Illegal selective logging and forest fires occur on a large scale in the northern Brazilian Amazon, contributing to an increase in tree mortality and a reduction in forest carbon stock. A total of 120 plots of 0.25 ha (30 ha) were installed in transitional ecosystems or ecotones (LOt) between the forested shade-loving campinarana (Ld) and dense-canopy rainforest, submontane (Ds), in the National Forest (Flona) of Anauá, southern Roraima. Measuring the diameters at breast height (DBH ≥ 10 cm) and the heights of 171 dead trees (fallen naturally, illegally exploited, and affected by forest fires), enabled the estimation of carbon content from the application of a biomass equation developed at Manaus, and the calculation of a correction factor, using the average height of the largest trees. From 2015-2017, we mapped the real extent of illegal selective logging and forest fires across the region with CLASlite and INPE/Queimadas. From measurements of 14,730 live and dead trees across 30 hectares (491 ± 15 trees·ha −1 ), the illegal selective logging and associated forest fires, and aggravation by severe El Niño droughts resulted in an 8.2% mortality of trees (40 ± 9 dead trees·ha −1 ) and a 3.5% reduction in forest carbon stock (6 ± 3 Mg·ha −1 ) in the short-term. The surface area or influence of forest fires of very high density were estimated in the south-central region of Roraima (8374 km 2 ) and the eastern region of the Flona Anauá (37 km 2 ). Illegal selective logging and forest fires in forest areas totaled 357 km 2 in the mosaic area, and 6 km 2 within Flona Anaua. Illegal selective logging and forest fires in the years of severe El Niño droughts threatened the maintenance of environmental services provided by Amazonian forests. selective logging with sustainable forest management or reduced-impact logging (RIL) focuses on the multiple use of timber and non-timber resources that are provided by forests, thereby preserving environmental services [9,11,12]. The long-term viability of the timber trade in the Brazilian Amazon depends on maintaining an adequate volume of legal timber extraction, whilst maintaining healthy forests [13]. Man's greed for the rapid and selective harvesting of high-value tropical timber as a commodity in the global marketplace has accelerated the loss of Amazonian habitats by deforestation and selective logging [2,7,14], with critical consequences for flora and fauna, and contributions to severe climate change.The indiscriminate use of fire by humans in areas of land-use conversion, from native forest to extensive ranching (cattle) and various agricultural uses, has contributed to an increase of burned areas inside and outside of the native forests of Roraima. The fuel of forest fires in Amazonia are residues that are left by illegal selective logging, fragmentation, and burned pastures [15,16]. In the past few decades, mega forest fires have been observed in the Amazon [3,17], specifically in Roraima [18][19][20], with strong interactions between the severity of El Niño droughts, and th...