The GenTree Dendroecological Collection, tree-ring and wood density data from seven tree species across Europe

The dataset presented here was collected by the GenTree project (EU-Horizon 2020), which aims to improve the use of forest genetic resources across Europe by better understanding how trees adapt to their local environment. This dataset of individual tree-core characteristics including ring-width series and whole-core wood density was collected for seven ecologically and economically important European tree species: silver birch (Betula pendula), European beech (Fagus sylvatica), Norway spruce (Picea abies), European black poplar (Populus nigra), maritime pine (Pinus pinaster), Scots pine (Pinus sylvestris), and sessile oak (Quercus petraea). Tree-ring width measurements were obtained from 3600 trees in 142 populations and whole-core wood density was measured for 3098 trees in 125 populations. This dataset covers most of the geographical and climatic range occupied by the selected species. The potential use of it will be highly valuable for assessing ecological and evolutionary responses to environmental conditions as well as for model development and parameterization, to predict adaptability under climate change scenarios

Between but not within species variation in the distribution of fitness effects

New mutations provide the raw material for evolution and adaptation. The distribution of fitness effects (DFE) describes the spectrum of effects of new mutations that can occur along a genome, and is therefore of vital interest in evolutionary biology. Recent work has uncovered striking similarities in the DFE between closely related species, prompting us to ask whether there is variation in the DFE among populations of the same species, or among species with different degrees of divergence, i.e., whether there is variation in the DFE at different levels of evolution. Using exome capture data from six tree species sampled across Europe we characterised the DFE for multiple species, and for each species, multiple populations, and investigated the factors potentially influencing the DFE, such as demography, population divergence and genetic background. We find statistical support for there being variation in the DFE at the species level, even among relatively closely related species. However, we find very little difference at the population level, suggesting that differences in the DFE are primarily driven by deep features of species biology, and that evolutionarily recent events, such as demographic changes and local adaptation, have little impact

The GenTree Platform: growth traits and tree-level environmental data in 12 European forest tree species

Background: Progress in the field of evolutionary forest ecology has been hampered by the huge challenge of phenotyping trees across their ranges in their natural environments, and the limitation in high-resolution environmental information. Findings: The GenTree Platform contains phenotypic and environmental data from 4,959 trees from 12 ecologically and economically important European forest tree species: Abies alba Mill. (silver fir), Betula pendula Roth. (silver birch), Fagus sylvatica L. (European beech), Picea abies (L.) H. Karst (Norway spruce), Pinus cembra L. (Swiss stone pine), Pinus halepensis Mill. (Aleppo pine), Pinus nigra Arnold (European black pine), Pinus pinaster Aiton (maritime pine), Pinus sylvestris L. (Scots pine), Populus nigra L. (European black poplar), Taxus baccata L. (English yew), and Quercus petraea (Matt.) Liebl. (sessile oak). Phenotypic (height, diameter at breast height, crown size, bark thickness, biomass, straightness, forking, branch angle, fructification), regeneration, environmental in situ measurements (soil depth, vegetation cover, competition indices), and environmental modeling data extracted by using bilinear interpolation accounting for surrounding conditions of each tree (precipitation, temperature, insolation, drought indices) were obtained from trees in 194 sites covering the species’ geographic ranges and reflecting local environmental gradients. Conclusion: The GenTree Platform is a new resource for investigating ecological and evolutionary processes in forest trees. The coherent phenotyping and environmental characterization across 12 species in their European ranges allow for a wide range of analyses from forest ecologists, conservationists, and macro-ecologists. Also, the data here presented can be linked to the GenTree Dendroecological collection, the GenTree Leaf Trait collection, and the GenTree Genomic collection presented elsewhere, which together build the largest evolutionary forest ecology data collection available

Traitement et valorisation des effluents en circuit court par la production de biomasse: Synthèse des principaux résultats

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Carbon and nutrient dynamics in short-rotation coppice of poplar and willow in a converted marginal land, a case study in central France

International audienceBioenergy woody biomass production shortens the life cycle of carbon and secures energy supplies. However, using fast growing trees in these woody crop systems such as in short rotation coppices (SRCs), implies an increasing risk of depleting the soil nutrient stocks by direct biomass removal and low nutrient return. The aim of this study was to quantify the impact of these woody crop systems after 4 years of growth on the soil quality (C and nutrient cycling) by monitoring tree components (i.e. shoot, litterfall, root system) instead of soils; C and nutrient contents in weed strips were also included into these analyses. Our results indicated that shoot biomass was similar in SRC-P and SRC-W 2 years after planting (4 t ha(-1)). However, after 4 years, willow outperformed poplar (21.9 vs. 8.6 t ha(-1), respectively) removing until 30 % of K soil pool. Litterfall increased between first and second rotation coppices (0.85 vs. 4 t ha(-1)) similarly for SRC-P and SRC-W, indicating biomass exportation and return were strongly imbalanced in SRCs crop systems. N pool in weed strips represented a significant contribution to N cycling in these SRC woody crop systems due to the presence of N-2-fixing plants. However, no differences were detected between poplar and willow crops. In low quality agricultural soils, which are the likely host for SRC implementation, we demonstrated that willow has a higher nutrient accumulation rate than poplar, particularly for K, Mg and P. Weed strips constitute an important reservoir of C and nutrients and should be studied further

Early effects of two planting densities on growth dynamics and water-use efficiency in Robinia pseudoacacia (L.) and Populus deltoides (Bartr. ex Marsh.) × P. nigra (L.) short rotation plantations

International audience& Key message Black locust is an interesting option for biomass production at sites prone to water shortage because the species combines water-use efficiency and a biomass yield largely superior to that of poplars under the conditions of the study. & Context Black locust (Robinia pseudoacacia L.) is an interesting tree species for woody biomass production. However, its potential for this purpose has been much less studied and characterized than that for species from the Salicaceae family (i.e., poplar and willow). & Aims The objective of our study was to evaluate the potential of black locust for biomass production as compared to that of poplar. & Methods We estimated biomass production, growth habit, and efficiency of water use of two provenances of black locust (1) compared to those of poplar (Populus deltoides Bartr. ex Marsh. × P. nigra L.), (2) at two planting densities, and (3) 2 and 4 years after planting

Relationships between change in total P stock of the plough layer and P balance after 15 years of composts applications

Understanding soil phosphorus (P) changes under continuous cropping over decades is an important agronomic and environmental issue. The objective of this study was to examine changes in total P stock of the plough soil layer of a cultivated ecosystem in relation to P balance. The long-term field experiment Qualiagro (INRA – Veolia Environnement) was established at Feucherolles, France, in 1998. Five treatments were designed and replicated in four blocks. Farmyard manure (FYM) and three types of composts (Municipal Solid Waste (MSW), Biowastes (BIOW) and Green Waste + Sewage Sludges (GWS)) were applied every two years at a rate of 4 t C ha-1. A control received no organic amendment. Changes of total P stock in the plough layer (0-28 cm) were compared to cumulated soil P balance since 1998, calculated as the difference between cumulated P input, as supplied through organic amendment and at seedling, and cumulated P output, by harvest of grains and crop residues if removed. Total soil P content and bulk soil density were determined at five soil sampling dates, crop yield and P content were measured annually. Cumulated P input for the 1998-2013 period ranged from 340 to 1695 kg P ha-1 for MSW and GWS respectively. Cumulated P export by crops was influenced by treatments. Soil bulk density increased less in amended soils than in control. A linear relationship between total soil P stock variation and soil P balance was found, close to the 1:1 line. These results confirm that P outputs through erosion, runoff and leaching were negligible. Contribution of subsoil to crop nutrition was estimated to be close to 0.5-1 kg P ha-1

Estimation of Genetic Parameters of Biomass Production and Composition Traits in Miscanthus sinensis Using a Staggered-Start Design

International audienceTraits for biomass production and composition make Miscanthus a promising bioenergy crop for different bioconversion routes. They need to be considered in miscanthus breeding programs as they are subjected to genetic and genetic x environment factors. The objective was to estimate the genetic parameters of an M. sinensis population grown during 4 years in two French locations. In each location, the experiment was established according to a staggered-start design in order to decompose the year effect into age and climate effects. Linear mixed models were used to estimate genetic variance, genotype x age, genotype x climate interaction variances, and residual variances. Individual plant broad-sense heritability means ranged from 0.42 to 0.62 for biomass production traits and were more heritable than biomass composition traits with means ranging from 0.26 to 0.47. Heritability increased through age for most of the biomass production and composition traits. Low genetic variance along with large genotype x age and genotype x climate interaction variances tended to decrease the heritability of biomass production traits for young plant ages. Most of the production traits showed large interaction variances for age and climate in both locations, while biomass composition traits highlighted large interaction variances due to climate in Orleans. The genetic and phenotypic correlations between biomass production and composition traits were positive, while hemicelluloses were negatively correlated with all traits. Selection is difficult on young plants as the heritability is too low. The joint improvement of biomass production and composition traits would help provide a better response of miscanthus to selection

Linkage Mapping of Biomass Production and Composition Traits in a Miscanthus sinensis Population

International audienceBreeding miscanthus for biomass production and composition is essential for targeting high-yielding genotypes suited to different end-uses. Our objective was to understand the genetic basis of these traits in M. sinensis, according to different plant ages and environmental conditions. A diploid population was established in two locations according to a staggered-start design, which distinguished the plant age effect from climatic condition effect. An integrated genetic map of 2602 SNP markers distributed across 19 LGs was aligned with the M. sinensis reference genome and spanned 2770 cM. The QTL mapping was based on best linear unbiased predictions estimated across three climatic conditions and at least three ages in both locations. A total of 260 and 283 QTL were related to biomass production and composition traits, respectively. In each location, 40-60% were related to biomass production traits and stable across different climatic conditions and ages and 30% to biomass composition traits. Twelve QTL clusters were established based on either biomass production or composition traits and validated by high genetic correlations between the traits. Sixty-two putative M. sinensis genes, related to the cell wall, were evidenced in the QTL clusters of biomass composition traits and orthologous to those of sorghum and maize. Twelve of them were differentially expressed and belonged to gene families related to the cell wall biosynthesis identified in other miscanthus studies. These stable QTL constitute new insights into marker-assisted selection (MAS) breeding while offering a joint improvement of biomass production and composition traits