HAL Id: hal-02751636
https://hal.inrae.fr/hal-02751636
Submitted on 3 Jun 2020
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Potential impacts of climate change on grassland productivity at French sites
Anne-Isabelle Graux, Romain Lardy, Gianni Bellocchi, Jean-François Soussana
To cite this version:
Anne-Isabelle Graux, Romain Lardy, Gianni Bellocchi, Jean-François Soussana. Potential impacts of climate change on grassland productivity at French sites. Colloque ACCAE - Adaptation au Changement Climatique de l’Agriculture et des Ecosystèmes, Oct 2010, Clermont-Ferrand, France.
2010, Adapting to climate change: agriculture and ecosystems. �hal-02751636�
Potential summer forage deficits were estimated in far future, more pronounced at Mirecourt (with, on average, -35% of current average values) than Avignon (-15%) and for deep than shallow soils
Summer and autumn GPP reductions in far future could result in dairy milk production drop with both extensively- and intensively-
managed permanent grasslands
Versailles
Avignon
Mirecourt
Toulouse Bordeaux
Rennes
Theix
Colmar Dijon
St-Etienne Mons
Lusignan
A simulation study was performed to extrapolate potential impacts of altered climate regimes on grassland
resources (SI: irrigated sown; S: rainfed sown;
PI: permanent intensive; PE: permanent extensive) on deep and shallow soils at 12 sites in France
An array of scenarios sketched to represent climate/soil/plant/management interactions
Climate change projections representative of conditions of
near future (2020-2049) and far future (2070-2099) were constructed from the Special Report on Emission Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC) using a
range of global circulation models (GCM) and settings which mark the limits of uncertainty associated with current climate modelling
Pasture Simulation Model
(PASIM) was employed to generate a variety of outputs related to
biomass productivity and carbon budget under future
and near past (1970-1999) climate conditions
Potential impacts of climate change on grassland productivity at French sites
Anne-Isabelle Graux, Romain Lardy, Gianni Bellocchi, Jean-François Soussana
Unité de Recherche sur l’Ecosystème Prairial, INRA, 234 avenue du Brézet, 63100 Clermont-Ferrand (France) Email: anne.isabelle@clermont.inra.fr
Air temperature increases of about 4.2 °C and rainfall decreases of about 250 mm yr-1
(median values) are estimated at Avignon
Projected
changes in
temperature
indicate up to extremes of 19-20 against ~15 °C registered with baseline scenario
Research supported by the Auvergne Region of France and by the ANR CLIMATOR project
Illustrative results
Regional projection of the SRES storyline A2 (divided world:
independently operating, self-reliant nations; continuously increasing population; regionally oriented economic development; slow and fragmented technological changes and improvements)
ARPEGE climate model, downscaled using the variable correction method (http://www.cnrm.meteo.fr/gmgec/arpege/arpege.html)
Results shown with focus on the estimated summer gross primary production (GPP) at two sites as the extremes of aridity conditions:
Avignon (sub-arid to arid) and Mirecourt (sub-humid to humid).
Avignon: variability of air temperature and rainfall (A2 scenario, ARPEGE model, two future horizons)
Probability to exceed the median annual rainfall of 910 mm reduces from ~50% down to about 6.6% in the far future
General conclusions
On average, C sequestration and forage provision are not estimated to be threatened by future climate changes (with greater inter-annual variability)
More favourable conditions to production especially in spring and winter may benefit of mowing and grazing (e.g., longer grazing periods)
Further investigations are ongoing:
On adaptive management options, to counteract the possible negative impact of climate change on grassland services
On determining to which extent these results may be of relevance at the entire enterprise level (to provide valuable information to managers and strategic planners)
