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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Sampling Methods and Specifications fo Forest Plantations.

(Philippines), Master of Science (University of the Philippines Los Baños)

Thesis Abstract:

Six basal are factors ofr point sampling specifications and five levels/magnitude of I. or 3Pee sampling specifications were investigated in independent comparisons with the standard 1090% inventory procedure under three types of forest plantation standa classified on the basis of the stand BDH class size in centimeters. The most efficient sampling specifications for these two techniques were then compared with some conventional forest sampling methods and their respective sampling specifications, the strip and the line fixed-area plot methods. Comparative efficiencies of the different sampling methods and specifications were analyzed based an accuracy, precision and cost of field measurements. The criterion suggested ny Grosenbaugh and Mesavage(1956) was also used as an additional efficency measure.

Statistically, all point sampling factor specifications gave non significantly different results. The same finding was obtained in the case of the variuos 3Pee sampling specifications tested. All other criteria of efficiency considered factor and 3Pee L speifications, respectively, for all tree-size forest plantation stand classes studied.

Based on accuracy of stand volume estimates, point sampling. 3Pee sampling, the conventional line fixed-area plot and strip samppling methods proved to be equally efficient. However, subsequent analyses which considered cost (measured in terms of field sampling time requirements), precision (measured in terms of size of variance) and ( Grosenbaugh and Mesavages's efficeincy criterion, showed that point sampling and 3Pee sampling techniques were superior to the others. Point sampling was further indetified to be more efficient than 3Pee sampling and is, Thereforem, the most applicable for use in the last stage/field sampling phase of inventory work in forest plantation situations.