Résumé
Key message Mixing sessile oak and Scots pine in central France to reduce intraspecific competition for water resources did not improve the ability of these two species to withstand severe drought during the summer. ContextIn order to reduce the impact of increasingly extreme droughts on forests, managers must adapt their practices to future climate conditions. Maintaining a greater diversity of tree species in temperate forest ecosystems is one of the recommended options.AimsWe addressed how interactions between sessile oak and Scots pine in mixed forests in central France affect their functional response to drought.MethodsWe characterized the carbon isotope composition (δ13C) in the tree growth rings formed during wet (2001, 2007) or dry (2003, 2004) summers for each of the two species growing both in pure and in mixed stands in order to compare the effect of stand composition on variations in carbon isotope discrimination (Δ13C) among contrasted years.ResultsThe severe drought in 2003 induced a strong decrease in Δ13C for all trees and in all stands as compared to 2001. This decrease was greater in pine than in oak. There was no significant difference between pure and mixed stands in the response of either species to drought.ConclusionMixing sessile oak and Scots pine in stands in central France does not improve the ability of either species to withstand severe drought during the summer.
Auteurs, date et publication :
Auteurs Damien Bonal , Mathilde Pau , Maude Toigo , André Granier , Thomas Perot
Publication : Annals of Forest Science
Date : 2017
Volume : 74
Issue : 4
Pages : 72
Catégorie(s)
#FORET OPTMix #INRAEAuteurs, date et publication :
Auteurs Félix Lallemand , Tomáš Figura , Claire Damesin , Chantal Fresneau , Chantal Griveau , Ninon Fontaine , Bernd Zeller , Marc-André Selosse
Publication : New Phytologist
Date : 2025
Volume : 221
Issue : 1
Pages : 12-17
Catégorie(s)
#ANR-Citation #INRAE #M-POETEAuteurs, date et publication :
Auteurs Shubham Krishna , Hugo N. Ulloa , Onur Kerimoglu , Camille Minaudo , Orlane Anneville , Alfred Wüest
Publication : Ecological Modelling
Date : 2025
Volume : 440
Pages : 109401
Catégorie(s)
#INRAE #OLAAuteurs, date et publication :
Auteurs Hélène Raynal
Date : 2025
Pages : 11
Catégorie(s)
#INRAE #RecordRésumé
Light under tree canopy cover is essential for the study and understanding of plant diversity, regeneration, plant growth and many other forest ecosystem processes; however, quantifying light is difficult and requires specialized equipment. That is why proxies or models predicting light availability can help scientists to obtain estimates of transmittance and forest managers to better assess and adjust silvicultural practices at a reasonable cost. The main objective of our research was to develop a model to predict local solar radiation transmittance from species basal area in mono-specific and mixed stands of sessile oak (Quercus petraea) and Scots pine (Pinus sylvestris). Models based on the Beer-Lambert law were fitted and compared using 163 measures of solar radiation transmittance obtained from hemispherical photographs and light sensors. In mono-specific stands, local transmittance was predicted by local basal area considered on a radius equaling approximately tree height. In mixed stands, the same model broken down into its mono-specific components (local basal area of each species multiplied by their own extinction coefficients) predicted transmittance well. The extinction coefficients we obtained were very close to those previously established for these species and did not differ between mono-specific and mixed stands. Our model explained 77% of the variation in transmittance when random effects were included and 64% of the variance without taking into account these random effects. The predictive value of the model was good with high accuracy (mean signed deviation not significantly different from zero) and a fairly high precision (relative mean absolute error=20%). The fact that tree canopy transmittance in mixed stands can be predicted by extinction coefficients obtained from mono-specific stands indicates that modifications in crown structure and leaf distribution are only slight, or even non-existent, when the two species grow in a mixture.
Auteurs, date et publication :
Auteurs Thomas Perot , Anders Mårell , Nathalie Korboulewsky , Vincent Seigner , Philippe Balandier
Publication : Forest Ecology and Management
Date : 2017
Volume : 390
Pages : 127-136
Catégorie(s)
#FORET OPTMix #INRAERésumé
The CenW ecosystem model simulates carbon, water, and nitrogen cycles following ecophysiological processes and management practices on a daily basis. We tested and evaluated the model using five years eddy covariance measurements from two adjacent but differently managed grasslands in France. The data were used to independently parameterize CenW for the two grassland sites. Very good agreements, i.e., high model efficiencies and correlations, between observed and modeled fluxes were achieved. We showed that the CenW model captured day-to-day, seasonal, and interannual variability observed in measured CO2 and water fluxes. We also showed that following typical management practices (i.e., mowing and grazing), carbon gain was severely curtailed through a sharp and severe reduction in photosynthesizing biomass. We also identified large model/data discrepancies for carbon fluxes during grazing events caused by the noncapture by the eddy covariance system of large respiratory losses of C from dairy cows when they were present in the paddocks. The missing component of grazing animal respiration in the net carbon budget of the grazed grassland can be quantitatively important and can turn sites from being C sinks to being neutral or C sources. It means that extra care is needed in the processing of eddy covariance data from grazed pastures to correctly calculate their annual CO2 balances and carbon budgets.
Auteurs, date et publication :
Auteurs Nicolas Puche , Nimai Senapati , Christophe R. Flechard , Katia Klumpp , Miko U. F. Kirschbaum , Abad Chabbi
Publication : Agronomy
Date : 2019
Volume : 9
Issue : 4
Pages : 183
Catégorie(s)
#ACBB #ACBB Lusignan #ANR-Citation #INRAEAuteurs, date et publication :
Auteurs Sabine Allou , Anne Tréguier , Nicolas Houdouin , Jean-Pierre Destouches , Laurent Beaulaton , Frédéric Marchand , Didier Azam
Date : 2025
Pages : 41
Catégorie(s)
#INRAE #PEARLAuteurs, date et publication :
Auteurs Anne Tréguier , Nicolas Houdouin , Jean-Pierre Destouches , Laurent Beaulaton , Frédéric Marchand , Didier Azam
Date : 2025
Pages : 113
Catégorie(s)
#INRAE #PEARLAuteurs, date et publication :
Auteurs M. Adam
Date : 2025
Catégorie(s)
#INRAE #PEARLAuteurs, date et publication :
Auteurs Franck Cattanéo , Jean Guillard , Seydina Diouf , Jane O'Rourke , David Grimardias
Publication : Science of The Total Environment
Date : 2025
Volume : 756
Pages : 144053