Fig. 6

Average annual C budget in coastal wetlands dominated by Phragmites (a) and Spartina (b), including the net ecosystem CO₂ exchange (NEE), net ecosystem CH₄ exchanges (CH₄), lateral detrital C flux (plant detritus), and sediments into the soil. The net uptake/loss values imply the net hydrologic C fluxes (i.e., DOC, POC, and DIC). All observed fluxes are presented as absolute values (g C m⁻² year⁻¹, ± 95% confidence intervals), and the arrows indicate the flux direction. The values in parentheses indicate the relative magnitude (%) of each flux normalized with the NEE