<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Paulo, Joana Amaral</style></author><author><style face="normal" font="default" size="100%">Tomé, José</style></author><author><style face="normal" font="default" size="100%">Tomé, Margarida</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nonlinear fixed and random generalized height–diameter models for Portuguese cork oak stands</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of Forest Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">height-diameter relationship</style></keyword><keyword><style  face="normal" font="default" size="100%">model calibration</style></keyword><keyword><style  face="normal" font="default" size="100%">nonlinear fixed effects model</style></keyword><keyword><style  face="normal" font="default" size="100%">nonlinear mixed effects model</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus Suber L</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">295-309</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">• Objective The objective of the research was to develop a generalized height–diameter model for Quercus suber L. in Portugal, which can be applied both to undebarked and debarked trees, with diameter at breast height over cork larger than 2.5 cm. • Methods A nonlinear fixed effects model (NLFEM) and a nonlinear mixed effects model (NLMEM) approaches were used. Parameters estimates were obtained using the SAS macro NLINMIX, which uses a linear approximation to the marginal likelihood function by expanding it with a first-order Taylor series on the random effects. The option of expanding on the random effects at their current empirical best linear unbiased predictors (EBLUP) was used. The fitted models were evaluated using an independent data set, together with an existing model specific for undebarked trees. To obtain subject specific predictions with the NLMEM, a conventional and an improved calibration procedures were applied, considering four different tree sub-sampling designs. Both proposed models included dominant height and stand density as covariates to explain plot variability. • Conclusions Validation indicated that, even in the situations where the NLMEM calibration is not possible, this model should be preferred. The differences between the validated models, which were more evident for young stands, were considered. No large differences in predictive accuracy were found between the calibrated NLMEM using the conventional or the improved calibration procedures, for all the considered sub-sampling designs.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Almeida, Alice M.</style></author><author><style face="normal" font="default" size="100%">Tomé, José</style></author><author><style face="normal" font="default" size="100%">Tomé, Margarida</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Development of a system to predict the evolution of individual tree mature cork caliber over time</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork caliber</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork growth index</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork growth models</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork thickness of complete rings</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0378112710004019</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">260</style></volume><pages><style face="normal" font="default" size="100%">1303 - 1314</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The development of a model for the prediction of the evolution of individual tree cork caliber over time, from a measurement taken at a certain point in time, was the main objective of this work. The model includes three sub-models: a model to predict the thickness of complete rings from cork caliber at tc years; a cork growth model (for complete rings) and a model to predict cork caliber at age tc from the corresponding thickness of (tc − 1) complete rings. The algebraic difference approach (ADA) as well as the generalized algebraic difference approach (GADA) were used in modeling cork growth. Several base models with one or two site-tree-speciﬁc parameters were ﬁtted to the data using the dummy variable approach. The selection of the cork growth model was based on several criteria: ﬁtting ability, prediction performance evaluated through the PRESS residuals and behaviour screened with available knowledge on the cork growth process. The ADA model derived from the log-logistic function with the asymptote as free parameter was selected. The models developed to predict cork caliber and the corresponding thickness of complete rings were based in the linear relationship between the two variables. The two models were simultaneously ﬁtted using two stage least squares approach. The predicted thickness of cork complete rings in a 9-year old cork is proposed as a cork growth index. The distribution of this index can be used to characterize the potential of a site for cork production.</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</style></notes></record></records></xml>