@article{oliveira_scolforo_mctague_dobner junior_soares scolforo_2022, title={Impact of the inclusion of the sociological position and upper-stem diameter in the taper modeling of Pinus taeda trees, subjected to different thinning regimes}, volume={8}, ISSN={["2666-7193"]}, DOI={10.1016/j.tfp.2022.100251}, abstractNote={The modeling of the taper and shape of the tree stem is of great interest to forest managers and can be carried out using different approaches. The objective of this study was to improve the accuracy of taper modeling, considering a methodology that combines generalization and calibration with an upper-stem diameter. An experiment was conducted with stands of Pinus taeda from southern Brazil that were unthinned and crown thinned at different levels. The destructive sampling was performed at age 30, accumulating the effect of the management regime over time. The model was developed in three parts: a) the Kozak variable exponent model was selected; b) the inclusion of variables was tested (sociological position, relative spacing index, thinning index, uniformity index, and site) in the exponent of the Kozak model of part “a”, allowing generalizations; c) upper-stem diameters at heights of 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 m were tested to calibrate the part "b" model, using the algebraic restriction method. The inclusion of the sociological position in the model exponent and the calibration with the upper-stem diameter at the stem height of 6 m reduced the RMSE and the MAE by 3%, with respect to volume (m³). The reduction of the error was concentrated mainly in the lower-stem section, considered the most economically valuable part. The methodology developed uses information available from a forest inventory to compute the sociological position of the trees and from harvesting for a single upper-stem diameter. Although the equation has been developed for unthinned and crown thinned stands at different intensities of loblolly pine (Pinus taeda), the extrapolation potential of the methodological approach is valid, making implementation feasible for other species and management alternatives.}, journal={TREES FORESTS AND PEOPLE}, author={Oliveira, Ximena Mendes and Scolforo, Henrique Ferraco and McTague, John Paul and Dobner Junior, Mario and Soares Scolforo, Jose Roberto}, year={2022}, month={Jun} }
 @article{schmidt_inoue sanquetta_mctague_silva_fraga filho_sanquetta_soares scolforo_2020, title={On the use of the Weibull distribution in modeling and describing diameter distributions of clonal eucalypt stands}, volume={50}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-2020-0051}, abstractNote={Weibull distributions have been widely used to describe tree stem diameter distributions. However, there is a scarcity of studies that suggest the best Weibull formulation. The parameters of the Weibull distribution are usually predicted by either the parameter prediction method (PPM) or the parameter recovery method (PRM), although other methods have been proposed. Thus, this study aimed to evaluate the performance of eight Weibull formulations and compare methods of parameter prediction to describe diameter distributions of clonal eucalypt stands in Brazil. Data originated from remeasurements of 56 plots at ages 3, 5, and 6 years. Weibull distributions were fitted using the maximum likelihood method and evaluated in a goodness-of-fit indicators ranking. The right-truncated two-parameter formulation showed the best results and was used to evaluate the methods of parameter prediction. Stand attributes showed a strong relationship with shape and scale parameters. Regression models were developed and resulted in accurate estimates using PPM. PRM used a growth and yield system to estimate the stand attributes, followed by the moment-based method. The modified cumulative distribution function regression (CDFR) approach was also evaluated, and it presented the poorest results. Although the PPM showed excellent results, PRM is recommended in older stands with inventory because it implicitly promotes compatibility among stand attributes.}, number={10}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Schmidt, Luciane Naimeke and Inoue Sanquetta, Mateus Niroh and McTague, John Paul and Silva, Gilson Fernandes and Fraga Filho, Clayton Vieira and Sanquetta, Carlos Roberto and Soares Scolforo, Jose Roberto}, year={2020}, month={Oct}, pages={1050–1063} }
 @article{scolforo_mctague_burkhart_roise_alvares_stape_2020, title={Site index estimation for clonal eucalypt plantations in Brazil: A modeling approach refined by environmental variables}, volume={466}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2020.118079}, abstractNote={Growth models have been applied to assess the growth potential for areas without previous forest plantation records and to update forest inventory when commercial stands have been planted. However, there is a lack of growth models capable of incorporating environmental variables for updating forest inventories and recomputing site quality throughout Brazil. Consequently, this research aimed to deliver a compatible set of prediction and projection growth equations with parameters refined by environmental variables. The dataset used through this study is composed of remeasurement information of 16 research sites in Brazil. At each site, the same eleven eucalypt clones were planted in single block plots. Extra block plots were also installed in 14 sites to evaluate eucalyptus growth under drier climate scenarios. Four different competing model forms were tested. A common parameter of the best compatible set of growth equations was refined to test the magnitude of the environment effect on the prediction and projections of dominant height/site index in clonal eucalypt stands in Brazil. The compatible set of Chapman-Richards growth equations displayed the most accurate estimates of dominant height for clonal eucalypt plantations in Brazil. The common asymptote parameters between the growth models were refined as a function of annual soil water deficit (SWD), and a gain in accuracy of the projected and predicted dominant height estimates was observed. It is relevant to highlight that the developed set of growth equations possesses the ability to make short-, medium- and long-term predictions and projections with more assuredness about the biological behavior and its soundness. This feature ensures accurate estimation of site-specific growth curves.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Scolforo, Henrique Ferraco and McTague, John Paul and Burkhart, Harold and Roise, Joseph and Alvares, Clayton Alcarde and Stape, Jose Luiz}, year={2020}, month={Jun} }
 @article{inoue sanquetta_mctague_scolforo_behling_sanquetta_schmidt_2020, title={What factors should be accounted for when developing a generalized taper function for black wattle trees?}, volume={50}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-2020-0163}, abstractNote={ Taper functions have been widely used for various purposes. Several functions were developed and successfully applied; however, most of these functions fail to account for the influence of stand-level and individual-tree effects of variation on the stem profile. Hence, we aimed in this study to assess how these factors influence the stem profile of black wattle (Acacia mearnsii De Wild.) trees in southern Brazil. There is a notable necessity for developing a domestic market for black wattle solid wood. The database was composed of 218 black wattle trees at age 10 years distributed across the state of Rio Grande do Sul, Brazil. A dimensionally compatible taper equation combined with the mixed-effect modeling approach was used. Additionally, auxiliary variables were included to build a generalized taper function that explains stem form variations. In general, all variables showed a significant influence on the stem profile, except the crown ratio. The inclusion of relative spacing and tree hierarchical position in the taper function resulted in higher accuracy when estimating stem diameters and total tree volume. This study indicates that accounting for attributes at the stand and individual-tree levels may improve stem profile predictions, as well as the biological soundness of the taper function. }, number={11}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Inoue Sanquetta, Mateus Niroh and McTague, John Paul and Scolforo, Henrique Ferraco and Behling, Alexandre and Sanquetta, Carlos Roberto and Schmidt, Luciane Naimeke}, year={2020}, month={Nov}, pages={1113–1123} }
 @article{scolforo_mctague_burkhart_roise_carneiro_stape_2019, title={Generalized stem taper and tree volume equations applied to eucalyptus of varying genetics in Brazil}, volume={49}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-2018-0276}, abstractNote={ Lack of generalized equations has prevailed in Brazil, because it is assumed that localized or climate-specific equations are needed. This study aimed to develop generalized stem taper and volume equations applicable to 11 eucalyptus clones and evaluate if climate variation impacts the accuracy of the estimates. A total of 693 trees evenly distributed across 11 clones at 21 sites were used for model fittings and predictive validation. The penalized mixed spline (PMS) approach was developed for predicting stem taper and volume along the stem profile. The Schumacher and Hall (1933) equation was used to predict total tree volume, while volume ratio equations were applied to predict merchantable volume. For every fitted equation, an annual climatic variable was included to assess the improvement in model performance. The overall results highlighted that climatic variation does not need to be accounted for in stem taper and volume modeling. All of the equations displayed desirable accuracy, but the generalized PMS equation may be preferred when the forestry enterprise looks to furnish a range of multiple forest products. The generalized total tree volume equation, combined with the ratio equations, is highly recommended when the forestry enterprise produces a single product. }, number={5}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Scolforo, Henrique Ferraco and McTague, John Paul and Burkhart, Harold and Roise, Joseph and Carneiro, Rafaela Lorenzato and Stape, Jose Luiz}, year={2019}, month={May}, pages={447–462} }
 @article{scolforo_mctague_burkhart_roise_alvares_stape_2019, title={Modeling whole-stand survival in clonal eucalypt stands in Brazil as a function of water availability}, volume={432}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2018.10.044}, abstractNote={Several approaches for modeling whole-stand survival or mortality have been reported in the literature, although this component is often times neglected for clonal eucalypt stands in Brazil. In addition, the traditional form for projecting whole-stand survival appears incomplete for clonal eucalypt stands, since this tree species is highly sensitive to lack of water in the environment. Consequently, this study aimed to define the best approach to estimate whole-stand survival in clonal eucalypt stands and to develop a new approach for modeling whole-stand survival as a function of cumulative soil water deficit. Remeasurement of sixteen research sites composed the database used in this study. At each research site, the same eleven eucalypt clones were planted in single block plots, which results in a total of 176 plots distributed across Brazil. Two traditional approaches (two-step approach and direct estimation) were tested for modeling whole-stand survival. Additionally a new approach that replaces the age term by cumulative soil water deficit (cumulative SWD) was compared to the best selected traditional approach to estimate whole-stand survival in clonal eucalypt stands. The direct projection approach of whole-stand survival displayed better results when compared to the two-step approach. In addition, the replacement of age by cumulative SWD in the direct estimation approach allowed for an increase in the explanatory ability of the developed difference model. The newly developed difference model employing the direct estimation approach constrained by cumulative SWD ensures that the environmental stress effect is reflected on the survival of clonal eucalypt stands over time, and it is more biologically sound for extrapolation purposes.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Scolforo, Henrique Ferraco and McTague, John Paul and Burkhart, Harold and Roise, Joseph and Alvares, Clayton Alcarde and Stape, Jose Luiz}, year={2019}, month={Jan}, pages={1002–1012} }
 @article{scolforo_mctague_burkhart_roise_mccarter_alvares_stape_2019, title={Stand-level growth and yield model system for clonal eucalypt plantations in Brazil that accounts for water availability}, volume={448}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2019.06.006}, abstractNote={Growth and yield (G &Y) model systems aim at forecasting forest productivity. The lack of environmental variables to account for how water availability constrains eucalyptus production in Brazil, however, is argued to be a major drawback of these model systems. Thus, this study aimed to develop a stand-level G & Y model system that accounts for water availability (G & Y with SWD), highlighting its usefulness when applied for clonal eucalypt stands under drier climatic conditions. The dataset is composed of remeasurement information of sixteen research sites that span all climatic regions in Brazil. A total of eleven eucalypt clones were planted in single block plots at each site, and extra replications under the rainfall exclusion system were also installed for these eleven clones in fourteen sites. Linear algebra techniques were used to simultaneously fit a compatible set of prediction and projection basal area equations. A stand-level volume equation was also developed. These equations were validated through the use of an independent dataset composed of the rainfall exclusion plots. Finally, the accuracy and usefulness of a conventional G & Y model system applied to clonal eucalypt stands in Brazil was compared to the new proposed G & Y model system, which accounts for the impact of water availability in eucalyptus productivity. The prediction and projection basal area equations accounting for water availability displayed estimates in the order of 5% more accurate compared to the conventional basal area modeling. Stand-level volume estimates were 40% and 74% less biased through the use of the new G & Y model system. This result highlighted how useful and powerful the newly developed approach is, since the model system was capable to provide accurate estimates through the use of the rainfall exclusion plots. The new G & Y model system is a powerful alternative to estimate forest afforestation yield and is fully capable to accurately update forest inventories. The model system can also be used for projecting how forest growth may be impacted by short-term climate variation.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Scolforo, Henrique Ferraco and McTague, John Paul and Burkhart, Harold and Roise, Joseph and McCarter, James and Alvares, Clayton Alcarde and Stape, Jose Luiz}, year={2019}, month={Sep}, pages={22–33} }
 @article{scolforo_mctague_raimundo_weiskittel_carrero_soares scolforo_2018, title={Comparison of taper functions applied to eucalypts of varying genetics in Brazil: application and evaluation of the penalized mixed spline approach}, volume={48}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-2017-0366}, abstractNote={Taper functions have been widely used with an existing array of model forms and methods. However, comparisons of contrasting statistical methods have been more limited. This study aimed to assess contrasting statistical approaches for achieving accurate stem taper and individual tree volume predictions, with focus on the novel penalized mixed spline (PMS) approach. The approaches were tested using four different eucalyptus genetic families planted in Brazil. For comparison, the predictions of diameter outside bark (dob) and volume using a 5th degree polynomial, the polynomial of integer and fractional powers, a segmented taper function, a variable exponent taper function, and a semi-parametric PMS were conducted. Comparisons using the generalized functions of every stem taper function with genetic family as an extra random component were also conducted. Data-splitting was used to test the accuracy of each taper function. PMS and the generalized PMS were the most accurate for both dob and volume, while the...}, number={5}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Scolforo, Henrique Ferraco and McTague, John Paul and Raimundo, Marcel Regis and Weiskittel, Aaron and Carrero, Omar and Soares Scolforo, Jose Roberto}, year={2018}, month={May}, pages={568–580} }
 @article{scolforo_soares scolforo_thiersch_thiersch_mctague_burkhart_ferraz filho_mello_roise_2017, title={A model of tropical tree diameter growth and its application to identify fast-growing Native tree species}, volume={400}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2017.06.048}, abstractNote={The Atlantic forest biome in Brazil possesses many suitable tree species for cultivation and restoration purposes. This biome was the most rapidly and extensively exploited forest type in Brazil and it displays areas ill-suited for eucalyptus cultivation. Since tropical tree species usually do not form growth rings and long-term growth data are still not available in Brazil, this study addressed a new approach to diameter growth rate estimation. The approach was developed in order to alleviate the shortage of species-specific growth information for the Atlantic forest biome. The two reasons for developing the approach were: (1) the possibility of increased ecological and economic diversification of plantation forests beyond eucalyptus, and (2) the potential to identify suitable tree species for restoration programs in the biome. Either reason requires growth models with sound biological properties. The data used in this study came from 20 native forest fragments and included six tropical tree species. Forest inventory to assess forest growth was first conducted in 2003, while the re-measurement was conducted in 2008. A non-linear exponential model, containing an asymptote parameter as a function of stand density, was fit to estimate tree species diameter growth rate for each of the six tree species in the study. Additionally, based on the exponential model, a formulation of the time required for each tree species to reach a given diameter was developed. The fitted models exhibited high variability among the six tree species, but they performed well with respect to tree growth behavior. Since the model accounted for stand density, it was possible to predict how different stand densities would affect each tree species growth over time. Finally, the tree species Triplaris gardneriana Weddell, Inga vera Willd. and Xylopia brasiliensis Spreng are recommended as potentially fast-growing tree species in the Atlantic forest biome. These tree species exhibited good growth rates regardless the stand density simulated (1600/ha, 2000/ha, and 2400/ha) to reach a dbh of 10 cm (Xylopia brasiliensis Spreng - 16 years, 17 years, and 18 years; Triplaris gardneriana Weddell - 15 years, 17 years, and 21 years; Inga vera Willd. - 25 years, 25.5 years, and 26 years) and showed promising potential for both restoration and production programs. The developed approach reveals a unique diameter growth rate prediction method.}, journal={Forest Ecology and Management}, author={Scolforo, Henrique Ferraco and Soares Scolforo, Jose Roberto and Thiersch, Claudio Roberto and Thiersch, Monica Fabiana and McTague, John Paul and Burkhart, Harold and Ferraz Filho, Antonio Carlos and Mello, Jose Marcio and Roise, Joseph}, year={2017}, pages={578–586} }
 @article{raimundo_scolforo_mello_scolforo_mctague_reis_2017, title={Geostatistics applied to growth estimates in continuous forest inventories}, volume={63}, DOI={10.5849/forsci.2016-056}, number={1}, journal={Forest Science}, author={Raimundo, M. R. and Scolforo, H. F. and Mello, J. M. and Scolforo, J. R. S. and McTague, J. P. and Reis, A. A.}, year={2017}, pages={29–38} }
 @article{scolforo_soares scolforo_stape_mctague_burkhart_mccarter_castro neto_loos_sartorio_2017, title={Incorporating rainfall data to better plan eucalyptus clones deployment in eastern Brazil}, volume={391}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2017.02.025}, abstractNote={The goals of this study were to identify and group three eucalyptus clones, each under coppice and clear-cut management regimes, into two or more groups based on similar growth rates; and fit a site index equation as a function of rainfall variables for each group to evaluate how different groups were impacted by climatic variation. The database came from the Continuous Forest Inventory (CFI) and weather stations. The CFI was conducted between 1994 and 2012, with climatic data also being gathered for the same period. The study area was managed by clear-cut and coppice regimes, with 126 and 72 CFI plots, respectively. The relationship between clones, management regimes and stand age with annual dominant height growth was assessed by linear mixed effects modeling. Ridge regression was applied for fitting each group as a function of the rainfall variables. Finally, ordinary Kriging was applied for each of the rainfall variables in the study area. Then, site index equations were applied to the generated maps enabling the observation of their pattern throughout the study area as well as their evaluation under a pessimistic climatic scenario. Three groups were defined, since each clone exhibited similar growth behavior under either management regimes; however, the 3 clones differ among each other. A significant reduction in the annual dominant height growth over time was observed for all 3 clones. Ridge regressions afforded good accuracy and equations with sound biological behavior. Applying the fitted site index equations to the maps of precipitation and rainy days enabled the definition of the most appropriate clone to be planted throughout the area. Site quality as a function of rainfall variables could be an important tool to better enable silvicultural planning, since it provides estimates of the site index and also enables the incorporation of short-term climate change.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Scolforo, Henrique Ferraco and Soares Scolforo, Jose Roberto and Stape, Jose Luiz and McTague, John Paul and Burkhart, Harold and McCarter, James and Castro Neto, Fernando and Loos, Rodolfo Araujo and Sartorio, Robert Cardoso}, year={2017}, month={May}, pages={145–153} }
 @article{scolforo_castro neto_soares scolforo_burkhart_mctague_raimundo_loos_fonseca_sartorio_2016, title={Modeling dominant height growth of eucalyptus plantations with parameters conditioned to climatic variations}, volume={380}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2016.09.001}, abstractNote={Dominant height growth equations, which given at some base age is defined as site index, is usually used to assess site quality. A flexible and accurate way to represent the potential productive capacity of forest stands of Eucalyptus spp. was developed. The generalized algebraic difference method was used, in which 15 dynamic equations were tested for modeling dominant height growth. The models were fitted to a data set derived from permanent plots located in the states of Bahia (BA) and Espirito Santo (ES), Brazil, with clonal eucalyptus plantations. The database was analyzed separately for the clear-cut and coppice regimes. The selection of the best-fitting model for each management regime was based on statistical fitting, predictive validation, and graphical analysis. After selection of the best model, one of its parameters were expanded with the addition of climatic variables that allowed for the creation of scenarios. The polymorphic modified Von Bertalanffy-Richards model with a single asymptote performed the best for the two management regimes. For clear-cut management, conditioning the slope parameter by the mean monthly precipitation obtained the best performance. For coppice management, the asymptote parameter conditioned by the mean monthly precipitation and its distribution throughout the year provided the best performance. The inclusion of the climate modifiers added flexibility for the models, which was represented by the interannual variations of precipitation. Expansions of the parameters did not mischaracterize the behavior of the modified Von Bertalanffy-Richards model for the management regimes studied. Climatic conditioning of the parameters of the slope and asymptote for the two management regimes led to accuracy gains in the estimates. Additionally, this enabled the generation of productivity scenarios based on the amount and distribution of the total precipitation for the areas under study.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Scolforo, Henrique Ferraco and Castro Neto, Fernando and Soares Scolforo, Jose Roberto and Burkhart, Harold and McTague, John Paul and Raimundo, Marcel Regis and Loos, Rodolfo Araujo and Fonseca, Sebastiao and Sartorio, Robert Cardoso}, year={2016}, month={Nov}, pages={182–195} }
 @article{mctague_2010, title={New and composite point sampling estimates}, volume={40}, ISSN={["0045-5067"]}, DOI={10.1139/x10-158}, abstractNote={ A new estimator for basal area is introduced that is based on the concepts of angle count and angle summation sampling. Using the ratio of the angle count basal area factor and the angle summation (borderline) factor, it is possible to estimate stand volume without measuring the diameters and distances of the trees included in the sample. Employing simulation of repeated sampling in a 40 ha forest of known population parameters, it is demonstrated that the new sampling methodology is unbiased and weakly correlated with conventional angle count sampling. Hence, considerable gains in efficiency are made by combining the two sampling methods with composite estimators. Two applications are explored with the new composite point sampling estimates, including the use of the big basal area factor sampling method and critical height sampling using a Max and Burkhart taper formulation. }, number={11}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={McTague, John Paul}, year={2010}, month={Nov}, pages={2234–2242} }
 @article{mctague_o'loughlin_raise_robison_kellison_2008, title={The SOHARC model system for growth and yield of southern hardwoods}, volume={32}, number={4}, journal={Southern Journal of Applied Forestry}, author={McTague, J. P. and O'Loughlin, D. and Raise, J. P. and Robison, D. J. and Kellison, R. C.}, year={2008}, pages={173–183} }