The effects of stand-age and inundation on carbon accumulation in mangrove plantation soil in Namdinh, Northern Vietnam

Mangroves are one of the most unique ecosystems, covering 75% of the world's subtropical and tropical coastlines (Ellison and Farnworth, 2001).Mangroves occur in transitional zones between terrestrial and marine habitats with a geographical distribution extending between 33 N and 38 S latitude (Horgarth, 1999).They strive in a very dynamic and harsh environment (Lugo and Snedaker, 1974;Hutchings and Saenger, 1987;McKee, 1996).Although this shallow transition region between the land and the ocean represents only 5% of the earth's surface, it is one of the most geochemically and biologically active areas in the biosphere (Twilley et al., 1992).The most significant and distinctive feature of this coastal area is water-logging, which causes more or less anoxia, strongly affecting the growth of mangroves.Additionally, due to inundation by sea water, mangroves typically flourish in an environment with unusually high salinity.Some species even grow in hypersaline conditions close to 90ppt (sea water = 35ppt) (Hogarth, 1999;Lovelock and Ball, 2002).However, mangroves are very well-adapted morphologically and physiologically to this inhospitable environment (Ball, 1988(Ball, , 2001;;Cram et al., 2001;Mimura et al., 2003).Surprisingly mangroves are considered to be highly productive, with an average productivity of 2500 mg C m -2 per day (Bunt, 1992;Clough, 1992).Many authors have estimated and evaluated biomass production of different mangrove forests world-wide (Komiyama et al.,