Mangrove forests and coastal marshes are typically considered N-limited ecosystems because of their high primary production. Therefore, mangrove plants are highly efficient at utilising soil nitrogen, making them an important sink for excess nitrogen from upstream. However, different mangrove species may still utilise nitrogen at different efficiencies, even though they share similar nitrogen pathways (see diagram on right). Reported nitrogen assimilation rates in mangrove plants ranged from 2 to 8 μmol g−1 h−1 under ambient nitrogen conditions,Datta, R.; Datta, B.K. (1999 ) "Desiccation induced nitrate and ammonium uptake in the red alga Catenella repens (Rhodophyta, Gigartinales)". Indian J. Geo Mar. Sci., 28: 458–460. and 19 to 251 μmol g−1 h−1 when the nitrogen supply was unlimited.
