2020 - UMR Silva

[hal-02948753] The global abundance of tree palms

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., &gt;= 10 cm diameter at breast height) abundance relative to co-occurring non-palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in &gt;80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long-term climate stability. Life-form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non-tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above-ground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.

ano.nymous@ccsd.cnrs.fr.invalid (Robert Muscarella) 20 Feb 2026

https://hal.inrae.fr/hal-02948753v1

[hal-02650649] Long-term thermal sensitivity of Earth’s tropical forests

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate.

ano.nymous@ccsd.cnrs.fr.invalid (Martin J P Sullivan) 17 Aug 2024

https://hal.umontpellier.fr/hal-02650649v1

[hal-04262493] Short-term impacts of the summer 2019 heatwave on ecosystem functioning inferred from ICOS flux towers in France

The frequency and intensity of extreme weather events are increasing in response to climate change. Among such events, heatwaves impact both public health and ecosystem functioning. In France, in 2019, two heatwaves took place between June and August, lasting however only a few days each. While the historical temperature record was broken at the end of June 2019, the intensity and duration of those two events differed between regions of France. In forests and crops, warm temperatures, together with moderate soil drought, led to a reduction in photosynthetic activity, inducing a loss of ecosystem productivity and carbon (C) sequestration. In particular, crop management, such as irrigation, could play an important role. In peatlands, the potential effect of heatwaves is more uncertain, as they often develop in humid areas. This study aimed at (i) describing how 2019 heatwave events impacted C and water vapour (₂O) fluxes at several forest, cropland and peatland sites within the ICOS ecosystem network in France, covering several soil, climate and vegetation conditions and (ii) exploring the physiological processes affected by the heatwaves. At all sites, CO₂ and ₂O fluxes, measured by eddy-covariance according to the ICOS protocols, were analysed to infer heatwave impacts on net ecosystem exchange (NEE), gross photoynthesis (GPP), ecosystem respiration (Reco), and evapotranspiration. Canopy conductance (gc) was inferred from evapotranspiration by inverting the Penman-Monteith equation. For forest sites, the heatwave generally caused a reduction of gc, especially after midday, which indicates a stomatal closure in response to higher VPD observed in the afternoon. This was concurrent with reduced NEE. Depending on sites, the forest would switch from a C sink to a C source, or become a weaker C sink, with total or only partial recovery after the heatwave. GPP was generally lower during the heatwave, again with total or partial recovery. Ecosystem respiration appeared to be stimulated by the higher temperatures, but frequently displayed inconsistent responses, possibly due to issues with partioning algorithms. At FR-Pue, where temperatures were the highest, the heatwave caused immediate, partial leaf mortality. Peatlands displayed no noticeable change in gc during the heatwaves, possibly due to surface temperatures not being as high as in forests, except for FR-LGt, where temperatures were higher and gc was reduced. That site became a stronger source of CO₂ during the heatwave. For crop sites, the most noticeable impacts were observed at the three maize-cropped sites, among which both FR-Gri (Paris area) and FR-Mej (Brittany) exhibited reduced photosynthetic activity and stomatal conductance (both up to about 50 %) in July, as plants had reached their maximal leaf development and soil moisture availability was limited. At the FR-Lam site, where maize was irrigated, no reduction in photosynthetic activity was observed; total crop production was even larger than usual. Heatwaves will become more common under climate change. Our results indicate that they will likely diminish ecosystems C sequestration. While the measured responses were expected (stomatal closure, its impact on photosynthesis, and increased respiration), modelling such events remains a challenge.

ano.nymous@ccsd.cnrs.fr.invalid (Pauline Buysse) 27 Oct 2023

https://hal.science/hal-04262493v1

[hal-02434220] TRY plant trait database – enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration , biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.

ano.nymous@ccsd.cnrs.fr.invalid (Jens Kattge) 09 Nov 2020

https://amu.hal.science/hal-02434220v1

[hal-03005990] Tree mode of death and mortality risk factors across Amazon forests

The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of tropical tree death remain largely unknown. Here we present a pan-Amazonian assessment of how and why trees die, analysing over 120,000 trees representing &gt; 3800 species from 189 long-term RAINFOR forest plots. While tree mortality rates vary greatly Amazon-wide, on average trees are as likely to die standing as they are broken or uprooted—modes of death with different ecological consequences. Species-level growth rate is the single most important predictor of tree death in Amazonia, with faster-growing species being at higher risk. Within species, however, the slowest-growing trees are at greatest risk while the effect of tree size varies across the basin. In the driest Amazonian region species-level bioclimatic distributional patterns also predict the risk of death, suggesting that these forests are experiencing climatic conditions beyond their adaptative limits. These results provide not only a holistic pan-Amazonian picture of tree death but large-scale evidence for the overarching importance of the growth–survival trade-off in driving tropical tree mortality.

ano.nymous@ccsd.cnrs.fr.invalid (Adriane Esquivel-Muelbert) 17 Nov 2020

https://hal.science/hal-03005990v1

[hal-03207504] Altered energy partitioning across terrestrial ecosystems in the European drought year 2018

Drought and heat events, such as the 2018 European drought, interact with the exchange of energy between the land surface and the atmosphere, potentially affecting albedo, sensible and latent heat fluxes, as well as CO 2 exchange. Each of these quantities may aggravate or mitigate the drought, heat, their side effects on productivity, water scarcity and global warming. We used measurements of 56 eddy covariance sites across Europe to examine the response of fluxes to extreme drought prevailing most of the year 2018 and how the response differed across various ecosystem types (forests, grasslands, croplands and peatlands). Each component of the surface radiation and energy balance observed in 2018 was compared to available data per site during a reference period 2004–2017. Based on anomalies in precipitation and reference evapotranspiration, we classified 46 sites as drought affected. These received on average 9% more solar radiation and released 32% more sensible heat to the atmosphere compared to the mean of the reference period. In general, drought decreased net CO 2 uptake by 17.8%, but did not significantly change net evapotranspiration. The response of these fluxes differed characteristically between ecosystems; in particular, the general increase in the evaporative index was strongest in peatlands and weakest in croplands. This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale’.

ano.nymous@ccsd.cnrs.fr.invalid (Alexander Graf) 25 Apr 2021

https://hal.inrae.fr/hal-03207504v1

[hal-03778635] The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

The FLUXNET2015 dataset provides ecosystem-scale data on CO 2 , water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.

ano.nymous@ccsd.cnrs.fr.invalid (Gilberto Pastorello) 16 Sep 2022

https://hal.science/hal-03778635v1

[hal-03051411] Energy, water and carbon exchanges in managed forest ecosystems: description, sensitivity analysis and evaluation of the INRAE GO+ model, version 3.0

The mechanistic model GO+ describes the functioning and growth of managed forests based upon biophysical and biogeochemical processes. The biophysical and biogeochemical processes included are modelled using standard formulations of radiative transfer, convective heat exchange, evapotranspiration, photosynthesis, respiration, plant phenology, growth and mortality, biomass nutrient content, and soil carbon dynamics. The forest ecosystem is modelled as three layers, namely the tree overstorey, understorey and soil. The vegetation layers include stems, branches and foliage and are partitioned dynamically between sunlit and shaded fractions. The soil carbon submodel is an adaption of the Roth-C model to simulate the impact of forest operations. The model runs at an hourly time step. It represents a forest stand covering typically 1 ha and can be straightforwardly upscaled across gridded data at regional, country or continental levels. GO+ accounts for both the immediate and long-term impacts of forest operations on energy, water and carbon exchanges within the soil–vegetation–atmosphere continuum. It includes exhaustive and versatile descriptions of management operations (soil preparation, regeneration, vegetation control, selective thinning, clear-cutting, coppicing, etc.), thus permitting the effects of a wide variety of forest management strategies to be estimated: from close to nature to intensive. This paper examines the sensitivity of the model to its main parameters and estimates how errors in parameter values are propagated into the predicted values of its main output variables.The sensitivity analysis demonstrates an interaction between the sensitivity of variables, with the climate and soil hydraulic properties being dominant under dry conditions but the leaf biochemical properties being most influential with wet soil. The sensitivity profile of the model changes from short to long timescales due to the cumulative effects of the fluxes of carbon, energy and water on the stand growth and canopy structure. Apart from a few specific cases, the model simulations are close to the values of the observations of atmospheric exchanges, tree growth, and soil carbon and water stock changes monitored over Douglas fir, European beech and pine forests of different ages. We also illustrate the capacity of the GO+ model to simulate the provision of key ecosystem services, such as the long-term storage of carbon in biomass and soil under various management and climate scenarios.

ano.nymous@ccsd.cnrs.fr.invalid (Virginie Moreaux) 10 Dec 2020

https://hal.inrae.fr/hal-03051411v1

[hal-02995533] Ecosystem transpiration and evaporation: insights from three water flux partitioning methods across FLUXNET sites

We apply and compare three widely applicable methods for estimating ecosystem transpiration (T) from eddy covariance (EC) data across 251 FLUXNET sites globally. All three methods are based on the coupled water and carbon relationship, but they differ in assumptions and parameterizations. Intercomparison of the three daily T estimates shows high correlation among methods (R between .89 and .94), but a spread in magnitudes of T/ET (evapotranspiration) from 45% to 77%. When compared at six sites with concurrent EC and sap flow measurements, all three EC‐based T estimates show higher correlation to sap flow‐based T than EC‐based ET. The partitioning methods show expected tendencies of T/ET increasing with dryness (vapor pressure deficit and days since rain) and with leaf area index (LAI). Analysis of 140 sites with high‐quality estimates for at least two continuous years shows that T/ET variability was 1.6 times higher across sites than across years. Spatial variability of T/ET was primarily driven by vegetation and soil characteristics (e.g., crop or grass designation, minimum annual LAI, soil coarse fragment volume) rather than climatic variables such as mean/standard deviation of temperature or precipitation. Overall, T and T/ET patterns are plausible and qualitatively consistent among the different water flux partitioning methods implying a significant advance made for estimating and understanding T globally, while the magnitudes remain uncertain. Our results represent the first extensive EC data‐based estimates of ecosystem T permitting a data‐driven perspective on the role of plants’ water use for global water and carbon cycling in a changing climate.

ano.nymous@ccsd.cnrs.fr.invalid (Jacob Nelson) 07 Jun 2022

https://hal.univ-lorraine.fr/hal-02995533v1

[hal-02974093] Territorialisation et écologisation dans la filière forêt-bois française : une rencontre fortuite ?

Cet article propose d’étudier les liens entre territorialisation et écologisation au sein de la filière forêt-bois française. Nous montrons que l’émergence parallèle des deux processus a permis de légitimer le territoire comme échelle pertinente de la mise en œuvre d’alternatives écologiques en forêt, mais aussi tout au long de la filière. Les changements de pratiques qui en résultent font apparaître aujourd’hui que les deux processus doivent être considérés comme concomitants, opérant à un moment clé dans la réorganisation des systèmes productifs et se nourrissant réciproquement, plutôt que réellement la cause ou la conséquence l’un de l’autre. Si les outils existants pour l’évaluation des pratiques sont pour l’essentiel au stade de développement, un front particulièrement fertile se développe à l’intersection des sciences de l’environnement et des sciences humaines.

ano.nymous@ccsd.cnrs.fr.invalid (Jonathan Lenglet) 12 Apr 2022

https://hal.science/hal-02974093v1

[hal-03006193] The pantropical response of soil moisture to El Niño

The 2015-2016 El Nino event ranks as one of the most severe on record in terms of the magnitude and extent of sea surface temperature (SST) anomalies generated in the tropical Pacific Ocean. Corresponding global impacts on the climate were expected to rival, or even surpass, those of the 1997-1998 severe El Nino event, which had SST anomalies that were similar in size. However, the 2015-2016 event failed to meet expectations for hydrologic change in many areas, including those expected to receive well above normal precipitation. To better understand how climate anomalies during an El Nino event impact soil moisture, we investigate changes in soil moisture in the humid tropics (between +/- 25 degrees) during the three most recent super El Nino events of 1982-1983,1997-1998 and 2015-2016, using data from the Global Land Data Assimilation System (GLDAS). First, we use in situ soil moisture observations obtained from 16 sites across five continents to validate and bias-correct estimates from GLDAS (r(2) = 0.54). Next, we apply a k-means cluster analysis to the soil moisture estimates during the El Nino mature phase, resulting in four groups of clustered data. The strongest and most consistent decreases in soil moisture occur in the Amazon basin and maritime southeastern Asia, while the most consistent increases occur over eastern Africa. In addition, we compare changes in soil moisture to both precipitation and evapotranspiration, which showed a lack of agreement in the direction of change between these variables and soil moisture most prominently in the southern Amazon basin, the Sahel and mainland southeastern Asia. Our results can be used to improve estimates of spatiotemporal differences in El Nino impacts on soil moisture in tropical hydrology and ecosystem models at multiple scales.

ano.nymous@ccsd.cnrs.fr.invalid (Kurt C Solander) 15 Nov 2020

https://hal.inrae.fr/hal-03006193v1

[hal-02934616] Phénotypage fin de la composition corporelle : calibration et comparaison directe de huit méthodes chez la chèvre laitière

Huit méthodes ont été comparées pour phénotyper la composition corporelle chez 20 chèvres laitières : la note d’état corporel (NEC), l’imagerie 3D pour estimer la NEC et reconstituer le corps entier, l’échographie, la tomodensitométrie (CT), le diamètre des adipocytes, l’espace de diffusion de l’eau deutérée (EDD2O) et l’impédancemétrie. Les différentes variables issues des méthodes testées ont été incluses dans des régressions linéaires pour déterminer la composition chimique du corps vide mesurée après abattage. Les équations les plus précises pour l’estimation de la masse de lipides combinent le poids vif et i) le poids total et le diamètre des adipocytes du tissu adipeux périrénal (R² = 0,95), ii) le volume des tissus gras mesuré par CT (R² = 0,92) ou iii) l’EDD2O (R² = 0,91). Les meilleures équations d’estimation de la masse de protéines incluent le poids vif et l’EDD2O (R² = 0,97) ou la NEC sternale (R² = 0,95). L’imagerie 3D corps entier et les mesures échographiques ne semblent pas être de bons estimateurs de la composition corporelle (R² ≤ 0.40).

ano.nymous@ccsd.cnrs.fr.invalid (S Lerch) 09 Sep 2020

https://hal.inrae.fr/hal-02934616v1

[hal-02565072] Why do forests respond differently to nitrogen deposition? A modelling approach

Elevated reactive nitrogen deposition can result in declines in belowground C allocation to mycorrhiza, potentially threatening the sustainability of forest ecosystems, especially with regard to ongoing global environmental changes. Previous studies showed that the vulnerability of mycorrhiza differs in different forests. In this paper, we introduce a model that explains such differences as resulting from the optimization of belowground tree C investment in forests with inorganic or organic N economy. According to the model, the optimization of belowground tree C investment in forests with organic N economy is governed by indirect competition between trees for available forms of N. We predict decreasing C investment in mycorrhiza with N deposition in systems dominated by an organic N economy. In contrast, in forests with inorganic N economy the optimization of belowground tree C investment is governed by direct competition between trees for available forms of N. We show that C investment in mycorrhiza does not depend on N deposition in the case of inorganic N economy. Parameterizing the model with data from spruce and beech temperate forests, we show that spruce forests are more sensitive to N deposition with a decrease of tree investment in mycorrhiza, which seems to be consistent with empirical findings. As mycorrhizae are essential for nutrients and water acquisition in trees, we suggest our approach could contribute to predicting the responses of forests to global environmental changes.

ano.nymous@ccsd.cnrs.fr.invalid (Pavel Rotter) 14 May 2020

https://hal.science/hal-02565072v1

[hal-02948750] Validation of Space-based albedo products from upscaled tower-based measurements over Heterogeneous and Homogeneous landscapes

Surface albedo is a fundamental radiative parameter as it controls the Earth’s energy budget and directly affects the Earth’s climate. Satellite observations have long been used to capture the temporal and spatial variations of surface albedo because of their continuous global coverage. However, space-based albedo products are often affected by errors in the atmospheric correction, multi-angular bi-directional reflectance distribution function (BRDF) modelling, as well as spectral conversions. To validate space-based albedo products, an in situ tower albedometer is often used to provide continuous “ground truth” measurements of surface albedo over an extended area. Since space-based albedo and tower-measured albedo are produced at different spatial scales, they can be directly compared only for specific homogeneous land surfaces. However, most land surfaces are inherently heterogeneous with surface properties that vary over a wide range of spatial scales. In this work, tower-measured albedo products, including both directional hemispherical reflectance (DHR) and bi-hemispherical reflectance (BHR), are upscaled to coarse satellite spatial resolutions using a new method. This strategy uses high-resolution satellite derived surface albedos to fill the gaps between the albedometer’s field-of-view (FoV) and coarse satellite scales. The high-resolution surface albedo is generated from a combination of surface reflectance retrieved from high-resolution Earth Observation (HR-EO) data and moderate resolution imaging spectroradiometer (MODIS) BRDF climatology over a larger area. We implemented a recently developed atmospheric correction method, the Sensor Invariant Atmospheric Correction (SIAC), to retrieve surface reflectance from HR-EO (e.g., Sentinel-2 and Landsat-8) top-of-atmosphere (TOA) reflectance measurements. This SIAC processing provides an estimated uncertainty for the retrieved surface spectral reflectance at the HR-EO pixel level and shows excellent agreement with the standard Landsat 8 Surface Reflectance Code (LaSRC) in retrieving Landsat-8 surface reflectance. Atmospheric correction of Sentinel-2 data is vastly improved by SIAC when compared against the use of in situ AErosol RObotic NETwork (AERONET) data. Based on this, we can trace the uncertainty of tower-measured albedo during its propagation through high-resolution EO measurements up to coarse satellite scales. These upscaled albedo products can then be compared with space-based albedo products over heterogeneous land surfaces. In this study, both tower-measured albedo and upscaled albedo products are examined at Ground Based Observation for Validation (GbOV) stations (https://land.copernicus.eu/global/gbov/), and used to compare with satellite observations, including Copernicus Global Land Service (CGLS) based on ProbaV and VEGETATION 2 data, MODIS and multi-angle imaging spectroradiometer (MISR).

ano.nymous@ccsd.cnrs.fr.invalid (Rui Song) 25 Oct 2023

https://hal.inrae.fr/hal-02948750v1

[hal-02541780] Carbon-nitrogen interactions in European forests and semi-natural vegetation - Part 1: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling

The impact of atmospheric reactive nitrogen (Nr) deposition on carbon (C) sequestration in soils and biomass of unfertilized, natural, semi-natural and forest ecosystems has been much debated. Many previous results of this dC∕dN response were based on changes in carbon stocks from periodical soil and ecosystem inventories, associated with estimates of Nr deposition obtained from large-scale chemical transport models. This study and a companion paper (Flechard et al., 2020) strive to reduce uncertainties of N effects on C sequestration by linking multi-annual gross and net ecosystem productivity estimates from 40 eddy covariance flux towers across Europe to local measurement-based estimates of dry and wet Nr deposition from a dedicated collocated monitoring network. To identify possible ecological drivers and processes affecting the interplay between C and Nr inputs and losses, these data were also combined with in situ flux measurements of NO, N2O and CH4 fluxes; soil NO−3 leaching sampling; and results of soil incubation experiments for N and greenhouse gas (GHG) emissions, as well as surveys of available data from online databases and from the literature, together with forest ecosystem (BASFOR) modelling.

ano.nymous@ccsd.cnrs.fr.invalid (Chris Flechard) 15 Jul 2020

https://hal.inrae.fr/hal-02541780v1

[hal-02934537] In vivo estimation of body composition: comparison of eight methods in dairy goats

The objective was to test 8 methods for estimation of empty body lipid (EBL) and protein (EBP) mass in dairy goats. The methods tested on 20 Alpine goats (3±0.6 years old; 226±9 DIM; 47 to 72 kg of BW) were: adipose cell size; deuterium oxide dilution space (D2OS); 3-dimension (3D) imaging: whole body 3D-scan and automatic 3D assessment of body condition score (3D-BCS); manual sternal and lumbar BCS and ultrasound imagery; computer tomography and bioelectrical impedance spectroscopy (BIS). Simple and multiple regressions (Proc GLM, SAS) were tested between different variables and EBL and EBP mass measured by chemical analyses after slaughter. Perirenal adipose tissue mass and cell diameter combined with BW provided the most accurate predictive equations for EBL (R2=0.95, residual coefficient of variation, rCV=12%). Nonetheless, such predictors can only be measured postmortem. The best equations for EBL derived from in vivo variables included BW combined with 1/ the volume of fatty tissues measured by computer tomography (R2=0.92, rCV=17%), 2/ the D2OS (R2=0.91, rCV=19%), and 3/ the BIS (R2=0.87, rCV=23%). D2OS combined with BW provided the best equation for EBP (R2=0.97, rCV=3%), whereas BW alone provided a fair EBP estimate (R2=0.92, rCV=4%). Manual BCS combined with BW provided good EBL and EBP estimations (R2=0.80 and 0.94, rCV=28 and 4%, respectively). BCS is a non-invasive technique and does not require particular equipment, but it is subjective and prone to operator bias. Compared to manual BCS, 3D-BCS combined with BW slightly decreased the accuracy of the predictive equation for EBL (R2=0.74, rCV=32%), and did not improve the estimation of EBP compared with BW alone. Ultrasound and whole body 3D imaging techniques were not satisfactory estimators of EBL and EBP (R2≤0.40).

ano.nymous@ccsd.cnrs.fr.invalid (Anne de La Torre) 09 Sep 2020

https://hal.inrae.fr/hal-02934537v1

[hal-02534416] Selecting for water use efficiency, wood chemical traits and biomass with genomic selection in a Eucalyptus breeding program

The selection of ideotypes combining high biomass production, high water use efficiency (WUE) and adequate wood properties is a major challenge in improving forest trees for industrial plantations. This issue was addressed in a field experiment evaluating 1130 clones of Eucalyptus urophylla * Eucalyptus grandis. Genomic selection using 3303 SNPs and the GBLUP model was carried out at age 55 months to select genitors and clones for stem volume (V55), WUE (using stable carbon isotope composition in stemwood, δ13C as a proxy, transformed into intrinsic WUE, Wi), as well as lignin (KL) and holocellulose (HCEL) contents. The variance components were mainly additive for δ13C(Wi), KL and HCEL, while they were highly non-additive for V55 (the ratio of dominance to additive variance was 130%). The narrow sense heritability was higher for Wi (h2 = 0.704) than for volume and wood traits (&lt;0.5), showing that this trait was under strong genetic control. Additive and total genetic correlations among traits were low (between −0.260 and 0.260) as were the correlations due to environmental effects (between −0.267 and 0.344), which suggests a rather independence among traits. The equal emphasis and the desired gain index selection methods were used to assess economic weights and to estimate the expected additive and total genetic gains. Different breeding objectives were defined with percentages weighting the economic coefficients or the desired gain for the equal emphasis or desired gain method, respectively. When the breeding objective gave emphasis to volume production using the percentages of 70%, 10%, 10%, and 10% for V55, HCEL, KL and Wi, respectively, positive gains were observed in both methods, but the correlation between index rankings were 0.686 and 0.635 for breeding and clonal selection, respectively. With a more balanced breeding objective using percentages such as 25%, 25%, 25%, 25% for V55, HCEL, KL and Wi, respectively, both index methods gave close positive gains and similar rankings, the correlation between index rankings ranging from 0.941 to 0.982 for parent selection and from 0.883 to 0.903 for clone selection. With more contrasted percentages between V55 and Wi, such as (80%, 10%, 10%, 0%) or (90%, 10%, 10%, −10%), the gain increased for V55 and was close to the maximum and decreased markedly for Wi. This study explores the magnitude of economic coefficients for index selection and shows that positive genetic gains can be achieved by associating biomass, a proxy of WUE and wood chemical traits. It provides encouraging results for selecting Eucalyptus varieties adapted to dry zones while maintaining good performances regarding other economic traits.

ano.nymous@ccsd.cnrs.fr.invalid (Jean-Marc Bouvet) 22 Aug 2022

https://hal.inrae.fr/hal-02534416v1

[hal-02938719] In situ 13CO2 labelling of rubber trees reveals a seasonal shift in the contribution of the carbon sources involved in latex regeneration

Rubber trees (Hevea brasiliensis) are the main source of natural rubber, extracted from latex, which exudes from the trunk after tapping. Tapped trees require large amounts of carbon (C) to regenerate the latex after its collection. Knowing the contribution of C sources involved in latex biosynthesis will help in understanding how rubber trees face this additional C demand. Whole crown 13CO2 pulse labelling was performed on 4-year-old rubber trees in June, when latex production was low, and in October, when it was high. 13C content was quantified in the foliage, phloem sap, wood, and latex. In both labelling periods, 13C was recovered in latex just after labelling, indicating that part of the carbohydrate was directly allocated to latex. However, significant amounts of 13C were still recovered in latex after 100 d and the peak was reached significantly later than in phloem sap, demonstrating the contribution of a reserve pool as a source of latex C. The contribution of new photosynthates to latex regeneration was faster and higher when latex metabolism was well established, in October, than in June. An improved understanding of C dynamics and the source–sink relationship in rubber tree is crucial to adapt tapping system practices and ensure sustainable latex production.

ano.nymous@ccsd.cnrs.fr.invalid (Ornuma Duangngam) 15 Sep 2020

https://hal.science/hal-02938719v1

[hal-02557077] Mining ecophysiological responses of European beech ecosystems to drought

The most accurate understanding of forest functioning during drought is crucial to improve the forecast of future forest productivity. Here we investigate the ecophysiological responses (i.e. primary production, evapotranspiration and water use efficiency) of European beech to drought events with the ecosystem model MuSICA, using as benchmark the observed fluxes at the experimental forest Hesse (France). We show that MuSICA is able to realistically simulate observed drought-induced limitations. Subsequently we use simulation experiments to provide: (1) a quantification of the reduction of ecosystem fluxes during the 2003 drought, (2) a partitioning of heat stress and water limitations during droughts, (3) an analysis of the impact of specific drought trajectories, and (4) an evaluation of the potential impact of projected climate change on the studied forest and (5) over the beech distributional range. Our results show that the 2003 drought resulted in a 17% reduction of annual gross primary production and in a 21% reduction of evapotranspiration at Hesse. The studied forest ecosystem is mostly sensitive to negative precipitation anomalies (82% of the reduced forest productivity in 2003) and almost insensitive to heat stress due to high temperatures (16%). Moreover, we show that the ecosystem fluxes are limited more by fast drought onsets in the early growing season (June-July) than by onsets later in the season. Deciphering the impact of future climate change on beech productivity is complicated by large uncertainties in projected future precipitation and in the severity of extreme dry years. Drastic reduction of ecosystem fluxes is only predicted with climate projections that show marked reductions in precipitation. However, increased CO2 fertilization in the future will counterbalance negative drought impacts. This modelling-based study improves our understanding of the functioning of an emblematic European tree species during extreme events and informs on potential future forest responses to projected climate change.

ano.nymous@ccsd.cnrs.fr.invalid (Fabio Gennaretti) 21 Dec 2021

https://hal.inrae.fr/hal-02557077v1

[hal-02544285] La croissance des forêts et les changements environnementaux

Les forêts de l’hémisphère nord sont plus productives qu’il y a plusieurs décennies. Telle est la tendance observée et quantifiée dans différentes études menées depuis les années 1970 et qui mettent en cause plusieurs facteurs : les modifications des régimes pluviothermiques, les dépôts azotés et l’augmentation de la concentration atmosphérique en dioxyde de carbone. À partir de données de l’inventaire forestier national, les auteurs de cet article se sont penchéssur l’évolution des forêts françaises. Leurs résultats à des échelles plus fines mettent en évidence des variations extrêmes (négative et positive) liées aux espèces et au contexte environnemental local qu’il conviendrait de suivre en « temps réel » compte tenu des grandes incertitudes futures liées au climat.

ano.nymous@ccsd.cnrs.fr.invalid (François F. Lebourgeois) 21 Apr 2020

https://hal.science/hal-02544285v1

[hal-02549007] Limiting factors of aspen radial growth along a climatic and soil water budget gradient in south-western Siberia

Understanding how climate and soil hydrology control tree growth is critical to predict the response of Siberian ecosystems to climate change. The general aim of this study was to (i) characterize the soil water budget and identify the factors controlling aspen (Populus tremula L.) radial growth in south-western Siberia, and (ii) assess its potential response to future climate change. Along a gradient of climate and soil hydrological conditions, soil water budgets were reconstructed by modeling at four sites, and dendrochronological analyses were performed. Aspen growth potential was simulated in response to different climate change scenarios represented by shifts in soil water budgets. Simulated soil water budgets varied with climate variables, specifically increased temperature and drier summer combined with varying winter precipitation occurring as snowfall.. We show that plant-available soil water and drainage gradually increased while stress decreased from the warmest and driest (south, forest-steppe zone) site to the coldest and wettest (north, southern taiga zone) site. Aspen radial growth was mainly limited by summer temperature in the north and by summer water deficit in the south. Surprisingly, we did not find clear evidence of snow level impact on radial growth, either positively in the south (water supply and protection against soil freezing) or negatively in the north (water-logging and drainage). In the context of climate change, water stress intensity could increase dramatically in the south inhibiting aspen growth; in those places summer soil water content depends on the refilling that occurs at snow-melt and increasing winter precipitation could alleviate stress levels. Conversely, in the north, aspen growth may mostly benefit from rising temperature.

ano.nymous@ccsd.cnrs.fr.invalid (Félix Bredoire) 21 Apr 2020

https://hal.inrae.fr/hal-02549007v1

[hal-02957456] Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought

Severe drought events are known to cause important reductions of gross primary productivity (GPP) in forest ecosystems. However, it is still unclear whether this reduction originates from stomatal closure (Stomatal Origin Limitation) and/or non-stomatal limitations (Non-SOL). In this study, we investigated the impact of edaphic drought in 2018 onGPPand its origin (SOL, NSOL) using a dataset of 10 European forest ecosystem flux towers. In all stations whereGPPreductions were observed during the drought, these were largely explained by declines in the maximum apparent canopy scale carboxylation rateV(CMAX,APP)(NSOL) when the soil relative extractable water content dropped below around 0.4. Concurrently, we found that the stomatal slope parameter (G(1), related to SOL) of the Medlynet al. unified optimization model linking vegetation conductance andGPPremained relatively constant. These results strengthen the increasing evidence that NSOL should be included in stomatal conductance/photosynthesis models to faithfully simulate bothGPPand water fluxes in forest ecosystems during severe drought. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

ano.nymous@ccsd.cnrs.fr.invalid (Louis Gourlez de La Motte) 05 Oct 2020

https://hal.inrae.fr/hal-02957456v1

[hal-02998427] Vers un site atelier de ruisseaux de plaine : la forêt de la Reine

La forêt de la Reine est un massif forestier de plus de 5000 ha, au Nord Est de la France. Cette forêt, qui est avant tout une grande zone humide qui alimente de nombreux cours d'eau temporaires, se situe au niveau de la plaine de la Woëvre, est ancienne, tirant son nom de la reine Brunehaut. En 1150, l’abbaye de Rangeval a été construite, accueillant des moines jusqu’à la Révolution française. Cs moines ont entretenu la forêt de la Reine jusqu’à la Révolution. De nombreux aménagements tels que des fossés ont été réalisés afin d’anticiper les potentiels risques d’inondation de la forêt et des cultures sous-jacentes, et d’améliorer la vie des villageois des alentours (aménagements de ruisseaux rectilignes pour l’alimentation en eau, création d’étangs, etc.). La conduite sylvicole de la forêt a été modifiée à plusieurs reprises depuis la fin du 17ème siècle. Il y a quelques années, le gestionnaire de la forêt (ONF) a entrepris de restaurer l’hydromorphologie de certains de ces petits cours, souvent temporaires, altérés chimiquement par les pratiques agricoles : retour au lit d’origine, mise en place de petits seuils poreux ou de déflecteurs en bois. Ces petits cours d’eau sont typiques des cours d’eau de tête de bassin versant lesquels représentent, selon les estimations, jusqu’à 80% du linéaire hydrographique total du bassin versant, contribuant ainsi de façon majeure à l’approvisionnement en eau des écosystèmes aval. Ils constituent un réceptacle final de la matière produite dans le bassin versant (matière allochtone), cette matière représentant la source principale de nutriments et d’énergie pour le fonctionnement de ces écosystèmes. Le projet « BV Plaine » vise à accroître nos connaissances sur ce type de cours d’eau pour lesquels il est difficile d’accéder à des milieux de référence. En s’appuyant sur une équipe interdisciplinaire, le projet « BV Plaine » assurera un suivi annuel, multiparamétrique, de quelques cours d’eau de tête de bassin versant, de référence et/ou restaurés, en plaine lorraine. Ce projet permettra de proposer ultérieurement un site observatoire original sur ces cours d’eau d’intérêt écologique et méconnus, de fédérer des chercheurs de la ZAM autour d’un même objet d’étude en y intégrant des sciences humaines, et d’acquérir des connaissances fondamentales sur le fonctionnement des cours d’eau de tête de bassin versant en plaine. Des études préalables sont en cours pour caractériser la topographie et le fonctionnement (débit, physico-chimie, biologie) de trois de ces petits cours d’eau, sous-affluents de la Moselle. Des appareils photographiques automatiques ont été installés pour suivre les évolutions des hauteurs d’eau en fonction des conditions météorologiques ainsi que le développement global de la végétation. Des campagnes de prélèvements ont été effectuées pour de premières caractérisations physico-chimiques (pH, conductivité, éléments majeurs, matière organique dissoute) et biologiques (prélèvements et identifications de macroinvertébrés aquatiques). Des contrastes chimiques sont d’ores et déjà visibles deux d’entre eux, pourtant distants de quelques centaines de mètres. Les communautés d’invertébrés sont également diversifiées, et incluent des espèces souvent peu étudiées et possédant des traits biologiques et écologiques caractéristiques des milieux temporaires.

ano.nymous@ccsd.cnrs.fr.invalid (Michael Danger) 10 Nov 2020

https://hal.univ-lorraine.fr/hal-02998427v1

[hal-03006008] Soil properties explain tree growth and mortality, but not biomass, across phosphorus-depleted tropical forests

We observed strong positive relationships between soil properties and forest dynamics of growth and mortality across twelve primary lowland tropical forests in a phosphorus-poor region of the Guiana Shield. Average tree growth (diameter at breast height) increased from 0.81 to 2.1 mm yr−1 along a soil texture gradient from 0 to 67% clay, and increasing metal-oxide content. Soil organic carbon stocks in the top 30 cm ranged from 30 to 118 tons C ha−1, phosphorus content ranged from 7 to 600 mg kg−1 soil, and the relative abundance of arbuscular mycorrhizal fungi ranged from 0 to 50%, all positively correlating with soil clay, and iron and aluminum oxide and hydroxide content. In contrast, already low extractable phosphorus (Bray P) content decreased from 4.4 to <0.02 mg kg−1 in soil with increasing clay content. A greater prevalence of arbuscular mycorrhizal fungi in more clayey forests that had higher tree growth and mortality, but not biomass, indicates that despite the greater investment in nutrient uptake required, soils with higher clay content may actually serve to sustain high tree growth in tropical forests by avoiding phosphorus losses from the ecosystem. Our study demonstrates how variation in soil properties that retain carbon and nutrients can help to explain variation in tropical forest growth and mortality, but not biomass, by requiring niche specialization and contributing to biogeochemical diversification across this region.

ano.nymous@ccsd.cnrs.fr.invalid (Jennifer Soong) 24 Jun 2022

https://hal.science/hal-03006008v1

[hal-03167870] The forestry & wood sector and climate change mitigation: From carbon sequestration in forests to the development of the bioeconomy

While the main challenge in intertropical and boreal regions is tackling deforestation and forest resource degradation, forests and forestry in temperate regions face what may appear to be contradictory goals: to increase atmospheric carbon capture through sequestration in biomass and soils, while providing a growing share of the resources needed to produce essential material goods and energy for human societies as well as gradually renewing forests to enable them to adapt to future climate conditions. Creating a balance between these potentially competing priorities has been the subject of intense societal and scientific debate in recent years, which has prompted us to examine all aspects of these issues in greater depth. INRAE and IGN, at the request of the French Ministries responsible for agriculture and forestry, have jointly undertaken a scientific assessment to shed light on the details of this debate, using the example of forests and the forestry & wood sectors in metropolitan France. The results of this important exercise are presented in this book.

ano.nymous@ccsd.cnrs.fr.invalid (Antoine Colin) 12 Mar 2021

https://hal.inrae.fr/hal-03167870v1

[hal-03966065] Using herbarium specimens to highlight the long term change of herbaceous plant growth in western European forests.

[...]

ano.nymous@ccsd.cnrs.fr.invalid (Jean-Claude Gegout) 31 Jan 2023

https://hal.science/hal-03966065v1

[hal-02931277] A Machine-Learning Approach for Classifying Defects on Tree Trunks using Terrestrial LiDAR

Three-dimensional data are increasingly prevalent in forestry thanks to terrestrial LiDAR. This work assesses the feasibility for an automated recognition of the type of local defects present on the bark surface. These sin-gularities are frequently external markers of inner defects affecting wood quality, and their type, size, and frequency are major components of grading rules. The proposed approach assigns previously detected abnormalities in the bark roughness to one of the defect types: branches, branch scars, epi-cormic shoots, burls, and smaller defects. Our machine learning approach is based on random forests using potential defects shape descriptors, including Hu invariant moments, dimensions, and species. The results of our experiments involving different French commercial species, oak, beech, fir, and pine showed that most defects were well classified with an average F 1 score of 0.86.

ano.nymous@ccsd.cnrs.fr.invalid (Van-Tho Nguyen) 05 Sep 2020

https://hal.science/hal-02931277v1

[hal-03045938] Natura 2000 forest habitats: climatic debt in lowlands and thermophilization in highlands

Natura 2000 is a European network of sites dedicated to the conservation of vulnerable habitats. The definitions of Natura 2000 habitats are mainly based on plant communities. We investigated if the increase of the dominance of warm-adapted species observed in plant communities, described as thermophilization, had already led to measurable changes in Natura 2000 forest habitats. We created 5701 pairs of neighboring forest plots by gathering plots surveyed before 1987 and after 1997 to reflect historical and recent climatic conditions. A Natura 2000 habitat type was assigned to each vegetation plot using an automatic classification program. We calculated a temperature index that synthesized the temperature range of each habitat, and compared the habitat temperature indexes of the recent and historical plots of each pair. We highlighted a significant overall shift of 4.8% ± 1.78 (CI 95%) of the pairs toward warmer habitats over the studied period. While the shift was not significant in lowlands, 11.1% ± 3.0 (CI 95%) of the pairs evolved toward warmer habitats in highlands. The excess of pairs with a warmer habitat in the recent period was interpreted as thermophilization of Natura 2000 forest habitats. Therefore, global warming has been strong enough to induce actual changes at the coarse-grained habitat resolution specifically targeted by public policies. The absence of significant results in lowlands suggests the existence of unrealized potential habitat changes, which can be considered as a climatic debt. These results call for differential prioritization levels and implementations of public policies for nature conservation in lowlands and highlands.

ano.nymous@ccsd.cnrs.fr.invalid (Lise Maciejewski) 21 Apr 2023

https://hal.science/hal-03045938v1

[hal-03014264] Snow cover duration trends observed at sites and predicted by multiple models

Abstract. Thirty-year simulations of seasonal snow cover in 22 physically based models driven with bias-corrected meteorological reanalyses are examined at four sites with long records of snow observations. Annual snow cover durations differ widely between models but interannual variations are strongly correlated because of the common driving data. No significant trends are observed in starting dates for seasonal snow cover, but there are significant trends towards snow cover ending earlier at two of the sites in observations and most of the models. A simplified model with just two parameters controlling solar radiation and sensible heat contributions to snowmelt spans the ranges of snow cover durations and trends. This model predicts that sites where snow persists beyond annual peaks in solar radiation and air temperature will experience rapid decreases in snow cover duration with warming as snow begins to melt earlier and at times of year with more energy available for melting.

ano.nymous@ccsd.cnrs.fr.invalid (Richard Essery) 05 Jan 2021

https://hal.science/hal-03014264v2

[hal-02959147] Drought effects on resource partition and conservation among leaf ontogenetic stages in epiphytic tank bromeliads

Studying the response to drought stress of keystone epiphytes such as tank bromeliads is essential to better understand their resistance capacity to future climate change. The objective was to test whether there is any variation in the carbon, water and nutrient status among different leaf ontogenetic stages in a bromeliad rosette subjected to a gradient of drought stress. We used a semi-controlled experiment consisting in a gradient of water shortage in Aechmea aquilega and Lutheria splendens. For each bromeliad and drought treatment, three leaves were collected based on their position in the rosette and several functional traits related to water and nutrient status, and carbon metabolism were measured. We found that water status traits (relative water content, leaf succulence, osmotic and midday water potentials) and carbon metabolism traits (carbon assimilation, maximum quantum yield of photosystem II, chlorophyll and starch contents) decreased with increasing drought stress, while leaf soluble sugars and carbon, nitrogen and phosphorus contents remained unchanged. The different leaf ontogenetic stages showed only marginal variations when subjected to a gradient of drought. Resources were not reallocated between different leaf ontogenetic stages but we found a reallocation of soluble sugars from leaf starch reserves to the root system. Both species were capable of metabolic and physiological adjustments in response to drought. Overall, this study advances our understanding of the resistance of bromeliads faced with increasing drought stress and paves the way for in-depth reflection on their strategies to cope with water shortage.

ano.nymous@ccsd.cnrs.fr.invalid (Mia Svensk) 06 Oct 2020

https://hal.science/hal-02959147v1

[hal-02948795] A portable, low-cost relaxed eddy accumulation (REA) system for quantifying ecosystem-level fluxes of volatile organics

Quantification of biogenic volatile organic compound (BVOC) fluxes into the atmosphere is crucial to understand their role in atmospheric oxidation and biogeochemical cycles. BVOC flux measurements were carried out in nine forest ecosystems using a relaxed eddy accumulation (REA) based sampling system, which is easily transportable, simple to operate and designed to be low-cost and therefore can easily be deployed at multiple remote locations. The REA measurements were carried out during daytime between 06:00 and 18:30 (Local Time) with a flux averaging period of 30 min. A detailed description of the REA sampling setup, operational procedure and validation by comparison with full eddy covariance (EC) BVOC flux measurements is provided. BVOC flux measurements from established long-term carbon and water flux tower sites in nine forest ecosystems are compared including Manitou Forest Observatory in Colorado, USA (pine woodland forest), Niwot Ridge AmeriFlux site in Colorado, USA (subalpine forest), Deer Canyon Preserve in New Mexico, USA (pinyon-juniper forest), Lei bamboo forest site near Taihuyuan, China, Qianyanzhou ChinaFLUX site in China (pine forest), Baskett Wildfire Refuge MOFlux site in Missouri, USA (deciduous oak forest), University of Michigan Biological Station PROPHET site in Michigan, USA (mixed deciduous forest), Changbai Mountain Forest Research Station in China (mixed deciduous forest) and the Guyaflux site (GF-Guy) in French Guiana (tropical rainforest). BVOC flux measurements using our REA setup confirm dominance of 2,3,2- methylbutenol (2,3,2-MBO) at the Manitou Forest Observatory and Niwot Ridge sites in Colorado. Monoterpene fluxes measured by REA showed good agreement (within ±10%) with monoterpene fluxes measured by PTR-MS at the Manitou Forest Observatory. The MOFlux site in Missouri was dominated by isoprene emissions (average flux of ~ 9.5 mg m−2 h−1) whereas the Deer Canyon site was dominated by α-pinene emissions (average flux ~ 0.73 mg m−2 h−1). Mixed deciduous forest sites at the PROPHET Station in Michigan and Changbai Mountain Forest Research Station in China primarily emitted isoprene along with some α-pinene, β-pinene and d-Limonene. Isoprene and α-pinene were the dominant BVOCs emitted from the subtropical Lei bamboo plantation at the Taihuyuan site in China while the pine forest site at Qianyanzhou in China were dominated by α-pinene emissions along with significant isoprene. BVOC measurements across different seasons (during 2009–2011) at a tropical forest site in French Guiana (Guyaflux site) revealed the dominance of isoprene emissions during all seasons. Irrespective of the type of the forest ecosystem, α-pinene was among the dominant monoterpenes emitted from all nine forests.

ano.nymous@ccsd.cnrs.fr.invalid (Chinmoy Sarkar) 31 Aug 2021

https://hal.inrae.fr/hal-02948795v1

[hal-02949790] A standard protocol for reporting species distribution models

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ano.nymous@ccsd.cnrs.fr.invalid (Damaris Zurell) 12 Nov 2020

https://hal.inrae.fr/hal-02949790v1

[hal-03048253] Vegetation unit assignments: phytosociology experts and classification programs show similar performance but low convergence

Aims: Assigning vegetation plots to vegetation units is a key step in biodiversity management projects. Nevertheless, the process of plot assignment to types is usually non-standardized, and assignment consistency remains poorly explored. To date, the efficiency of automatic classification programs has been assessed by comparing them with a unique expert judgment. Therefore, we investigated the consistency of five phytosociology expert judgments, and the consistency of these judgements with those of automatic classification programs. Location: Mainland France. Methods: We used 273 vegetation plots distributed across France and covering the diversity of the temperate and mountainous forest ecosystems of Western Europe. We asked a representative panel of five French organizations with recognized expertise in phytosociology to assign each plot to vegetation units. We provided a phytosociological classification including 228 associations, 43 alliances and eight classes. The assignments were compared among experts using an agreement ratio. We then compared the assignments suggested by three automatic classification programs with the expert judgments. Results: We observed small differences among the agreement ratios of the expert organizations; a given expert organization agreed with another one on association assignment one time in four on average, and one time in two on alliance assignment. The agreement ratios of the automatic classification programs were globally lower, but close to expert judgments. Conclusions: The results support the current trend toward unifying the existing classifications and specifying the assignment rules by creating guiding tools, which will decrease inter-observer variation. As compared to a pool of phytosociology experts, programs perform similarly to individual experts in vegetation unit assignment, especially at the alliance level. Although programs still need to be improved, these results pave the way for the creation of habitat time series crucial for the monitoring and conservation of biodiversity.

ano.nymous@ccsd.cnrs.fr.invalid (Lise Maciejewski) 03 May 2022

https://hal.science/hal-03048253v1

[hal-03257738] Pflanzen im Rhythmus der Jahreszeiten beobachten

Wie reagiert die Natur auf den Klimawandel? Pflanzen im Rhythmus der Jahreszeiten beobachten. Mit 60 ausgewählten Pflanzen, deren Beobachtung phänologisch besonders interessant ist. Mit detaillierten Fotografien und Zeichnungen. Wann blüht das Busch-Windröschen, wann färben sich die Blätter des Feld-Ahorns? Dieser Beobachtungsführer bietet sämtliche Informationen, um in die phänologische Beobachtung der Pflanzen einzusteigen. Denn im Gegensatz zu den meteorologischen Jahreszeiten unterscheiden sich Anfang und Ende der phänologischen Jahreszeiten von Jahr zu Jahr sowie nach Region. Die charakteristischen Entwicklungsstadien typischer Pflanzen zeigen an, wo wir uns im phänologischen Jahr befinden. Jede der 60 Arten, die als phänologischer Marker dienen, wird detailliert vorgestellt: Identifikationsmerkmale, Ökologie und Verbreitung, Kalender des Jahreszyklus, Fotografien der Stadien.

ano.nymous@ccsd.cnrs.fr.invalid (Vincent Badeau) 11 Jun 2021

https://agroparistech.hal.science/hal-03257738v1

[hal-02504844] Selective and taxon-dependent effects of semi-feral cattle grazing on tree regeneration in an old-growth Mediterranean mountain forest

[...]

ano.nymous@ccsd.cnrs.fr.invalid (Xavier Fortuny) 11 Mar 2020

https://univ-lyon1.hal.science/hal-02504844v1

[hal-02942642] Sensitivity of gross primary productivity to climatic drivers during the summer drought of 2018 in Europe

In summer 2018, Europe experienced a record drought, but it remains unknown how the drought affected ecosystem carbon dynamics. Using observations from 34 eddy covariance sites in different biomes across Europe, we studied the sensitivity of gross primary productivity (GPP) to environmental drivers during the summer drought of 2018 versus the reference summer of 2016. We found a greater drought-induced decline of summer GPP in grass- lands (−38%) than in forests (−10%), which coincided with reduced evapotranspiration and soil water content (SWC). As com- pared to the ‘normal year’ of 2016, GPP in different ecosystems exhibited more negative sensitivity to summer air temperature (Ta) but stronger positive sensitivity to SWC during summer drought in 2018, that is, a stronger reduction of GPP with soil moisture deficit. We found larger negative effects of Ta and vapour pressure deficit (VPD) but a lower positive effect of photosynthetic photon flux density on GPP in 2018 compared to 2016, which contributed to reduced summer GPP in 2018. Our results demonstrate that high temperature-induced increases in VPD and decreases in SWC aggravated drought impacts on GPP.

ano.nymous@ccsd.cnrs.fr.invalid (Zheng Fu) 18 Sep 2020

https://hal.inrae.fr/hal-02942642v1

[hal-02870299] Which oak provenances for the 22nd century in Western Europe? Dendroclimatology in common gardens

The current distribution area of the two sympatric oaks Quercus petraea and Q. robur covers most of temperate Western Europe. Depending on their geographic location, populations of these trees are exposed to different climate constraints, to which they are adapted. Comparing the performances of trees from contrasting populations provides the insight into their expected resilience to future climate change required for forest management. In this study, the descendants of 24 Q. petraea and two Q. robur provenances selected from sites throughout Europe were grown for 20 years in three common gardens with contrasting climates. The 2420 sampled trees allowed the assessments of the relationship between radial growth and climate. An analysis of 15-year chronologies of ring widths, with different combinations of climate variables, revealed different response patterns between provenances and between common gardens. As expected, provenances originating from sites with wet summers displayed the strongest responses to summer drought, particularly in the driest common garden. All provenances displayed positive significant relationships between the temperature of the previous winter and radial growth when grown in the common garden experiencing the mildest winter temperatures. Only eastern provenances from continental cold climates also clearly expressed this limitation of growth by cold winter temperatures in the other two common gardens. However, ecological distance, calculated on the basis of differences in climate between the site of origin and the common garden, was not clearly related to the radial growth responses of the provenances. This suggests that the gradient of genetic variability among the selected provenances was not strictly structured according to climate gradients. Based on these results, we provide guidelines for forest managers for the assisted migration of Quercus petraea and Q. robur provenances.

ano.nymous@ccsd.cnrs.fr.invalid (Didier Bert) 08 Jan 2021

https://hal.science/hal-02870299v1

[hal-03029648] Diversity and potentiality of multi-criteria decision analysis methods for agri-food research

AbstractThere is a growing demand for moving towards sustainable agri-food systems which per nature covers a complex network of activities and domains; such systems will benefit from multi-criteria decision analysis (MCDA) methods. Although some reviews on MCDA in agri-food research have been published, none of them covered the whole value chain. In this article, a corpus of 954 articles published by INRA scientists from 2007 to 2017 was used to study the diversity and potentiality of MCDA techniques. For the first time, experts from more than 10 agri-food domains worked altogether to annotate the articles, carry out a multivariate analysis, and finally interpret the statistical results to identify the specificities of certain domains and the complementarities between domains and to suggest avenues for future agri-food research. One-third of the studies were based only on a list of indicators, even when their purpose was to choose, sort, or rank options. Regardless of the scientific discipline in the agri-food sector, MCDA studies rarely considered temporal dynamics, spatial scale changes, or stakeholder contributions. As the agri-food system becomes increasingly sustainable in the near future, the use of MCDA methods will accelerate. To become more effective, they will have to include ecosystem services, even outside the scope of ecological studies. Similarly, MCDA studies will need to include participatory science to involve stakeholders (i.e., public authorities, governmental agencies) and end-users (i.e., farmers, producers, industrials, consumers) in the construction of the multi-criteria evaluation but also in the resulting decisions.

ano.nymous@ccsd.cnrs.fr.invalid (Geneviève Gésan-Guiziou) 22 Nov 2021

https://hal.inrae.fr/hal-03029648v1

[hal-03179773] Temporal trends in tree defoliation and response to multiple biotic and abiotic stresses

The vitality of forests depends on multiple biotic and abiotic stresses that can act in an interactive way. Tree defoliation levels are therefore subject to long-term changes and shorter-term hazards that need to be monitored in the context of ongoing climate change. In this study, we analysed the combined effects of drought, insect attack and tree nutritional status on the level of defoliation in three major hardwood species in Europe: European beech (Fagus sylvatica), sessile oak (Quercus petraea) and pedunculate oak (Quercus robur). The forest condition data set was collected in the long-term intensive monitoring network in France (RENECOFOR). The average level of defoliation observed was 20% but varied considerably between plots and trees. From 1997 to 2015, beech defoliation worsened by 10% while oak defoliation stabilized over time. For the three tree species, crown defoliation was generally higher in the event of insect attack (increased by 2.6% to 7.5% depending on the tree species) and under drought (increased by 5.9%), while the effect of the tree nutritional statue was less consistent (from - 5.6% to + 10%) these factors acting synergistically. This study highlights the fact that the different stresses a tree species undergoes act in a complex and interactive way, with species-specific responses. In a context of increasing abiotic and biotic stresses, their combined analysis appears to be a necessity at a time when forest owners need to adapt their management to cope with climate change, particularly through the choice of tree species to be favoured in the future.

ano.nymous@ccsd.cnrs.fr.invalid (Maude Toïgo) 25 Aug 2022

https://hal.inrae.fr/hal-03179773v1

[hal-02948828] Microgeographic local adaptation and ecotype distributions: The role of selective processes on early life‐history traits in sympatric, ecologically divergent Symphonia populations

Trees are characterized by the large number of seeds they produce. Although most of those seeds will never germinate, plenty will. Of those which germinate, many die young, and eventually, only a minute fraction will grow to adult stage and reproduce. Is this just a random process? Do variations in germination and survival at very young stages rely on variations in adaptations to microgeographic heterogeneity? and do these processes matter at all in determining tree species distribution and abundance?We have studied these questions with the Neotropical Symphonia tree species. In the Guiana shield, Symphonia are represented by at least two sympatric taxa or ecotypes, Symphonia globulifera found almost exclusively in bottomlands, and a yet undescribed more generalist taxon/ecotype, Symphonia sp1. A reciprocal transplantation experiment (510 seeds, 16 conditions) was set up and followed over the course of 6 years to evaluate the survival and performance of individuals from different ecotypes and provenances.Germination, survival, growth, and herbivory showed signs of local adaptation, with some combinations of ecotypes and provenances growing faster and surviving better in their own habitat or provenance region. S. globulifera was strongly penalized when planted outside its home habitat but showed the fastest growth rates when planted in its home habitat, suggesting it is a specialist of a high‐risk high‐gain strategy. Conversely, S. sp1 behaved as a generalist, performing well in a variety of environments.The differential performance of seeds and seedlings in the different habitats matches the known distribution of both ecotypes, indicating that environmental filtering at the very early stages can be a key determinant of tree species distributions, even at the microgeographic level and among very closely related taxa. Furthermore, such differential performance also contributes to explain, in part, the maintenance of the different Symphonia ecotypes living in intimate sympatry despite occasional gene flow.

ano.nymous@ccsd.cnrs.fr.invalid (Niklas Tysklind) 30 Sep 2020

https://hal.science/hal-02948828v1

[hal-03040730] In situ estimation of genetic variation of functional and ecological traits in Quercus petraea and Q. robur

Predicting the evolutionary potential of natural tree populations requires the estimation of heritability and genetic correlations among traits on which selection acts, as differences in evolutionary success between species may rely on differences for these genetic parameters. In situ estimates are expected to be more accurate than measures done under controlled conditions which do not reflect the natural environmental variance. The aim of the current study was to estimate three genetic parameters (i.e., heritability, evolvability, and genetic correlations) in a natural mixed oak stand composed of Quercus petraea and Quercus robur about 100 years old, for 58 traits of ecological, and functional relevance (growth, reproduction, phenology, physiology, resilience, structure, morphology, and defense). First, we estimated genetic parameters directly in situ using realized genomic relatedness of adult trees and parentage relationships over two generations to estimate the traits' additive variance. Secondly, we benefited from existing ex situ experiments (progeny tests and conservation collection) installed with the same populations, thus allowing comparisons of in situ heritability estimates with more traditional methods. Heritability and evolvability estimates obtained with different methods varied substantially and showed large confidence intervals; however, we found that in situ were less precise than ex situ estimates, and assessments over two generations (with deeper relatedness) improved estimates of heritability while large sampling sizes are needed for accurate estimations. At the biological level, heritability values varied moderately across different ecological and functional categories of traits, and genetic correlations among traits were conserved over the two species. We identified limits for using realized genomic relatedness in natural stands to estimate the genetic variance, given the overall low variance of genetic relatedness and the rather low sampling sizes of currently used long-term genetic plots in forestry. These limits can be overcome if larger sample sizes are considered, or if the approach is extended over the next generation.

ano.nymous@ccsd.cnrs.fr.invalid (Hermine Alexandre) 16 Sep 2024

https://hal.inrae.fr/hal-03040730v1

[hal-02927318] How does contemporary selection shape oak phenotypes?

Most existing forests are subjected to natural and human-mediated selection pressures, which have increased due to climate change and the increasing needs of human societies for wood, fibre and fuel resources. It remains largely unknown how these pressures trigger evolutionary changes. We address this issue here for temperate European oaks (Quercus petraeaandQ. robur), which grow in mixed stands, under even-aged management regimes. We screened numerous functional traits for univariate selection gradients and for expected and observed genetic changes over two successive generations. In both species, growth, leaf morphology and physiology, and defence-related traits displayed significant selection gradients and predicted shifts, whereas phenology, water metabolism, structure and resilience-related traits did not. However, the direction of the selection response and the potential for adaptive evolution differed between the two species.Quercus petraeahad a much larger phenotypic and genetic variance of fitness thanQ. robur. This difference raises concerns about the adaptive response ofQ. roburto contemporary selection pressures. Our investigations suggest thatQ. roburwill probably decline steadily, particularly in mixed stands withQ. petraea, consistent with the contrasting demographic dynamics of the two species.

ano.nymous@ccsd.cnrs.fr.invalid (Hermine Alexandre) 01 Sep 2020

https://hal.inrae.fr/hal-02927318v1

[hal-02948749] The global distribution of leaf chlorophyll content

Leaf chlorophyll is central to the exchange of carbon, water and energy between the biosphere and the atmosphere, and to the functioning of terrestrial ecosystems. This paper presents the first spatially-continuous view of terrestrial leaf chlorophyll content (Chl(Leaf)) at the global scale. Weekly maps of Chl(Leaf) were produced from ENVISAT MERIS full resolution (300 m) satellite data using a two-stage physically-based radiative transfer modelling approach. Firstly, leaf-level reflectance was derived from top-of-canopy satellite reflectance observations using 4-Scale and SAIL canopy radiative transfer models for woody and non-woody vegetation, respectively. Secondly, the modelled leaf-level reflectance was input into the PROSPECT leaf-level radiative transfer model to derive Chl(Leaf). The Chl(Leaf) retrieval algorithm was validated using measured Chi(Leaf) data from 248 sample measurements at 28 field locations, and covering six plant functional types (PFTs). Modelled results show strong relationships with field measurements, particularly for deciduous broadleaf forests (R-2 = 0.67; RMSE = 9.25 mu g cm(-2); p < 0.001), croplands (R-2 = 0.41; RMSE = 13.18 mu g cm(-2); p < 0.001) and evergreen needleleaf forests (R-2 = 0.47; RMSE = 10.63 mu g cm(-2); p < 0.001). When the modelled results from all PFTs were considered together, the overall relationship with measured Chl(Leaf )remained good (R-2 = 0.47, RMSE = 10.79 mu g cm(-2); p < 0.001). This result is an improvement on the relationship between measured Chl(Leaf) and a commonly used chlorophyll-sensitive spectral vegetation index; the MERIS Terrestrial Chlorophyll Index (MTCI; R-2 = 0.27, p < 0.001). The global maps show large temporal and spatial variability in Chl(Leaf), with evergreen broadleaf forests presenting the highest leaf chlorophyll values, with global annual median values of 54.4 mu g cm(-2). Distinct seasonal Chl(Leaf) phenologies are also visible, particularly in deciduous plant forms, associated with budburst and crop growth, and leaf senescence. It is anticipated that this global Chl(Leaf) product will make an important step towards the explicit consideration of leaf-level biochemistry in terrestrial water, energy and carbon cycle modelling.

ano.nymous@ccsd.cnrs.fr.invalid (H. Croft) 25 Oct 2023

https://hal.inrae.fr/hal-02948749v1

[hal-03043585] Traits controlling shade tolerance in tropical montane trees

Tropical canopies are complex, with multiple canopy layers and pronounced gap dynamics contributing to their high species diversity and productivity. An important reason for this complexity is the large variation in shade tolerance among di erent tree species. At present, we lack a clear understanding of which plant traits control this variation, e.g., regarding the relative contributions of whole-plant versus leaf traits or structural versus physiological traits. We investigated a broad range of traits in six tropical montane rainforest tree species with di erent degrees of shade tolerance, grown under three di erent radiation regimes (under the open sky or beneath sparse or dense canopies). The two distinct shade-tolerant species had higher fractional biomass in leaves and branches while shade-intolerant species invested more into stems, and these di erences were greater under low radiation. Leaf respiration and photosynthetic light compensation point did not vary with species shade tolerance, regardless of radiation regime. Leaf temperatures in open plots were markedly higher in shade-tolerant species due to their low transpiration rates and large leaf sizes. Our results suggest that interspeci c variation in shade tolerance of tropical montane trees is controlled by species di erences in whole-plant biomass allocation strategy rather than by di erence in physiological leaf traits determining leaf carbon balance at low radiation.

ano.nymous@ccsd.cnrs.fr.invalid (Elisée Bahati Ntawuhiganayo) 07 Dec 2020

https://hal.science/hal-03043585v1

[hal-02527995] Distribution of soil properties along forest-grassland interfaces: Influence of permanent environmental factors or land-use after-effects?

Soil properties vary spatially according to land use; both because land users have selected specific soil properties for specific land uses, and land uses modify the soil properties. However, permanent environment factors and land-use effects are unlikely to display the exact same spatial patterns. Study of the spatial and historical patterns of distribution of soil properties could help to separate between these two causes. In this aim, we studied 22 forest-grassland interfaces with controlled historical configurations in northeast France. In each land use (forest and grassland), three distances to the edge (edge, periphery and core) and two land-use histories (ancient and recent) were studied.Along forest-grassland interfaces, forests were usually located slightly upslope of grasslands, and mainly because this non-random topographic position the topsoil texture was significantly more silty in forests, and clayey in grasslands. After statistically controlling for the effects of topography and soil texture, we observed two main gradients of variation in soil properties according to the distance-to-edge (acidity in forest and nutrient content in grassland). In forest, pH and Ca dropped from the edges to the peripheries (15 m distance), while in grassland, C, N, P and Na sharply increased from the edges to the cores (25 m distance). These results demonstrate, through the edge effect, the strong influence of the land use on a part of soil properties. Furthermore, less than two centuries after grassland afforestation or deforestation, we observed that soil properties in recent forests and recent grasslands were respectively closer to their current land use than to their former land use. These results demonstrate a rapid change in soil properties after land-use change. However, recent forests and recent grasslands kept a legacy of soil texture from their former land use, respectively. Recent grasslands also kept a lower soil density, N and Na content compared to ancient grasslands.Hence, this study of forest-grassland interfaces show strong and short-scale relationships between land use and soil properties and suggest that they express both original choices of land users for specific soil properties and land-use after-effects. The non-random topographic position of the forest-grassland interfaces indicates a conscious choice of this positioning by the land users, for agronomic reasons. Beyond that, land use, through vegetation composition and management practices, also has a strong impact on soil properties. The fact that land-use changes affect most soil properties after only a few decades confirms the existence of land-use effects over time.

ano.nymous@ccsd.cnrs.fr.invalid (Maxime Burst) 21 Dec 2021

https://hal.inrae.fr/hal-02527995v1

[hal-03043589] Contrasting Dependencies of Photosynthetic Capacity on Leaf Nitrogen in Early- and Late-Successional Tropical Montane Tree Species

Differences in photosynthetic capacity among tree species and tree functional types are currently assumed to be largely driven by variation in leaf nutrient content, particularly nitrogen (N). However, recent studies indicate that leaf N content is often a poor predictor of variation in photosynthetic capacity in tropical trees. In this study, we explored the relative importance of area-based total leaf N content (N tot) and within-leaf N allocation to photosynthetic capacity versus light-harvesting in controlling the variation in photosynthetic capacity (i.e. V cmax , J max) among mature trees of 12 species belonging to either early (ES) or late successional (LS) groups growing in a tropical montane rainforest in Rwanda, Central Africa. Photosynthetic capacity at a common leaf temperature of 25˚C (i.e. maximum rates of Rubisco carboxylation, V cmax25 and of electron transport, J max25) was higher in ES than in LS species (+ 58% and 68% for V cmax25 and J max25 , respectively). While N tot did not significantly differ between successional groups, the photosynthetic dependency on N tot was markedly different. In ES species, V cmax25 was strongly and positively related to N tot but this was not the case in LS species. However, there was no significant trade-off between relative leaf N investments in compounds maximizing photosynthetic capacity versus compounds maximizing light harvesting. Both leaf dark respiration at 25˚C (+ 33%) and, more surprisingly, apparent photosynthetic quantum yield (+ 35%) was higher in ES than in LS species. Moreover, R d25 was positively related to N tot for both ES and LS species. Our results imply that efforts to quantify carbon fluxes of tropical montane rainforests would be improved if they considered contrasting within-leaf N allocation and photosynthetic N tot dependencies between species with different successional strategies.

ano.nymous@ccsd.cnrs.fr.invalid (Camille Ziegler) 07 Dec 2020

https://hal.science/hal-03043589v1

[hal-03206201] Valuation de la ressource territoriale et formes de circularité : la labellisation dans la filière forêt-bois française (Alpes, Jura, Vosges)

La multiplication des labels territoriaux dans le secteur forêt-bois semble s’inscrire en réponse aux pressions croissantes et combinées d’une économie mondialisée et aux exigences sociales et environnementales, conditions d’un développement durable. Partant des développements récents en économie territoriale, nous élargissons la question de la spécification de la ressource bois par l’analyse des modalités de sa valuation. À travers l’étude des démarches de labellisation dans les Alpes, les Vosges et le Jura, nous analysons les portefeuilles de valeur construits et mobilisés par le collectif et nous mettons en évidence les différentes formes de circularité qui y sont liées. Nous montrons que les labels bois se construisent de plus en plus surdes valeurs de territorialité, à travers l’activation de différentes formes de proximité. Encore très récentes, ces démarches s’instiguent en « contre-normes » et remettent en cause le modèle productif dominant sur la base d’alternatives territorialisées.

ano.nymous@ccsd.cnrs.fr.invalid (Jonathan Lenglet) 23 Apr 2021

https://agroparistech.hal.science/hal-03206201v1

[hal-02948755] Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests

Selective logging, fragmentation, and understory fires directly degrade forest structure and composition. However, studies addressing the effects of forest degradation on carbon, water, and energy cycles are scarce. Here, we integrate field observations and high‐resolution remote sensing from airborne lidar to provide realistic initial conditions to the Ecosystem Demography Model (ED‐2.2) and investigate how disturbances from forest degradation affect gross primary production (GPP), evapotranspiration (ET), and sensible heat flux (H). We used forest structural information retrieved from airborne lidar samples (13,500 ha) and calibrated with 817 inventory plots (0.25 ha) across precipitation and degradation gradients in the eastern Amazon as initial conditions to ED‐2.2 model. Our results show that the magnitude and seasonality of fluxes were modulated by changes in forest structure caused by degradation. During the dry season and under typical conditions, severely degraded forests (biomass loss ≥66%) experienced water stress with declines in ET (up to 34%) and GPP (up to 35%) and increases of H (up to 43%) and daily mean ground temperatures (up to 6.5°C) relative to intact forests. In contrast, the relative impact of forest degradation on energy, water, and carbon cycles markedly diminishes under extreme, multiyear droughts, as a consequence of severe stress experienced by intact forests. Our results highlight that the water and energy cycles in the Amazon are driven by not only climate and deforestation but also the past disturbance and changes of forest structure from degradation, suggesting a much broader influence of human land use activities on the tropical ecosystems.

ano.nymous@ccsd.cnrs.fr.invalid (Marcos Longo) 13 Oct 2020

https://hal.inrae.fr/hal-02948755v1

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Productions 2020

HAL : Dernières publications

[hal-02948753] The global abundance of tree palms

[hal-02650649] Long-term thermal sensitivity of Earth’s tropical forests

[hal-04262493] Short-term impacts of the summer 2019 heatwave on ecosystem functioning inferred from ICOS flux towers in France

[hal-02434220] TRY plant trait database – enhanced coverage and open access

[hal-03005990] Tree mode of death and mortality risk factors across Amazon forests

[hal-03207504] Altered energy partitioning across terrestrial ecosystems in the European drought year 2018

[hal-03778635] The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

[hal-03051411] Energy, water and carbon exchanges in managed forest ecosystems: description, sensitivity analysis and evaluation of the INRAE GO+ model, version 3.0

[hal-02995533] Ecosystem transpiration and evaporation: insights from three water flux partitioning methods across FLUXNET sites

[hal-02974093] Territorialisation et écologisation dans la filière forêt-bois française : une rencontre fortuite ?

[hal-03006193] The pantropical response of soil moisture to El Niño

[hal-02934616] Phénotypage fin de la composition corporelle : calibration et comparaison directe de huit méthodes chez la chèvre laitière

[hal-02565072] Why do forests respond differently to nitrogen deposition? A modelling approach

[hal-02948750] Validation of Space-based albedo products from upscaled tower-based measurements over Heterogeneous and Homogeneous landscapes

[hal-02541780] Carbon-nitrogen interactions in European forests and semi-natural vegetation - Part 1: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling

[hal-02934537] In vivo estimation of body composition: comparison of eight methods in dairy goats

[hal-02534416] Selecting for water use efficiency, wood chemical traits and biomass with genomic selection in a Eucalyptus breeding program

[hal-02938719] In situ 13CO2 labelling of rubber trees reveals a seasonal shift in the contribution of the carbon sources involved in latex regeneration

[hal-02557077] Mining ecophysiological responses of European beech ecosystems to drought

[hal-02544285] La croissance des forêts et les changements environnementaux

[hal-02549007] Limiting factors of aspen radial growth along a climatic and soil water budget gradient in south-western Siberia

[hal-02957456] Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought

[hal-02998427] Vers un site atelier de ruisseaux de plaine : la forêt de la Reine

[hal-03006008] Soil properties explain tree growth and mortality, but not biomass, across phosphorus-depleted tropical forests

[hal-03167870] The forestry & wood sector and climate change mitigation: From carbon sequestration in forests to the development of the bioeconomy

[hal-03966065] Using herbarium specimens to highlight the long term change of herbaceous plant growth in western European forests.

[hal-02931277] A Machine-Learning Approach for Classifying Defects on Tree Trunks using Terrestrial LiDAR

[hal-03045938] Natura 2000 forest habitats: climatic debt in lowlands and thermophilization in highlands

[hal-03014264] Snow cover duration trends observed at sites and predicted by multiple models

[hal-02959147] Drought effects on resource partition and conservation among leaf ontogenetic stages in epiphytic tank bromeliads

[hal-02948795] A portable, low-cost relaxed eddy accumulation (REA) system for quantifying ecosystem-level fluxes of volatile organics

[hal-02949790] A standard protocol for reporting species distribution models

[hal-03048253] Vegetation unit assignments: phytosociology experts and classification programs show similar performance but low convergence

[hal-03257738] Pflanzen im Rhythmus der Jahreszeiten beobachten

[hal-02504844] Selective and taxon-dependent effects of semi-feral cattle grazing on tree regeneration in an old-growth Mediterranean mountain forest

[hal-02942642] Sensitivity of gross primary productivity to climatic drivers during the summer drought of 2018 in Europe

[hal-02870299] Which oak provenances for the 22nd century in Western Europe? Dendroclimatology in common gardens

[hal-03029648] Diversity and potentiality of multi-criteria decision analysis methods for agri-food research

[hal-03179773] Temporal trends in tree defoliation and response to multiple biotic and abiotic stresses

[hal-02948828] Microgeographic local adaptation and ecotype distributions: The role of selective processes on early life‐history traits in sympatric, ecologically divergent Symphonia populations

[hal-03040730] In situ estimation of genetic variation of functional and ecological traits in Quercus petraea and Q. robur

[hal-02927318] How does contemporary selection shape oak phenotypes?

[hal-02948749] The global distribution of leaf chlorophyll content

[hal-03043585] Traits controlling shade tolerance in tropical montane trees

[hal-02527995] Distribution of soil properties along forest-grassland interfaces: Influence of permanent environmental factors or land-use after-effects?

[hal-03043589] Contrasting Dependencies of Photosynthetic Capacity on Leaf Nitrogen in Early- and Late-Successional Tropical Montane Tree Species

[hal-03206201] Valuation de la ressource territoriale et formes de circularité : la labellisation dans la filière forêt-bois française (Alpes, Jura, Vosges)

[hal-02948755] Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests