Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing
Abstract
The objective of this study was to analyze three strategies for fitting hypsometric models for Pinus taeda stands with different spacings. Data from a forest inventory containing 100 trees (5 stands x 4 plots x 5 trees) were used. Four hypsometric models were tested at the plot-level. The selected model was used in the individual adjustment, verifying the significance of the inclusion of the variables of sociological position, uniformity index and number of trees per hectare (strategy 2). In the model selected in strategy 2, the inclusion of a random effect parameter at the plot level was verified. The validation of the recommended model was carried out using the bootstrap method. All adjustments resulted in accurate estimates of total height, with RMSE and MAE values lower than 1.20 m and 0.98 m, respectively, considering an average total height of 20.1 m. In strategy 1, model (1) was selected. In strategy 2, the inclusion of sociological location and number of trees per hectare was significant and improved the estimates. In strategy 3, the inclusion of the random effect at the plot level further improved the model of strategy 2. The generalized mixed effects model was validated by the bootstrap method, and accurate estimates were presented in a short range. It is concluded that generalized mixed modeling is recommended and provides a unique fit for the five planting distances considered.
Files
How to cite
Padilha, A. K.; Oliveira, X. M. D.; Mayrinck, R. C.; Barbosa, L. O.; Homczinski, I. (2025). Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing. TreeDimensional, 14(e025049), 1-9. https://doi.org/10.55746/treed.2025.01.049.
@article{padilha2025,
title={Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing},
author={Padilha, Ana Karoline and Oliveira, Ximena Mendes de and Mayrinck, Rafaella Carvalho and Barbosa, Lorena Oliveira and Homczinski, Isabel},
journal={TreeDimensional},
year={2025},
volume={14},
number={e025049},
pages={1-9},
doi={10.55746/treed.2025.01.049}
}TY - JOUR AU - Padilha, Ana Karoline AU - Oliveira, Ximena Mendes de AU - Mayrinck, Rafaella Carvalho AU - Barbosa, Lorena Oliveira AU - Homczinski, Isabel TI - Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing JO - TreeDimensional PY - 2025 VL - 14 IS - e025049 SP - 1 EP - 9 DO - 10.55746/treed.2025.01.049 AB - The objective of this study was to analyze three strategies for fitting hypsometric models for Pinus taeda stands with different spacings. Data from a forest inventory containing 100 trees (5 stands x 4 plots x 5 trees) were used. Four hypsometric models were tested at the plot-level. The selected model was used in the individual adjustment, verifying the significance of the inclusion of the variables of sociological position, uniformity index and number of trees per hectare (strategy 2). In the model selected in strategy 2, the inclusion of a random effect parameter at the plot level was verified. The validation of the recommended model was carried out using the bootstrap method. All adjustments resulted in accurate estimates of total height, with RMSE and MAE values lower than 1.20 m and 0.98 m, respectively, considering an average total height of 20.1 m. In strategy 1, model (1) was selected. In strategy 2, the inclusion of sociological location and number of trees per hectare was significant and improved the estimates. In strategy 3, the inclusion of the random effect at the plot level further improved the model of strategy 2. The generalized mixed effects model was validated by the bootstrap method, and accurate estimates were presented in a short range. It is concluded that generalized mixed modeling is recommended and provides a unique fit for the five planting distances considered. KW - total height model KW - generalized model KW - sociological position KW - uniformity index KW - bootstrap validation. ER -
Padilha, A. K.; Oliveira, X. M. D.; Mayrinck, R. C.; Barbosa, L. O.; Homczinski, I. (2025). Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing. TreeDimensional, 14(e025049), 1-9. https://doi.org/10.55746/treed.2025.01.049. Import via Mendeley Web Importer using DOI 10.55746/treed.2025.01.049
Add to Zotero using DOI 10.55746/treed.2025.01.049 Padilha, A. K.; Oliveira, X. M. D.; Mayrinck, R. C.; Barbosa, L. O.; Homczinski, I. (2025). Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing. TreeDimensional, 14(e025049), 1-9. https://doi.org/10.55746/treed.2025.01.049.
Padilha, A. K.; Oliveira, X. M. D.; Mayrinck, R. C.; Barbosa, L. O.; Homczinski, I. (2025). Fixed and mixed effects hypsometric equations for Pinus taeda L. stands with different spacing. TreeDimensional, 14(e025049), 1-9. https://doi.org/10.55746/treed.2025.01.049.