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Blog Post 5

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Methods:

3 transects (plots) on each study site were established at a length of 9.5m starting from the city sidewalk and running toward the house. Each transect has a 0.5m spacing on either side of the centre. The first transect centre is placed 0.5m from the edge (driveway) of the area being studied. The following transects are placed 1m away from the initial centreline of the previous transect to prevent overlap.

The total area sampled in each plot is 28.5m. Transects are labelled from A to F.

A, B, and C are located in the diverse site. D, E, and F are located on the grass lawn. They are labelled in order from South to North, with transect A at the most Southerly position.

Species recordings are plotted at the measured distance from the sidewalk along with a measured distance away from the transect line to provide an x,y coordinate of where the species was located and in what conditions.
A positive y location indicates a position South of the line and a negative y location indicates a position North of the line.
A further recording of whether or not the species was located in an area with vegetation or ground cover is made with a Y/N indication and a sub-indicator code for logs, rocks, and others. A recording without a sub indicator means that it was found on vegetation.

Transect F

 

Transect A

 

Transect E close-up

Results:

Number of species located in diverse area (Transects A,B,C):

Transect A: 11

Transect B: 2

Transect C: 1

Composition:

Spiders: 4

Beetles: 3

Caterpillars: 7

Location type (Transects A,B,C):

Total species in/on vegetation/cover: 10

Total species in non-vegetated/cover location: 4

Total: 14

 

Number of species located in grass area (Transects D,E,F):

Transect D: 0

Transect E: 0

Transect F: 5

Composition:

Ants: 5

Location type (Transects D,E,F):

Total species in/on vegetation/cover: 0

Total species in non-vegetated/cover location: 5

Total: 5

 

Changes in methodology:

The method I used to collect the data has so far been effective. Being able to sample the entire site has the advantage of eliminating many assumptions that would be necessary if I were performing randomized or representative samples of just a portion of the site.

This sampling strategy only works well because the site size is relatively small and it is possible to sample the entire area in a reasonable amount of time.

The challenge is to ensure that the transect line is placed in an exact location each time. For this, I used a tape measure and a length of string attached to a railroad spike. When the spike is placed in the ground, it is possible to accurately measure locations for the centreline of the transect without movement.

I will continue to sample this site in this manner so that my data remains consistent.

Blog Post #5: Design Reflections

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During the initial data collection one of the difficulties that I encountered was maintaining a bearing through heavy brush and windfalls. The data collection itself went more or less according to the planned strategy. The distribution of invasive species has not always been consistent with my expectations. There has been more invasive species in the interior of the ecological reserve than originally observed. They are often distributed along relic skid trails and foot paths. I am satisfied with the sample design and technique so far. I plan on continuing to systematically collect data at the predetermined specified intervals in order to minimize sampling bias such as ease of walking and selecting locations with vegetation that support my hypothesis.

Blog Post 5

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I modified my data collection strategy from my initial plan, as I could not do spore counts on the fronds as it is spring time and the new fronds did not have spores and the mature fronds had dispersed their spores. Instead I measured the width of the widest pinna of the longest frond, which still gives an indication of the capacity of the frond to carry spores, so I think this approach will work. I also decided to just count the new fronds per crown as it was very difficult to count all the fronds, as many were rotting or broken and it was hard to determine which were viable fronds and which were not. Just counting the new fronds should still give an indication of the vitality of the fern.

In terms of laying out a 15m rope marked at 3 m intervals and then selecting the closest fern to that point, this worked well and I will continue to do this. I will increase the distance between sampling lines from 1m to 2m as the ferns can be as much as 2m across so I do not want to be counting the same fern on two different sampling lines.

Post 4

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Comparing the three different sampling strategies, the fastest sampling time was with the haphazard method (12 hours 30 minutes), then systematic random (12 hours 36 minutes), and then random (12 hours 42 minutes).

When comparing the percentage errors using the different sampling techniques for the two most common species, the most accurate method was systematic random sampling (7.2% and 5.5%). The next lowest sampling percentage error was with the haphazard technique (10% and 13.4%) and the highest sampling percentage errors was with the random sampling technique (11.5% and 25.5%).

When comparing the percentage errors using the different sampling techniques for the two rarest species, the most accurate method on average was haphazard sampling (52.6% and 48.8%). The next lowest sampling percentage error was with the systematic random technique (5.1% and 170%) and the highest sampling percentage error was with the random sampling technique (52.6% and 248%).

The accuracy with all techniques was greatest with the most abundant species. When the species were abundant the most accurate technique was the systematic sampling technique, but when the species were rare, all the methods had high error rates. It is difficult to conclude that one sampling method is superior to others as there was a wide range of species abundance, so I would select the method that required less time to complete.

Blog 3

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The organism I have chosen to study is the Western Sword Fern (Polystichum munitum), a common fern found in the Pacific North West region.  The fern is commonly found in moist, mild and shady environments.

The reason I decided to study this organism is that it is commonly found throughout Pacific Spirit Regional Park, however there were some locations on within the gradient of study that I observed fewer sword ferns present. At the creek site (Site 2), on the west bank of the stream there were fewer ferns, however on the east bank of the stream there were many more. The ferns at the interior site (Site 1) appeared to be more vigorous and larger than the ferns at site 2. Site 1 is located amongst large coniferous trees and it appears that less light makes it through to the forest floor. This is an environment that would suit sword fern growth so I would predict that the ferns may grow more vigorously or have greater abundance at this site compared to the creek site (site 1). The banks of the creek are relatively open to the sun as the creek runs south and the trees at the edge of the forest have been thinned or cleared as the creek passes beneath the road. I would expect that this site, although moist, the sun exposure may affect the sword fern growth. I did notice that the ferns were more prevalent on the east side of the creek than the west side, and again this may be due to the sun exposure the different banks experience.

I hypothesize that the fern growth will be greater in the more shady areas of the forest as measured by crown count per unit area, and frond length. I am also interested in counting the density of spores to determine if that also varies by site. The explanatory variable will be the amount of light at each site classified as high and low. The response variable of crown number/ plot and frond length will also be continuous variables.

Sample of field journal entry including observations of different sites.

Blog post 4

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Blog Post 4

Which technique is the most efficient in terms of time spent sampling?

Systematic: Sampling along a topographic gradient 4 hours, 5 minutes (20 minutes faster than haphazard)

This is from a distance based sampling strategy.

Percent error

Systematic: Sampling along a topographic gradient

Percent error common species (Eastern Hemlock): 12.9%

Percent error rare species (Striped Maple): 46.9%

Random: Distance, random or systematic

Percent error common species (Eastern Hemlock): 13.6%

Percent error rare species (Striped Maple): 58.9%

Haphazard or subjective sampling:

Percent error common species (Eastern Hemlock): 6.5%

Percent error rare species (Striped Maple): 100%

 

The most accurate sample strategy for common species was Haphazard or subjective sampling.

The most accurate sample strategy for rare species was Systematic: Sampling along a topographic gradient.

The accuracy for rare species declined over the sampling methods used.

The accuracy rate changed in relation to species abundance.  The less abundant a species was correlated with a greater increase in error of collecting a sample for that species.

24 sample points was not enough points to capture the number of species in this community. In the Haphazard sample, the error rate of 100% would miss this species entirely. The sample strategy that most captured this species still had an error rate of 46.9%, which greatly under-represents this species.  Adding more sample locations would reduce the error rate.

Blog Post 3

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Blog Post 3

My hypothesis is that when considered in a small scale residential garden setting; insects, isopods, and arthropods increase in diversity and abundance when there is a diversity of plants and ground cover (large woody debris/rocks).

I predict that I will find a diverse range of insects, isopods, and arthropods in the diverse garden setting that are not present or are greatly reduced in the relatively uniform grass lawn setting, despite that the grass lawn setting contains more cover overall.  I expect to find this diversity in and immediately around the plants and ground cover, but not on the bare earth in-between the plants and ground cover.

A potential response variable will be an increased abundance and diversity of insects, isopods, and arthropods in the diverse cover setting.  I think that this will happen because the range of habitat and food source options are greater in the diverse setting and that this can support greater abundance and diversity in insect, isopod, and arthropod populations.

I have chosen to sample the plants, and ground cover (large woody debris/rocks) in the more diverse setting as one collective group (diversity).  I will also sample the bare earth in-between plants and ground cover in this setting (lack of diversity) to determine if any recorded diversity is isolated to the plants and ground cover within this setting.  The final sample will be the grass lawn (lack of diversity).

The response variable is continuous because it is a count.  The predictor variable is categorical, which is the type of cover.

There has been a long history in ecological literature which suggests that things which provide habitat or food (plant and ground cover diversity) correlates with diversity of the things that need or consume them (insect, isopod, and arthropod populations) (Hutchinson, G. 1959).

It is possible that plant diversity alone is not sufficient to determine a link between increased plant habitat or resources and increased insect diversity.  A bottom-up approach or an examination of various trophic levels in the environment suggest that things like nutrient availability, or plant pathogens, among others, could have cascading effects that influence things like population density and diversity in insect populations (Hunter, M., & Price, P. 1992).  It is also possible that the size of the area is too small to provide a meaningful effect.

For the purposes of this study, I will focus on using a generalized definition of plant diversity and ground cover which does not include nutrient availability, the presence of pathogens, water availability, etc., but rather focuses on the quantity, characteristics, size, and distribution of the plants and structures.

Observations:

April 24, 2018

1:30 pm

Weather: Sunny, 19 degrees

I have observed two funnel web structures on two separate pieces of wood that simulate a fallen tree branch and rotting stump and one caterpillar on a sword fern plant (diversity).  I have not observed anything in the lawn setting, despite there being more overall cover (lack of diversity).  I have also not observed anything in the bare earth patches between the diverse plants/ground cover.

 

Uniform grass cover

 

Funnel webs

 

Uniform setting vs. diverse setting

 

Caterpillar on sword fern

 

Field note tally

 

References:

Hunter, M., & Price, P. (1992). Playing Chutes and Ladders: Heterogeneity and the Relative Roles of Bottom-Up and Top-Down Forces in Natural Communities. Ecology, 73(3), 724-732.

Hutchinson, G. (1959). Homage to Santa Rosalia or Why Are There So Many Kinds of Animals? The American Naturalist, 93(870), 145-159.

Blog 7: Theoretical Perspectives

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The field study project on the red squirrel’s conifer cone totals in his midden and conifer cone totals within a 20 meter radius bring to light an understanding of foraging behaviors of this mammal  In particular, the emphasis is on understanding whether a red squirrel in an urban environment locates a habitat similar to a wild squirrel’s habitat.  Of note, are the ‘mast’ years when conifer trees produce more amounts of cones than normal years and what this relation has on the Scots pine that make up the majority of his urban habitat.  The placement of the trees in relation to his cache or midden present unique space use patterns that may reflect similar patterns in a wild habitat.  The diameter of the conifer trees, the species of tree and cone producing capabilities, pilfering of cones from other squirrels, predatory considerations and tree canopy cover are some of the other issues to be touched upon for urban red squirrel habitat.

Cache and Nest Characteristics of the Red Squirrel in an Ariᴢona Mixed conifer Forest (1986) by David R. Patton, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado.

Keywords:  Mammal ecology, ethology, sciuridae, rodentia, foraging, habitat, space use patterns, urbaniᴢation.

Blog 9: Field Research

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I very much enjoyed coming up with an experiment and then conducting it by myself. It was very challenging to come up with an idea since when I first started this class there was very heaving snow fall occurring so it was hard to really explore somewhere to find something that was interesting for me to want to further investigate.

It was challenging to set up the experiment where I had to make some modifications when mapping out the experiment guide lines so that it fit the rule of 10 and also limiting down on what I was wanting to examine since at first my idea was too broad. However, once  I had a clear outline for my experiment I had no troubles collecting data and was not too difficult interpreting the data.

By doing this experiment I have learn how much dedication and time is need when conducting ecological experiments where even for my experiment more data is needed to be collected over a larger time period to determine exactly what weather condition effects moss richness and if it changes during different seasons of the years. Where this also shows just how interconnected everything is in the environment and how ecology theories are important in understand some of these relationships found in nature.

Blog Post 2: Sources of Scientific Information

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The source of ecological information I have chosen is the following citation:  Muñoz, P. T., Torres, F. P., & Megías, A. G. (2014). Effects of roads on insects: A review. Biodiversity and Conservation, 24(3), 659-682. This paper is an academic, peer-reviewed review. The authors are affiliated with the University of Grenada in Spain, the paper includes in text citations and a bibliography of the citations used so it can be considered academic material. The authors acknowledge the feedback received from the three anonymous reviewers so the article was peer reviewed. The title of the paper describes it as a review and the paper does not include any method or results sections.