Responses of carbon dynamics to nitrogen deposition in typical freshwater wetland of Sanjiang plain

The effects of nitrogen deposition (n-deposition) on the carbon dynamics in typical calamagrostis angustifolia wetland of sanjiang plain were studied by a pot-culture experiment during two continuous plant growing seasons. elevated atmospheric n-deposition caused significant increases in the aboveground net primary production and root biomass; moreover,a preferential partition of carbon to root was also observed. different soil carbon fractions gained due to elevated n-deposition and their response intensities followed the sequence of labile carbon > dissolved organic carbon > microbial biomass carbon,and the interaction between n-deposition and flooded condition facilitated the release of different carbon fractions. positive correlations were found between coand chfluxes and liable carbon contents with n-deposition,and flooded condition also tended to facilitate chfluxes and to inhibit the cofluxes with n-deposition. the increases in soil carbon fractions occurring in the nitrogen treatments were significantly correlated with increases in root,aboveground parts,total biomass,and their carbon uptake. our results suggested that n-deposition could enhance the contents of active carbon fractions in soil system and carbon accumulation in plant of the freshwater wetlands. © 2014 yang wang et al.