<b>Datasets of organic carbon sources in global coastal wetlands</b>

A database of 424 surface sediment/soil records, including 284 quantitative data sets and 140 qualitative data sets, from 216 articles was established (Tables S1 and S2). Sediment core data were analyzed across six depth intervals (0-10 cm, 10-20 cm, 20-40 cm, 40-60 cm, 60-80 cm, and 80-100 cm), yielding 60 datasets to examine organic C source variations with depth (Table S3). Chemical characteristics and category of main biomarkers mentioned in this manuscript and previous studies were list in Table S4.