User: | Open Learning Faculty Member:
The virtual forest tutorial allowed for the testing of three different sampling strategies in the Snyder-Middleswarth Natural Area: systemic sampling, random sampling, and haphazard sampling. The technique that had the fastest estimated sampling technique was systematic sampling with a time of 12 hours, 36 minutes followed by random sampling and then haphazard sampling.
Yes, the accuracy changes with species abundance for all three sampling techniques. The percent error for the common species was very low compared to the percent error for the rare species. The two most common species were the Eastern Hemlock and the Sweet birch and appeared to be best represented by systemic and haphazard sampling methods. The two most rare species were the Striped Maple and the White Pine and appeared to be best represented by the same sampling methods.
Based on the values of the Shannon Weiner diversity index, systemic and haphazard are the most accurate since they have the highest value at T=1.5 E=1.4.
| Tree Species | Actual Density | Systemic Density | % Error | Haphazard Density | % Error | Random Density | % Error | |
| Common | Eastern hemlock | 469.9 | 476 | 1.3 | 500 | 6.4 | 456 | -3.0 |
| Sweet birch | 117.5 | 116 | -1.3 | 108 | -8.1 | 200 | 70.2 | |
| Rare | Striped maple | 17.5 | 4 | -77.1 | 16 | -8.6 | 0 | -100.0 |
| White pine | 8.4 | 8 | -4.8 | 4 | -52.4 | 0 | -100.0 |
