## 5 Conclusions  
This study demonstrated that important differences in SIF\({}_{\text{d}}\) within and across biomes can be captured and quantified with satellite SIF\({}_{\text{d}}\) observations from OCO-2. Spatial patterns and variability investigated at biome level through statistical analyses of the observations yielded: (1) EBF SIF\({}_{\text{d}}\) in every class had higher integrated SIF than other classes within each biome. (2) The highest mean SIF of EBF occurred in the Amazon. (3) SIF is most strongly correlated with vapor pressure deficit (VPD) for most vegetation classes in most biomes, followed by canopy temperature (T\({}_{\text{can}}\)), although the strength and direction of the correlations depend on biome. Phenological analysis examined beyond mean differences determined that: (1) Amazon SIF\({}_{\text{d}}\) had the highest year-round values of integrated SIF\({}_{\text{d}}\) and the smallest seasonal pulse integrated SIF\({}_{\text{d}}\); (2) complex patterns of year-round and seasonal SIFd are captured by satellite measurements of SIF. (3) Pantanal EBF had the highest total integrated SIF\({}_{\text{d}}\) due to a large seasonal pulse, and (4) the SIF\({}_{\text{d}}\) length of season for vegetation classes only explains 30% of the variation in total integrated SIF\({}_{\text{d}}\); thus, the length of season is probably more closely tied to leafing patterns and leaf area, whereas integrated SIF\({}_{\text{d}}\) captures variations in photosynthetic activity separate from structural differences. In other words, SIF and traditionally used vegetation indices may similarly define the length of seasons (vegetation indices and SIF both increase with leaf area increases), but peak season responses where traditional vegetation indices tend to saturate, are being better captured by SIF. To our knowledge, no studies have examined OCO-2 data for a comparison of vegetation class-specific SIF or phenology in the tropics. Because SIF is more mechanistically coupled to photosynthetic activity than more commonly used vegetation indices in remote sensing studies of ecosystem dynamics, our results provide novel satellite estimates of differences in productivity across biomes and vegetation types and these measurements quantify differences in SIF in continuous units (Wm\({}^{-2}\)nm\({}^{-1}\)sr\({}^{-1}\)), also in contrast to vegetation indices. **Supplementary Materials:** The following are available online at [[http://www.mdpi.com/2072-4292/11/15/1746/s1](http://www.mdpi.com/2072-4292/11/15/1746/s1)]([http://www.mdpi.com/2072-4292/11/15/1746/s1](http://www.mdpi.com/2072-4292/11/15/1746/s1)), **Table S1**. List of abbreviations and variables used. **Table S2**. IGBP classification and descriptions. **Table S3**. Table of values for the distribution of SIF observations by biome and vegetation class: number of footprints, area, and percent of biome and percent of Brazil. **Table S4**. Vegetation class-specific mean SIF\({}_{\text{d}}\) for each biome. **Table S5**. \(p\)-values of [PERSON]'s HSD Test for differences in Biome level SIF\({}_{\text{d}}\) (AVC) across Brazilian Biomes. \(p\)-values below significance level of 0.05 are highlighted. **Table S6**. \(p\)-values of [PERSON]'s HSD Test for differences in vegetation class-specific SIF\({}_{\text{d}}\) across Brazilian Biomes. \(p\)-values below significance level of 0.05 are highlighted. Table S2. List of abbreviations and variables used. **Figure S1**. Plots of residuals for all OCO-2 SIF data examination for normality. L to R: Residuals vs. Fitted, q-q plot, histogram of residuals. **Figure S2**. Plots of residuals for Amazon biome OCO-2 SIF data examination for normality. L to R: Residuals vs. Fitted, q-q plot, histogram of residuals. **Figure S3**. Plots of residuals for Atlantic Forest biome OCO-2 SIF data examination for normality. L to R: Residuals vs. Fitted, q-q plot, histogram of residuals. **Figure S4**. Plots of residuals for Caating biome OCO-2 SIF data examination for normality. L to R: Residuals vs. Fitted, q-q plot, histogram of residuals.