Blog Post 4: Sampling Strategies
Which technique had the fastest estimated sampling time?
I found systematic sampling to having the fastest sampling time, and haphazard sampling to have the slowest.
Compare the percentage error of the different strategies for the two most common and two rarest species. Did the accuracy change with species abundance? Was one sampling strategy more accurate than another?
The accuracy did change between the two most common and rarest species. I found sampling accuracy increases with an increase in species abundance. I found random sampling to be more accurate the haphazard and systematic.
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Calculations
total quadrats sampled: 4 |
| species | # of individuals |
# of quadrats where found |
total basal area (m2) |
density (stems/ha) |
frequency (% quadrats) |
dominance (m2/ha) |
relative density |
relative frequency |
relative dominance |
relative importance value |
dispersion (Morisita index) |
| Red maple | 15 | 4 | 2.0 | 375.0 -19.6% 403.7 |
100.0% 0.0% 91.0% |
51.0 -18.6% 52.1 |
57.7 -13.5% 46.0 |
40.0 -7.2% 35.0 |
59.8 -10.3% 35.2 |
52.5 -10.7% 38.7 |
0.99 15.56% 0.93 |
| White oak | 1 | 1 | 0.3 | 25.0 -25.0% 74.5 |
25.0% -24.2% 35.0% |
8.5 -25.0% 24.7 |
3.8 -19.2% 8.5 |
10.0 -29.7% 13.5 |
10.0 -17.3% 16.7 |
7.9 -23.3% 12.9 |
** * 1.99 |
| Witch hazel | 7 | 2 | 0.2 | 175.0 31.2% 142.4 |
50.0% 51.5% 36.0% |
5.2 12.5% 5.1 |
26.9 41.3% 16.2 |
20.0 40.6% 13.8 |
6.2 24.0% 3.5 |
17.7 38.8% 11.2 |
1.71 -42.86% 2.79 |
| Red/black oaks | 2 | 2 | 0.7 | 50.0 50.0% 46.7 |
50.0% 51.5% 24.0% |
17.8 52.1% 19.3 |
7.7 61.5% 5.3 |
20.0 40.6% 9.2 |
20.8 67.8% 13.0 |
16.2 54.5% 9.2 |
0.00 * 2.64 |
| Striped maple | 1 | 1 | 0.1 | 25.0 -25.0% 13.6 |
25.0% -24.2% 3.0% |
2.8 -25.0% 0.9 |
3.8 -19.2% 1.5 |
10.0 -29.7% 1.2 |
3.2 -17.3% 0.6 |
5.7 -25.4% 1.1 |
** * 67.71 |
| Total | 26 | – | 3.4 | 650.0 | – | 85.2 | 100.0 | 100.0 | 100.0 | 100.0 | – |
Shannon-Wiener’s index of diversity for the community: 1.1 9.5% 1.8
Estimates of time commitment
- Quadrats sampled: 4 @ 30 minutes each = 120 minutes
- Distance traveled between quadrats: 511 m. @ 3mph = 6 minutes
- Total time to sample: 2 hours, 6 minutes