The Optimal Threshold for PPS (Tree volume)
DOI:
https://doi.org/10.54652/rsf.2002.v32.i1.221Keywords:
forest inventory, tree selection plan, optimal thresholdAbstract
The aim of this work was determination of optimal threshold for PPS for tree volume based on databases of most recent forest inventory on Economic forest management region "Konjuh" Kladanj. Discrete approximation for PPS is applied here (Mandaliaz, 2001).
It is found that optimal diameter thresholds are 5 cm - 30 cm and > 31 cm for two diameter intervals and 5 cm - 20 cm, 21 cm - 44 cm and > 45 cm for three diameter intervals. Results show that with diameter interval number increase, tree volume precision increases as well, with decreasing relative difference between PPS factor. It could be conclude that, keeping concentric circles as tree selection plan, it could be worthwhile to have up to tree circles (optimal threshold). Then there is no significant deference between increased number of thresholds and angle account (exact PPS), but here appears a question of edge trees and costs.
Further, using applied method it could be discussed tree selection proportional to prediction (PPP) assuming two-stage tree selection procedure.
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