Historical changes in seagrass beds in a rapidly urbanizing area of Guangdong Province: Implications for conservation and management

摘要: Abstract Rapid urbanization leads to an accelerating decline of seagrass beds. The status beds along the entire coastline a rapidly urbanizing area, Guangdong Province, was examined document change in and explore determinants seagrasses characteristics their plasticity. Thirteen were newly discovered with total area as 679.04 ha, whereas eleven known have decreased from 972.55 ha 858.67 ha seven them having disappeared recent decade primarily due exacerbated construction artificial shorelines beach dams, increased nutrient inputs fish caging shrimp pond culture, oyster mangrove planting shellfish collection. leaf nitrogen content Halophila ovalis, which dominated largest beds, (2.09 ± 0.24)% 2011 (3.39 ± 0.18)% 2017, indicating enhanced eutrophication. optimum seawater dissolved inorganic phosphorus levels for beccarii 40 μmol/L 2.5 μmol/L, respectively. standing stock plant dimensions H. positively correlated sediment mud content. Longer, wider leaves, greater aboveground belowground biomass observed at lower salinities, that prefers hyposaline habitats. High shoot density could induce intraspecific competition followed by self-thinning beccarii, leading reduced biomass, root length. Thus, long-term monitoring Province is needed unravel mechanisms develop effective management strategies.