Date of Award
Program or Major
Master of Science
Mark J Ducey
Thomas D Lee
Jeffrey H Gove
Forest inventory is an important part of forest planning and management. While land managers risk making misinformed management decisions when relying on low quality inventory data, they also must balance the data they collect with the time investment necessary for sampling. We compared abundance and density estimates of large trees 45.72 cm (18 in) or greater in diameter at breast height sampled with fixed area sampling, horizontal point sampling, and two forms of distance sampling (line transect sampling and point transect sampling), a sampling method primarily used in wildlife surveys. To compare the time investments of each form of distance sampling, we also recorded implementation time in the field and created linear regressions from which the required time to sample a specific number of trees with a given method could be predicted. Results suggest that in most cases, fixed area sampling and (or) horizontal point sampling out-perform distance sampling and produce more precise and accurate estimates of large trees, even when the sampled trees are present at various levels of density. However, it was also found that in some cases, distance sampling has the potential to out-perform traditional inventory methods and land managers are likely to prefer using point transect sampling over line transect sampling.
Breton, Connor, "Invisible trees and meeting management needs: A comparison of distance sampling and traditional forest inventory methods." (2018). Master's Theses and Capstones. 1221.
Available for download on Wednesday, September 11, 2019