Salt marshes are key ecosystems for biogeochemical cycling of nutrients in coastal areas, providing essential sequestration of contaminants and elemental organic forms while recycling these last to more bioavailable forms. Extracellular phosphatase-mediated phosphorus biogeochemical cycling acquires this way a reinforced role. In terms of speciation, salt marsh sediments exhibited a large pool of P in a bioavailable form (> 60%), being this pool characterized by being readily accessible to plants by weak chemical reactions. Regarding phosphatase activity, the acid isoform was found to be the most abundant pH-isoform present in salt marsh rhizosediments. A positive correlation could be found between humic acid bound P and total and acid phosphatase activities, possibly driven by the action of acid phosphatase on the acidic molecules of humic acids, using organic P as substrate, and releasing inorganic P into the desorbable P-pool. This process is more evident during the cold seasons, where the largest necromass input is observed entering the sediments, due to seasonal plant senescence. It could also be observed a positive correlation between inorganic phosphorus forms and phosphatase activity, consistent with phosphatases-driven inorganic phosphorus production from the recycling of organic forms, and thus a possible direct effect of phosphatase, as it was described for other ecosystems. This biogeochemical cycling is key for the ecosystem nutrient recycling, while passive remediator of eutrophication, but also for maintaining the salt marsh areas high primary productivity and their role as habitat, shelter and feeding ground of many animal species.

盐沼是沿海地区营养物质生物地球化学循环的关键生态系统，提供了对污染物和元素有机形式的必要隔离，同时将这些物质循环利用为更具生物可利用性的形式。细胞外磷酸酶介导的磷生物地球化学循环通过这种方式获得了强化作用。就物种形成而言，盐沼沉积物以生物可利用形式（> 60％）表现出大量的P，该池的特点是植物易于通过弱化学反应获得。关于磷酸酶活性，发现酸性异构体是盐沼根沉积物中最丰富的 pH 异构体。腐植酸之间存在正相关关系结合 P 和总磷酸酶和酸性磷酸酶的活性，可能是由酸性磷酸酶对腐植酸酸性分子的作用驱动的，使用有机 P 作为底物，并将无机 P 释放到可解吸的 P 池中。这一过程在寒冷季节更为明显，由于季节性植物衰老，观察到最大的坏死物质输入进入沉积物。还可以观察到无机磷形式与磷酸酶活性之间呈正相关，这与磷酸酶驱动的有机形式再循环产生的无机磷相一致，因此磷酸酶可能直接影响其他生态系统。这种生物地球化学循环是生态系统养分循环的关键，而富营养化的被动修复，