Effect of climate change, CO2 trends, nitrogen addition, and land-cover and management intensity changes on the carbon balance of European grasslandsReport as inadecuate




Effect of climate change, CO2 trends, nitrogen addition, and land-cover and management intensity changes on the carbon balance of European grasslands - Download this document for free, or read online. Document in PDF available to download.

* Corresponding author 1 LOCEAN - Laboratoire d-Océanographie et du Climat : Expérimentations et Approches Numériques 2 LSCE - Laboratoire des Sciences du Climat et de l-Environnement Gif-sur-Yvette 3 CSIRO - Commonwealth Scientific and Industrial Research Organisation 4 IIASA - International Institute for Applied Systems Analysis Laxenburg 5 LMD - Laboratoire de Météorologie Dynamique 6 Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences 7 PARVATI - Processus de la variabilité climatique tropicale et impacts LOCEAN - Laboratoire d-Océanographie et du Climat : Expérimentations et Approches Numériques 8 URAC - Grassland Ecosystems Research Group, Agronomy Unit

Abstract : Several lines of evidence point to European managed grassland ecosystems being a sink of carbon. In this study, we apply ORCHIDEE-GM a process-based carbon cycle model that describes specific management practices of pastures and the dynamics of carbon cycling in response to changes in climatic and biogeochemical drivers. The model is used to simulate changes in the carbon balance i.e., net biome production NBP of European grasslands over 1991–2010 on a 25 km × 25 km grid. The modeled average trend in NBP is 1.8–2.0 g C m−2 yr−2 during the past two decades. Attribution of this trend suggests management intensity as the dominant driver explaining NBP trends in the model 36–43% of the trend due to all drivers. A major change in grassland management intensity has occurred across Europe resulting from reduced livestock numbers. This change has ‘inadvertently’ enhanced soil C sequestration and reduced N2O and CH4 emissions by 1.2–1.5 Gt CO2-equivalent, offsetting more than 7% of greenhouse gas emissions in the whole European agricultural sector during the period 1991–2010. Land-cover change, climate change and rising CO2 also make positive and moderate contributions to the NBP trend between 24% and 31% of the trend due to all drivers. Changes in nitrogen addition including fertilization and atmospheric deposition are found to have only marginal net effect on NBP trends. However, this may not reflect reality because our model has only a very simple parameterization of nitrogen effects on photosynthesis. The sum of NBP trends from each driver is larger than the trend obtained when all drivers are varied together, leaving a residual – nonattributed – term 22–26% of the trend due to all drivers indicating negative interactions between drivers.

Keywords : ORCHIDEE-GM carbon balance land-cover change management intensity climate change European grassland





Author: Jinfeng Chang - Philippe Ciais - Nicolas Viovy - Nicolas Vuichard - Mario Herrero - Petr Havlík - Xuhui Wang - Benjamin Sultan -

Source: https://hal.archives-ouvertes.fr/



DOWNLOAD PDF




Related documents