Ecobeaker: Prairie Sampling
Review:
Population distribution
patterns
Read
Background
in workbook.
Start EcoBeaker on computer.
Load Prairie Sampling.
50m x 50m Prairie Study Area with Prairie Dock (population size = 230).
Take sample using 10m x 10m
quadrat.
How many plants are in your sample? (10)
What is your scaling factor? (50 * 50) / (10 * 10) = 2500 / 100 = 25. (sampling effort = 100)
Record data in table.
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Trial 6
Trial 7
Trial 8
Trial 9
Trial 10
Number Sampled
10
10
10
10
10
10
10
10
10
10
Scaling Factor
25
25
25
25
25
25
25
25
25
25
Population Estimate
250
250
250
250
250
250
250
250
250
250
Run 10 trials.
Sampling Parameters
-> increase number of quadrants to 5 -
Set
.
New scaling factor 2500 / 500 = 5. (sampling effort = 500)
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Trial 6
Trial 7
Trial 8
Trial 9
Trial 10
Number Sampled
43
43
43
43
43
43
43
43
43
43
Scaling Factor
5
5
5
5
5
5
5
5
5
5
Population Estimate
215
215
215
215
215
215
215
215
215
215
Sampling Parameters
-> increase number of quadrants to 10 -
Set
. New scaling factor 2500 / 1000 = 2.5. (sampling effort = 1000)
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Trial 6
Trial 7
Trial 8
Trial 9
Trial 10
Number Sampled
88
88
88
88
88
88
88
88
88
88
Scaling Factor
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Population Estimate
220
220
220
220
220
220
220
220
220
220
Graph Population Estimate vs. Sampling Effort' compare with actual population
size.
Briefly describe the relationship between sampling effort and variability in population size estimate. Larger sampling effort should yields less variability and better estimate of population size.
Now try patchy distribution.
Markers
->
Three Species
: big bluestem, butterflyweed, prairie phlox.
Population Sizes
: 80 each, but random, patchy, even distribution.
Prairie Study Area
:
Random: butterflyweed
Patchy: prairie phlox
Even: big bluestem
Repeat quadrants for all 3 species.