A survey to determine effects of human interference on grassland and disturbed area herbaceous plants, vertebrates and invertebrates at York University

Hypothesis
Human activity disturbs essential land and resources necessary for
species survival. Due to this, increased human interference will result in a
reduction in the number of individuals of both non-human vertebrates,
invertebrates and plants within an ecosystem.
Predictions:
1.    The higher the abundance of humans, the
lower the abundance of both non-human vertebrates and invertebrates.
2.    The higher the abundance of humans, the
lower the abundance of both native and exotic plants.
Location
Data was collected at York University’s Keele campus at two
habitats; a grassland next to a small woodlot with no water source and a
disturbed area next to a well circulated road. GPS coordinates for the
grassland was 43.776126, -79.49628 and for the disturbed area was 43.776088,
-79.439102. Elevation for the grassland and disturbed area were 176.309174m and
174.439102m respectively. The weather was mostly sunny with temperatures
reaching 13C and humidity reaching 45% and wind speeds of 23km/h.
Meta-Data
Data was collected from the grassland and disturbed area
(43.776126, -79.49628 and 43.776088, -79.439102 respectively) on York University’s
Keele campus. Data was collected via visual survey using transects (two 30m
transects), pan traps, 1mx1m quadrats, sweep nets and point survey techniques.
For the first data set we obtained the abundance of native plants, abundance of
exotic plants, and total number of flowers via quadrat sampling
(n=25) along a 50m transect (east to west in the grassland and the
disturbed area). Every two metres a quadrat was placed on alternating sides of
the transect. The number of individuals of native and exotic plant species were
counted within the quadrat. Grass species (except sedges) were considered to be
exotic and all other plants were considered native. Next, the total number of
observed flowers within the quadrat were counted; all levels of inflorescence
(i.e. buds and blossoming) were considered flowers.
For the second dataset a 50m transect was drawn (east to west for
both grassland and disturbed area) and the measured variables were abundance of
woody plants, canopy cover, ground cover, and total number of flowers.
Abundance of woody plants were counted every 2m within 0.5m of the transect.
Only plants larger than 1.5m in height were counted. Having a height
requirement decreased the probability of counting a non-woody plant. Also,
every two metres, the vegetative ground cover and canopy cover was approximated
in percent by visually dividing the ground and canopy space into quadrats, then
the area covered was estimated by the surveyor as a percentage of the total
space. Total number of flowers were counted within 0.5m of the transect on both
sides every 2m. In both areas, 25 counts were completed.
For the third dataset, abundance of vertebrates, diversity of
vertebrates, abundance of invertebrates observed and abundance of humans were
measured in the grassland and disturbed area. A 50 m transect was drawn (east
to west) and point surveys were conducted via visual inspection of the area
within a 50m radius of the start point of the transect. The total number of
vertebrates, diversity of vertebrates and abundance of humans was observed for
a 15-minute period (n=2). Then in 15 minutes, all humans not part of the study
group were counted to survey pedestrian circulation. This was to check for the
level of human interference. Following, the abundance of invertebrates was
counted (i.e. insects, mollusks, etc.) within a 5.0m radius of the start of the
transect for 15-minutes for n=2.
For the fourth dataset (measuring abundance of invertebrates in
pan traps and abundance of invertebrates caught in sweep nets), 6 pan traps
(blue, white, yellow) were placed 3 meters apart along a 50m transect while
alternating colors. The pan trap was left for 45 minutes and then the number of
invertebrates caught were counted. Then, along the 50m transect, sweep nets
were used to catch any invertebrates (flying and ground-dwelling). The nets
were swept upwards from a left to right motion on the grass and tall plants. In
the disturbed area, sweep nets were swept very low to the ground as there was
little to no tall vegetation (primarily grass cover). For both areas, the pan
traps were placed once and the sweep nets conducted 10 times.
Methods:
50m transects (combining two 30m transects) were run (east to
west) in both the grassland and disturbed area; quadrat samples were taken on
both sides of the transect every 2m (n=25). To count the abundance of native
and exotic herbaceous plants, surveyors used a 1.00m x 1.00m quadrat to
visually inspect and sample individuals. Sampling was conducted by the surveyor
counting the abundance of native and exotic herbaceous plants per the
bottom-left quarter of the quadrat, the sampling was then multiplied by a factor
of 4 to gain total abundance. Total number of flowers were counted and
inspected by the surveyor (inflorescences were counted as individual flower
units).
For woody plants, a 50m transect was run (east to west) and for
every 2m a surveyor observed for woody plants (defined as plants with a height
greater than or equal to 1.5m) within 0.5m of the transect (n=25). At these
points canopy and ground coverage was estimated via surveyor’s visual
inspection, by visualizing quadrats above and below the surveyor. As well,
total flower numbers were recorded similarly within the 0.5m area (from the
transect) as described above.
Point surveys were conducted for periods of 15 minutes (n = 2) for
the abundance of vertebrates, diversity of vertebrates, abundance of invertebrates,
and abundance of humans. The survey involved running a transect for 50m and a
surveyor visually inspecting and counting for the abundance of vertebrates,
diversity of vertebrates and abundance of humans within a 50m radius of the
transect start point. Diversity of species was determined via visual
inspection. Within a 5m radius of the transect start point abundance of
invertebrates was measured.
Pan traps were set 3m apart while alternating colours (yellow,
blue, white) along the length of a transect (50m). Each pan trap was one
replicate (n=6) and the total number of invertebrates within the pan trap were
counted and recorded. Then, sweep nets were conducted next to the 50m transect.
Each sweep was one replicate (n=10) and the total number of invertebrates found
at the end of the sweep were counted and recorded.
Variable Definitions
Abundance of native plants – The visual inspection and count of
native plant species (primarily flowering species) per a 1.0m x 1.0m quadrat.
Numerical, discrete.
Abundance of exotic plants – The visual inspection and count of
exotic plant species (primarily grass species) per a 1.0m x 1.0m quadrat.
Numerical, discrete.
Total number of flowers (quadrat) – The visual inspection and
count of flowers (inflorescences were counted as single units) per a 1.0m x
1.0m quadrat. Numerical, discrete.
Abundance of woody plants – The visual inspection and count of
woody plants (taller than 1.5m). Numerical, discrete.
Canopy cover – The visual estimation of the percent area covered
by the canopy of the woody plants. Numerical, continuous.
Ground cover - The visual estimation of the percent area covered
by the herbaceous plants on the ground. Numerical, continuous.
Total number of flowers (transect)– The visual inspection and
count of flowers within 0.5m of the transect on both sides. Numerical,
discrete.
Abundance
of vertebrates – The visual inspection and count of vertebrate species in the
radius of the point survey. Numerical, discrete.
Vertebrate species – The visual inspection and count of the
diversity of vertebrate species within the radius of the point survey.
Numerical, discrete.
Abundance of invertebrates – The visual inspection and count of
invertebrate species in the radius of the point survey. Numerical, discrete.
Abundance of invertebrates pan traps – The visual inspection and
count of invertebrates caught in pan traps during a 45 minute period.
Numerical, discrete.
Abundance of invertebrates sweeps – The visual inspection and
count of invertebrates caught in sweep nets over a 50m transect. Numerical,
discrete.