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Post One: Observations

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The study area chosen for this field study is in the Lower Mainland, in an area where many small creeks transect the topography. This particular creek meanders in an approximately north to south direction with residential homes backing onto it from both eastern and western banks. From the relatively flat areas of the back yards, there is a slope of about forty five degrees for approximately twenty five to forty feet ending at the edge of the creek. Spanning one back yard is a distance of approximately seventy five feet.

At the time the homes were built, in 1983, the engineering of the housing development was required to include a large scale drainage plan. The solution was to run an approximately three foot in diameter metal pipe from the east to the west across the creek (see area indicated on Google overhead map). To accomplish this task, the entire western bank of the creek was cleared of all trees and vegetation. The heavy equipment that was brought in to install the pipe left very few remnants of plant life. Since that time, the re-growth of the plants and trees in the creek bank of my own back yard is exciting and provides opportunities for study.

Overhead Google map of the area – unable to load to the blog.

Over the years, staff from the Federal Department of Fisheries have visited the creek to promote it as a salmon spawning creek where human traffic is discouraged. The Municipality of Surrey staff have come by to inform the residents of plans to build a public trail through the creek. As of this date, the trail has not been built.
During years of family life, participating in “Christmas tree chipping” events where evergreen seedlings were given to be planted along municipal “green belt” areas, has resulted in human interference with the natural process of vegetative succession. The status of the area at this time is that there are three types of vegetation within this riparian slope. One is where no seedlings were planted and has a well-established growth of cottonwood trees with other minor varieties of plant life underneath. The second is where the evergreen trees were planted and have thrived, creating a different undergrowth type. The third is at the area where the pipe crosses the creek; this area, due to the former clearing of trees receives more direct sunlight and consists mostly of smaller, lower growing shrubs.
Interesting questions for a potential project are:
1. The impacts of the amount of sunlight on the undergrowth for each of the three area types: evergreen trees, deciduous trees or no trees.
2. A comparison of this area of the creek bank to that of another area up stream that was not cleared when the subdivision was created.
3. What invasive species have demonstrated in the years since the area became residential and how widespread are they becoming?

 

 

Blog Post 3: Ongoing Field Observations

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Study Date / Time :  Oct 1, 2017 from 3:00 to 5:00 pm
Weather: Overcast with warm temperatures (±19○C)

I plan on studying the spatial distribution of invasive species within the ecological reserve, particularly along well delineated and abrupt edges with residential development.  The environmental gradients I have chosen are distance from the reserves edges to residential development and soil development (thickness and moisture regime) relative to the Coastal Douglas fir and Garry oak ecosystems.

During this field assessment I focused on assessing the south boundary, where the topography ranges from wide, gentle benches separated by bedrock hummocky terrain. “True” Garry oak zones appear to only occur on the bedrock hummocks, where soil thicknesses are generally less than or equal to 0.2m and are rapidly to very well drained. Although, it should be noted that some areas within the Garry oak ecosystems are actively being succeeded by Douglas fir.  The Douglas fir stands are found mostly on wide, gentle benches at lower elevations. These benches are mostly covered in a veneer (≤1.0m) of rubble and silt colluvium underlying a variably thin(≤0.3m) layer of organics.  In the southwest area of the reserve pockets of loose, sand marine deposits were found to underlie the aforementioned colluvium , cumulatively up to 1.5m thick.  In appears that the Douglas fir stands favour sites with thicker soils that are mostly well drained. Some small local areas with moderately well to imperfect drainage are also found on these benches.

While I have observed numerous invasive species so far during my field observations and past excursions I plan on narrowing the number species down to a select few. These include the most prevalent species:  Cirsium arvense (Canada thistle), Daphne laureola (spurge laurel), Senecio jacobaea (tansy ragwort) and Ilex aquifium (English holly).  It is currently early fall and some of the herbaceous plants are beginning to die off. This may lead to errors in further assessments.  For this reason, I likely will exclude Canada thistle and tansy ragwort from my studies.

During this field assessment I made some rough estimates of densities and / or cover class by percent for English holly and spurge laurel. Based on these observations there are notable differences in the distribution and abundance of invasive species between the two ecosystems immediately along the south edge adjacent to residential development.  Invasive species appear to have more successfully colonized the Douglas fir ecosystems, specifically  on benches and depressions with thicker soils. As well, there is a correlation between increased light availability due to gaps in forest canopy and the higher frequencies of invasive species.  In contrast, the Garry oak ecosystems have an abundance of light availability but appear to have less invasive species. It is thought that this is due to these areas having thinner soils with drier moisture regimes in comparison to the Douglas fir stands.

Hypothesis: The presence and abundance of invasive species in the ecological reserve is influenced by close proximity to the forest edges adjacent to residential development and the Douglar fir and Garry oak ecosystems.

My null hypothesis is that the distance from residential development and the two dominant ecosystems have no effect on the spatial distribution of the invasive species.

Response variable: Presence and abundance of English holly and spurge laurel.
Predictor variable: Distance from edges adjacent to residential development ; soil thickness  and moisture regimes.

          
Figure 1. Garry oak ecosystem with ~≤1.0% invasive species


Figure 2. Garry oak ecosystem adjacent to development


Figure 3. Daphne laureola seedling


Figure 4. Field Notes

Blog Post 7: Theoretical Perspectives

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The theoretical basis for my research project examines how varying levels of urbanization impacts bird species presence and abundance. To examine this I’m collecting data on bird species presence and abundance (response variable) within three areas that represent different levels of urbanization as determined by the percent cover of natural and anthropogenic habitat (explanatory variable).

Based on other research related to bird species presence and abundance along urban gradients (Hartje 2017, Blair 1996) there theoretically should be a difference in the species richness and abundance between sites with different levels of urbanization. More particularly, the most urbanized sites should theoretically have the lowest species richness, and the most natural sites should theoretically have the highest species richness. However, previous studies have not always aligned and some have found that species richness was highest in intermediately disturbed sites (Blair 1996) whereas other studies found species richness highest in the most naturalized sites (Hartje 2017). It will be interesting to see where the results from my research align in this respect. While theoretically abundance should also be highest in more natural sites, previous studies (Blair 1996) found that highly urbanized sites often have the highest overall abundance due to large flocks of a single species. Again, it will be interesting to see how my results compare to the other literature on the topic and if they align with the theoretical perspectives on bird species richness and abundance along urbanized gradients.

It is also important to think about how both species richness, and natural habitat is examined and characterized. Theoretically, species richness includes all species, both native and non-native, but it might be beneficial to tease these categories apart. For example, if an intermediately urbanized site has the highest species richness but hosts exclusively non-native species then its value as bird habitat would likely not be comparable to natural areas where species richness might be lower but is dominated by native bird species. Additionally when classifying habitat it is important to think about the impact native and non-native plant species play. An invasive Himalayan blackberry (Rubus armeniacus) thicket may host similar abundance values as a thicket of native vegetation but the overall species richness will be higher in the native thicket (Astley 2010). As a result, when classifying habitat should blackberry thickets theoretically be categorized as natural or anthropogenic habitat? While I won’t have the ability to examine these issues in my research project their theoretical impact on bird species presence and abundance, and the ways of evaluating overall richness and abundance do provide something to think about and will be mentioned in the final report.

Keywords: urban habitat, urbanization gradient, non-native species, bird species presence and abundance.

Post 2: Scientific Research

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Anna Zacaruk

September 30, 2017

I found a few interesting scientific papers on the subject of light competition in plants, with one of the most interesting being “The importance of light quality in crop-weed competition” by Lui JG et al. The paper discusses the notion that plant competition is thought to be driven by limiting resources such as light, which may disrupt physiological processes. The authors believe that changes in light resources may initiate a “shade avoidance response” in plants where they constrain their own development and reduce their own reproductive fitness in attempt to avoid growing in shaded areas and compete with other plants for light.

Another paper I found was called “Weed community characteristics and crop performance: a neighbourhood approach” by Pollnac FW et al. This paper discusses the possibility that the presence of weeds in crop fields causes crop yield reductions. The hypothesis tested was that increased weed species richness would decrease the effects of competition on spring wheat target plant performance. The authors ended up finding that species richness had no significant direct effect on spring wheat biomass, yield, or relative growth rate and that there were no significant neighbour species interaction terms. However, they did find that increasing weed species richness had a negative impact on the growth of individual weed species.

Both papers I’ve chosen are academic papers written by Lui JG et al., and Pollnac TW et al. respectively. The two papers are both apart of the “WEED RESEARCH” Journal, which is “An International Journal of Weed Biology Ecology and Vegetation Management.” Both reports contain in text citations, multiple tables, results sections, bibliography and authors. Each paper is based off of experiments and testing performed by the authors, and each has detailed results sections. Considering this is an internationally published academic journal, and both papers are Peer-Reviewed, I would consider these both Academic, Peer-Reviewed Research papers.

Liu, J.G., K.J. Mahoney, P.H. Sikkema, and C.J. Swanton. 2008. The importance of light quality in crop-weed competition. Weed Research 49: 217-224.

Pollnac, F.W., B.D. Maxwell, and F.D. Menalled. 2008. Weed community characteristics and crop performance: a neighbourhood approach. Weed Research 49: 242-250.

Post 1: Observations

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Anna Zacaruk

September 29, 2017

After considering many different areas to study, I decided that an outdoor experiment at this time of year (autumn) in my region would be too complicated and risky knowing how unpredictable the weather is in Alberta. With permission from Dr. Percy Hebert, I’ve decided to do my project in my greenhouse, using some equipment from my mother who has her degree in agriculture and specializes in reclamation projects. I have decided to compare the interspecific competition between a weed plant species (dandelions) and a non-weed plant species (marigolds) for a light source. I was considering growing the plants for roughly 7 weeks in the same pots to see which will outcompete the other in both light and light-restricted conditions. My study area is technically my greenhouse, which has windows that are East and South facing. I intend to grow the plants in pots along the window sill in plastic potting trays until germinated, and then randomly remove some plants to a tray where light is limited by some sort of barrier (I was thinking mesh or burlap of some sort). I anticipate to allow the plants to grow for 7-8 weeks.

Questions I currently have are:

  1. How will limited light affect competition between dandelions and marigolds?
  2. How will limited light affect plant leaf and root growth?
  3. How will limited light affect plant overall (dry) biomass?
I found a few interesting scientific papers on the subject of light competition in plants, with one of the most interesting being “The importance of light quality in crop-weed competition” by Lui JG et al. The paper discusses the notion that plant competition is thought to be driven by limiting resources such as light, which may disrupt physiological processes. The authors believe that changes in light resources may initiate a “shade avoidance response” in plants where they constrain their own development and reduce their own reproductive fitness in attempt to avoid growing in shaded areas and compete with other plants for light.
Another paper I found was called “Weed community characteristics and crop performance: a neighbourhood approach” by Pollnac FW et al. This paper discusses the possibility that the presence of weeds in crop fields causes crop yield reductions. The hypothesis tested was that increased weed species richness would decrease the effects of competition on spring wheat target plant performance. The authors ended up finding that species richness had no significant direct effect on spring wheat biomass, yield, or relative growth rate and that there were no significant neighbour species interaction terms. However, they did find that increasing weed species richness had a negative impact on the growth of individual weed species.
I am curious to see what my findings may be, and if they will differ from those of the scientific papers I have been reading. Stay tuned for the riveting results!!!

 

Initial Data/Plan

Blog Post 6: Data Collection

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I have now completed around half of my point count surveys within the Burnaby Lake Regional Park area in an effort to measure bird species presence and abundance along an urbanized gradient (Site 1 – Urbanized Area, Site 2 – Moderately Urbanized Area, Site 3 – Naturalized Area).

To date, I have completed 4 replicate point count surveys in each of three areas (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. Since revising my research design as highlighted in Blog Post 5 I have had no issues in implementing it. Performing surveys between dawn and 10:00am has resulted in a high level of bird detectability. 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. Overall, the switch to Burnaby Lake Regional Park and the revised hypothesis seems to be going very well and this was a good decision to make sooner rather than later in the research project.

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 anthropogenic habitat (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.

Looking at the data quickly some ancillary patterns reveal that the species richness is lowest in the most urbanized area but further analysis will be required to determine whether species richness is highest in the moderately urbanized or naturalized area. Bird abundance has been quite high throughout all the sites so it has been hard to determine which site has the highest abundance. Site 1 does have large flocks of rock doves flying 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.

Post 8: Tables and Graphs

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The data I collected was easy to summarize in a bar graph. The outcome was slightly unexpected. When the stats were run (ANOVA), I determined that my result was not significant. As my sample size (n=5 for both conditions) was small, the standard deviation turned out to be quite large. This likely was why my data was insignificant. A method that would likely decrease deviation would be to collect more samples. However, as this is not a study I plan on publishing, I don’t want to cause additional disturbance to the natural environment.

Blog post #2: Sources of Scientific Information

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I have selected a chapter out of an online publication from the B.C. Ministry of Forests.  Chapter 5: Coastal Douglas-fir zone provides detailed information about the classification, distribution and ecological characteristics of the Coastal Douglas fir zone.  For anyone who is interested the link is as follows: https://www.for.gov.bc.ca/hfd/pubs/docs/srs/srs06.pdf

Based on the flow chart for discriminating among different sources of information this publication is academic, peer-reviewed review material.  I arrived at this conclusion because F. Nuszdorfer, K. Klinka, and D. Demarchi are (were) the leading forest ecologists who researched and oversaw the biogeoclimatic ecosystem classification system for B.C.  Within the acknowledgments section there are numerous authors and colleagues at the Ministry Forests and Ministry of Environment identified  who reviewed individual chapters as well as the overall manuscript.  As well, when I did a Google search of the publication with “times cited”  over 5000 hits were displayed.

F.C. Nuszdorfer et al. Chapter 5: Coastal Douglas-fir Zone. Ecosystems of British Columbia. B.C. Ministry of Forests, 1991. www.for.bc.ca/hfd/pubs/ss/srs06.pdf. Web. 2 Oct. 2017.

Blog Post #1: Observations of

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Study Date: September 19, 2017 from 3:30 to 5:00 pm

Weather: Clear skies with warm temperatures (±18○C)

The area I have selected for my research project is a small ecological reserve that is found near my home in Nanoose Bay, Vancouver Island. In my spare time over the past 7 months I have cleared a path through mature, second growth stands to gain access to this reserve for recreational use. The eco-reserve has been set aside by the powers that be for the conservation of old growth / mature second growth,  coastal Douglas fir stands. The eco-reserve is roughly  90 hectares and is bordered by relatively low density, residential development on its north, south and west edges. The terrain across the study area is comprised of  lowland benches and bedrock hummocks. Slope gradients typically range from 10 to 25% on benches with short breaks of up to 45% off  the sides of bedrock hummocks.

I have observed from this field reconnaissance and past outings that there are two dominant ecosystems within the study area. The first is the Garry oak ecosystem which appears to occur more on bedrock hummocky terrain. The second is mature and old growth stands of Douglas fir with lesser amounts of western red cedar, western hemlock and trace amounts of grand fir and big leaf maple.  During my first field observations I assessed two possible sample sites.

Site #1: Garry Oak Ecosystem

Location: 49○ 16′ 33″ N 124○ 10′ 32″ W
Terrain: Gentle to moderate (10-35% ) benches and bedrock hummocks.
Soil: Rubble and silt colluvial veneer underlying ≤0.3m of organics, cumulatively ≤0.8m thick. Drainage: Rapid to well drained.
Forest stand: Garry oak site series comprised of Garry oaks with lesser amounts of Douglas fir and arbutus (see Figure. 2). Stand is open canopy and low density.
Under-storey: electrified cat tails moss, grass, white fawn lilies and hookers onion.

Site #2: Douglas fir stand

Location: 49○ 16′ 54″ N 124○ 10′ 02″ W
Terrain: Gentle (10-25% ) benches.
Soil: Clay, rubble, silt and sand colluvial veneer, generally less than or equal to 1.0m thick.
Drainage: Rapid to well drained.
Forest stand: Open to moderately dense, old growth Douglas fir with minor western red cedar, grand fir and western hemlock (see Figure.3).
Under-storey: young western red cedar, various Vaccinium spp, salel, sword fern, bracken fern, dull Oregon grape, ocean spray and step moss.

As well, I observed the following invasive biota in the under-storey of both ecosystems: holly, tansy, Himalayan blackberries, spurge laurel,  scotch broom, thistle and a grass (not certain of species, will have to research) (see Figures 4 & 5).

I have come up with the following questions for the subject of my research project:

  1. Is there a relationship between the distance from the eco-reserve edges adjacent to residential development and the number of invasive species and their abundance?
  2. Do invasive species vary between the Garry oak ecosystem and the  coastal Douglas fir stands ?
  3. If there is quantifiable difference in invasive species and their abundances between the two ecosystems, what are the potential factors that affect the colonization rates for the invasive species?

 

 

 

 

 

 

 

 

Figure 1. Coastal Douglas-Fir Protected Areas in Nanoose Bay & Parksville. Source: http://www.cdfcp.ca

  

Figure 2. Transition area between coastal Douglas fir and Garry Oak ecosystems, near sample site #1
 

Figure 3.  Old growth coastal Douglas fir stand at sample Site #2.

  

Figure 4. Holly
 

Figure 5.  Spurge laurel

Post 7: Theoretical Perspectives

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In my project, I am looking at the effects of community structure on the growth of Farlow’s Seaweed. In specific, I’m determining whether there is a difference between the growth of Farlow’s Seaweed when it is dominant (completely based on number of Farlow’s seaweed compared to other species present within the tide pool) in a tide pool vs. when it is not. Theoretically, I believe that interspecific nutrient competition is the main driving force behind the different growth rates. In my study, I looked at tide pools as “semi-closed” environments. What I mean by this is that the shared pool of nutrients available to all organisms is refreshed in high tides, but when it is low tide there is a minimal intake of new nutrients. As a result, organisms within the tide pools will have to compete for nutrients. Growth rates for algae are significantly influenced by how well they can out-compete other species for nutrients (White et al., 2013; McConico and Vogt, 2013). Based on my observations, I believe that Farlow’s Seaweed is not a good competitor for resources, and will grow much better (I’m using weight as a measurement) in environments with little competition from other species. When there is a large source of competition for nutrients, Farlow’s Seaweed is expected to be smaller in size.

 

Key phrases: nutrient limitation, interspecific competition, community structure.