Response of C and N cycles to N fertilization in Sphagnum and Molinia-dominated peat mesocosms

作     者：Fabien Leroy Sébastien Gogo Christophe Guimbaud André-Jean Francez Renata Zocatelli Christian Défarge Léonard Bernard-Jannin Zhen Hu Fatima Laggoun-Défarge 

作者机构：University of OrleansISTO CNRSISTO BRGM ISTO University of OrleansLPC2E CNRSLPC2E UMR CNRS 6553 ECOBIO University of Rennes 1 University of Orleans Cellule R&D CETRAHE School of Environmental Science and Engineering Shandong University 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2019年第31卷第3期

页      面：264-272页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 083001[工学-环境科学] 07[理学] 08[工学] 09[农学] 0903[农学-农业资源与环境] 0713[理学-生态学] 

基　　金：research conducted in the Labex VOLTAIRE (ANR-10-LABX-100-01) the financial support provided to the PIVOTS project by the Région Centre–Val de Loire:ARD 2020 program,CPER 2015-2020,the European Union who invests in Centre-Val de Loire with the European Regional Development Fund supported by the AMIS(FAte and IMpact of AtmospherIc PollutantS)project funded by the European Union,under the Marie Curie Actions IRSES(International Research Staff Exchange Scheme),within the Seventh Framework ProgrammeFP7-PEOPLE-2011-IRSES 

主　　题：CO2 and CH4 N2O Peatland Plant community composition Sphagnum moss Graminoid 

摘      要：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(CO_2, CH_4, N_2O) fluxes, and dissolved organic carbon(DOC)and total dissolved N(TN) contents are affected by a shift from Sphagnum mosses to Molinia caerulea dominated peatlands combined with N fertilization. Increasing N deposition did not alter the C fluxes(CO_2 exchanges, CH_4 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 N_2O emissions, which were also controlled by the plant communities with the presence of Molinia caerulea reducing N_2O 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.