(Table 3) Isotope data from nine sites on a north-south transect from the Con...

calc. % C4: Estimates are based on 5% C4 plants in the Congo area and a d13C value of C4 plants of -21 per mil.

计算所得的C4植物占比（% C4）：该估算以刚果地区C4植物（C4 plants）占比5%及C4植物的d13C值为-21‰作为依据。