RT Journal Article
T1 Improvement in accuracy of aboveground biomass estimation in Eucalyptus nitens plantations: Effect of bole sampling intensity and explanatory variables
A1 Pérez Cruzado, César
A1 Rodríguez Soalleiro, Roque
K1 Eucalyptus nitens
K1 Biomass
K1 Ratio type estimators
K1 Wood basic density
K1 Wood moisture
K1 Crown variables
AB Two sets of aboveground biomass equations were fitted for stem only and stem plus crown predictive variables in Eucalyptus nitens plantations in Northern Spain. A sample of 40 trees was chosen after a complete study of variation in tree height and diameter in the region. The trees were felled and the biomass was divided into the following components: wood, bark, thick branches, thin branches, twigs, leaves and dead branches along the stem. Bole biomass was estimated by systematic subsampling of one 5 cm-thick disk every 0.5 m. Such intensive subsampling enabled determination of the effect of subsampling intensity on accuracy and bias of wood estimation, considering two ratio-type estimators: stem weight to dry matter, determined by the complete weighing (CW) method (i.e. of the fresh weight of the entire stem) and volume to dry matter, determined by the partial weighing (PW) method. The changes in moisture content and basic density along the stem explained the serious risk of dry mass or weight overestimation when a systematic subsample is considered. The average basic density was usually found at a relative height of 30–35% along the stem. The default choice of the bottom disk or log as the first section resulted in overestimations for the CW method and underestimations for the PW one. The biomass equations were fitted by seemingly unrelated regression, with corrections for heteroscedasticity carried out by weighted fitting. Diameter at breast height was the best explanatory variable, and the inclusion of height did not improve the accuracy, except for wood. The inclusion of crown variables improved the predictive ability for crown fractions, increasing the accuracy for estimating thick branches (by 10.8%), twigs (by 19.1%) and leaves (by 17.3%). The biomass of each fraction decreased in the following order: wood > bark > thick branches > dead branches along the stem > leaves > thin branches > twigs. The changes in these percentages with diameter class and the predictive ability of the fitted equations were also studied.
PB Elsevier
YR 2011
FD 2011
LK https://hdl.handle.net/10347/39297
UL https://hdl.handle.net/10347/39297
LA eng
NO Pérez-Cruzado, C., & Rodríguez-Soalleiro, R. (2011). Improvement in accuracy of aboveground biomass estimation in Eucalyptus nitens plantations: Effect of bole sampling intensity and explanatory variables. Forest Ecology and Management, 261(11), 2016–2028. https://doi.org/10.1016/j.foreco.2011.02.028
NO This is the author’s version of the work. The definitive version was published in Forest ecology and management, vol. 261, nº11 (2011), available online at: https://doi.org/10.1016/j.foreco.2011.02.028
NO The study was funded by the Spanish Ministry of Education and Science (SUM2006-00006-00-00) and a FPU-MEC Spanish Fellowship awarded to the correspondent author.
DS Minerva
RD 27 abr 2026