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In the Virtual Forest tutorial, of the three sampling strategies that I used, the haphazard or subjective sampling technique had the fastest estimated sampling time at 4 hours and 26 minutes, followed by random sampling at 4 hours and 54 minutes and then systematic sampling along a topographic gradient at 12 hours and 37 minutes.
Of the two most common species, Eastern Hemlock (EH) and Sweet Birch (SB), the systematic sampling had a percentage error of -22% for EH and -14.9% for SB. With random sampling, the percentage error was 2.5% for EH and 21% for SB. With haphazard or subjective sampling, the percentage error was 32% for EH and 80% for SB. Therefore for these two common species, it would appear that random sampling had the lowest percentage error for EH and systematic sampling had the lowest percentage error for SB. If you average the percentage error of the two sample techniques, random sampling presented the least amount of percentage error for the common species of trees.
Of the two rarest species, Striped Maple (SM) and White Pine (WP), the percentage error for the systematic sampling technique was 128% and -100% respectively. Random sampling had a percentage error of 25% for SM and -100% for WP. For haphazard or subjective sampling, the percentage error for SM was 141% and -100%. All three sampling techniques failed to record any occurrences of White Pine trees. Random sampling had the smallest percentage error for SM making it the most effective sampling technique for this rare species.
Accuracy for all species was relatively consistent with the 3 sampling techniques except for the most rare species of White Pine which was undetected in all methods. The most abundant species were more accurate although percentage error was high amongst all recorded species.
Based on the results, all three sampling techniques showed fairly consistent results although random sampling appeared to be the most effective for the most abundant tree type. However, for the Red Maple, a more rare tree, the systematic sampling using a topographic gradient method was the most effective with only a 0.9% percentage error. However, this method took the longest so may not be the most feasible method to use in this case. For the Yellow Birch tree, a more common tree, the haphazard or subjective sampling method had the least percentage error at only 3.7%. This method was the fastest method but it could pose problems of bias amongst the researcher in the field.
