Fig. 5

Schematic pictures of the effect of sediment on the photosynthesis, stable isotope sulfur (δ³⁴S), FAA (free amino acid) and flavone of seagrasses. a indicated that seagrass growing in sediment in eutrophic bay with lower particle size, showed smaller rETR (relative electron transport rate) and Ek_ETR (the minimum saturating irradiance), while higher FAA and Flavone accumulated in the belowground tissue to counteract anoxic stress. b indicated that beach sand addition indirectly enhanced rETR and Ek_ETR by improving the growth condition for seagrass with lower flavone and FAA. N: sediment nitrogen. S: sediment sulfur. Eh: sediment redox potential, measuring the oxidation/reduction state. The bigger the circle, the higher the content or value