title: Priming effect and microbial diversity in ecosystem functioning and response to global change: a modeling approach using the SYMPHONY model.
abstract: Integration of the priming effect (PE) in ecosystem models is crucial to better predict the consequences of global change on ecosystem carbon (C) dynamics and its feedbacks on climate. Over the last decade, many attempts have been made to model PE in soil. However, PE has not yet been incorporated into any ecosystem models. Here, we build plant/soil models to explore how PE and microbial diversity influence soil/plant interactions and ecosystem C and nitrogen (N) dynamics in response to global change (elevated CO2 and atmospheric N depositions). Our results show that plant persistence, soil organic matter (SOM) accumulation, and low N leaching in undisturbed ecosystems relies on a fine adjustment of microbial N mineralization to plant N uptake. This adjustment can be modeled in the SYMPHONY model by considering the destruction of SOM through PE, and the interactions between two microbial functional groups: SOM decomposers and SOM builders. After estimation of parameters, SYMPHONY provided realistic predictions on forage production, soil C storage and N leaching for a permanent grassland. Consistent with recent observations, SYMPHONY predicted a CO2 -induced modification of soil microbial communities leading to an intensification of SOM mineralization and a decrease in the soil C stock. SYMPHONY also indicated that atmospheric N deposition may promote SOM accumulation via changes in the structure and metabolic activities of microbial communities. Collectively, these results suggest that the PE and functional role of microbial diversity may be incorporated in ecosystem models with a few additional parameters, improving accuracy of predictions.
authors: INRA, UR874 (Unité Recherche d'Ecosystème prairial), 5 Chemin de Beaulieu, 63039, Clermont-Ferrand, France.
authors: Nazia
authors: N
authors: Perveen
authors: Sébastien
authors: S
authors: Barot
authors: Gaël
authors: G
authors: Alvarez
authors: Katja
authors: K
authors: Klumpp
authors: Raphael
authors: R
authors: Martin
authors: Alain
authors: A
authors: Rapaport
authors: Damien
authors: D
authors: Herfurth
authors: Frédérique
authors: F
authors: Louault
authors: Sébastien
authors: S
authors: Fontaine
mesh_terms: D044822:Biodiversity; D002244:Carbon / Q000378:metabolism; D057965:Carbon Sequestration; D017753:Ecosystem; D008962:Models, Theoretical; D009584:Nitrogen / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D006109:Poaceae; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012987:Soil; D002244:Carbon; D009584:Nitrogen
keywords: C sequestration; C/N coupling; bank functioning; nutrient cycling; nutrient mining; plant/soil interactions