Publication Date:
1982-06-01
Description:
This study investigated size and number of plots needed to precisely estimate tree mortality, mean dead basal area, mean dead volume, mean live basal area, and mean live volume in stands infested with the spruce budworm, Choristoneurafumiferana (Clemens).Depending on the parameter, precision of four different plot sizes (0.02, 0.04, 0.08, 0.40 ha) was examined. For most parameters the 0.04-ha plot appears to be approximately as precise as the larger plot sizes. Variables which affect the precision of the plot sizes are percent mortality, patchy distribution of the character of interest, and the variability associated with the population of interest. The precision of two, three, four, and five plots per stand was investigated. The coefficient of variation of the mean is reduced the greatest between two and three plots; subsequent reductions beyond three plots are not great. The number of plots needed based on sampling theory varied according to the parameter and the variability associated with the parameter. It was determined that the time involved in evaluating three 0.04-ha plots was approximately the same as needed to evaluate two 0.08-ha plots.
Print ISSN:
0045-5067
Electronic ISSN:
1208-6037
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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