Résumé
Fungi are the main organisms responsible for plant biomass degradation in soils. While many studies have evaluated the impact of tree species on the taxonomic diversity of soil fungi, very few of them have addressed their functional gene diversity. In the present study, we assessed the impact of tree species, differing with respect to litter quality, and sampling dates on the diversity of four expressed fungal gene families: one housekeeping gene used as taxonomic marker and three others encoding key enzymes implicated in lignocellulose degradation selected as functional markers. This was performed by the high throughput sequencing of gene-fragments amplified from forest soil mRNA using fungal specific primers. Messenger RNAs were extracted from 10 soil samples collected over two seasons in plots planted with either the conifer Picea abies or the angiosperm Fagus sylvatica in a common garden experiment. Independently of the gene-family, less than 20% of the fungal transcripts were identified in both forest types. For all four fungal gene-families, variance partitioning identified the tree species and its interaction with the sampling plot as the factors that contributed most to global gene diversity (between 29% and 32%), while the sampling dates accounted for less than 9%. Further analysis of the contribution of soil proprieties revealed that the tree species-generated C/N ratio is the most important factor driving functional gene distribution (between 6% and 29% of the variation explained). Similarly, for each fungal gene family, statistical analyses identified tree species as the main factor responsible for variations in similarity between samples (as estimated by the Bray-Curtis beta diversity index). These results highlight that tree species, differing with respect to litter quality, selected different soil fungal communities expressing different set of genes involved in plant organic matter degradation. (C) 2016 Elsevier Ltd. All rights reserved.
Auteurs, date et publication :
Auteurs Florian Barbi , Elsa Prudent , Laurent Vallon , Marc Buee , Audrey Dubost , Arnaud Legout , Roland Marmeisse , Laurence Fraissinet-Tachet , Patricia Luis
Publication : Soil Biology and Biochemistry
Date : 2016
Volume : 100
Pages : 149-159
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #FORET BreuilRésumé
Over the last decades, the U-and Th-series nuclides were successfully used to determine weathering rates in various environments. The objective of this study is to assess the potential impact of the vegetation change on the U- and Th-series signal recorded in forested soils. This study was carried out from the experimental forest site of Breuil-Chenue (Morvan, France) developed by the INRA-BEF team. The native forest of the site was partially clear-felled in 1976 and replaced by monospecific plantations stands (Oak and Douglas fir). U- and Th-series disequilibria were measured in 2011 in the podzolic soils developed under the native forest, and in the two replanted stands. Separation of primaryminerals (biotite, muscovite and perthitic feldspar) and selective extractions of the Fe and Al oxides were performed to investigate the distribution of U and Th among these soil fractions. The selective extractions suggest that a significant part of U and Th is primarily held by Fe-bearing silicates. Our results suggest that the tree substitution seems to produce a large dissolution of these minerals under the Oaks, resulting to a release of U and Th. However, below 25 cm no impact of this release was observed on U-series disequilibria. A scenario allowing to reconcile the significant mobilization of U and the constancy of U-series disequilibria is proposed. Above 25 cm, additional pedogenic redistribution of U and Th isotopes occurs in all the profiles, inducing some discrepancies between U-series disequilibria. A clear correlation between the (Th-230/U-234) ratios and the proportions of amorphous and interlayer Al hydroxides has been highlighted. This correlation suggests a mobility of U and Th isotopes strongly associated to Al dynamics in these soils rather than Fe, despite the primary location of U in the Fe-bearing silicates and the overwhelming reported control of U-VI by Fe-oxides in oxidized environments. These pedogenic processes make the shallowest horizons of podzolic soils unsuitable for U-series dating. In contrast, a soil production rate can be deduced from the deepest soil layers which do not show such effects on the U-series nuclides. The reproducible U-series disequilibria measured in four whole-profile replicates emphasize the robustness and the significance of the "long-lived" U-series disequilibria in deep soil layers relative to long-term weathering rates, independent of transient perturbations such as land cover changes. Finally, because Ra can strongly accumulates in plants, the (Ra-226/Th-230) ratios in the different soils were affected by the flux of Ra-226 released by litter degradation. The use of this ratio as a long-term chronometer should therefore be performed with caution in such contexts. No direct impact of the vegetation type on the (Ra-228/Th-232) ratios was identified, due to the short Ra-228 half-life. (C) 2016 Elsevier B.V. All rights reserved.
Auteurs, date et publication :
Auteurs Sophie Rihs , Adrien Gontier , Eric Pelt , David Fries , Marie-Pierre Turpault , Francois Chabaux
Publication : Chemical Geology
Date : 2016
Volume : 441
Pages : 106-123
Catégorie(s)
#FORET Breuil #INRAERésumé
Forest plantation is a widely used silvicultural practice throughout Europe most particularly to renew planted forest stands. The long term impact of forest plantations on soil fertility is a major concern for forest managers and policy makers, in particular in the context of global change because forests endure increased climatic and/or silvicultural and/or nutritional pressure. In the present study we investigated the tree species effects on soil solution chemistry and major elements fluxes, to better understand the impact of tree species on soil processes and fertility. The chemical composition of throughfall and soil solutions were compared between six 35-year-old monospecific stands (Norway spruce, Corsican pine, sessile oak, European beech, Douglas fir and Nordmann fir) and the reference plot (beech and oak coppice with standards) of the common garden experiment at the Breuil-Chenue Experimental site (Burgundy, France). Tree species had a strong effect on the chemistry of throughfall and soil solution, in particular on the relative contribution of nitrate, sulfate and dissolved organic carbon to the anionic charge. Mean concentrations of major elements varied widely between stands. Nitrate concentrations were highest for the Douglas fir and Corsican pine probably due to the tree species effect on nitrification processes. In both stands, the nitrate leaching causes large acidification with high drainage losses of magnesium, calcium and monomeric aluminum. For Norway spruce, sessile oak, European beech and reference plot, sulfate and dissolved organic carbon were the main anionic drivers for solution chemistry and nutrient fluxes. Soil acidification processes were less intense in these stands and aluminum was mainly transported in the soil profile by Al-cheluviation by dissolved organic compounds. The results of this study suggest that tree species strongly influence the chemistry of throughfall and soil solutions and may strongly influence on the short-term (35 years) soil pedogenic processes from weak acidification and crypto-podzolisation to strong soil acidification. (C) 2016 Elsevier B.V. All rights reserved.
Auteurs, date et publication :
Auteurs Arnaud Legout , van der Heijden Gregory , Jaffrain Jerome , Boudot Jean-Pierre , Ranger Jacques
Publication : Forest Ecology and Management
Date : 2016
Volume : 378
Pages : 244-258
Catégorie(s)
#FORET Breuil #INRAEAuteurs, date et publication :
Auteurs Amandine Laffite , Alessandro Florio , Kasaina Sitraka Andrianarisoa , Charline Creuze des Chatelliers , Brigitte Schloter‐Hai , Sidy M. Ndaw , Charlotte Periot , Michael Schloter , Bernd Zeller , Franck Poly , Xavier Le Roux
Publication : Environmental Microbiology
Date : 2025
Volume : 22
Issue : 3
Pages : 1141-1153
Catégorie(s)
#FORET Breuil #INRAERésumé
Forest soil fertility can be defined as a combination of physical, chemical and biological factors characterising the biomass production capacity of the soil. However, numerous ecological variables affect tree growth and the aim of the present study was to investigate the specific influence of soil chemical properties on tree productivity at 49 acidic forest sites. A standardized tree productivity index based on tree height expressed as dominant height of the studied stand divided by maximum tree height observed at the same age for the same species in the same climatic region was firstly computed at each site. This index is assumed to limit the influence of species, ages and climate. A soil database was also compiled with data on soil properties from 47 temperate (France) and two tropical (Congo, Brazil) sites. Data included seven tree species, varying in age from 1 to 175 years. Commonly used indicators such as C:N ratio, soil pH, as well as available and total pools of soil nutrients were compared to the standardized tree productivity index, to find the most reliable indicator(s). Nutrient pools at fixed mineral soil depths (down to 100 cm) were used, as well as (for 11 stands) the depth comprising 95% of fine roots. Our results show that none of the common soil chemical parameters tested in this paper could individually explain stand productivity. Combinations of different parameters were also tested using PCA and they could better explain the variability of the data set but without being able to separate the sites according to their standardized tree productivity index. Moreover, random Forests performed on our dataset were unable to properly predict the standardized tree productivity index. Our results reinforce the idea that the influence of the soil chemical fertility on stand productivity is complex and the soil chemical parameters alone (individually or combined) are poor predictors of tree productivity as assessed by the H0:Hmax index. In this paper we focused on static soil chemical indicator and more dynamic indictors, such as nutrient fluxes involved in the biogeochemical cycles, could better explain stand productivity. A companion paper (Legout et al., 2020) focuses on the connection between productivity and different components of the biogeochemical cycle, using data from 11 of the stands presented in this paper.
Auteurs, date et publication :
Auteurs Karna Hansson , Jean-Paul Laclau , Laurent Saint-André , Louis Mareschal , Gregory van der Heijden , Claude Nys , Manuel Nicolas , Jacques Ranger , Arnaud Legout
Publication : Forest Ecology and Management
Date : 2020
Volume : 461
Pages : 117843
Catégorie(s)
#ANR-Citation #FORET Breuil #INRAERésumé
Many forest ecosystems are developed on acidic and nutrient-poor soils and it is not yet clearly understood how forests sustain their growth with low nutrient resources. In forestry, the soil chemical fertility is commonly defined, following concepts inherited from agronomy, as the pool of plant-available nutrients in the soil at a given time compared to the nutritional requirement of the tree species. In this two-part study, Part 1 (Hansson et al., 2020) showed, through the compiled dataset of 49 forest ecosystems in France, Brazil and Republic of Congo, the limits of this definition of soil chemical fertility in forest ecosystem contexts. In this study (Part 2), we investigated the nutrient pools and fluxes between the different ecosystem compartments at 11 of the 49 sites in order to better characterize the role of the biogeochemical cycling of nutrients in the chemical fertility of forest ecosystems, and in particular the roles of the biological and geochemical components of biogeochemical cycling. The analysis of our dataset shows different types of biogeochemical functioning. When the geochemical component (inputs through mineral weathering and/or atmospheric inputs, capillary rise) is predominant, sufficient nutrients are provided to the plant-soil system to ensure tree nutrition and growth. Conversely, when the geochemical component of the cycle brings too few nutrients to the plant-soil system, the biological component (litterfall, plant internal cycling) becomes predominant in tree nutrition and growth. In the latter case, forest production may be high even when pools of nutrients in the soil reservoir are low because small but active nutrient fluxes may continuously replenish the soil reservoir or may directly ensure tree nutrition by bypassing the soil reservoir. This study highlights the necessity to include biogeochemical cycling and recycling fluxes in the definition and diagnosis methods of soil chemical fertility in forest ecosystems. We show that the chemical fertility is not only supported by the soil in forest ecosystem but by the sum of all the ecosystem’s compartments and fluxes between these pools.
Auteurs, date et publication :
Auteurs Arnaud Legout , Karna Hansson , Gregory van der Heijden , Jean-Paul Laclau , Louis Mareschal , Claude Nys , Manuel Nicolas , Laurent Saint-André , Jacques Ranger
Publication : Forest Ecology and Management
Date : 2020
Volume : 461
Pages : 117844
Catégorie(s)
#ANR-Citation #FORET Breuil #INRAERésumé
Background: Intensive silvicultural practices and the planting of monospecific forests of coniferous, that are more productive compared to hardwoods may threaten over the mid to long-term the sustainability of soil chemical fertility of forest ecosystems, and are a major concern for forest managers and policy.
Methods: We investigated the tree species effect (Quercus sessiliflora Smith, Fagus sylvatica L., Picea abies Karst., Pseudotsuga menziesii Mirb. Franco., Abies nordmanniana Spach. and Pinus nigra Arn. ssp. laricio Poiret var. corsicana) on the change over time of soil chemical properties and nutrient pool sizes in the mineral and organic layers of the soil during the 45 years after the plantation of the Breuil-Chenue common garden experiment (Burgundy, France). The organic and mineral soil layers down to 70-cm depth were sampled in the different monospecific plots in 1974, 2001 and 2019.
Results: Exchangeable Ca and Mg pools and soil pH increased on average over time in the 0–70 cm soil profile in most stands. However, in the topsoil layers (0–15 cm), the decrease of pH, the increase of exchangeable acidity over time under the coniferous stands and the decrease of exchangeable K pools in most stands highlighted that soil acidification is still on-going at Breuil-Chenue site but the intensity of this process depends on the tree species. Indeed, three groups of species could be distinguished: i) Nordmann fir (Abies nordmanniana Spach.)/Norway spruce (Picea abies Karst.) where acidolysis and chelation occurred, resulting in the most pronounced pH decrease in the topsoil, ii) Douglas fir (Pseudotsuga menziesii Mirb. Franco.)/Laricio pine (Pinus nigra Arn. ssp. laricio Poiret var. corsicana) where acidification caused by elevated nitrification rates is probably currently compensated by larger weathering and/or atmospheric depositions fluxes, and iii) oak (Quercus sessiliflora Smith)/beech (Fagus sylvatica L.) where soil acidification was less intense. Counterintuitively, soil acidification at Breuil-Chenue site resulted in an increase in soil CEC which limited the loss of nutrient cations. This change in soil CEC was most likely explained by the precipitation/dissolution dynamics of aluminium (Al) (hydr)oxides in the interfoliar space of phyllosilicates and/or the increase in soil carbon (C) content in the topsoil layers.
Conclusion: After 45 years, tree species continue to exert influence on the chemical fertility of the soil and the pedogenetic processes which in turn may impact forest ecosystem functions and services.
Auteurs, date et publication :
Auteurs Margaux Clesse , Arnaud Legout , Jacques Ranger , Bernd Zeller , Gregory van der Heijden
Publication : Forest Ecosystems
Date : 2025
Volume : 9
Pages : 100043
Catégorie(s)
#ANR-Citation #FORET Breuil #INRAERésumé
Purpose Douglas-fir occupies a growing role in the European timber industries but its effects on soils and the environment are still not well understood. We monitored the biogeochemical cycle of major elements in 11 representative mature stands throughout France over the 2013 to 2020 period to better understand repercussions on soil processes.
Auteurs, date et publication :
Auteurs Alexia Paul , Arnaud Legout , Bernd Zeller , Gregory van der Heijden , Pascal Bonnaud , Arnaud Reichard , Gilles Nourrisson , Jacques Ranger
Publication : Plant and Soil
Date : 2025
Volume : 479
Issue : 1-2
Pages : 207-231
Catégorie(s)
#ANR-Citation #FORET Breuil #INRAERésumé
In rural areas, nitrate concentrations in surface waters most often originate from the leaching of excess N fer tilizer in agricultural lands, whereas forested catchments often have good water quality. However, Douglas-fir plantations may induce nitrogen cycle unbalances which may lead to an excess of nitrate production in the soil. We hypothesize that the excess of production of nitrate in the soil and nitrate leaching to streamwater is greater in catchments planted with Douglas fir. We used paired catchments in both France and Luxembourg with different land covers (Douglas-fir, Spruce, Deciduous, Grassland and clearcut) which were monitored over a 3–5 year period in order to assess the effect of Douglas-fir plantations on the chemical composition of surface water. Nitrate concentration in the soil and groundwater were also monitored. The results show that nitrate concen trations in streams draining Douglas-fir catchments were two to ten times higher than in streams draining other land covers, but were similar to the clearcut catchment. Nitrate concentrations under Douglas-fir in groundwater (up to 50 mg L− 1) and in the soil were also higher than under all other land covers. Soil nitrate concentration was related to stream nitrate concentration. This suggests that soil processes, through excessive nitrate production under Douglas-fir, are driving the nitrate concentration in the stream water and our hypothesis of a transfer of a fairly large proportion of this excessive production from the soil to the stream is supported. This study also shows that nitrate concentrations in surface and ground waters in rural areas could also originate from Douglas fir forested catchments. The impact of Douglas-fir is nevertheless reduced downstream through a dilution effect: mixing tree species at the catchment scale could thus be a solution to mitigate the effect of Douglas-fir on nitrate concentration in surface waters.
Auteurs, date et publication :
Auteurs Alexia Paul , Christophe Hissler , Alessandro Florio , Serge Didier , Benoit Pollier , Gregory Van Der Heijden , Etienne Dambrine , Jacques Ranger , Bernd Zeller , Arnaud Legout
Publication : Environmental Pollution
Date : 2025
Volume : 336
Pages : 122477
Catégorie(s)
#ANR-Citation #FORET Breuil #INRAE #M-POETERésumé
In European forests, most tree species form symbioses with ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi. The EM fungi are classified into different morphological types based on the development and structure of their extraradical mycelium. These structures could be root extensions that help trees to acquire nutrients. However, the relationship between these morphological traits and functions involved in soil nutrient foraging is still under debate.
Auteurs, date et publication :
Auteurs Khalfallah F. , Bon L. , El Mazlouzi M. , Bakker M.R. , Fanin N. , Bellanger R. , Bernier F. , De Schrijver A. , Ducatillon C. , Fotelli M.N. , Gateble G. , Gundale M.J. , Larsson M. , Legout A. , Mason W.L. , Nordin A. , Smolander A. , Spyroglou G. , Vanguelova E.I. , Verheyen K.
Publication : Mycorrhiza
Date : 2025
Volume : 34
Issue : 3
Pages : 203-216