Plant communities play an important role in the C-sink function of peatlands. However, global change and local perturbations are expected to modify peatland plant communities, leading to a shift from Sphagnum mosses to vascular plants. Most studies have focused on the direct effects of modification in plant communities or of global change (such as climate warming, N fertilization) in peatlands without considering interactions between these disturbances that may alter peatlands' C function. We set up a mesocosm experiment to investigate how Greenhouse Gas (CO2, CH4, N2O) fluxes, and dissolved organic carbon (DOC) and total dissolved N (TN) contents are affected by a shift from Sphagnum mosses to Mania caerulea dominated peatlands combined with N fertilization. Increasing N deposition did not alter the C fluxes (CO2 exchanges, CH4 emissions) or DOC content. The lack of N effect on the C cycle seems due to the capacity of Sphagnum to efficiently immobilize N. Nevertheless, N supply increased the N2O emissions, which were also controlled by the plant communities with the presence of Molinia caerulea reducing N2O emissions in the Sphagnum mesocosms. Our study highlights the role of the vegetation composition on the C and N fluxes in peatlands and their responses to the N deposition. Future research should now consider the climate change in interaction to plants community modifications due to their controls of peatland sensitivity to environmental conditions. (C) 2018 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
1.Univ Orleans, ISTO, UMR 7327, F-45071 Orleans, France 2.CNRS, ISTO, UMR 7327, F-45071 Orleans, France 3.Bur Rech Geol & Minieres, ISTO, UMR 7327, BP 36009, F-45060 Orleans, France 4.Univ Orleans, LPC2E, UMR 7328, F-45071 Orleans, France 5.CNRS, LPC2E, UMR 7328, F-45071 Orleans, France 6.Univ Rennes 1, UMR 6553, CNRS, ECOBIO, Rennes, France 7.Univ Orleans, Cellule R&D CETRAHE, F-45072 Orleans 2, France 8.Shandong Univ, Sch Environm Sci & Engn, Jinan, Shandong, Peoples R China
Recommended Citation:
Leroy, Fabien,Gogo, Sebastien,Guimbaud, Christophe,et al. Response of C and N cycles to N fertilization in Sphagnum and Molinia-dominated peat mesocosms[J]. JOURNAL OF ENVIRONMENTAL SCIENCES-CHINA,2019-01-01,77:264-272