Canadian Forest Service Publications

Line intersect sampling for the density and bark area of logging residue susceptible to the spruce beetle; Dendroctonus rufipennis (Kirby) 1987. Safranyik, L.; Linton, D.A. Agriculture Canada, Ministry of State for Forestry and Mines, Pacific and Yukon Region, Victoria, BC. Information Report BC-X-295. 10 p.

Year: 1987

Issued by: Pacific Forestry Centre

Catalog ID: 2670

Language: English

Series: Information Report (PFC - Victoria)

Availability: Order paper copy (free), PDF (download)

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Abstract

Twenty-two clearcut areas were sampled in central British Columbia using the line intersect method to: (a) determine the density and bark area of stumps and logs susceptible to attack by the spruce beetle, Dendroctonus rufipennis (Kirby), (b) calculate sample sizes for a predetermined degree of precision, and (c) develop new estimating procedures based on counts of intersected pieces. Estimates based on line intersect sampling were compared with estimates based on fixed plot sampling. The mean density (173.6) and mean bark area (161.6 m2) per hectare of stumps was 12.2 and 3.9 times greater than the corresponding means for logs and tops. There were no statistically significant differences between the line intersect and fixed plot samples in estimates of either mean density or mean bark area per hectare of stumps, and variances were strongly related to means. Using line transects, less sampling time was required to estimate mean stump density and mean stump bark area per hectare with a half confidence belt equal to 0.2 (mean) than using fixed plots. Equations to estimate piece density and bark area per hectare based on counts of intersected pieces are presented.