3.3 Relating allometric behavior to watershed characteristics
We calculated mutual information to understand which watershed characteristics in Figure S1 (elevation, precipitation, and land-cover) share the most information with cumulative respiration (Figure 4). We selected HEF quantile groupings with consistent scaling behavior between basins (Q10-30: Uncertain, and Q80-100: Super-linear) to assess whether basin or scaling had more consistent relationships to respiration. Maximum elevation consistently shared the most information with cumulative respiration (i.e., shared the strongest spatial relationship with respiration as quantified by mutual information) for Uncertain (Q10-Q30) quantiles in both basins, followed by forested land-cover (Figure 4). Precipitation shared the most information with cumulative respiration for Super-linear Q80-100) quantiles in both basins, followed by maximum elevation in the WRB, and human-influenced land-cover in the YRB. The consistency in highest mutual information between HEF quantiles (maximum elevation for Q10-30 and precipitation for Q80-100) indicates these factors may share similar relationships to allometric scaling patterns in the two study basins, which suggests the potential to generalize these relationships to other basins.