Potential carbon and nutrient sinks associated with the growth of seagrass, Zostera marina, in three bay systems on the southern coast of Korea

초록

Seagrass habitats are increasingly recognized as important blue carbon ecosystems. However, assessments of their carbon sink capacity have largely focused on sedimentary organic carbon stocks, potentially overlooking carbon incorporation associated with seagrass biomass and production. In this study, we quantified carbon and nutrient incorporation associated with the growth of Zostera marina meadows, representing a transient biological reservoir rather than long-term carbon sequestration, in three bay systems along the southern coast of Korea using measurements of plant productivity and tissue carbon (C), nitrogen (N), and phosphorus (P) contents. Seagrass productivity exhibited pronounced seasonal variation, with annual production ranging from 623 to 1556 g DW m(-2) yr(-1) across the sites. The C, N, and P contents of seagrass tissues ranged from 34.1% to 39.9%, 1.9-4.9%, and 0.1-0.3%, respectively. Based on these values, the estimated annual whole-plant C, N, and P incorporations were 229-570 g C m(-2) yr(-1), 19-58 g N m(-2) yr(-1), and 1.2-2.9 g P m(-2) yr(-1), respectively. The substantial incorporation of C, N, and P into Z. marina biomass demonstrates the important role of seagrass meadows in coastal C and nutrient cycling and suggests that they may partially support climate change mitigation and nutrient filtration in coastal ecosystems although these estimates do not represent long-term sequestration. Incorporating productivity-driven C fluxes into blue carbon assessments may improve estimates of ecosystem services provided by seagrass meadows under ongoing climate change.

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