Blog Post 4: Mohn Mill Sampling

Q) Which technique had the fastest estimated sampling time? 

The systematic technique had the fastest estimated sampling time.

Haphazard: 13h 44m

Systematic: 6h 48m

Random: 11h 5m

Q) Compare the percentage error of the different strategies for the two most common and two rarest species. 

The most common species were Red maple (91.0% frequency) followed by Witch hazel (36.0% frequency). The rarest species were Black cherry, Sweet birch, American basswood, Yellow birch, and White ash all at a 1.0% frequency. However, I did not select these rare species for analyses because the sampling did not pick up on these species. Instead, I chose two of the rarest species that were detected by the sampling strategies implemented in this experiment (White Pine and Downy Juneberry at 6% frequency).

 Percentage error = (estimated – actual)/(actual) x 100%

Table 1. Percentage Errors of 3 Different Sampling Strategies:

Q. Did the accuracy change with species abundance? Was one sampling strategy more accurate than another?

The accuracy changed with abundance – the greater the abundance the lower the percentage error, the smaller the abundance the higher the percent error. It did not seem that any one sampling method was more accurate for abundant species. However, I did observe a difference in accuracy in the rare species, where the haphazard method was the most accurate, the systematic method least accurate, and the random method falling in between. However, it is difficult to conclude the accuracy of these three strategies just based on these data sets, because variable were not kept consistent (ie. number of samples harvested).