Author： Yang Yong C. Kung Fan H.
Publisher： Society of American Foresters
ISSN： 0022-1201
Source： Journal of Forestry, Vol.81, Iss.4, 1983-04, pp. : 224-227
Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.
Abstract
Use of order statistics and of "jackknifing" in the second phase of double sampling can increase the accuracy and precision of regression estimates. This approach is especially useful for volume estimation where the cost ratio and the correlation between volume determination and diameter measurement are high. Spacing of the selected and ranked sample is at the optimum when both volume and diameter are normally distributed. The advantages and superiority of the procedure may diminish if the assumptions of normality and high correlation are not met. The additional costs of ranking and sample selection should be justified by the improved efficiency. Other potential applications include biomass studies and combined aerial photographic and field inventory.
Access to resources
Recommend
