## 3 Results and Discussion
The lower and upper hinges of the boxes correspond to the 25 th and 75 th percentiles of the data, the central solid line represents the median, whiskers extend to 1.5*IQR (i.e., Inter-Quartile Range) from the hinges, and red stars represent outliers outside the range of the whiskers. Figure 5: (**a**) Coefficient of determination (R\({}^{2}\)) and (**b**) corresponding significance level (\(p\)) values between the biomass, as calculated by the allometric equations based on the field data and RSI (Ri, Rj) derived from the band reflectances of Sentinel-1/2 images corresponding to the pixel overlapping each field measurement location. The RSI was calculated using the complete combinations for a pair of wavebands, i and j.  
Figure 3: Box-and-whisker plots of biomass (per plot) measured during fieldwork for monodominant and non-monodominant plots. The lower and upper hinges of the boxes correspond to the 25 th and 75 th percentiles of the data, the central solid line represents the median, whiskers extend to 1.5*IQR (i.e., Inter-Quartile Range) from the hinges, and red stars represent outliers outside the range of the whiskers. The combination of the Sentinel-2 VH and VV bands does not yield high correlations. Moreover, the combination of the Sentinel-1 bands the Sentinel-2 bands perform adequately for only two combinations, namely that of Sentinel-1 VH with the red-edge and NIR bands of Sentinel-2 (R\({}^{2}\) = 0.53 and R\({}^{2}\) = 0.58, respectively). Incorporation of Sentinel-1 and Sentinel-2 bands has been shown to yield higher accuracies than the stand-alone sensors' bands [37; 52]; nevertheless, that was not the case in the current study. In Figure 5, it is actually evident that information from Sentinel-2 is a better predictor of AGB in comparison to Sentinel-1, which concurs with a study mapping AGB in a West African dryland forest from [PERSON] et al. [36]. It is perhaps the case that more sophisticated algorithms for incorporating information from SAR and optical satellites can yield higher accuracies and that the spectral indices used in the current study cannot adequately capture the  
Figure 6: Coefficient of determination (R\({}^{2}\)) (**a**) and corresponding significance level (_p_) values (**b**) as in Figure 5. In this scenario only the plots where teak is the dominant species are considered. Figure 7: Coefficient of determination (R\({}^{2}\)) (**a**) and corresponding significance level (_p_) values (**b**) as in Figure 5. In this scenario, only the non-monodominant (**top**) and monodominant (**bottom**) plots are considered. complementary information from these sensors, resulting in lower R\({}^{2}\) values when using the Sentinel-1 and 2 datasets synergistically. Lastly, the RSI spectral indices did not yield results differing considerably from the NDSI; hence, the latter are not presented. When considering only the field samples for which teak is the dominant species (Figure 6), the same spectral windows with the full dataset (Figure 5) seem to appear, only with higher correlations at the band combinations 2, 3 and 6, 7, and 8A (\(0.70\leq\) R\({}^{2}\leq 0.74\)). The highest correlation found for the teak-dominant samples was R\({}^{2}\) = 0.74 for the band combination 3-7. The fact that we considered plots with a single dominant species seems to increase the correlation. Moreover, the combination of the Sentinel-1 and NIR, which demonstrated high correlation for the entire dataset, is not present in the teak dataset; in this case, the Sentinel-1 yielded high correlation when coupled with the visible (bands 2-5 with R\({}^{2}\) = 0.62 for band 4) or the SWIR bands (R\({}^{2}\) = 0.58). For the other 2 dominant species, namely mahogany and acacia, there was no statistically acceptable correlation achieved (\(p<0.001\)); hence, the results are not presented herewith. This is perhaps attributed to the small size of the dataset, as most of the sample plots are primarily planted with teak. In the third scenario (Figure 7), the role of monodominance was examined.