Fig. 1: Geological map and sampling sites for the PRB.
From: Carbonate weathering enhances nitrogen assimilatory uptake in rivers globally
a, Geological map47 and sampling sites of the PRB. b, The distribution of DIC concentration in the PRB. The two-sided Mann–Whitney test is applied to evaluate the differences, where P < 0.01 is considered highly significant, P < 0.05 is considered significant and P values ≥0.05 indicate no statistical significance. NBP, Nan-bei Pan River Basin; YJ, Yujiang River Basin; HL, Hongliu River Basin; XJ, Xijiang River Basin; PRD, Pearl River Delta; BJ, Beijiang River Basin; DJ, Dongjiang River Basin. The dotted black line in b is the median value of DIC for each sub-basin.
