-
[hal-02629130] Identifying the tree species compositions that maximize ecosystem functioning in European forests
1. Forest ecosystem functioning generally benefits from higher tree species richness, but variation within richness levels is typically large. This is mostly due to the contrasting performances of communities with different compositions. Evidencebased understanding of composition effects on forest productivity, as well as on multiple other functions will enable forest managers to focus on the selection of species that maximize functioning, rather than on diversity per se. 2. We used a dataset of 30 ecosystem functions measured in stands with different species richness and composition in six European forest types. First, we quantified whether the compositions that maximize annual above-ground wood production (productivity) generally also fulfil the multiple other ecosystem functions (multifunctionality). Then, we quantified the species identity effects and strength of interspecific interactions to identify the “best” and “worst” species composition for multifunctionality. Finally, we evaluated the real-world frequency of occurrence of best and worst mixtures, using harmonized data from multiple national forest inventories. 3. The most productive tree species combinations also tended to express relatively high multifunctionality, although we found a relatively wide range of compositions with high- or low-average multifunctionality for the same level of productivity. Monocultures were distributed among the highest as well as the lowest performing compositions. The variation in functioning between compositions was generally driven by differences in the performance of the component species and, to a lesser extent, by particular interspecific interactions. Finally, we found that the most frequent species compositions in inventory data were monospecific stands and that the most common compositions showed below-average multifunctionality and productivity. 4. Synthesis and applications. Species identity and composition effects are essential to the development of high-performing production systems, for instance in forestry and agriculture. They therefore deserve great attention in the analysis and design of functional biodiversity studies if the aim is to inform ecosystem management. A management focus on tree productivity does not necessarily trade-off against other ecosystem functions; high productivity and multifunctionality can be combined with an informed selection of tree species and species combinations.
ano.nymous@ccsd.cnrs.fr.invalid (Lander Baeten) 29 Dec 2024
https://hal.inrae.fr/hal-02629130v1
-
[hal-02356964] Alpha diversity of vascular plants in European forests
Aim. The former continental‐scale studies modelled coarse‐grained plant species‐richness patterns (gamma diversity). Here we aim to refine this information for European forests by (a) modelling the number of vascular plant species that co‐occur in local communities (alpha diversity) within spatial units of 400 m2; and (b) assessing the factors likely determining the observed spatial patterns in alpha diversity. Location. Europe roughly within 12°W–30°E and 35–60°N. Taxon. Vascular plants. Methods. The numbers of co‐occurring vascular plant species were counted in 73,134 georeferenced vegetation plots. Each plot was classified by an expert system into deciduous broadleaf, coniferous or sclerophyllous forest. Random Forest models were used to map and explain spatial patterns in alpha diversity for each forest type separately using 19 environmental, land‐use and historical variables. Results. Our models explained from 51.0% to 70.9% of the variation in forest alpha diversity. The modelled alpha‐diversity pattern was dominated by a marked gradient from species‐poor north‐western to species‐rich south‐eastern Europe. The most prominent richness hotspots were identified in the Calcareous Alps and adjacent north‐western Dinarides, the Carpathian foothills in Romania and the Western Carpathians in Slovakia. Energy‐related factors, bedrock types and terrain ruggedness were identified as the main variables underlying the observed richness patterns. Alpha diversity increases especially with temperature seasonality in deciduous broadleaf forests, on limestone bedrock in coniferous forests and in areas with low annual actual evapotranspiration in sclerophyllous forests. Main conclusions. We provide the first predictive maps and analyses of environmental factors driving the alpha diversity of vascular plants across European forests. Such information is important for the general understanding of European biodiversity. This study also demonstrates a high potential of vegetation‐plot databases as sources for robust estimation of the number of vascular plant species that co‐occur at fine spatial grains across large areas.
ano.nymous@ccsd.cnrs.fr.invalid (Martin Večeřa) 18 Nov 2019
https://hal.science/hal-02356964v1
-
[hal-02147493] Climatic controls of decomposition drive the global biogeography of forest-tree symbioses
The identity of the dominant root-associated microbial symbionts in a forest determines the ability of trees to access limiting nutrients from atmospheric or soil pools sequester carbon and withstand the effects of climate change. Characterizing the global distribution of these symbioses and identifying the factors that control this distribution are thus integral to understanding the present and future functioning of forest ecosystems. Here we generate a spatially explicit global map of the symbiotic status of forests, using a database of over 1.1 million forest inventory plots that collectively contain over 28,000 tree species. Our analyses indicate that climate variables—in particular, climatically controlled variation in the rate of decomposition—are the primary drivers of the global distribution of major symbioses. We estimate that ectomycorrhizal trees, which represent only 2% of all plant species7, constitute approximately 60% of tree stems on Earth. Ectomycorrhizal symbiosis dominates forests in which seasonally cold and dry climates inhibit decomposition, and is the predominant form of symbiosis at high latitudes and elevation. By contrast, arbuscular mycorrhizal trees dominate in aseasonal, warm tropical forests, and occur with ectomycorrhizal trees in temperate biomes in which seasonally warm-and-wet climates enhance decomposition. Continental transitions between forests dominated by ectomycorrhizal or arbuscular mycorrhizal trees occur relatively abruptly along climate-driven decomposition gradients; these transitions are probably caused by positive feedback effects between plants and microorganisms. Symbiotic nitrogen fixers—which are insensitive to climatic controls on decomposition (compared with mycorrhizal fungi)—are most abundant in arid biomes with alkaline soils and high maximum temperatures. The climatically driven global symbiosis gradient that we document provides a spatially explicit quantitative understanding of microbial symbioses at the global scale, and demonstrates the critical role of microbial mutualisms in shaping the distribution of plant species.
ano.nymous@ccsd.cnrs.fr.invalid (B. Steidinger) 04 Dec 2024
https://hal.science/hal-02147493v1
-
[hal-02903210] Habitats forestiers et forêts habitées
Les 26 et 27 mars 2019 se tenait, au sein du Domaine national de Chambord, un colloque international regroupant une centaine de participants originaires d’une dizaine de pays. Cet évènement scientifique venait conclure le projet de recherche interdisciplinaire COSTAUD « Contribution des ongulés sauvages au fonctionnement de l’écosystème et aux services rendus à Chambord », financé par la Région Centre-Val de Loire au titre de son Appel à Projets de Recherche d’Intérêt Régional (édition 2015). Intitulé Habitats forestiers et forêts habitées, il visait à questionner les interactions existant en forêt et ses habitats associés entre la faune et les usages, modes de gestion et pratiques sociales, en se structurant autour de quatre thèmes. Le thème 1 du colloque s’est intéressé aux facteurs environnementaux et humains à l’origine des populations animales actuelles Dans le thème 2, il s’agissait d’interroger l’influence de la faune, en l’occurrence des grands herbivores, sur le fonctionnement des écosystèmes. Le thème 3 a abordé les conséquences des modes de gestion des habitats forestiers, afin d’en identifier les impacts sur la faune, notamment sur sa distribution spatiale. Enfin le thème 4 s’est intéressé à la manière dont la faune pouvait être valorisée par la société, c’est-à-dire aux usages et pratiques sociales associés à la faune sauvage et aux milieux forestiers.
ano.nymous@ccsd.cnrs.fr.invalid (Christophe Baltzinger) 24 Nov 2021
https://hal.inrae.fr/hal-02903210v1
-
[hal-02181076] Air temperature optima of vegetation productivity across global biomes.
The global distribution of the optimum air temperature for ecosystem-level gross primary productivity ([Formula: see text]) is poorly understood, despite its importance for ecosystem carbon uptake under future warming. We provide empirical evidence for the existence of such an optimum, using measurements of in situ eddy covariance and satellite-derived proxies, and report its global distribution. [Formula: see text] is consistently lower than the physiological optimum temperature of leaf-level photosynthetic capacity, which typically exceeds 30 °C. The global average [Formula: see text] is estimated to be 23 ± 6 °C, with warmer regions having higher [Formula: see text] values than colder regions. In tropical forests in particular, [Formula: see text] is close to growing-season air temperature and is projected to fall below it under all scenarios of future climate, suggesting a limited safe operating space for these ecosystems under future warming.
ano.nymous@ccsd.cnrs.fr.invalid (Mengtian Huang) 02 Oct 2025
https://hal.science/hal-02181076v1
-
[hal-03547659] Habitats forestiers et forêts habitées : actes du colloque
Le colloque intitulé « Habitats forestiers et forêts habitées » venait conclure le projet de recherche interdisciplinaire COSTAUD « Contribution des ongulés sauvages au fonctionnement de l’écosystème et aux services rendus à Chambord », financé par la Région Centre-Val de Loire au titre de son Appel à Projets de Recherche d’Intérêt Régional (édition 2015). Lors de ce colloque, la forêt, part de notre imaginaire et de nos paysages, est ainsi apparue comme un lieu de rencontre entre l’homme et la faune sauvage, un espace d’interactions multiples, comme le montrent les présentations orales filmées et désormais en ligne. Certaines contributions ont donné lieu à des articles regroupés dans ce numéro thématique de la Revue forestière française. Ils questionnent l’empreinte passée de nos activités, les déterminants actuels et leurs enjeux, ainsi que les perspectives d’évolution des forêts et des habitats qui les composent. Pluridisciplinaires, les approches mises en œuvre abordent l’écologie de la faune sauvage et des forêts, et tiennent compte de leurs représentations sociales et de la fréquentation touristique associée à ces patrimoines naturel et culturel. Elles associent sciences humaines et sociales, sciences de la vie et sciences de l’environnement.
ano.nymous@ccsd.cnrs.fr.invalid (Christophe Baltzinger) 28 Jan 2022
https://hal.inrae.fr/hal-03547659v1
-
[hal-02411666] The commonness of rarity: Global and future distribution of rarity across land plants
A key feature of life’s diversity is that some species are common but many more are rare. Nonetheless, at global scales, we do not know what fraction of biodiversity consists of rare species. Here, we present the largest compilation of global plant diversity to quantify the fraction of Earth’s plant biodiversity that are rare. A large fraction, ~36.5% of Earth’s ~435,000 plant species, are exceedingly rare. Sampling biases and prominent models, such as neutral theory and the k-niche model, cannot account for the observed prevalence of rarity. Our results indicate that (i) climatically more stable regions have harbored rare species and hence a large fraction of Earth’s plant species via reduced extinction risk but that (ii) climate change and human land use are now disproportionately impacting rare species. Estimates of global species abundance distributions have important implications for risk assessments and conservation planning in this era of rapid global change.
ano.nymous@ccsd.cnrs.fr.invalid (Brian Enquist) 31 May 2021
https://hal.science/hal-02411666v1
-
[hal-02789758] The dominant environmental driver of leaf water stable isotope enrichment differs for 2H compared to 18O
Several important isotopic biomarkers derive at least part of their signal from leaf water stable isotope composition (e.g., leaf wax δ2H, cellulose δ2H and δ18O, lignin δ18O). In order to interpret these isotopic proxies, it is therefore helpful to know which environmental variable most strongly controls leaf water stable isotope enrichment. We collated observations of the stable isotope compositions of leaf water, xylem water, and atmospheric vapour, along with air temperature and relative humidity, to test whether the dominant driver of leaf water 2H enrichment could differ from that for 18O enrichment. Our dataset comprises 620 observations from 39 sites with broad geographical coverage. We limited our analysis to daytime observations, when the photosynthetic processes that incorporate the leaf water isotopic signal into organic material take place. The Craig-Gordon equation was generally a good predictor for daytime leaf water stable isotope composition for both δ2H (R2=0.93, p<0.001) and δ18O (R2=0.70, p<0.001). Solving the Craig-Gordon equation requires knowledge of relative humidity, air temperature, and the stable isotope compositions of xylem water and atmospheric vapour. However, it is not possible to invert the Craig-Gordon equation to solve for one of these parameters unless the others are known. Here we show that the two isotopic signals of 2H and 18O are predominantly driven by different environmental variables: leaf water δ2H correlated most strongly with the δ2H of atmospheric vapour (R2=0.79, p<0.001), whereas leaf water δ18O correlated most strongly with air relative humidity (R2=0.45, p<0.001). We conclude that these two isotopic measures are not simply mirror images in the environmental information that they carry. This has with crucial implications for interpretation of isotopic proxies that derive at least part of their composition from leaf water stable isotopes.
ano.nymous@ccsd.cnrs.fr.invalid (Lucas A. Cernusak) 05 Jun 2020
https://hal.inrae.fr/hal-02789758v1
-
[hal-02111822] Soils Drowned in Water Impoundments: A New Frontier
Water impoundments have major impacts on biogeochemical cycles at the local and global scales. However, although reservoirs flood soils, their biogeochemical evolution below water and its ecological consequences are very poorly documented. We took advantage of the complete emptying of the Guerlédan Reservoir (Brittany, France) to compare the composition of soils flooded for 84 years with that of adjacent non-flooded soils used as reference, in 3 situations contrasted by their soil type (Cambisol and Podzol) and initial land-use (forest or grassland). In the annual drawdown zone, upper horizons of submerged soils are eroded, especially near the upper shore and on slopes. In the permanently drowned area, silty sediments cover drowned soils. Compared to reference soils, forest soils drowned for 84 years maintain their original morphological differentiation, but colors are dull, and the humus (O horizons) have virtually disappeared. Spodic horizons are depleted in poorly crystallized iron minerals while the accumulation of amorphous aluminum compounds remains unchanged. Soil bulk density increases as well as pH while total phosphorus content is almost unchanged. On the other hand, the pH of drowned grassland soils is lower by almost one unit, and the total phosphorus content was halved compared to reference soils. In this context, in addition to the effects of flooding, differences are attributed to post-1950 changes in agricultural practices i.e., liming and fertilization. Organic matter stocks decrease by almost 40%. This rate is similar in Cambisols and Podzols. Assuming that carbon was lost as CO2 and CH4, the corresponding flux averaged over the reservoir’s life is close to global areal estimates of CO2 emissions in temperate reservoirs and offsets a significant proportion of the carbon burial in reservoir sediments. Hence, flooded soils contribute significantly to the GHG budget of reservoirs, provide original long-term experimental sites to measure the effects of anoxia on soils and contain archives of past soil properties.
ano.nymous@ccsd.cnrs.fr.invalid (Jim Félix-Faure) 26 Apr 2019
https://hal.science/hal-02111822v1
-
[hal-02624543] Interannual and seasonal variations in ecosystem transpiration and water use efficiency in a tropical rainforest
Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern driven by Rg, with maximum values for ET in July and August and for WUE at the beginning of the year. By removing radiation effects during water depleted periods, we showed that soil water stress strongly reduced ET. In contrast, drought conditions enhanced radiation-normalized WUE in almost all the years, suggesting that the lack of soil water had a more severe effect on ecosystem evapotranspiration than on photosynthesis. Our results are of major concern for tropical ecosystem modeling because they suggest that under future climate conditions, tropical forest ecosystems will be able to simultaneously adjust CO2 and H2O fluxes. Yet, for tropical forests under future conditions, the direction of change in WUE at the ecosystem scale is hard to predict, since the impact of radiation on WUE is counterbalanced by adjustments to soil water limitations. Developing mechanistic models that fully integrate the processes associated with CO2 and H2O flux control should help researchers understand and simulate future functional adjustments in these ecosystems.
ano.nymous@ccsd.cnrs.fr.invalid (Maricar Aguilos) 26 May 2020
https://hal.inrae.fr/hal-02624543v1
-
[hal-02372828] Soil N2O, CH4, and CO2 Fluxes in Forest, Grassland, and Tillage/No-Tillage Croplands in French Guiana (Amazonia)
The agricultural landscape of French Guiana (Amazonia) is expected to undergo substantial change as a result of rapid population growth in the region. Such changes in the landscape will lead to the conversion of tropical forests into land destined for agricultural use. Little information is available on the effect of different agricultural systems on greenhouse gas (GHG) emissions in French Guiana. For our experiment, two hectares of forest were cleared, without the use of fire, at the Combi experimental site (sandy-clayey Ferralsol) at the end of 2008. After one year with legume and grass cover, the site was modified to include the following three fertilized agricultural systems: (1) Grassland (Brachiaria ruziziensis, mowed), (2) cropland (maize/soybean rotation) with disc tillage, and (3) cropland (maize/soybean rotation) with no-tillage in direct seeding. Soil N2O, CH4, and CO2 fluxes were measured with dark chambers from May 2011 to November 2014. Our results show that grassland was a significantly lower emitter of N2O but a significantly higher emitter of CH4 compared to the two cropland systems studied. We did not observe significant differences between the two cropland systems for N2O and CH4 fluxes. Measurements of the net ecosystem CO2 exchange would be useful to better compare the role of different agricultural systems as a source of GHGs.
ano.nymous@ccsd.cnrs.fr.invalid (Caroline Petitjean) 26 May 2020
https://agroparistech.hal.science/hal-02372828v1
-
[hal-02011754] Explaining the larger seed bank of an invasive shrub in non-native versus native environments by differences in seed predation and plant size
•Background and aims - Large, persistent seed banks contribute to the invasiveness of non-native plants, and maternal plant size is an important contributory factor. We explored the relationships between plant vegetative size (V) and soil seed bank size (S) for the invasive shrub (Ulex europaeus) in its native range and in non-native populations, and identified which other factors may contribute to seed bank variation between native and invaded regions. •Methods - We compared the native region (France) with two regions where Ulex is invasive, one with seed predators introduced for biological control (New Zealand) and another where seed predators are absent (La Réunion). We quantified seed bank size, plant dimensions, seed predation, and soil fertility for six stands in each of the three regions.•Key results - Seed banks were 9 to 14 times larger in the two invaded regions compared to native France. We found a positive relationship between current seed bank size and actual plant size, and that any deviation from this relationship was probably due to large differences in seed predation and/or soil fertility. We further identified three possible factors explaining larger seed banks in non-native environments: larger maternal plant size, lower activity of seed predators and higher soil fertility. •Conclusions - In highlighting a positive relationship between maternal plant size and seed bank size, and identifying additional factors that regulate soil seed bank dynamics in non-native ranges, our data offer a number of opportunities for invasive weed control. For non-native Ulex populations specifically, management focusing on 'S' (i.e. the reduction of the seed bank by stimulating germination, or the introduction of seed predators as biological control agents), and/or 'V' (i.e. by cutting mature stands to reduce maternal plant biomass) offers the most probable combination of effective control options.
ano.nymous@ccsd.cnrs.fr.invalid (Mark Bakker) 13 Feb 2019
https://hal.science/hal-02011754v1
-
[hal-02621961] Améliorer la qualité des plants et leur taux de reprise
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Nathalie Ollat) 26 May 2020
https://hal.inrae.fr/hal-02621961v1
-
[hal-02622305] Diagnosis of forest soil sensitivity to harvesting residues removal – A transfer study of soil science knowledge to forestry practitioners
Forest biomass is a source of renewable energy that can contribute to meeting international targets for reducing greenhouse gas emissions. However, removing forest harvesting residues may cause important nutrient losses. Because negative effects of increased nutrient removal are not systematic, forest managers need tools for soil sensitivity assessment, to decide whether they can or not increase biomass harvesting without impairing long term forest productivity and health. This study follows two goals: (i) define forest ecosystem sensitivity indicators derived from soil physico-chemical analyses and (ii) build and test a simplified tool that predicts such soil sensitivity. After screening international literature, nutrient concentration in the topsoil was chosen as the simplest and currently most accurate indicator of soil sensitivity. With a consolidated database on French forest soils, we built diagnostic keys that predict soil sensitivity using only five parameters: humus form, topsoil texture, depth of CaCO3 apparition, ecological region, and rooting depth. We performed a statistical evaluation of the simplified tool on independent data sets and evaluated it in the field with potential users. As compared with the existing French forest soils sensitivity indicator, our diagnosis tool displayed lower high and low sensitivities classification errors and allowed to differentiate sensitivity into five elemental ones (Ca, Mg, K, P and N). All participating end users agreed with the necessity of such indicator and appreciated the simplicity of diagnosis with our tool. This study shows a complete research and development process, from the translation of scientific knowledge into an indicator of sustainable forest management to the simplification for assimilation.
ano.nymous@ccsd.cnrs.fr.invalid (Samuel Durante) 26 May 2020
https://hal.inrae.fr/hal-02622305v1
-
[hal-02373054] Biomasse microbienne carbonée et activités enzymatiques : gammes de valeurs obtenues pour différents sols agricoles français et belges
Depuis plusieurs décennies, les micro-organismes du sol ont été identifiés comme des acteurs majeurs du fonctionnement des sols et certaines variables microbiennes (abondance, diversité et activités) sont utilisées pour évaluer la qualité biologique des sols. Plus particulièrement, les activités enzymatiques d’origine microbienne impliquées dans la minéralisation des matières organiques des sols suscitent un fort intérêt ; néanmoins, aucun référentiel n’existe actuellement afin de les utiliser comme des indicateurs prédictifs des fonctions inhérentes à la fertilité des sols agricoles. Dans ce contexte, nous avons mesuré six activités enzymatiques (protéases, arginine- et leucine- aminopeptidases, β-glucosidases, phosphatases acides, arylsulfatases) impliquées dans la décomposition / minéralisation des matières organiques du sol, ainsi que la biomasse microbienne, sur six dispositifs expérimentaux situés dans différents contextes pédoclimatiques français et belges. Les résultats obtenus confirment que la gamme de valeurs d’activités enzymatiques et de biomasse microbienne mesurées pour différents types de sols est très large. Ainsi, les moyennes par dispositif des activités enzymatiques (exprimées par gramme de sol) varient d’un facteur compris entre 2,7 (pour les protéases) et 9,7 (pour les arylsulfatases). Concernant le carbone de la biomasse microbienne, les moyennes par dispositif varient de 159 à 488 µg C g-1 sol. Nos résultats montrent que cette biomasse microbienne, exprimée comme une fraction du carbone organique du sol, varie de 1,5 à 3,1 %. Cette variabilité des activités enzymatiques et de la biomasse microbienne en fonction des sites apparaît fortement liée aux différences de caractéristiques physico-chimiques des sols, et certainement au mode d’occupation des sols. Notamment, les variables microbiennes mesurées sont toutes significativement corrélées, certaines positivement (protéases, arginine- et leucine- aminopeptidases, β-glucosidases, biomasse microbienne), d’autres négativement (phosphatases acides, arylsulfatases) à la teneur en argile du sol. Nos résultats confirment ainsi la nécessité de disposer, pour chaque type de sol, d’un référentiel de valeurs d’activités enzymatiques et de biomasse microbienne avant d’envisager le développement d’indicateurs de fertilité des sols basés sur ces métriques.
ano.nymous@ccsd.cnrs.fr.invalid (Caroline Petitjean) 25 Apr 2022
https://hal.science/hal-02373054v1
-
[hal-02625305] Chilling and forcing temperatures interact to predict the onset of wood formation in Northern Hemisphere conifers
The phenology of wood formation is a critical process to consider for predicting how trees from the temperate and boreal zones may react to climate change. Compared to leaf phenology, however, the determinism of wood phenology is still poorly known. Here, we compared for the first time three alternative ecophysiological model classes (threshold models, heat-sum models and chilling-influenced heat-sum models) and an empirical model in their ability to predict the starting date of xylem cell enlargement in spring, for four major Northern Hemisphere conifers (Larix decidua, Pinus sylvestris, Picea abies and Picea mariana). We fitted models with Bayesian inference to wood phenological data collected for 220 site-years over Europe and Canada. The chilling-influenced heat-sum model received most support for all the four studied species, predicting validation data with a 7.7-day error, which is within one day of the observed data resolution. We conclude that both chilling and forcing temperatures determine the onset of wood formation in Northern Hemisphere conifers. Importantly, the chilling-influenced heat-sum model showed virtually no spatial bias whichever the species, despite the large environmental gradients considered. This suggests that the spring onset of wood formation is far less affected by local adaptation than by environmentally driven plasticity. In a context of climate change, we therefore expect rising winter-spring temperature to exert ambivalent effects on the spring onset of wood formation, tending to hasten it through the accumulation of forcing temperature, but imposing a higher forcing temperature requirement through the lower accumulation of chilling.
ano.nymous@ccsd.cnrs.fr.invalid (Nicolas Delpierre) 04 Apr 2024
https://hal.inrae.fr/hal-02625305v1
-
[hal-02311392] The functional trait spectrum of European temperate grasslands
Questions What is the functional trait variation of European temperate grasslands and how does this reflect global patterns of plant form and function? Do habitat specialists show trait differentiation across habitat types? Location Europe. Methods We compiled 18 regeneration and non-regeneration traits for a continental species pool consisting of 645 species frequent in five grassland types. These grassland types are widely distributed in Europe but differentiated by altitude, soil bedrock and traditional long-term management and disturbance regimes. We evaluated the multivariate trait space of this entire species pool and compared multi-trait variation and mean trait values of habitat specialists grouped by grassland type. Results The first dimension of the trait space accounted for 23% of variation and reflected a gradient between fast-growing and slow-growing plants. Plant height and SLA contributed to both the first and second ordination axes. Regeneration traits mainly contributed to the second and following dimensions to explain 56% of variation across the first five axes. Habitat specialists showed functional differences between grassland types mainly through non-regeneration traits. Conclusions The trait spectrum of plants dominating European temperate grasslands is primarily explained by growth strategies which are analogous to the trait variation observed at the global scale, and secondly by regeneration strategies. Functional differentiation of habitat specialists across grassland types is mainly related to environmental filtering linked with altitude and disturbance. This filtering pattern is mainly observed in non-regeneration traits, while most regeneration traits demonstrate multiple strategies within the same habitat type.
ano.nymous@ccsd.cnrs.fr.invalid (Emma Ladouceur) 26 May 2020
https://hal.science/hal-02311392v1
-
[hal-04215185] Are mixtures a good option to reduce drought-induced risk of forest decline? Carbon accounting and economic approach.
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Sandrine Brèteau-Amores) 22 Sep 2023
https://hal.inrae.fr/hal-04215185v1
-
[hal-02625278] The effect of stumpage prices on large-area forest growth forecasts based on socio-ecological models
Forest ecosystems are typical examples of socio-ecological systems. However, in terms of modelling, the social aspect has been given far less attention than the ecological aspect. In this study, we modelled the impact of eco- nomic and social factors on the occurrence of harvesting. This harvest model was then integrated into an individual- based model of forest growth designed for large-area forec asts. The resulting s ocio-ecological model was then used to produce volume predictions for two regions of France. Among the economic factors, the annual stumpage prices in interaction with the species proved to be a signi fi cant predictor of harvest occurrence. Simulating different stum- page price evolutions made it possible to predict supply curves for the two regions. Projections until 2060 showed that increases in stumpage prices will be detrimental to st anding volumes in both regions. Integrating the demand for wood products into such socio-ecological models in forestry would be a major improvement.
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Fortin) 26 May 2020
https://hal.inrae.fr/hal-02625278v1
-
[hal-02118104] Are 40 years better than 55 ? An analysis of the reduction of forest rotation to cope with drought events in a Douglas fir stand
Key message : Reduction of forest rotation is analyzed as a potential adaptation strategy for a Douglas fir stand to cope with drought-induced risk of forest decline. The methodology combines a water balance modeling and an economic approach. Results show that, from an economic perspective, adaptation (immediate or delayed) is always better than the absence of adaptation. Context : Reduction of rotation length emerges as a potential adaptation strategy to cope with climate change. Aim : The study aims to address the reduction of rotation length to deal with the drought-induced risk of forest decline taking a multidisciplinary approach. Methods : We estimate probabilities and impacts of drought events quantified by water balance modeling and we evaluate, from an economic point of view, the reduction of rotation length to cope with the drought-induced risk of forest decline. We compare three different adaptation strategies at the economic level: absence of adaptation, immediate adaptation, and delayed adaptation. Results : Results suggest that immediate reduction of rotation length is associated with the best economic return, followed by delayed adaptation and, finally, by the absence of adaptation. This result is sensitive to the level of timber loss in the event of drought occurrence. If the loss of timber volume is higher than 48%, then delayed adaptation may be preferable to immediate adaptation. Conclusion : Beyond the specificities of the case study, this paper proposes a multidisciplinary approach to address adaptation strategies.
ano.nymous@ccsd.cnrs.fr.invalid (Nathalie Bréda) 06 Apr 2020
https://hal.science/hal-02118104v1
-
[hal-03003259] Cartographie des forêts anciennes et récentes de France – un point d’étape
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Jean-Luc Dupouey) 13 Nov 2020
https://hal.univ-lorraine.fr/hal-03003259v1
-
[hal-02376012] Opportunités et défis de la diffusion ouverte : témoignage de responsables de revues
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Odile Contat) 22 Nov 2019
https://hal.univ-lorraine.fr/hal-02376012v1
-
[hal-03029969] Détection automatique de la moelle sur des images d'extrémités de grumes de Douglas brutes de sciage
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Rémi Decelle) 03 Dec 2020
https://hal.science/hal-03029969v1
-
[hal-02275651] A new algorithm to automatically detect the pith on rough log-end images
X-ray computer tomography has proved to be efficient for measuring internal and external characteristics of logs that are relevant for estimating wood quality at the sawmill. However, this technology remains expensive (two sawmills in France are equipped) and there is a need to provide low-cost tools for smaller sawmills. It could help them become more competitive. There is also a need for new tools available everywhere , for example to estimate wood quality on the harvester, at the road side, or on the log yard (e.g. with mobile-phone cameras). Contrary to X-ray scans, low-cost cameras provide very different images. Moreover few works have been done on such cameras so far. The pith in log end images is an important feature. It is usually required to detect other wood characteristics (for example annual rings) and to process further toward wood quality estimation. The pith's location is a real challenging problem for untreated log ends. In this context, we propose a robust and efficient algorithm to address this challenge. It consists of a mixture between Hough Transform and an approach based on state-of-the-art algorithms, known as Hough-based algorithms. We validated the proposed method on RGB images of Douglas fir taken with a digital camera after harvesting wood in the forest. The obtained results show a better detection of the pith on rough log end images than some state-of-the-art algorithms. The algorithm may process images in real-time which is compatible with sawmill requirements.
ano.nymous@ccsd.cnrs.fr.invalid (Rémi Decelle) 20 Feb 2020
https://inria.hal.science/hal-02275651v1
-
[hal-02095574] Background mortality drivers of European tree species : climate change matters
Increases in tree mortality rates have been highlighted in different biomes over the past decades. However, disentangling the effects of climate change on the temporal increase in tree mortality from those of management and forest dynamics remains a challenge. Using a modelling approach taking tree and stand characteristics into account, we sought to evaluate the impact of climate change on background mortality for the most common European tree species. We focused on background mortality, which is the mortality observed in a stand in the absence of abrupt disturbances, to avoid confusion with mortality events unrelated to long-term changes in temperature and rainfall. We studied 372 974 trees including 7312 dead trees from forest inventory data surveyed across France between 2009 and 2015. Factors related to competition, stand characteristics, management intensity, and site conditions were the expected preponderant drivers of mortality. Taking these main drivers into account, we detected a climate change signal on 45% of the 43 studied species, explaining an average 6% of the total modelled mortality. For 18 out of the 19 species sensitive to climate change, we evidenced greater mortality with increasing temperature or decreasing rainfall. By quantifying the mortality excess linked to the current climate change for European temperate forest tree species, we provide new insights into forest vulnerability that will prove useful for adapting forest management to future conditions.
ano.nymous@ccsd.cnrs.fr.invalid (Adrien Taccoen) 14 Dec 2020
https://hal.science/hal-02095574v2
-
[hal-02165403] Infiltration from the Pedon to Global Grid Scales: An Overview and Outlook for Land Surface Modeling
Infiltration in soils is a key process that partitions precipitation at the land surface into surface runoff and water that enters the soil profile. We reviewed the basic principles of water infiltration in soils and we analyzed approaches commonly used in land surface models (LSMs) to quantify infiltration as well as its numerical implementation and sensitivity to model parameters. We reviewed methods to upscale infiltration from the point to the field, hillslope, and grid cell scales of LSMs. Despite the progress that has been made, upscaling of local-scale infiltration processes to the grid scale used in LSMs is still far from being treated rigorously. We still lack a consistent theoretical framework to predict effective fluxes and parameters that control infiltration in LSMs. Our analysis shows that there is a large variety of approaches used to estimate soil hydraulic properties. Novel, highly resolved soil information at higher resolutions than the grid scale of LSMs may help in better quantifying subgrid variability of key infiltration parameters. Currently, only a few LSMs consider the impact of soil structure on soil hydraulic properties. Finally, we identified several processes not yet considered in LSMs that are known to strongly influence infiltration. Especially, the impact of soil structure on infiltration requires further research. To tackle these challenges and integrate current knowledge on soil processes affecting infiltration processes into LSMs, we advocate a stronger exchange and scientific interaction between the soil and the land surface modeling communities.
ano.nymous@ccsd.cnrs.fr.invalid (Harry Vereecken) 25 Jun 2019
https://hal.sorbonne-universite.fr/hal-02165403v1
-
[hal-02052715] Compositional response of Amazon forests to climate change
Most of the planet's diversity is concentrated in the tropics, which includes many regions undergoing rapid climate change. Yet, while climate-induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether the floristic and functional composition of intact lowland Amazonian forests have been changing by evaluating records from 106 long-term inventory plots spanning 30 years. We analyse three traits that have been hypothesized to respond to different environmental drivers (increase in moisture stress and atmospheric CO2 concentrations): maximum tree size, biogeographic water-deficit affiliation and wood density. Tree communities have become increasingly dominated by large-statured taxa, but to date there has been no detectable change in mean wood density or water deficit affiliation at the community level, despite most forest plots having experienced an intensification of the dry season. However, among newly recruited trees, dry-affiliated genera have become more abundant, while the mortality of wet-affiliated genera has increased in those plots where the dry season has intensified most. Thus, a slow shift to a more dry-affiliated Amazonia is underway, with changes in compositional dynamics (recruits and mortality) consistent with climate-change drivers, but yet to significantly impact whole-community composition. The Amazon observational record suggests that the increase in atmospheric CO2 is driving a shift within tree communities to large-statured species and that climate changes to date will impact forest composition, but long generation times of tropical trees mean that biodiversity change is lagging behind climate change.
ano.nymous@ccsd.cnrs.fr.invalid (Adriane Esquivel-Muelbert) 28 Feb 2019
https://hal.umontpellier.fr/hal-02052715v1
-
[hal-02399726] The cost of deer to trees: changes in resource allocation from growth-related traits and phenolic content to structural defence
Background and aims-Plants may use various defence mechanisms to protect their tissues against deer browsing and the allocation of resources to defence may trade-off with plants' growth. In a context of increasing deer populations in European forests, understanding the resource allocation strategies of trees is critical to better assess their ability to face an increasing browsing pressure. The aim of this study was to determine how deer removal affects the resource allocation to both defensive and growth-related traits in field conditions for three tree species (Abies alba, Picea abies and Fagus sylvatica). Methods-We compared eight pairs of fenced-unfenced plots to contrast plots with and without browsing pressure. The pairs were set up in 2005 and 2014 to compare different fencing duration. We measured leaf and shoot traits related to the defence against herbivores (phenolic content, structural resistance, C:N ratio) and to the investment in plants' growth and productivity (specific leaf area and nutrient content). Key results-For the three species, the structural resistance of leaves and shoots was negatively correlated with SLA, nutrient content and phenolic content. For Abies alba, exclusion of deer decreased shoot structural resistance in favour of higher nutrient content, SLA and phenolic content. The fencing duration had no effect on the different measured traits. Conclusions-Our results support the assumption of a trade-off between structural defence and growth-related traits at the intraspecific scale for the three studied species. We also confirmed the hypothesis that exposure to deer browsing is involved in the resource allocation of woody species. For Abies alba, fencing led to a change in resource allocation from structural defence to growth-related traits and chemical defence.
ano.nymous@ccsd.cnrs.fr.invalid (Julien Barrere) 09 Dec 2019
https://hal.science/hal-02399726v1
-
[hal-03325874] Circularities and proximities within resource valuation systems: insights from territory-based initiatives in the forestry sector
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Jonathan Lenglet) 25 Aug 2021
https://hal.science/hal-03325874v1
-
[hal-03325876] Valuation de la ressource territoriale et formes de circularité : la labellisation dans la filière forêt-bois française (Alpes, Jura, Vosges)
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Jonathan Lenglet) 25 Aug 2021
https://hal.science/hal-03325876v1
-
[hal-02320571] Quelle pertinence du modèle diversité-productivité-perturbations pour analyser l’influence des pratiques agricoles sur la diversité des prairies permanentes du Massif central ?
Un modèle a été réalisé pour évaluer l’impact des pratiques agricoles sur la diversité des prairies. Pour tester les prédictions d’un modèle théorique d’écologie, le modèle d’équilibre dynamique, nous avons suivi 18 prairies permanentes du Massif central aux pédoclimats et modes de gestion variés. Nous avons mis en évidence une diminution de la richesse spécifique liée à l’augmentation de la quantité de biomasse exportée (pâturée ou fauchée) et une diminution de la richesse fonctionnelle liée à l’augmentation de la productivité. Ces effets n’expliquent toutefois qu’une faible part de la variabilité observée entre sites. La quantité de biomasse exportée dépend du nombre de fauches et du chargement animal annuel ; la productivité était avant tout dépendante des précipitations durant la période d’étude, et non de la fertilisation. Nous discutons de l’intérêt et des limites de l’utilisation du modèle pour la gestion de la diversité des prairies.
ano.nymous@ccsd.cnrs.fr.invalid (Rémi Perronne) 18 Oct 2019
https://hal.science/hal-02320571v1
-
[hal-02276947] Long‐term influence of early human occupations on current forests of the Guiana Shield
To decipher the long-term influences of pre-Columbian land occupations on contemporary forest structure, diversity, and functioning in Amazonia, most of the previous research focused on the alluvial plains of the major rivers of the Amazon basin. Terra firme, that is, nonflooded forests, particularly from the Guiana Shield, are yet to be explored. In this study, we aim to give new insights into the subtle traces of pre-Columbian influences on present-day forests given the archaeological context of terra firme forests of the Guiana Shield. Following archaeological prospects on 13 sites in French Guiana, we carried out forest inventories inside and outside archaeological sites and assessed the potential pre-Columbian use of the sampled tree species using an original ethnobotanical database of the Guiana Shield region. Aboveground biomass (320 and 380 T/ha, respectively), basal area (25–30 and 30–35 m2/ha, respectively), and tree density (550 and 700 stem/ha, respectively) were all significantly lower on anthropized plots (As) than on nonanthropized plots (NAs). Ancient human presence shaped the species composition of the sampled forests with Arecaceae, Burseraceae, and Lauraceae significantly more frequent in As and Annonaceae and Lecythidaceae more frequent in NAs. Although alpha diversity was not different between As and NAs, the presence of pre-Columbian sites enhances significantly the forest beta diversity at the landscape level. Finally, trees with edible fruits are positively associated with pre-Columbian sites, whereas trees used for construction or for their bark are negatively associated with pre-Columbian sites. Half a millennium after their abandonment, former occupied places from the inner Guiana Shield still bear noticeable differences with nonanthropized places. Considering the lack of data concerning archaeology of terra firme Amazonian forests, our results suggest that pre-Columbian influences on the structure (lower current biomass), diversity (higher beta diversity), and composition (linked to the past human tree uses) of current Amazonian forests might be more important than previously thought.
ano.nymous@ccsd.cnrs.fr.invalid (Guillaume Odonne) 19 Dec 2023
https://hal.umontpellier.fr/hal-02276947v1
-
[hal-02346487] Precipitation mediates sap flux sensitivity to evaporative demand in the neotropics
Transpiration in humid tropical forests modulates the global water cycle and is a key driver of climate regulation. Yet, our understanding of how tropical trees regulate sap flux in response to climate variability remains elusive. With a progressively warming climate, atmospheric evaporative demand [i.e., vapor pressure deficit (VPD)] will be increasingly important for plant functioning, becoming the major control of plant water use in the twenty-first century. Using measurements in 34 tree species at seven sites across a precipitation gradient in the neotropics, we determined how the maximum sap flux velocity (vmax) and the VPD threshold at which vmax is reached (VPDmax) vary with precipitation regime [mean annual precipitation (MAP); seasonal drought intensity (PDRY)] and two functional traits related to foliar and wood economics spectra [leaf mass per area (LMA); wood specific gravity (WSG)]. We show that, even though vmax is highly variable within sites, it follows a negative trend in response to increasing MAP and PDRY across sites. LMA and WSG exerted little effect on vmax and VPDmax, suggesting that these widely used functional traits provide limited explanatory power of dynamic plant responses to environmental variation within hyper-diverse forests. This study demonstrates that long-term precipitation plays an important role in the sap flux response of humid tropical forests to VPD. Our findings suggest that under higher evaporative demand, trees growing in wetter environments in humid tropical regions may be subjected to reduced water exchange with the atmosphere relative to trees growing in drier climates.
ano.nymous@ccsd.cnrs.fr.invalid (Charlotte Grossiord) 17 Aug 2024
https://hal.umontpellier.fr/hal-02346487v1
-
[hal-04216429] Localisation des réserves carbonées dans le houppier de Chênes pédonculés
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Sylvie-Annabel Sabatier) 24 Sep 2023
https://hal.inrae.fr/hal-04216429v1
-
[hal-04492051] Analyse de l'évolution de la production de truffe noire du Périgord (Tuber Melanosporum Vitad.) de 1903-1904 à 1988-1989 dans le Vaucluse
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Meili Baragatti) 06 Mar 2024
https://hal.inrae.fr/hal-04492051v1
-
[hal-03139548] Kinetics of growth responses of a root encountering an obstacle
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Marie-Béatrice Bogeat-Triboulot) 12 Feb 2021
https://hal.inrae.fr/hal-03139548v1
-
[hal-02384139] Fructification du Hêtre et des Chênes en France : rôle des températures, du pollen et du bilan de carbone et relation avec la croissance des peuplements
Dans cette étude, nous avons analysé les déterminants environnementaux de la variabilité spatiale et temporelle de la fructification des trois espèces feuillues européennes majeures : Quercus robur, Quercus petraea et Fagus sylvatica. Nous avons étudié les relations entre la production de fruits, l’émission de pollen, les ressources carbonées et hydriques et les conditions climatiques sur la période 1994-2007 (14 ans) à partir de 48 peuplements du réseau RENECOFOR. La production moyenne des fruits est de 251 kg/ha/an pour les Chênes et de 174 kg/ha/an pour le Hêtre. Pour le Hêtre, la production suit un rythme bisannuel très net et est synchrone entre les sites. Elle apparaît beaucoup plus variable pour les Chênes sans synchronisme net. Pour les Chênes, la fructification dépend très fortement des conditions thermiques durant la période d’émission du pollen (début avril) confirmant l’hypothèse du synchronisme pollinique pour ces espèces. Pour le Hêtre, la production dépend très fortement des écarts de température estivale entre les années. Pour les deux espèces, les relations entre la production de fruits et les différents déterminants suivent des lois non linéaires avec des forts effets seuil et des interactions complexes. Enfin, pour le Hêtre, la croissance radiale est réduite en cas de forte fructification alors que les années de bonne glandée sont aussi des années de forte croissance pour les Chênes. Les deux espèces présentent donc deux comportements opposés concernant les stratégies d’allocation entre la croissance radiale et la production de fruits.
ano.nymous@ccsd.cnrs.fr.invalid (François F. Lebourgeois) 28 Nov 2019
https://agroparistech.hal.science/hal-02384139v1
-
[hal-02168619] Nondestructive and Fast Vibration Phenotyping of Plants
The frequencies of free oscillations of plants, or plant parts, depend on their geometries, stiffnesses, and masses. Besides direct biomechanical interest, free frequencies also provide insights into plant properties that can usually only be measured destructively or with low-throughput techniques (e.g., change in mass, tissue density, or stiffness over development or with stresses). We propose here a new high-throughput method based on the noncontact measurements of the free frequencies of the standing plant. The plant is excited by short air pulses (typically 100 ms). The resulting motion is recorded by a high speed video camera (100 fps) and processed using fast space and time correlation algorithms. In less than a minute the mechanical behavior of the plant is tested over several directions. The performance and versatility of this method has been tested in three contrasted species: tobacco (Nicotiana benthamian), wheat (Triticum aestivum L.), and poplar (Populus sp.), for a total of more than 4000 data points. In tobacco we show that water stress decreased the free frequency by 15%. In wheat we could detect variations of less than 1 g in the mass of spikes. In poplar we could measure frequencies of both the whole stem and leaves. The work provides insight into new potential directions for development of phenotyping.
ano.nymous@ccsd.cnrs.fr.invalid (Emmanuel de Langre) 28 Jun 2019
https://hal.science/hal-02168619v1
-
[hal-02501278] Wood formation and tree adaptation to climate
This special issue of Annals of Forest Science compiles ten papers on “Wood formation and tree adaptation to climate”, which were presented at “Le Studium” International Conference in May 2018 in Orléans (France). These papers present observational, experimental and modelling studies investigating the influence of climatic changes on tree growth from the hour to the century, and from the cell to the landscape
ano.nymous@ccsd.cnrs.fr.invalid (Cyrille Rathgeber) 06 Mar 2020
https://hal.science/hal-02501278v1
-
[hal-02737975] Wood formation and tree adaptation to climate
Key message This special issue of Annals of Forest Science compiles ten papers on "Wood formation and tree adaptation to climate", which were presented at "Le Studium" International Conference in May 2018 in Orleans (France). These papers present observational, experimental and modelling studies investigating the influence of climatic changes on tree growth from the hour to the century, and from the cell to the landscape.
ano.nymous@ccsd.cnrs.fr.invalid (Cyrille Rathgeber) 02 Jun 2020
https://hal.inrae.fr/hal-02737975v1
-
[hal-01972724] Influence of annual climatic variations, climate changes, and sociological factors on the production of the Périgord black truffle (Tuber melanosporum Vittad.) from 1903–1904 to 1988–1989 in the Vaucluse (France)
From 1903–1904 to 1988–1989, the two World Wars and sociological factors as rural desertification and changes in land uses mainly explained the decline of black truffle production in the Vaucluse department, which well reflects that of the whole of France. These can be correlated with the annual climatic variations as well as, from 1924–1925 to 1948–1949, the raw production rates of the managed truffle orchard of Pernes-les-Fontaines located in Vaucluse. The two methods used (correlation coefficients and Bayesian functional linear regression with Sparse Step functions) gave consistent results: the main factor explaining the annual variations of truffle production was the summer climatic water deficit of the year n. A general model including the rural exodus and the cumulated climatic water deficit of summer months both allowed to well explain the evolution of truffle production from 1903–1904 to 1988–1989 in the Vaucluse and its huge decrease. During that period, global warming had little effect. However, in the twenty-first century, all the scenarios predict increased summer water stress for the Mediterranean region, which could greatly affect black truffle production.
ano.nymous@ccsd.cnrs.fr.invalid (Meïli Baragatti) 07 Jan 2019
https://hal.science/hal-01972724v1
-
[hal-02437587] TOFF, a database of traits of fish to promote advances in fish aquaculture
Functional traits can be valuable pieces of information for aquaculture research and management. Although fish traits have been the focus of an abundant research, trait datasets for these organisms are difficult to access and often unpractical to achieve meta-analyses without a time-consuming extensive review. Already available large-scale compilations include trait information for many fish species but not as detailed as required for aquaculture purpose. Here, we introduce the TOFF (i.e. Traits OF Fish), a database focusing on fish functional traits that aims at bringing together behavioral, morphological, phenological, and physiological traits always coupled to environmental measurement context into a single open-source access repository. TOFF hosts data from published field and experimental studies. Here, we release data for 228 traits for 174 species extracted from 165 publications and present a collaborative platform. We ultimately aim at providing an inclusive and accessible data resource to facilitate advances in aquaculture development
ano.nymous@ccsd.cnrs.fr.invalid (Thomas Lecocq) 13 Jan 2020
https://hal.science/hal-02437587v1
-
[hal-02317168] Icthyodiversity as a driving force to promote new agro-ecological approach for Sander lucioperca rearing
Icthyodiversity as a driving force to promote new agro-ecological approach for Sander lucioperca rearing. Aquaculture Europe 2019
ano.nymous@ccsd.cnrs.fr.invalid (Marielle Thomas) 15 Oct 2019
https://hal.science/hal-02317168v1
-
[hal-02263853] Annotation data about multi criteria assessment methods used in the agri-food research: The French national institute for agricultural research (INRA) experience
This data article contains annotation data characterizing MultiCriteria Assessment (MCA) Methods proposed in the agri-food sector by researchers from INRA, Europe's largest agricultural research institute (INRA, http://institut.inra.fr/en). MCA can be used to assess and compare agricultural and food systems, and support multi-actor decision making and design of innovative systems for crop production, animal production and processing of agricultural products. These data are stored in a public repository managed by INRA (https://data.inra.fr/; https://doi.org/10.15454/WB51LL).
ano.nymous@ccsd.cnrs.fr.invalid (Geneviève Gésan-Guiziou) 05 Aug 2019
https://hal.science/hal-02263853v1
-
[hal-02352504] The effect of tree diversity on the resistance and recovery of forest stands in the French Alps may depend on species differences in hydraulic features
As climate change should lead to an increase in the vulnerability and the sensitivity of forests to extreme climatic events, quantifying and predicting their response to more severe droughts remains a key task for foresters. Furthermore, recent works have suggested that tree diversity may affect forest ecosystem functioning, including their response to extreme events. In this study we aimed at testing whether the growth response of forest stands to stressful climatic events varied between mixed and monospecific stands, under various environmental conditions. We focused on beech-fir forests (Fagus sylvatica [L.] and Abies albs [L.]) and beech-oak forests (F. sylvatica [L.] and Quercus pubescent [L.]) in the French Alps. We used a dendrochronological dataset sampled in forest plots organized by triplets (one mixture and two monospecific stands) distributed in six sites along a latitudinal gradient. We tested (1) whether stand diversity (two-species stands vs monospecific stands) modulates the stands' response to drought events in terms of productivity, (2) whether species identity may drive the diversity effect on resistance and recovery, and (3) whether this can be explained by interspecific interactions. We found that (1) interspecific differences in response to extreme drought events (possibly due to interspecific differences in hydraulic characteristics) can induce a mixture effect on stand growth, although it appeared (2) to be strongly depending on species identity (positive effect only found for beech-fir mixed stands), while (3) there were no significant non-additive effects of diversity on stand resistance and recovery, except for some specific cases. Overall, our study shows that promoting selected mixed stands management may buffer extreme drought effect on stand productivity.
ano.nymous@ccsd.cnrs.fr.invalid (Marion Jourdan) 20 Jul 2022
https://hal.science/hal-02352504v1
-
[hal-02622295] Massive postglacial gene flow between European white oaks uncovered genes underlying species barriers
Oaks are dominant forest tree species widely distributed across the Northern Hemisphere, where they constitute natural resources of economic, ecological, social and historical value. Hybridisation and adaptive introgression have long been thought to be major drivers of their ecological success. Therefore, the maintenance of species barriers remains a key question, given the extent of interspecific gene flow. In this study, we made use of the tremendous genetic variation among four European white oak species (31 million single nucleotide polymorphisms (SNPs)) to infer the evolutionary history of these species, study patterns of genetic differentiation and identify reproductive barriers. We first analysed the ecological and historical relationships among these species and inferred a long-term strict isolation followed by a recent and extensive postglacial contact using approximate Bayesian computation. Assuming this demographic scenario, we then performed backward simulations to generate the expected distributions of differentiation under neutrality to scan their genomes for reproductive barriers. We finally identified important intrinsic and ecological functions driving the reproductive isolation. We discussed the importance of identifying the genetic basis for the ecological preferences between these oak species and its implications for the renewal of European forests under global warming.
ano.nymous@ccsd.cnrs.fr.invalid (Thibault Leroy) 07 Dec 2023
https://hal.inrae.fr/hal-02622295v1
-
[hal-02432407] Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought
Abundant Neotropical canopy-tree species are more resistant to drought-induced branch embolism than what is currently admitted. Large hydraulic safety margins protect them from hydraulic failure under actual drought conditions.ContextXylem vulnerability to embolism, which is associated to survival under extreme drought conditions, is being increasingly studied in the tropics, but data on the risk of hydraulic failure for lowland Neotropical rainforest canopy-tree species, thought to be highly vulnerable, are lacking.AimsThe purpose of this study was to gain more knowledge on species drought-resistance characteristics in branches and leaves and the risk of hydraulic failure of abundant rainforest canopy-tree species during the dry season.MethodsWe first assessed the range of branch xylem vulnerability to embolism using the flow-centrifuge technique on 1-m-long sun-exposed branches and evaluated hydraulic safety margins with leaf turgor loss point and midday water potential during normal- and severe-intensity dry seasons for a large set of Amazonian rainforest canopy-tree species.ResultsTree species exhibited a broad range of embolism resistance, with the pressure threshold inducing 50% loss of branch hydraulic conductivity varying from − 1.86 to − 7.63 MPa. Conversely, we found low variability in leaf turgor loss point and dry season midday leaf water potential, and mostly large, positive hydraulic safety margins.ConclusionsRainforest canopy-tree species growing under elevated mean annual precipitation can have high resistance to embolism and are more resistant than what was previously thought. Thanks to early leaf turgor loss and high embolism resistance, most species have a low risk of hydraulic failure and are well able to withstand normal and even severe dry seasons.
ano.nymous@ccsd.cnrs.fr.invalid (Camille Ziegler) 14 Dec 2020
https://hal.umontpellier.fr/hal-02432407v1
-
[hal-02626083] Genetic differentiation in functional traits among European sessile oak populations
The vulnerability of forest species and tree populations to climate change is related to the exposure of the ecosystem to extreme climatic conditions and to the adaptive capacity of the population to cope with those conditions. Adaptive capacity is a relatively under-researched topic within the forest science community and there is an urgent need to understand to what extent particular combinations of traits have been shaped by natural selection under climatic gradients, potentially resulting in adaptive multi-trait associations. Thus, our aim was to quantify genetic variation in several leaf and woody traits that may contribute to multi-trait associations in which intraspecific variation could represent a source for species adaptation to climate change. A multi-trait approach was performed using nine Quercus petraea provenances originating from different locations that cover most of the species' distribution range over Europe and that were grown in a common garden. Multiple adaptive differences were observed between oak provenances but also some evolutionary stasis. Also, our results revealed higher genetic differentiation in traits related to phenology and growth than in those related to xylem anatomy, physiology and hydraulics for which no genetic differentiation was observed. The multiple associations between those traits and climate variables resulting from multivariate and path analyses suggest a multi-trait association largely involving phenological and growth traits for Quercus petraea. © The Author(s) 2019. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
ano.nymous@ccsd.cnrs.fr.invalid (Jose Manuel Torres Ruiz) 26 May 2020
https://hal.inrae.fr/hal-02626083v1
-
[hal-02789564] Définir une densité de plantation : comment et pour quels objectifs?
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Céline Meredieu) 05 Jun 2020
https://hal.inrae.fr/hal-02789564v1
-
[hal-04144342] Genetic architecture of leaf specialized metabolites in sessile oak (Quercus petraea)
Specialized metabolites contribute to plant defense against pathogens and herbivores, and to their protection against abiotic stresses (e.g. UV radiation, drought). In the context of global change, natural variation of these traits may become even more important to mitigate extreme climatic and biotic events and be a source of adaptive solutions in natural populations. Leaf specialized metabolites (LSM) were previously shown to be variable and to impact herbivore damage in populations of European white oaks. Here, we aim to describe the natural variation of LSM in sessile oaks across Europe and identify the underlying genetics to better understand the evolutionary forces shaping this variation. We sampled 225 individuals from nine provenances growing in a common garden in France and used high-throughput liquid chromatography coupled to non-targeted mass spectrometry to quantify 219 molecules. In addition, we performed whole genome sequencing of all individuals at low-coverage (~10X) to generate 1,4 millions markers (SNPs). We found that linkage disequilibrium decreased over 3 kb and that oak provenances displayed little genetic differentiation (pairwise FST<0.05). Genetic variation explained over 50% of the variation for 187 molecules and a genome-wide association study identify significant associations for 147 LSM. Overall, our results suggest that sessile oak provenances display extensive variation for LSM and that this variation has a very strong genetic component with many LSM having simple genetic architectures. On-going analyses of the signatures of natural selections and genes at these loci will help better understand the selective forces maintaining variation within provenances.
ano.nymous@ccsd.cnrs.fr.invalid (Domitille Coq--Etchegaray) 28 Jun 2023
https://hal.inrae.fr/hal-04144342v1
