Logging residue sampling methodology for Northeastern Ontario

Abstract

The objective of this study was to develop and test statistically justifiable methods of estimating logging residue in cutover areas of northeastern Ontario. Two sampling designs and ten sample units were chosen and tested using computer simulation in both finite and infinite sample frames for six cutovers with merchantable residue. All six populations showed clustered spatial distributions. Degrees of clumping were strongly related to residue density rather than cutover type. Precision of estimating residue volume was poorer than that of estimating residue density. Measuring butts only on plots or narrow strips resulted in poor estimation of residue density because of void sample units. Measuring partial logs or using transects achieved higher precision of estimation. A circular transect design was developed for avoiding biased estimation caused by residue orientation. The use of circular transects resulted in better estimates than double or triangular transects. Systematic sampling using randomly oriented transects is unbiased but gave no advantage over simple random sampling. Random sampling with poststratification using circular transects and simple random sampling measuring partial logs on narrow strips are two alternatives to single line transect methods. However, none of the above methods could provide precise estimates of residue pieces per hectare for cutovers with low densities of residue. The reliable minimum estimate method could apply to residue inspection in certain low density cutovers, but no satisfactory results for cases with very low density of residue (less than 17 piecesper hectare) occurred. Alternate methods of assessing stumpage aimed at eliminating the problem of residue should be investigated.