## 4 Discussion
### Carbon Analysis by Land Use and Land Cover
Studies explain that precipitation has little influence on leaf production, at only 29.6%, and that the main climatic factor for this production is insolation (70.4%), as shown in this work [99]. It is reported that the temporal variability of CO\({}_{2}\)Flux is positively correlated with precipitation [34], which was in agreement with our findings regarding the EBF class; however, the correlation was negative for most classes. Furthermore, an increase in NPP was observed in the Amazon Forest, in which the EBF will establish larger portions of carbon in future scenarios, while the MF, CS and WSV classes will present lower levels of NPP [41]. The sum of the first two principal components analyses explained 93.8% of the total data variation, considered adequate to respond to the relationships of the variables analyzed [73], allowing identification of the components that can help in the characterization of land use and land cover of the BLA derived from remotely sensed data [77]. A great affinity of GPP with EBF was observed, because this class had the highest biomass production by GPP values, as well as the largest forest classes in the BLA, and with the highest absorption and carbon sink by CO\({}_{2}\)Flux [15]. However, the GPP was even more distant from WB and UBL, because these classes did not show any absorption in GPP [41]. It was possible to observe that GPP characterized classes with greater carbon absorption, as well as those that did not absorb any carbon, and the principal components analysis was efficient in demonstrating this. It could be observed that the CO\({}_{2}\)Flux variable was more associated with the WB and UBL classes, as these classes had the highest and most positive values, and this variable was the most distant for EBF, the class that had the lowest values in all years. This shows that the CO\({}_{2}\)Flux variable was efficient in characterizing the carbon ratio for WB and UBL classes without vegetation, indicating higher CO\({}_{2}\) emission, more than that of the vegetative classes, and the carbon sink capacity of the EBF class [34; 42]. Despite the changes in land use and land cover, with a decrease in forests and an increase in anthropized areas, in general, no significant trends were detected in the data for the GPP, CO\({}_{2}\)Flux and Rainfall variables. [PERSON]'s test confirmed the stationarity of the historical series, i.e., the observations were invariant with respect to the chronology of their occurrences [80]. In this test, the \(p\)-value was less than 0.05 only for the EBF and MF classes, in which an increase in GPP values was observed after 2013 and 2017, respectively, years of La Nina influence [95]. In addition, [PERSON]'s test claimed to show a possible increase in GPP for forest classes over the years, i.e., increased CO\({}_{2}\) capture and carbon absorption [9; 89; 102]. Studies indicate that there will be expansion of carbon fixation in the western portion of the BLA (>1500 gC m\({}^{-2}\)). On the other hand, there will be an intensification of carbon emissions in the southern areas (<710 gC m\({}^{-2}\)) [41], in the sense demonstrated in this work. The analysis of anomalies in the values of GPP and CO\({}_{2}\)Flux determined the impact of changes in CO\({}_{2}\) emissions and absorption that occurred in the region [15] and, therefore, it was important to estimate their temporal and spatial variations to understand the responses of the carbon to climate change and land use and land cover [12; 16; 17; 21]. Although the evidence that the forest classes have increased their absorption and stock of carbon over the years, a change in precipitation was observed, with possible decreases in rainfall for the region of the \"arc of deforestation\" [2; 30; 31; 44], where most of the changes in land use and land cover were observed, mainly from forest classes to other uses [34].