Carbon and Nitrogen Stocks and Burial Rates in Intertidal Vegetated Habitats of a Mesotidal Coastal Lagoon

Coastal vegetated ecosystems such as saltmarshes and seagrasses are important sinks of organic carbon (OC) total nitrogen (TN), with large global local variability, driven by the confluence many physical ecological factors. Here we show that sedimentary OC TN stocks intertidal saltmarsh (Sporobolus maritimus) seagrass (Zostera noltei) habitats increased between two- fourfold along a decreasing flow velocity gradient in Ria Formosa lagoon (south Portugal). A similar twofold increase was also observed for burial rates S. maritimus almost one order magnitude Z. noltei. Stable isotope mixing models identify allochthonous particulate matter main source to pools both (39–68%). This is second estimate first noltei, small, fast-growing species widely distributed Europe (41,000 ha) which area presently expanding (8600 ha 2000s). Its wide range (29–99 Mg ha−1) (15–122 g m2 y−1) highlight importance investigating drivers variability develop blue models. The (7–11 (2–4 m−2 noltei were generally higher than elsewhere. (29–101 3–11 ha−1, respectively) (19–39 3–5 lower those located estuaries subjected larger accumulation terrestrial matter.