3.1 Allometric scaling of aerobic respiration by hyporheic exchange flux quantiles
We observed allometric scaling in both basins, particularly for higher HEF quantiles (Figure 2, Figure S3). However, we also observed a range of behaviors in the strength (R2 values) and slopes of cumulative allometric scaling patterns across the study basins. For lowest HEF quantiles (Q10-Q30) we observed lower mean R2 values (R2 < 0.80) consistently across basins, indicating weaker (“Uncertain”) allometric scaling behavior (Figure 2, Figure S3). Conversely, mean R2 values for Q40-100 were consistently higher than the 0.80 threshold across both basins, indicating stronger allometric scaling relationships (Figure 2, Figure S3). For Q40-100, we observed increasing trends in slopes, with consistent Super-linear scaling at highest quantiles (Q80-100) in both basins. For the WRB, scaling shifted from Linear (Q40-Q50) to Super-linear (Q60-Q100), while in the YRB, scaling shifted from Sublinear (Q40-Q60) to Linear (Q70) to Super-linear (Q80-100) (Figure S3). We also fitted single regression lines to each basin as a whole, independent of HEF (Figure S4). Based on our R2 threshold of 0.8, both basins exhibited Uncertain scaling behavior, though we note that both slopes are well above 1 (3.2 and 1.9 for WRB and YRB, respectively).