## 4 Discussion
### Spatial Carbon Flux in the Legal Amazon  
The greater values for GPP were found in the north, west and central areas, coinciding with the forest classes, mainly the EBF class, and the maximum values agree with those of [PERSON] et al. [10], who also observed a higher peak of GPP near the equator. [8; 15]. On the other hand, the EBF, MF, SV and WSV decreased in extension. while GL, CL, UBL, PW and WB classes increased, these land use and land cover changes affecting the whole region due to the decrease in GPP, which may lead to an exacerbation of climate change [43], as seen during 2015/16. 2015/16 was a year of extreme drought due to El Nino [95], and these changes aggravate emissions, due to greater carbon losses from deforestation and forest fires. Moreover, those areas that are no longer forested also tend to absorb less carbon [35; 36; 94]. Thus, in this area there is a deficiency in carbon absorption, with poor or no absorption [15]. Similar to the findings in this work, carbon absorption averaged 75.1 gC m\({}^{-2}\) year\({}^{-1}\) in the northern and central parts of the BLA, and less than 40 gC m\({}^{-2}\) year\({}^{-1}\) in the eastern and southern parts of the region [8; 15]. The lowest values of CO\({}_{2}\)Flux were found in the central and western regions of the BLA, represented by the forest classes EBF, DBF, MF and WSV, with the EBF class having the smaller value [34], and the highest values were also observed in the border between the northeast and south regions, where the SV, GL, CL, UBL, PW and WB classes were verified [34; 42]. Therefore, it can be verified that forest areas that were converted to other uses resulted in higher CO\({}_{2}\)Flux values, which characterize CO\({}_{2}\) sources, while large areas of continuous forest tend to have lower values and contribute positively to the balance of carbon as sinks, helping to mitigate the impacts of climate change [18; 34; 42]. The lowest precipitation was observed in the east to south edges of the studied area and in the State of Roraima, areas corresponding to the Cerrado biome [4; 49], or the transition areas between Amazonia-Cerrado biomes [44], as observed for the previous variables, with the lowest GPP and highest CO\({}_{2}\)Flux, where the SV, GL, CL and UBL classes were verified. This fact occurs due to the climate regime of the Cerrado biome, of the \"Aw\" type (tropical climate, with dry winter), on the border between east and south of the BLA, with well-defined rainy and dry periods [51; 52]. The spatial distribution of XCO\({}_{2}\) hotspots was concentrated in the central and south-eastern region of the BLA, where the majority of the anthropic classes were observed, represented by higher CO\({}_{2}\) emissions compared to forests, and was influenced by climate change [16; 17; 21; 96] and land use and cover changes[93]. Most of the central, north and west regions of the BLA showed insignificant spatial clusters or coldspots at the 90% confidence level, demonstrating a certain balance of XCO\({}_{2}\), regions coinciding with the EBF class (main forest class). In the eastern Amazon, spatial coldspots were found with 90% confidence, and more representative in 2016 [97]. Hotspots showed lower values in 2018 than in other years, showing a 0.7% reduction in annual averages of XCO\({}_{2}\), compared to 2015 [34]. As expected, the maximum values of precipitation were found in the regions of the State of Amapa and the northwest of Amazonas and northeast of Para, close to the Equator, which has an \"Af\" type climate, characterized by high temperatures and a rainy season all year round [51; 52]. These values explain the findings for GPP, in which greater precipitation also shows greater absorption and storage of carbon per area and vice versa. In places of high precipitation, higher GPP values were observed, while for dry places, lower values occurred [9]. The CHIRPS data were satisfactory for the spatiotemporal assessment of precipitation in the BLA and represented an efficient alternative to data from meteorological stations [43].