The three sampling strategies used in the virtual forest tutorial are random, systematic, and haphazard. In total, 7 species were sampled. All three sampling strategies measured total basal area, density, frequency, dominance, relative density, relative frequency, relative dominance, relative importance value, and dispersion (Morisita index).
The estimated time for all the samplings is listed below:
-Systematic sampling- 5 hours, 4 minutes
-Haphazard or subjective sampling-12 hours, 44 minutes
-Random sampling- 4 hours 35 minutes
The random sampling technique had the fastest estimated sampling time.
The two most common species that was present in all the sampling technique were Eastern Hemlock and Sweet Birch whereas the two rarest were White Pine and Striped Maple.
Calculation of percentage error in different sampling techniques-
- Systematic sampling
Most Common Species Rarest Species
Eastern Hemlock- 60.5% White Pine- Absent
Sweet Birch- 53% Striped Maple- Absent
- Haphazard or subjective sampling
Most Common Species Rarest Species
Eastern Hemlock- 48.4% White Pine- 32.8%
Sweet Birch- 0.68% Striped Maple- 40%
- Random sampling
Most Common Species Rarest Species
Eastern Hemlock- 6.72% White pine – Absent
Sweet Birch- 2.16% Striped Maple- 56.25%
The accuracy did change with species abundance as the percentage error was high for abundant species. The accuracy of the sampling strategy depends on the species of study. For common species, random sampling is considered more accurate with the fastest sampling time. On the other hand, for rare species, Haphazard sampling gives more accurate results.
There is not usually that much different in sampling times, something must have been off there.
You are also studying plants so hopefully this helped you think of your experimental design