my project proved to have some challenges. Due to the timeframe of my sampling, the dirt samples were hard to collect with the years first real snow dump falling down. The two plots I was sampling also proved to be quite rocky, so it took some time to find spots I could dig to an acceptable depth as to have a soil core that would be indicative of the actual soil pH. When I was preparing the samples for testing with a pH meter I had to pick out as much of the organic matter and gravel as possible which also proved challenging. Once the samples were separated down to just dirt, I used the pH meter get some actual numbers, but the pH read was rather uniform in its distribution across the samples, hovering at around 6 pH. Even the control sample of just distilled water read a surprisingly low pH level of 5.75.  I definitely need to re-approach how I’m going to gather my data; however, I’m relatively sure that the results are due to my methods used rather than the actual samples. I found online that most studies use a salt dilution to help the sensor pick up the pH, as in distilled water there may be too few ions for the sensor to properly pick up the change in pH from one sample to the next. The other solution is to use a more even distribution as some researchers just use a 1:1 ratio for water to soil mix it up and give it 5 minutes to settle. I also plan on acquiring a sieve to help remove the remaining organic matter that I couldn’t grab and double check the results of the pH meter with pH strips. I think with the sieve and using a closer ratio of dirt to water the actual pH should be easier to pick up, and the pH strips will allow me to double check my results.

Blog Post 2: Sources of Scientific Information

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Blog Post 2: Sources of Scientific Information

The article titled Using plant functional traits to understand the landscape distribution of multiple ecosystem services is academic, peer-reviewed research material.

 

It is academic material because:

It is authored by experts in the field who are specialised in the article’s topic.

The article includes in-text citations as well as an extensive reference list.


 

It is peer-reviewed because although the acknowledgements section does not explicitly state that the article was reviewed, the thanks given to those who gave insightful comments can be taken as such.

 

It is research material because it includes a Materials and Methods and a Results section.

Blog Post 1: Observations

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Blog Post 1: Observations – General Brock Park, Vancouver, BC

Observations by: Harriette Laroco
Location: General Brock Park, Vancouver, BC
Date: Monday, 18 February 2019
Weather: Clear, sunny skies; slight wind
Time of Observation: 15:09-15:48

My field research project will cover General Brock Park, in the Kensington-Cedar Cottage neighbourhood in Vancouver, BC. It is a small city park that is 2.11 hectares in size. The park is in a residential area of Vancouver and is frequented by local residents and their pets, as well as wildlife such as chipmunks, crows, and geese. In warmer weather, the park is also frequently used by local sports teams.

Figure 1. Satellite image of General Brock Park using Google Maps.

My first observations were made on Monday, February 18, 2019 when the park was covered in snow. Recent rainfall caused some snow to melt, leaving some grass patches to be seen. The snow had also become icy.

Figure 2. Snow-covered General Brock Park, facing SE

The park is tree-lined with rolling green hills to the south (now snow-covered). Right outside of the park bounds are residential streets and houses. Towards the northwestern side of the park is a small street hockey area and to the southwest is a small playground (Figure 3 and Figure 4, respectively).

Figure 3. Street hockey area at northwestern end of General Brock Park

Figure 4. Playground at southwestern end of General Brock Park

The snow allowed me to observe some animal tracks (Figure 5, Figure 6, Figure 7).

Figure 5. Paw prints

Figure 6. Bird print set 1

Figure 7. Bird print set 2

 

Figure 8. Field notes – Monday, 18 February 2019

Some questions I drew during this initial observation period were:

  1. How has the frequency of human and domesticated animal use of the park affected the park’s vegetation?
  2. Why are chestnut burrs more prominently found towards tops of trees?
  3. Why are chestnut burrs found in greater numbers in the trees found towards the south of the park?

Post 3: Ongoing Field Observations at Cinnamon Ridge Burn Site

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After another visit, I decided that 3 or 4 attributes of the disturbed vs. original site might be interesting to measure and contrast.

  1. Different species of plants that might be found in the 2 different areas.
  2. Abundance of individuals of each of the different species, especially the dominant species.
  3. Amount of ground that is open and/or covered by some of the unique parts of the community such as the crust made up of lichens and mosses.

In the paper by Lee, they used three different techniques to sample, which I also used to record and sample for my field study:

  • “walkabout” – in order to assess plants species which occurred at low population densities
  • transects – that would allow them to systematically collect information about the abundance of species
  • quadrats within those transects – to provide a visual estimation of the amount of ground covered by different species using a Daubenmire frame sized at 50cm x 20cm

In addition, since the paper pointed out that physical characteristics were important, I decided to also sample:

  • temperature – using a digital probe
  • soil pH – by collecting a soil sample and using a digital pH meter
  • soil conductivity – by collecting a soil sample and using a chemistry lab at TRU.

Finally, I measured the slope of the area using clinometer, which was a grade of 10%.

This site represents an ecotone, where there is a rapid change in character between the two areas.  The clear difference is the presence of sagebrush in the old area and lack of sagebrush in the burned area.  There was the presence of bunchgrass in both areas but also the presence of particular species that are non-native “weedy”/invasive species in the burned area.

Hypothesis: The more recently assembled plant community in the burned area should have a greater species richness (number of species) than would a climax community in the unburned area.  This would be due to the absence of ground-shading sagebrush.

Prediction: If I collect quantitative data then I will be able to record the presence of more species in the burned area than the unburned area.

I would expect similar patterns with respect to the abundance and other measures of diversity.  On the basis of Hanna, there would be more annual grasses in the burned area than in the unburned area.

Categorial variable: burned vs. unburned

Response: measures of abundance, species richness, diversity index (indices)