## 3 Results
### Comparison of \(\mathrm{SIF_{d}}\) among Vegetation Classes within Biomes  
Our analysis of mean OCO-2 \(\mathrm{SIF_{d}}\) measurements distinguished forest from other classes' \(\mathrm{SIF_{d}}\) in the cases of EBF, but not DBF. In every biome, we found EBF \(\mathrm{SIF_{d}}\) to be significantly different than all other vegetation classes (Tukey's HSD, \(p<0.001\)) Figure 4, panels a-f, Tables S4 and S6). Amazon EBF \(\mathrm{SIF_{d}}\) had the highest mean of any class in any biome (mean = 0.38 Wm\({}^{-2}\)nm\({}^{-1}\)sr\({}^{-1}\)) (Figure 4, panels a-f, Tables S4 and S6). However, DBF \(\mathrm{SIF_{d}}\) was not significantly different than GRA, SAV, or WSAV in any of the biomes. Among the non-forest classes, mean \(\mathrm{SIF_{d}}\) analysis based on measurements from OCO-2 were partially able to distinguish GRA \(\mathrm{SIF_{d}}\) from SAV \(\mathrm{SIF_{d}}\), but not able to differentiate SAV \(\mathrm{SIF_{d}}\) from WSAV \(\mathrm{SIF_{d}}\). In the Amazon, GRA \(\mathrm{SIF_{d}}\) was significantly lower than all other classes (mean = 0.26, \(p<0.01\)) Figure 4 panel a Tables S4 and S6). In the Atlantic Forest, Caatinga, and Cerrado GRA \(\mathrm{SIF_{d}}\) (mean = 0.25, 0.14, 0.20 Wm\({}^{-2}\)nm\({}^{-1}\)sr\({}^{-1}\), respectively; Table S4) was not significantly different than SAV \(\mathrm{SIF_{d}}\) (mean = 0.25, 0.16, 0.23 Wm\({}^{-2}\)nm\({}^{-1}\)sr\({}^{-1}\), respectively; Table S4) but, GRA \(\mathrm{SIF_{d}}\) in the Pampa and Pantanal biomes (mean = 0.23, 0.22 Wm\({}^{-2}\)nm\({}^{-1}\)sr\({}^{-1}\), respectively; Table S4) were significantly lower than SAV \(\mathrm{SIF_{d}}\) (mean = 0.27, 0.25 Wm\({}^{-2}\)nm\({}^{-1}\)sr\({}^{-1}\), respectively; Tukey's HSD, \(p<0.05\)) (Figure 4, panels b-f, Tables S4 and S6). No difference was found among SAV, and WSAV \(\mathrm{SIF_{d}}\) in any of the biomes. The results of a two-way ANOVA showed there was a significant interaction between biome and vegetation class on \(\mathrm{SIF_{d}}\) (ANOVA F (20,1056) = 1.922). Therefore, to further investigate the comparison means of \(\mathrm{SIF_{d}}\) of vegetation classes across biomes would require an exploration of the combination of biome and vegetation class as main effects. Figure 3: (a) Differences in (a) \(\mathrm{SIF_{d}}\) for all vegetation classes aggregated (AVC) for each biome. (b) CV of monthly \(\mathrm{SIF_{d}}\) for all vegetation classes aggregated (AVC) for each biome. Boxplots representing the minimum, 1 st quartile, mean, 3 rd quartile, and maximum \(\mathrm{SIF_{d}}\) for vegetation classes in each Brazilian biome are shown. Outliers are represented by dots. Significant differences in means indicated by group symbols A, B, C.  
Monthly Mean \(\mathrm{SIF_{d}}\) Correlations to \(T_{\mathrm{cant}}\), \(T_{\mathrm{air}}\), and VPD  
In the Amazon, DBF and EBF \(\mathrm{SIF_{d}}\) were not significantly correlated with \(\mathrm{T_{can}}\), \(\mathrm{T_{air}}\) or VPD. The range of values for \(\mathrm{T_{can}}\), \(\mathrm{T_{air}}\), and VPD for DBF and EBF were smaller than other vegetation classes and the range of \(\mathrm{SIF_{d}}\) values slightly smaller (Figures S2-S4). Amazon GRA, SAV and WSAV \(\mathrm{SIF_{d}}\) were significantly negatively correlated with \(\mathrm{T_{can}}\), \(\mathrm{T_{air}}\), and VPD (r between \(-0.72\) and \(-0.35\), \(p<0.05\), Table 1). Amazon GRA, SAV, and WSAV \(\mathrm{SIF_{d}}\) had the strongest correlation with VPD (r = \(-0.81\), r = \(-0.6\), r = \(-0.55\), respectively, \(p<0.001\)) and less correlated with \(\mathrm{T_{air}}\) (r = \(-0.72\), r = \(-0.35\), r = \(0.40\), respectively, \(p<0.001\)) and \(\mathrm{T_{can}}\) (r = \(-0.7\), r = \(-0.35\), r = \(0.41\), respectively, \(p<0.001\)), which were similar in strength and direction with \(\mathrm{SIF_{d}}\) in these classes. This indicates that variations in \(\mathrm{SIF_{d}}\) are more driven by changes in VPD than to \(\mathrm{T_{can}}\) or \(\mathrm{T_{air}}\).