Résumé
The sustainability of forest ecosystems may be at stake especially in forests on base-poor soils due to reduced nutrient deposition and intensified silvicultural practices. Understanding nutrient availability and cycling is therefore essential to manage forest soil fertility. This study aims to assess in a beech plot Mg and Ca vertical transfer in soil and root uptake using an isotopic tracing experiment. A simulated rainfall containing a small amount (960 g Mg.ha(-1); 530 g Ca.ha(-1)) of highly enriched Mg-26 and Ca-44 was sprayed on the forest floor of a 35-yr-old beech plot. The isotopic composition of fine roots and of the soil exchangeable Mg and Ca pool was monitored during 1 year. A pool and flux model (IsoMod) was developed to predict the labeling of the soil and vertical transfer of tracers. Tracers (Ca-44 and Mg-26) were immediately retained in the thin litter layer. During the following year, Mg and to a lesser extent Ca were progressively released. After 1 year, the exchangeable Mg and Ca pools of the upper mineral layer (0-5 cm) were strongly labeled (similar to 660 aEuro degrees, representing similar to 55 % of the tracer input and similar to 370 aEuro degrees, similar to 41 % of the tracer input respectively). A significant proportion (similar to 8 % Mg-26, similar to 2 % Ca-44) of tracer was leached through the soil, below 10 cm. This amount was much larger than what was predicted using a simple mixing model. The Ca and Mg isotopic composition of fine roots at all depths was close or lower than that of exchangeable Ca and Mg respectively. An in situ ecosystem-scale Mg-26 and Ca-44 isotopic tracing experiment was successfully carried out. Tracers were at first strongly retained in the litter layer, then progressively transferred to soil horizons below. Nutrient cycling of Mg and Ca were proven to be very different. Mg had a higher mobility in the soil than Ca, and nutrient uptake sources were proven to be different.
Auteurs, date et publication :
Auteurs Gregory van der Heijden , Arnaud Legout , Andrew J. Midwood , Carol-Ann Craig , Benoit Pollier , Jacques Ranger , Etienne Dambrine
Publication : Plant and Soil
Date : 2013
Volume : 369
Issue : 1-2
Pages : 33-45
Catégorie(s)
#FORET Breuil #INRAERésumé
Many forest stands grow on acid and nutrient poor soils. To better understand how they cope with very low mineral resources, we investigated (1) Mg and Ca uptake in relation to depth, and (2) the allocation of these elements from the roots to the canopy, using a multi-isotopic (Mg-26, Ca-44) tracing experiment in a beech stand on a very poor soil. The distribution of the tracers in the soil was taken from van der Heijden et al. (Plant Soil 369:33-45, 2013a, Geoderma 195-196:12-22, 2013b, For Ecol Manag 293:65-78, 2013c). A model simulating Mg, Ca, Mg-26 and Ca-44 uptake was developed and applied to estimate the vertical distribution of Mg and Ca uptake in the soil profile. The vertical distribution of tracers in aboveground biomass was measured from four felled trees 2 years after the application of the tracers. The modeled distribution of root uptake in relation to depth shows differences between Mg and Ca: the main source of Mg uptake is the litter layer (circa. 43 % of total uptake) and the top mineral soil (0-5 cm) for Ca (circa. 42 %). The deeper soil layers (15-60 cm) also contribute to uptake. The study does not show clear evidence that uptake occurs in the very deep soil layers (> 70 cm). The distribution of tracers in the aboveground biomass shows a vertical gradient from the stump to the canopy with no or very small amounts of tracers being observed in the foliage during the 2 years after the application of tracers. This suggests that Mg and Ca transport from roots to leaves along the xylem sap flow is quite slow. As Ca and Mg supply to the trees from deep soil horizons is not evidenced, and tracer transport from roots to the leaves is slow, we suggest that the tree internal pool of Ca and Mg may be more active than previously thought. This pool may act as a buffer when nutrient availability is in shortage.
Auteurs, date et publication :
Auteurs Gregory van der Heijden , Etienne Dambrine , Benoit Pollier , Bernhard Zeller , Jacques Ranger , Arnaud Legout
Publication : Biogeochemistry
Date : 2015
Volume : 122
Issue : 2-3
Pages : 375-393
Catégorie(s)
#FORET Breuil #INRAERésumé
Many forest soils are acidic and have very low plant-available pools of magnesium. Past and present sylvicultural, nutritional and/or climatic pressures endured by forest ecosystems can result in net losses of nutrients and ecosystem function losses. Liming with a carbonate product is an alternative to counteract these degradations but the effects of liming on the biogeochemical cycling of nutrients over time and the dynamics of Mg released from liming products are still unclear. We studied the Mg isotopes composition in four paired-treatment experimental beech forest ecosystems in northern France. At the sites where dolomitic lime was applied, the variation in exchangeable and foliar δ26Mg demonstrated the direct contribution of dolomite-derived Mg to the replenishment of topsoil exchangeable pools and to tree nutrition improvement: dolomite-derived Mg was incorporated into the biological cycling which allows its retention on the mid to long term in the soil–plant system. At the sites limed with calcium carbonate, the changes in exchangeable and foliar Mg contents and δ26Mg observed on the long term suggest that the applied product contained a small amount of Mg and/or that Mg cycling changed after liming, to cope in particular with the low Mg availability. Lastly, our results highlight the high δ26Mg of the organic layer (humus): fractionation processes occurring within this layer (mineralization/ageing of organic matter, preferential retention of 26 Mg) could explain these singular signatures that could greatly influence the topsoil Mg exchangeable pools.
Auteurs, date et publication :
Auteurs Mélanie Court , Gregory Van Der Heijden , Pascale Louvat , Emile Bolou-Bi , Guillaume Caro , Julien Bouchez , Benoit Pollier , Serge Didier , Claude Nys , Laurent Saint-André , Arnaud Legout
Publication : Biogeochemistry
Date : 2021
Volume : 153
Issue : 2
Pages : 115-134
Catégorie(s)
#FORET Breuil #INRAERésumé
In many forest ecosystems, plant-available pools of Mg, Ca, and K are assumed to be stored in the soil as exchangeable cations adsorbed on the cation exchange complex (exchangeable pools). However, between soil minerals and exchangeable cations exists a gradient of Mg, Ca, and K storage forms that have not been fully characterized and may play an important role in plant nutrition and biogeochemical cycles. We hypothesize that sources of Mg, Ca, and K in the soil other than the conventionally measured exchangeable pools are plant-available on very short time scales (<1 day). In the present study, we developed and applied an isotopic dilution technique using the stable isotopes (26)mg, Ca-44, and K-41 to trace and quantify the pools of Mg, Ca, and K (isotopically exchangeable pools) in the soil of a hardwood forest that contribute directly to equilibrium processes between the soil water and the soil. We characterize the equilibrium between the soil and soil solution using both a batch approach and a flow-through approach in order (i) to develop and determine the best routine method to measure the isotopically exchangeable pools and (ii) to further the characterization of the forms of storage of Mg, Ca, and K in the isotopically exchangeable pools. We first show that the flow-through reactor approach (equilibrium in unsaturated soil columns) is the most adequate to measure the isotopically exchangeable pools with the fewest equilibrium disturbances. We then show that isotopically exchangeable pools of Mg, Ca, and K are greater than traditionally measured exchangeable pools. The isotopically exchangeable pools of Mg, Ca, and K are mainly composed of traditionally measured exchangeable pools (88.8-98.5% for Mg, 74.7-97.7% for Ca, and 68.7-77.1% for K) but are also composed of pools extracted with the Tamm reagent (oxalic acid, pH 3) and nitric acid (1 mol.L-1): 1.5-11.2% for Mg, 2.3-25.3% for Ca, and 22.9-31.3% for K. Storage forms of Mg, Ca, and K in the isotopically exchangeable pool could include chelation with soil organic matter, retention on soil aluminum and iron oxides and hydroxides through phosphate and/or organic acid bridges and site-specific adsorption. The isotopic dilution method is a relevant tool to quantify the plant-available pools of Mg, Ca, and K on short time scales (source and sink pools) and is a very promising approach to characterize and quantify the processes responsible for the depletion and/or replenishment of these pools over longer time scales.
Auteurs, date et publication :
Auteurs Gregory van der Heijden , Jeremie Bel , Carol-Ann Craig , Andrew J. Midwood , Louis Mareschal , Jacques Ranger , Etienne Dambrine , Arnaud Legout
Publication : Acs Earth and Space Chemistry
Date : 2018
Volume : 2
Issue : 4
Pages : 292-313
Catégorie(s)
#FORET Breuil #INRAERésumé
Liming is a known forest management procedure used to amend nutrient-poor soils such as soils of acidic forests to rectify cation deficiencies and to restore soil pH. However, although this procedure is well known for its beneficial effect on the forest trees, its relative impact on the functional and taxonomic diversity of the soil bacterial communities has been poorly investigated. In this study, we characterized the ability of the soil bacteria to weather soil minerals and to hydrolyze chitin. A collection of 80 bacterial strains was isolated from the Scleroderma citrinum ectomycorrhizosphere and the adjacent bulk soil in two stands of mature beeches (Fagus sylvatica) developed on very acidic soil and presenting two levels of calcium (Ca) availability: a control plot as well as a plot amended with Ca in 1973. All the bacterial isolates were identified by partial 16S rRNA gene sequence analysis as members of the genera Burkholderia, Bacillus, Dyella, Kitasatospora, Micrococcus, Paenibacillus, Pseudomonas, and Rhodanobacter. Using a microplate assay for quantifying the production of protons and the quantity of iron released from biotite, we demonstrated that the bacterial strains from the amended plot harbored a significant higher mineral weathering potential that the ones isolated from the control plot. Notably, the weathering efficacy of the ectomycorrhizosphere bacterial isolates was significantly greater than that of the bulk soil isolates in the control treatment but not in the amended plot. These data reveal that forest management, here mineral amendment, can strongly affect the structure of bacterial communities even over the long term. (C) 2011 Elsevier Ltd. All rights reserved.
Auteurs, date et publication :
Auteurs S. Uroz , M. -P. Turpault , L. Van Scholl , B. Palin , P. Frey-Klett
Publication : Soil Biology and Biochemistry
Date : 2011
Volume : 43
Issue : 11
Pages : 2275-2282
Catégorie(s)
#FORET Breuil #INRAERésumé
Most forest ecosystems grow on acid and nutrient poor soils. In many cases, a slow degradation of forest soil chemical fertility due to increasing external pressures (decreasing atmospheric inputs, intensification of biomass harvesting and silvicultural practices) has been observed and is a growing concern in the international forest community. When the pressure endured by low fertility forest ecosystems is too intense, nutrient losses and ecosystem function losses may occur, forest decline being the ultimate stage of this process. In such cases, forest liming with a carbonate product is a solution to restore soil fertility and reduce soil acidity, globally improve the ecosystem functioning and compensate for nutrient losses caused by biomass harvest and exportation. However, the effects of liming on ecosystem processes and the biogeochemical cycling of nutrients in forest ecosystems are still unclear. We studied the dynamics of magnesium and calcium originating from the dissolution of liming products in the different compartments (organic and mineral soil layers and, aboveground biomass) of five long-term (20 to 40 years) monitoring beech (Fagus sylvatica L.) plots located in Northern France from ecosystem magnesium and calcium budgets. Compared to the control plots, soil exchangeable pools of Mg and Ca in the 0-15 cm mineral soil layer increased during the first decade after liming but these differences rapidly decreased after 20-30 years. The effect of liming on foliar concentrations and tree growth was still observed after 40 years, most probably because the biological cycling of these elements was more dynamic in the limed plots. Liming increased the decomposition rate of the soil organic layer but the pools of Mg and Ca in this layer remained relatively stable over time, probably because Mg and Ca concentrations in foliage and litterfall increased after the liming. Liming effects varied between sites depending on the liming product and amount, and the initial chemical fertility level of the soil. Although liming operations may help improve forest soil fertility, they may also generate nutrient deficiencies and/or imbalances for nutrients that are poorly available in the soil. The planning of liming operations therefore necessitates a thorough soil chemical fertility diagnosis.
Auteurs, date et publication :
Auteurs Melanie Court , Gregory van der Heijden , Serge Didier , Claude Nys , Claudine Richter , Noemie Pousse , Laurent Saint-Andre , Arnaud Legout
Publication : Forest Ecology and Management
Date : 2018
Volume : 409
Pages : 872-889
Catégorie(s)
#FORET Breuil #INRAERésumé
The fate of leaf lipids upon early diagenesis was monitored in a two year litterbag experiment in a soil and at the water-sediment interface of an adjacent pond. The biomarker content of degrading leaves exhibited substantial variability among litterbags, even for a given time step within a given environmental condition, likely reflecting natural microenvironmental variability. Due to this variability and the oxic conditions in the pond, no substantial difference between the soil and the pond could be evidenced in the biomarker degradation pattern. An occasional increase in the abundance of several biomarkers (beta-sitosterol, oleanolic acid, C-16 phytyl ester, C-27 n-alkane) was also noted during the experiment, which was attributed to release of bound compounds and/or an external contribution. Nevertheless, absolute quantification showed that the concentration of all lipid constituents was reduced, but they exhibited different decay profiles: (i) rapid extensive degradation (phytyl ester), (ii) exponential-like decrease (fatty lipids) and (iii) variable degradation profile (polycyclic triterpenoids). However, all the main constituents initially present in the senescent leaves were still detected after two years of degradation in both environments. Fatty lipids abundances generally decreased to < 10% of the initial content but the main distribution features (carbon number maximum and predominance) remained unchanged. The results thus tend to validate their use as proxy for source and environment in ancient organic matter. They also suggest that, on a mid-term basis, a plant biomarker signature is not substantially affected by differential degradation in soil and at the water-sediment interface, at least for a qualitative approach. (C) 2016 Elsevier Ltd. All rights reserved.
Auteurs, date et publication :
Auteurs Thanh Thuy Nguyen Tu , Celine Egasse , Christelle Anquetil , Florent Zanetti , Bernd Zeller , Sylvain Huon , Sylvie Derenne
Publication : Organic Geochemistry
Date : 2017
Volume : 104
Pages : 35-41
Catégorie(s)
#FORET Breuil #INRAERésumé
The crystal structures as well as the amount of hydroxy-interlayered clay minerals resulting from the Al-hydroxylation process in temperate acidic soil developed in a forest were studied by modeling experimental X-ray diffraction (XRD) patterns. The <2 mu m clay fraction of this soil was separated into four sub-fractions of different particle sizes (<0.05, 0.05-0.1, 0.1-0.2, and 0.2-2 mu m), and XRD patterns were obtained after different treatments of the samples (i.e., calcium saturation and air-drying, ethylene-glycol solvation, or potassium saturation and heating at 110 degrees C). The qualitative analysis of the experimental XRD patterns revealed the presence of hydroxy-interlayered-smectite (HIS) and hydroxy-interlayered-vermiculite (HIV) phases commonly considered in the description of clay mineralogy in acidic soil environments. Quantitative information derived from the fitting procedure for the different sub-fractions allowed for the determination of the complex mineralogy of the <2 mu m clay fraction through the identification and quantification of ten clay phases. The results revealed that the HIS and HIV clay phases considered so far in the literature actually consist of three-component randomly interstratifled mixed-layer minerals (MLMs) with contrasting relative proportions of smectite, hydroxy-interlayers (HI) and illite layers. Moreover, the quantitative results derived from this study showed that these two MLMs account for less than 50% of the total HI layer abundance. In that regard, most HI layers are present in illite-rich MLMs with poorly resolved XRD reflections, The contrasting behaviors of smectite and HI layers in the coarsest 0.2-2 mu m sub-fraction compared to those in the finer sub-fraction indicated the possible increase of the layer charge of the expandable layers in the coarsest sub-fraction. Finally, it was shown that the detailed structural analysis derived from the methodology used in the present study is conducive for estimating the degree of expandable layer transformation in natural soil samples while reconciling the specific behaviors of expandable and HI layers from natural soil with those described by laboratory experiments performed on monomineralic samples. (C) 2014 Elsevier B.V. All rights reserved.
Auteurs, date et publication :
Auteurs Jean-Christophe Viennet , Fabien Hubert , Eric Ferrage , Emmanuel Tertre , Arnaud Legout , Marie-Pierre Turpault
Publication : Geoderma
Date : 2015
Volume : 241
Pages : 75-86
Catégorie(s)
#FORET Breuil #INRAERésumé
Storage of selenium and iodine can greatly vary between forest ecosystems, but the influence of tree species on partitioning and recycling of those elements remains elusive. In this study, contents of Se and I were measured in tree compartments, litterfall, humus, and soil horizons in monospecific stands of Douglas fir, pine, spruce, beech, and oak under identical climatic and edaphic conditions. The cycle of each element was characterized in terms of stocks and fluxes. Lowest concentrations were in wood (Se: 8–13 μg kg−1; I: <16.5 μg kg−1). Senescing organs had higher Se and I content, than the living parts of trees due to direct exposure to atmospheric deposition, with some variation between coniferous and deciduous trees. For all stands, low amounts of Se and I were involved in biological cycle as reflected by low root uptake. In humus, the enrichment of elements greatly increased with the stage of organic matter (OM) degradation with average factors of 10 and 20 for Se and I. OM degradation and element persistence in humus was influenced by tree species. Deciduous trees, with low biomass, and fast degradation of OM stored less Se and I in humus compared to fir and spruce with high humus biomass. Interestingly, tree species did not affect soil reserves of Se and I. Concentration ranges were 331–690 μg Se kg−1 and 4.3–14.5 mg I kg−1. However, the divergent vertical profiles of the elements in the soil column indicated greater mobility of I. Selenium concentrations regularly decreased with depth in correlation with OM and Fe oxides content. For iodine, the maximum iodine concentration at a soil depth of 15 to 35 cm was caused by a parallel precipitation/sorption behavior of aluminium and organic iodine dissolved in the topsoil.
Auteurs, date et publication :
Auteurs Paulina Pisarek , Maïté Bueno , Yves Thiry , Arnaud Legout , Hervé Gallard , Isabelle Le Hécho
Publication : Science of The Total Environment
Date : 2025
Volume : 809
Pages : 151174
Catégorie(s)
#FORET Breuil #INRAERésumé
Background Among forest management practices, forest tree species substitution influences biogeochemical cycles and soil interactions rapidly (decades) and significantly. Methods We studied the impact of tree species on forest floor properties in 27-year-old monospecific stands of oak, beech, spruce and Douglas-fir, grown in common garden. Results In spite of similar litterfall C-inputs (1.3-1.8 Mg ha(-1) yr(-1)), C-stocks strongly differed between coniferous (16-21 Mg ha(-1)) and broadleaved (7-9 Mg ha(-1)) forest floors. The large C-mineralization under oak (196 C-mu g C-total-g(-1) d(-1)) relatively to other stands (125-147 C-mu g C-total-g(-1) d(-1)) and the large dissolved organic carbon release under broadleaved forest floors may explain this difference. Spruce forest floor exhibited the lowest net nitrification and the largest contribution of organic anions to the anionic charge of aqueous leachate (62.5 % +/- 1.7). Conversely, Douglas-fir forest floor exhibited the largest relative nitrification and the largest contribution of nitrate to the anionic charge (70.8 % +/- 0.7). Conclusion We conclude that tree species induce a specific signature in term of proton donors at the forest floor level (organic vs nitric acid), which involves potential impacts on pedogenetic processes in the mineral horizon beneath.
Auteurs, date et publication :
Auteurs Florence Trum , Hugues Titeux , Jacques Ranger , Bruno Delvaux
Publication : Annals of Forest Science
Date : 2011
Volume : 68
Issue : 4
Pages : 837-847