Relationships between porewater nutrients and seagrasses in a subtropical carbonate environment

摘要: The primary source of nutrients for seagrass growth is considered to be the sediment porewater. Porewater nutrient concentrations were measured in 18 beds across Florida Bay, USA, a shallow, seagrass-dominated subtropical embayment, during summers 1987 and 1988. Concentrations porewater varied widely, with median values 0.34 μM soluble reactive phosphorus (SRP) 78.6 NH 4 + . SRP positively correlated. Due spatial heterogeneity, there no apparent trends depth (down 40 cm) concentrations. concentration was highest areas supporting Halodule wrightii, intermediate Thalassia testudinum, lowest sediments without seagrasses. There similar relationship SRP, but not , significantly correlated total standing crop. Elemental content (both N P) green leaves T. testudinum function Standing crop content, leaves. results support hypothesis that porewaters are most important growth. In this carbonate environment, availability limits development, controls species composition, beds.