Formação de fuste do mogno africano (khaya grandifoliola C. Dc.) no início da cultura

• Autor(a) principal: Matias, Renan Krupok
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10347
• topic: Inventário florestal; DAP; Altura total; Altura do fuste; Modelagem; Forest inventory; DBH; Total height; Stem height; Modeling; CIENCIAS AGRARIAS::AGRONOMIA

The worldwide demand for timber and non-timber products has been growing every year and to keep up with this need, Brazilian companies are investing in new research and technologies with forestry plants such as African mahogany. This study aimed to carry out a forest inventory of a commercial mahogany (Khaya grandifoliola) plantation in the first years after planting. The African mahogany population is located on a private property in the municipality of Piracanjuba in the state of Goiás, where seedlings of seminal origin from a commercial nursery were used. Twenty random plots with 15 m radius were allocated and the total height, DBH, crown area and stem height of all trees within the plots were measured, together with the estimated forest cover of each plot. To measure the total height and stem, a digital clinometer was used where the operator was 15 m from the target tree. The DBH was collected using a stick and the crown areas were obtained through the ellipse area formula using the two diameters collected in the field using a measuring tape. Using a related forest densiometer it was possible to estimate the incidence of light in the soil. Four hypsometric models were pre-selected and adjusted by linear regression. The selection of the best equation was performed based on the adjusted determination coefficient and estimate standard error (Syx%). The models were also validated by assessing the predictability (ρ) and square root mean deviation (RMSE). The results showed a strong relationship between the dependent variable total height and the independent stem height and DBH. At four years of age, the largest class of stem height ranges from 3,1 to 4,1 m and most trees have a DBH ranging from 0,084 to 0,126 m. The percentage of trees that already have a stem higher than 6 m in height is 8,35%. The percentage of trees that have already reached 50 cm of DBH at this age is null. The linear model is slightly better for estimating total heights (Ht) with of 0,61 and Syx% of 14,64%. To estimate the height of the stem (Hf) the best models are the Quadratic and Weibull models, where the validation of the Quadratic model showed that the estimates are reliable with an error of 24,11% and the Weibull model with 24,86%