Sampling With Unequal Probabilities to Estimate Cubic-foot Volume Growth on Permanent Sample Plots

Wien

1974

3 Tab., 8 Lit. Ang.

Unselbständiges Werk

673

200144711

The combination of unequal probability sampling and the optical dendrometer makes it possible to eliminate tree-volume tables along with their inherent errors and express the results on an area basis. Repeated computer drawn samples were used to analyze the sampling method. The results of a field trial were comparable to the results of the repeated computer-drawn samples. An analysis of repeated optical dendrometer measurements of individual trees over time suggests that upperstem diameter changes can be determined after only two growing seasons and that there should be little difficulty in measuring cubic-foot volume growth on permanent research plots at four to five-year intervals. An analysis was made of data for sample estimates from 50 repeated computer samples representing four measurement times. The estimated growth varied little from the actual growth.