Auteurs, date et publication :

Auteurs M Sanaullah , Cornelia Rumpel , X Charrier , A Chabbi

Publication : Plant and Soil

Date : 2025

Volume : 352

Issue : 1-2

Pages : 277–288


Catégorie(s)

#ACBB #ACBB Lusignan #INRAE

Résumé

Background and aims Modification in grazing intensity causes functional changes in permanent grasslands, e.g. in carbon (C) cycling. However, we still know little about how the soil organic C of permanent grasslands responds to grazing intensity.


Auteurs, date et publication :

Auteurs Herfurth Damien , Vassal Nathalie , Louault Frédérique , Alvarez Gael , Pottier Julien , Picon-Cochard Catherine , Bosio Isabelle , Carrère Pascal

Publication : Plant and Soil

Date : 2025

Volume : 394

Issue : 1-2

Pages : 239-255


Catégorie(s)

#ACBB #ACBB Theix #INRAE

Résumé

Contrasting microbial community composition and activity at different soil depths may affect root litter decomposition. These effects have up to now been investigated mainly in laboratory studies, which may not be able to take into account complex in situ conditions. Our study aimed to analyze the composition and activity of microbial communities after addition of 13C labeled wheat root litter to a loamy soil under grassland at 30, 60 and 90 cm depths, during a three-year field experiment. We investigated the dynamics of bacterial and fungal abundances and community structures by DNA genotyping and pyrosequencing of 16S and 18S rDNAs. The genetic structures of bacterial and fungal communities were evaluated by automated ribosomal intergenetic spacer analysis. The functions of these communities were analysed by determination of extracellular enzyme activities and viable microbial communities involved in 13C labeled organic matter decomposition studied by 13C PLFAs.


Auteurs, date et publication :

Auteurs Muhammad Sanaullah , Abad Chabbi , Pierre-Alain Maron , Karen Baumann , Vincent Tardy , Evgenia Blagodatskaya , Yakov Kuzyakov , Cornelia Rumpel

Publication : Soil Biology and Biochemistry

Date : 2025

Volume : 103

Pages : 28-38


Catégorie(s)

#ACBB #ACBB Lusignan #INRAE

Résumé

Forecasted climate change impacts on temperate forest ecosystems include increased summer drought. Forest managers can increase the resistance of forest stands against summer drought by reducing stand density and favoring tree species mixtures. These strategies have been studied separately, but their combined effect on increasing forest stand resistance to summer drought is unknown. The main objective of our study was to quantify tree species interaction effects on radial growth during a water stress period and to determine whether these effects changed with different levels of competition reflected by stand density. The study was based in the Orleans state forest (Central France) at a long-term triplet experimental site (OPTMix) with pure and mixed stands of mature Quercus petraea and Pinus sylvestris. The experimental design comprised three repetitions of two densities (low and medium) in each composition (pure oak, mixed stands, pure pine). We monitored tree radial growth with 216 manual dendrometers placed throughout 18 plots, on small, medium and large trees. We analyzed three consecutive years with contrasted water stress: no water stress, a summer stress period, and a late summer stress period. We found that mixture did not improve tree growth of the either species during the summer water stress period. On the other hand, there was a mixture effect during the late summer water stress period but only in medium-density stands inversely for the two species studied. More growth occurred for oaks in mixtures while, inversely, more growth occurred for pines in monocultures. A density effect occurred only for oaks, which grew more in lower-density stands than in medium-density stands. Finally, tree size did not influence seasonal resistance to drought.


Auteurs, date et publication :

Auteurs Jordan Bello , Patrick Vallet , Thomas Perot , Philippe Balandier , Vincent Seigner , Sandrine Perret , Camille Couteau , Nathalie Korboulewsky

Publication : Forest Ecology and Management

Date : 2019

Volume : 432

Pages : 436-445


Catégorie(s)

#FORET OPTMix #INRAE

Résumé

Ecologists have long argued about the modification of plant competition along abiotic gradients, and particularly along resource gradients. Through simulations, we evaluated the impact of bramble defoliation by roe deer on the response of oak seedlings to bramble presence along two resource gradients. We set up a controlled experiment crossing: (i) two light availabilities (10% and 30% incident radiation), (ii) two water regimes (normal rainfall and a reduced water regime) and (iii) three bramble defoliation modes (non-defoliated brambles, brambles defoliated in June and brambles defoliated in late July). Control plots contained no brambles. We found that, the intensity of the competition remained constant along the gradients, while the importance of the competition significantly increased with increasing resource availability. Our results further show that bramble defoliation causes a significant decrease in both competition intensity and importance and that the effect depends on both the demographic parameter and the defoliation period. Furthermore, defoliation did not change the patterns of competition intensity and importance along the resource gradients. We emphasize the importance of considering both disturbances, such as deer defoliation, and various demographic parameters related to plant phenology and plant response dynamics in the characterization of plant-plant interactions.


Auteurs, date et publication :

Auteurs Lisa Laurent , Anders Mårell , Nathalie Korboulewsky , Sonia Saïd , Philippe Balandier

Publication : Forest Ecology and Management

Date : 2017

Volume : 391

Pages : 239-245


Catégorie(s)

#FORET OPTMix #INRAE

Auteurs, date et publication :

Auteurs Marie-Eve Monchamp , Piet Spaak , Isabelle Domaizon , Nathalie Dubois , Damien Bouffard , Francesco Pomati

Publication : Nature Ecology & Evolution

Date : 2025

Volume : 2

Issue : 2

Pages : 317-324


Catégorie(s)

#INRAE #OLA

Résumé

In soil, the link between microbial diversity and carbon transformations is challenged by the concept of functional redundancy. Here, we hypothesized that functional redundancy may decrease with increasing carbon source recalcitrance and that coupling of diversity with C cycling may change accordingly. We manipulated microbial diversity to examine how diversity decrease affects the decomposition of easily degradable (i.e., allochthonous plant residues) versus recalcitrant (i.e., autochthonous organic matter) C sources. We found that a decrease in microbial diversity (i) affected the decomposition of both autochthonous and allochthonous carbon sources, thereby reducing global CO2 emission by up to 40%, and (ii) shaped the source of CO2 emission toward preferential decomposition of most degradable C sources. Our results also revealed that the significance of the diversity effect increases with nutrient availability. Altogether, these findings show that C cycling in soil may be more vulnerable to microbial diversity changes than expected from previous studies, particularly in ecosystems exposed to nutrient inputs. Thus, concern about the preservation of microbial diversity may be highly relevant in the current global-change context assumed to impact soil biodiversity and the pulse inputs of plant residues and rhizodeposits into the soil.
IMPORTANCE With hundreds of thousands of taxa per gram of soil, microbial diversity dominates soil biodiversity. While numerous studies have established that microbial communities respond rapidly to environmental changes, the relationship between microbial diversity and soil functioning remains controversial. Using a well-controlled laboratory approach, we provide empirical evidence that microbial diversity may be of high significance for organic matter decomposition, a major process on which rely many of the ecosystem services provided by the soil ecosystem. These new findings should be taken into account in future studies aimed at understanding and predicting the functional consequences of changes in microbial diversity on soil ecosystem services and carbon storage in soil.


Auteurs, date et publication :

Auteurs Pierre-Alain Maron , Amadou Sarr , Aurore Kaisermann , Jean Lévêque , Olivier Mathieu , Julien Guigue , Battle Karimi , Laetitia Bernard , Samuel Dequiedt , Sébastien Terrat , Abad Chabbi , Lionel Ranjard

Publication : Appl. Environ. Microbiol.

Date : 2018

Volume : 84

Issue : 9

Pages : e02738-17


Catégorie(s)

#ACBB #ACBB Lusignan #Genosol #INRAE

Auteurs, date et publication :

Auteurs B. Le Vu , Brigitte Vinçon-Leite , B. J. Lemaire , N. Bensoussan , M. Calzas , C. Drezen , J. F. Deroubaix , N. Escoffier , Y. Dégrés , C. Freissinet , A. Groleau , J. F. Humbert , G. Paolini , F. Prévot , C. Quiblier , E. Rioust , B. Tassin

Publication : Biogeochemistry

Date : 2025

Volume : 106

Issue : 2

Pages : 229-242


Catégorie(s)

#INRAE #OLA

Auteurs, date et publication :

Auteurs Marttiina V. Rantala , Rosalie Bruel , Aldo Marchetto , Andrea Lami , Jorge E. Spangenberg , Marie-Elodie Perga

Publication : Science of The Total Environment

Date : 2025

Volume : 782

Pages : 146923


Catégorie(s)

#INRAE #OLA

Auteurs, date et publication :

Auteurs M.-A. Coutellec , T. Caquet

Publication : Journal of Evolutionary Biology

Date : 2011

Volume : 24

Issue : 10

Pages : 2248-2257


Catégorie(s)

#INRAE #PEARL