RT Journal Article
T1 Short Communication. A comparison of estimation methods for fitting Weibull and Johnson’s SB functions to pedunculate oak (Quercus robur) and birch (Betula pubescens) stands in northwest Spain
A1 Gorgoso Varela, José Javier
A1 Rojo Alboreca, Alberto
K1 Knoebel and Burkhart
K1 Location parameter
K1 Percentiles
K1 Maximum likelihood
K1 Moments
K1 Mode
AB Aim of study: In this study we compared the accuracy of the Weibull and the Johnson’s SB functions for describing diameter distributions in pedunculate oak (Quercus robur L.) and birch (Betula pubescens Ehrh.) stands.Area of study: Galicia (Northwest Spain).Material and Methods: A total of 172 diameter distributions in pedunculate oak and 202 in birch stands were finally evaluated. We compared the accuracy of three commonly used estimation methods of the Weibull and four estimation methods of the Johnson’s SB functions for describing these diameter distributions.Main results. For Quercus robur L. stands, the most suitable methods were the Percentiles followed by Maximum Likelihood for the Weibull PDF and the method of Moments for the Johnson’s SB PDF. For Betula pubescens Ehrh. stands, the best fits obtained with the Percentiles and Maximum Likelihood methods were also superior to the method of Moments, whereas the Conditional Maximum Likelihood and method of Moments provided the best results for the Johnson’s SB PDF, depending on the statistic and the value of the location parameter considered.Research highlights: Both distributions were suitable. The results were better for pedunculate oak than for birch stands.
PB Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)
SN 2171-5068
YR 2014
FD 2014
LK http://hdl.handle.net/10347/21615
UL http://hdl.handle.net/10347/21615
LA eng
NO Gorgoso Varela, José Javier, Rojo Alboreca,Alberto. (2014). Short Communication. A comparison of estimation methods for fitting Weibull and Johnson’s SB functions to pedunculate oak (Quercus robur) and birch (Betula pubescens) stands in northwest Spain. "Forest Systems", Vol. 23, n.3  p. 500-505
NO The present study was financially supported by the following: Asociación Galega Monte-Industria, withinthe project “Elaboración de modelos de crecimiento y producción para la gestión sostenible de las masas deabedul” (2000/CG488); the Xunta de Galicia, within the project “Estudio epidométrico de las masas deQuercus robur L. en Galicia y su influencia sobre la calidad de la madera” (PGIDT99MA29101); and bythe Ministerio de Educación y Ciencia and ERDF, within the project “Modelos dinámicos de crecimientoy capacidad de secuestro de carbono de bosques de frondosas autóctonas del noroeste peninsular”(AGL2007-66739-CO2-01/FOR)The Unidade de Xestión Forestal Sostible (UXFS) is cofunded by the Xunta de Galicia («Programa deConsolidación y Estructuración de Unidades de Investigación Competitivas 2011») and the EuropeanUnion ERDF programme
DS Minerva
RD 24 abr 2026