DINÂMICA TEMPORAL DO USO E COBERTURA DA TERRA E SUAS RELAÇÕES COM O FOGO EM TERRAS INDÍGENAS DO ESTADO DO MARANHÃO (1985-2023)

Abstract

Indigenous Territories play a strategic role in environmental conservation and in maintaining socio-biodiversity, particularly in ecological transition zones subjected to intense anthropogenic pressures. Within this context, the state of Maranhão, located between the Amazon and Cerrado biomes, is part of the MATOPIBA agricultural frontier, where the expansion of agribusiness, deforestation, and the intensive use of fire have driven profound transformations in land use and land cover. Against this background, this dissertation aims to analyze the temporal dynamics of land use and land cover and their relationships with fire in Indigenous Territories in the state of Maranhão, Brazil, over the period from 1985 to 2023. The study integrates remote sensing techniques, geoprocessing, and spatial analysis within the Google Earth Engine platform, using historical datasets from MapBiomas (Collection 9), MapBiomas Fire (Collection 3), and deforestation data from PRODES/INPE. The analysis focused on forest and savanna formations, fire recurrence, critical years of vegetation loss and burned area, as well as the estimation of greenhouse gas emissions associated with deforestation and wildfires, based on IPCC guidelines and the Brazilian Forest Reference Emission Level (FREL). Additionally, data on territorial conflicts and violence against Indigenous peoples were incorporated, based on reports from the Indigenous Missionary Council (CIMI). The results indicate that, although Indigenous Territories have maintained extensive areas of native vegetation throughout the historical series, significant losses have occurred, primarily associated with external pressures. Over the study period, Indigenous Territories lost 185,327 hectares of native vegetation, of which 66.9% corresponded to forest formations and 33.1% to savanna formations. Nevertheless, these territories still retained 2,028,755 hectares of native vegetation in 2023, with 81.2% classified as forest formations. Fire recurrence exhibited spatially concentrated patterns, reaching up to 37 events per pixel over the time series. Higher recurrence levels were observed in territories such as Araribóia, Kanela, and Porquinhos dos Canela-Apãnjekra, with intensification during extreme climatic events such as the 2015–2016 El Niño. During this period, the Araribóia Indigenous Territory recorded approximately 200,652 hectares burned, corresponding to about 48.5% of its total area. Emission estimates revealed that fire accounted for the majority of greenhouse gas emissions, surpassing those resulting from direct deforestation. Between 2013 and 2023, total emissions associated with fire and deforestation reached approximately 709 Mt CO₂eq, with around 85% attributed to fire and 15% to deforestation. The integrated analysis highlights the relationship between environmental degradation, socio-territorial conflicts, and the weakening of territorial governance. It is concluded that the protection of Indigenous Territories in Maranhão goes beyond environmental conservation and is inseparable from the enforcement of territorial rights and the recognition of traditional knowledge, particularly in the context of Integrated Fire Management. These findings underscore the need for public policies that integrate continuous environmental monitoring, territorial governance, and coordinated management strategies as key mechanisms for mitigating deforestation, wildfires, and greenhouse gas emissions.