Variations in organic carbon and its impact on tidal creeks within vegetation communities in the coastal wetlands of the Yangtze Estuary

doi:10.3969/j.issn.1000-5641.2019.01.017

Abstract

Abstract: Tidal creeks are identified as an important pathway for carbon exchange between coastal wetlands and the adjacent environment. This study investigated the seasonal variations in dissolved organic carbon (DOC) and particulate organic carbon (POC) in tidal creeks within typical vegetation communities (Poaceae and Cyperaceae) in the coastal wetlands of the Yangtze Estuary. The results showed that during ebb the concentrations of organic carbon components changed gradually along the altitude gradient from high marsh to low-lying shallow water areas outside the creeks. Generally, spring tides increased the organic carbon abundance in both creeks, relative to neap tide. In the Poaceae creek, with high plant biomass and soil carbon stocks, the DOC concentrations were significantly higher compared to the Cyperaceae creek during ebb across all seasons. In contrast, the POC contents were lower in the Poaceae creek compared to the Cyperaceae creek. The results of this study indicated that the Poaceae creek functioned as a net export (source) of DOC throughout the year but as a net sink of POC, and the Cyperaceae creek functioned as a net source of organic carbon over all seasons.

Key words: tidal creek system, organic carbon, seasonal variation, vegetation type, tide

CLC Number:

P933

FEI Bei-li, XIE Li-na, LI Shi-hua, CHEN Wei, GE Zhen-ming. Variations in organic carbon and its impact on tidal creeks within vegetation communities in the coastal wetlands of the Yangtze Estuary[J]. Journal of East China Normal University(Natural Sc, 2019, 2019(1): 156-165.

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