Utilização do escaneamento a laser terrestre nos manguezais da reserva biológica estadual de Guaratiba, Rio de Janeiro - RJ

Abstract

Mangroves are tropical coastal ecosystems with typical vegetation and their own contours. Manually obtaining structural parameters in this environment is difficult and laborious, and terrestrial laser scanning (TLS) is an alternative to improve and optimize data collection. Scanning can be difficult due to external factors such as climate and tree arrangement, and errors commonly found in laser scanning methodology, such as point clouds, trunk deformation or DBH height. The objective of this study is to test the use of TLS to determine structural parameters in mangrove forests, by comparing it with the traditional phytosociological survey method. The objective of this study is to determine the best method and solutions for using TLS in mangroves, validated through the comparison of both methods used. To achieve this, scans were conducted at 14 stations in Guaratiba State Biological Reserve (GSBR) in Rio de Janeiro municipality, including six stations in well-developed forests (Fringe), 6 in forests with intermediate development (Basin-Multstemmed), and two in scrub forests (Transition). Data were collected using both traditional and TLS methods in all stations. The results show that for Fringe and Basin forests, the data present little discrepancy between the methods, allowing the observation of similar structural development characteristics in these forests. The MAPE values for fringe forests were 7.39% for mean DBH and 13.92% for mean height. Using RMSE and RMSE%, the values obtained were 1.17 cm (8.92%) for mean DBH and 2.09 m (19.57%) for mean height. For basin forests, the MAPE values were 4.67% for mean DBH and 6.33% for mean height. Using RMSE and RMSE%, the values were 0.38 cm (5.18%) for mean DBH and 0.39 m (6.66%) for mean height. In transition forests, the MAPE values were 10.43% for mean DBH and 8.52% for mean height. Using RMSE and RMSE%, the values were 0.42 cm (12.6%) for mean DBH and 0.38 m (12.9%) for mean height. In addition to the parameters mentioned, Density (live trunks.ha-¹) and Basal Area (m².ha-¹) were also tested and the values obtained by the TLS method showed satisfactory values when compared to the reference method.