Sousa Ana I, Lillebø Ana I, Caçador Isabel, Pardal Miguel A
IO-Institute of Oceanography, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon, Portugal.
Environ Pollut. 2008 Dec;156(3):628-35. doi: 10.1016/j.envpol.2008.06.022. Epub 2008 Aug 5.
Salt marshes are among the most productive ecosystems in the world, performing important ecosystem functions, particularly nutrient recycling. In this study, a comparison is made between Mondego and Tagus estuaries in relation to the role of Spartina maritima in nitrogen retention capacity and cycling. Two mono-specific S. maritima stands per estuary were studied during 1yr (biomass, nitrogen (N) pools, litter production, decomposition rates). Results showed that the oldest Tagus salt marsh population presented higher annual belowground biomass and N productions, and a slower decomposition rate for litter, contributing to the higher N accumulation in the sediment, whereas S. maritima younger marshes had higher aboveground biomass production. Detritus moved by tides represented a huge amount of aboveground production, probably significant when considering the N balance of these salt marshes. Results reinforce the functions of salt marshes as contributing to a reduction of eutrophication in transitional waters, namely through sedimentation processes.
盐沼是世界上生产力最高的生态系统之一，发挥着重要的生态系统功能，尤其是养分循环功能。在本研究中，对蒙德古河河口和塔霍河河口的滨海米草在氮保留能力和循环方面的作用进行了比较。在1年的时间里，对每个河口的两个单物种滨海米草群落进行了研究（生物量、氮库、凋落物产量、分解速率）。结果表明，塔霍河最古老的盐沼种群具有更高的年地下生物量和氮产量，凋落物分解速率较慢，这使得沉积物中的氮积累量更高，而滨海米草较年轻的盐沼地上生物量产量更高。潮汐搬运的碎屑代表了大量的地上产量，从这些盐沼的氮平衡角度考虑可能意义重大。结果强化了盐沼在促进过渡水域富营养化减少方面的功能，即通过沉积过程。
