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For this assignment, I used the area systematic, random, and haphazard sampling strategies in the virtual forest tutorial. The technique with the fasted estimated sampling time was the area systematic sampling strategy (12 hours, 5 minutes). I compared the percentage error of the different strategies to the two most common species (Eastern hemlock & sweet birch) and two rarest species (Striped maple & white pine).
I found that as the species abundance increased so did the percentage error. For example, in the systematic area sampling method 228 species were counted and there was a 1.6 percentage of error for Eastern hemlock. Comparing this to the haphazard area sampling method, which had a species abundance of 297 samples, the Eastern hemlock percentage of error was 39.2%.
It appears the random sampling strategy was the most accurate. Below is a summary of the data collected during the three sampling strategies I tested.
Area – Systematic: Area sampled 2400m2, 24 samples
Two most common species:
Eastern hemlock – Density 462.5 –1.6% error
Sweet birch – Density 170.8 – 45.4% error
Two rarest species
Striped maple – Density 8.3 – 52.6% error
White pine – Density 4.2 – 50% error
Species abundance: total species sampled 228
This sampling strategy had the Fastest estimated sampling time
Area – Random: Area sampled 2400m2, 24 samples
Two most common species:
Eastern hemlock – Density 462.5 –1.6% error
Sweet birch – 158.3 – 34.7% error
Two rarest species
Striped maple – Density 4.2 – 76% error
White pine – Density 12.5 – 48.8% error
Species abundance: total species sampled 216
Area – Haphazard: Area sampled 2400m2, 24 samples
Two most common species:
Eastern hemlock – Density 654.2 –39.2% error
Sweet birch – Density 120.8 – 2.8% error
Two rarest species
Striped maple – Density 50.0 – 185.7% error
White pine – Density 8.3 – 1.2% error
Species abundance: total species sampled 297
