Developing Allometric Equations for Teak Plantations Located in the Coastal Region of Ecuador from Terrestrial Laser Scanning Data

Aguilar, Fernando J.; Nemmaoui, Abderrahim; Peñalver, Alberto; Rivas, José R.; Aguilar, Manuel A.

doi:10.3390/f10121050

Cited by 16 publications

(28 citation statements)

References 64 publications

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“…Este equipo es capaz de capturar millones de puntos 3D con una precisión de distancia nominal de alrededor de ± 2 mm a lo largo de un intervalo de 0.6 m a 330 m y campos de visión vertical y horizontal de 300° y 360°, respectivamente. Los parámetros óptimos de calidad y tiempo se realizaron de acuerdo con lo propuesto por Aguilar et al (2019a). Se tomaron imágenes RGB panorámicas mediante la propia cámara de 70 Megapixeles que incorpora el instrumento.…”

Section: Metodología Del Inventario Digital Mediante Tlsunclassified

Precisión y eficiencia del inventario de plantaciones de teca en Ecuador mediante escáner láser terrestre

Romeo

Torres

Nemmaoui

et al. 2021

MYB

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El objetivo de la investigación fue evaluar la precisión y eficiencia del método de inventario forestal usando el escáner láser terrestre para la determinación de variables dendrométricas en plantaciones de teca (Tectona grandis Linn. F.). Se establecieron sitios de muestreo circulares de 500 m2 en plantaciones de teca de tres predios de la región Costa de Ecuador donde se usaron las metodologías de inventario forestal tradicional y del escáner láser terrestre, registrando las variables dendrométricas (diámetro normal, altura total y radio de copa) y el tiempo de trabajo necesario para complementar el inventario de cada parcela. Las estimaciones de los índices dasométricos para cada método de inventario y la eficiencia relativa del método del escáner láser terrestre con respecto al inventario forestal tradicional fueron contrastadas mediante pruebas de inferencia estadística. La prueba de contrastes estadísticos aplicada no detectó diferencias significativas entre los dos métodos de inventario en relación tanto con las variables dasométricas medidas como con los tiempos de trabajo registrados en cada parcela. Los valores de eficiencia relativa evidenciaron cierta superioridad del inventario realizado con el escáner láser terrestre sobre el realizado con el inventario forestal tradicional. El presente estudio permite concluir que el método del escáner láser terrestre para la elaboración de inventarios forestales en plantaciones de teca es preciso para la estimación de variables dasométricas, siendo más eficiente que el de inventario tradicional.

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Section: Metodología Del Inventario Digital Mediante Tlsunclassified

Precisión y eficiencia del inventario de plantaciones de teca en Ecuador mediante escáner láser terrestre

Romeo

Torres

Nemmaoui

et al. 2021

MYB

Self Cite

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“…Common methods for estimating forest AGB are based on indirect relationships between tree structure parameters such as diameter at breast height (DBH) and tree height [6,7]. An allometric equation established by destructive sampling is an indirect method for estimating AGB, which can be applied to large-scale sample estimation [8,9]. However, the accuracy is not satisfactory when estimating individual trees or small samples.…”

Section: Introductionmentioning

confidence: 99%

“…This indirect estimation method produces an error propagation chain, in which the largest source of error is allometric equation [13,14]. This allometric measurement is valid when it is applied within the productivity and species range of calibration data, but it may lead to greater uncertainty in large-scale biomass mapping [6,8,9]. Thus, it is necessary to develop a method for non-destructive biomass estimation that can properly balance the relationship between accuracy and efficiency.…”

Section: Introductionmentioning

confidence: 99%

AdQSM: A New Method for Estimating Above-Ground Biomass from TLS Point Clouds

et al. 2020

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Forest above-ground biomass (AGB) can be estimated based on light detection and ranging (LiDAR) point clouds. This paper introduces an accurate and detailed quantitative structure model (AdQSM), which can estimate the AGB of large tropical trees. AdQSM is based on the reconstruction of 3D tree models from terrestrial laser scanning (TLS) point clouds. It represents a tree as a set of closed and complete convex polyhedra. We use AdQSM to model 29 trees of various species (total 18 species) scanned by TLS from three study sites (the dense tropical forests of Peru, Indonesia, and Guyana). The destructively sampled tree geometry measurement data is used as reference values to evaluate the accuracy of diameter at breast height (DBH), tree height, tree volume, branch volume, and AGB estimated from AdQSM. After AdQSM reconstructs the structure and volume of each tree, AGB is derived by combining the wood density of the specific tree species from destructive sampling. The AGB estimation from AdQSM and the post-harvest reference measurement data show a satisfying agreement. The coefficient of variation of root mean square error (CV-RMSE) and the concordance correlation coefficient (CCC) are 20.37% and 0.97, respectively. AdQSM provides accurate tree volume estimation, regardless of the characteristics of the tree structure, without major systematic deviations. We compared the accuracy of AdQSM and TreeQSM in modeling the volume of 29 trees. The tree volume from AdQSM is compared with the reference value, and the determination coefficient (R2), relative bias (rBias), and CV-RMSE of tree volume are 0.96, 6.98%, and 22.62%, respectively. The tree volume from TreeQSM is compared with the reference value, and the R2, relative Bias (rBias), and CV-RMSE of tree volume are 0.94, −9.69%, and 23.20%, respectively. The CCCs between the volume estimates based on AdQSM, TreeQSM, and the reference values are 0.97 and 0.96. AdQSM also models the branches in detail. The volume of branches from AdQSM is compared with the destructive measurement reference data. The R2, rBias, and CV-RMSE of the branches volume are 0.97, 12.38%, and 36.86%, respectively. The DBH and height of the harvested trees were used as reference values to test the accuracy of AdQSM’s estimation of DBH and tree height. The R2, rBias, and CV-RMSE of DBH are 0.94, −5.01%, and 9.06%, respectively. The R2, rBias, and CV-RMSE of the tree height were 0.95, 1.88%, and 5.79%, respectively. This paper provides not only a new QSM method for estimating AGB based on TLS point clouds but also the potential for further development and testing of allometric equations.

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“…It also provides basic data for tree volume, biomass and carbon stock estimation. A common approach is to input tree attributes (DBH, tree height and specific wood density) into an allometric model established by destructive methods to estimate tree volume or above-ground biomass (AGB) [3][4][5][6]. These indirect methods are often based on different assumptions, which makes it difficult to carry out any meaningful verification of the measured results.…”

Section: Introductionmentioning

confidence: 99%

“…Uncertainty is hard to quantify or even unknown [7]. This indirect estimation method introduces the error propagation chain, and the largest source of error comes from the allometric equation [6,8]. The real and direct measurement of tree volume or biomass is to cut down and weigh the mass of all the trees in the plot.…”

Section: Introductionmentioning

confidence: 99%

A New Quantitative Approach to Tree Attributes Estimation Based on LiDAR Point Clouds

et al. 2020

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Tree-level information can be estimated based on light detection and ranging (LiDAR) point clouds. We propose to develop a quantitative structural model based on terrestrial laser scanning (TLS) point clouds to automatically and accurately estimate tree attributes and to detect real trees for the first time. This model is suitable for forest research where branches are involved in the calculation. First, the Adtree method was used to approximate the geometry of the tree stem and branches by fitting a series of cylinders. Trees were represented as a broad set of cylinders. Then, the end of the stem or all branches were closed. The tree model changed from a cylinder to a closed convex hull polyhedron, which was to reconstruct a 3D model of the tree. Finally, to extract effective tree attributes from the reconstructed 3D model, a convex hull polyhedron calculation method based on the tree model was defined. This calculation method can be used to extract wood (including tree stem and branches) volume, diameter at breast height (DBH) and tree height. To verify the accuracy of tree attributes extracted from the model, the tree models of 153 Chinese scholartrees from TLS data were reconstructed and the tree volume, DBH and tree height were extracted from the model. The experimental results show that the DBH and tree height extracted based on this model are in better consistency with the reference value based on field survey data. The bias, RMSE and R2 of DBH were 0.38 cm, 1.28 cm and 0.92, respectively. The bias, RMSE and R2 of tree height were −0.76 m, 1.21 m and 0.93, respectively. The tree volume extracted from the model is in better consistency with the reference value. The bias, root mean square error (RMSE) and determination coefficient (R2) of tree volume were −0.01236 m3, 0.03498 m3 and 0.96, respectively. This study provides a new model for nondestructive estimation of tree volume, above-ground biomass (AGB) or carbon stock based on LiDAR data.

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Developing Allometric Equations for Teak Plantations Located in the Coastal Region of Ecuador from Terrestrial Laser Scanning Data

Cited by 16 publications

References 64 publications

Precisión y eficiencia del inventario de plantaciones de teca en Ecuador mediante escáner láser terrestre

Precisión y eficiencia del inventario de plantaciones de teca en Ecuador mediante escáner láser terrestre

AdQSM: A New Method for Estimating Above-Ground Biomass from TLS Point Clouds

A New Quantitative Approach to Tree Attributes Estimation Based on LiDAR Point Clouds

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