Equações volumétricas e o modelo que utiliza o fator de forma médio: um estudo de caso na Amazônia Central
Models were tested to fit observed data from merchantable tree species of two distinct locations of Central Amazonia. To choice the best models, we sought to compare these models with one of the widest used model to estimate the volume of wood in the Amazon rainforest. This model consists of using t...
| Autor principal: | Gimenez, Bruno Oliva |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/5087 http://lattes.cnpq.br/5693293146677192 |
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Models were tested to fit observed data from merchantable tree species of two distinct locations of Central Amazonia. To choice the best models, we sought to compare these models with one of the widest used model to estimate the volume of wood in the Amazon rainforest. This model consists of using the cylinder volume adapted (π x DBH²/4 x Hc) multiplied by a mean form factor (0.7). To carry out this study, 54 sample trees with DBH ≥ 30 cm were taken from an area clear cut for agriculture projects in Rorainópolis, Southern Roraima. Furthermore, 64 sample trees of the genus Eschweilera with DBH≥10 cm were scaled with climbing technical in E.E.S.T/INPA (ZF-2). In both areas eight volume models were tested: four models of single entry with independent variable diameter at breast height (DBH) and four models of double-entry with independent variables DBH and commercial height (Hc). In Rorainópolis, eight models were additionally tested with the substitution of the independent variable DAP by the independent variable diameter of the stump (Dtoco). The model that best fit the data and the reality of the south region of Roraima was the Husch (V = 0.000503 * DBH^2.157162) due to their consistent stats (R² adjusted 0.8997 and Syx 1.38 m³) and for not having the commercial height as an independent variable. To calculate the volume of wood from the independent variable Dtoco, the best model is the simple entry Husch (V = 0.002603 * DBH^1.761132) (R²adj. 0.7890 and Syx 1.93 m³). However, for the areas that have stumps and the trees felled we can measure the commercial height and use the Schumacher e Hall model of double entry (V = 0.000263 * Dtoco^1.782244 * Hc^0.765729) can also be used since it had the best statistics among all models with these variables (R ² adj. 0.8723 and Syx 1.51 m³). In ZF-2, the model of Husch (V = 0.000320 * DBH^2.242681) is the most suitable for calculating wood volume for the genus Eschweilera, because this model presents very consistent statistics (R²adj. 0.9750 and Syx 0.07 m³) and it does not have the commercial height as an independent variable. The model that uses the mean form factor is not the best method to estimate the volume of wood in both study areas. This calculation method is still prevalent in Rorainópolis and is closely related to the illegal deforestation in the region, since in forest inventories Hc is overrated which results in higher no sampling errors. |