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All reforestation methods can support tropical tree diversity recovery, but drivers and species composition vary
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/616505/)International audienceTropical landscapes are undergoing rapid transformation due to human activities and global change. Forest restoration has emerged as a key strategy to mitigate biodiversity loss and climate warming. However, a standardized assessment of how different restoration methods contribute to biodiversity recovery and conservation remains lacking. Here, we present the first comprehensive comparison of tree diversity restoration and the drivers of recovery across five main reforestation methods (naturally regenerating forests, biodiverse restoration plantings, short- and long-rotation tree monocultures, agroforests) relative to three reference systems (agropastoral lands, degraded and conserved forest remnants). Tree inventories were conducted in 519 plots (900 m2 each) across two forest types (rainforest and seasonally dry forest) in the Atlantic forest of São Paulo state, Brazil, encompassing over 39,000 trees and 869 species. We found that: (1) all reforestation methods except short-rotation monoculture plots supported tree diversity recovery. In the rainforest, conserved remnant plots maintained the highest average Shannon diversity (Hill 1 = 29 ± 14), while naturally regenerating forests and restoration plantings approached the diversity of degraded remnant plots (15 ± 5). In seasonally dry forest, biodiverse restoration plantings and agroforests reached diversity levels comparable to conserved remnants (15 ± 6). Additionally, (2) recovery was influenced by forest age, climate (water availability), soil fertility, and landscape context, though the relative importance of these factors varied by method. Climate and landscape context were more influential for recovery in naturally regenerating forests, while soil conditions played a greater role in biodiverse restoration plantings. Lastly, (3) species composition in naturally regenerating forests most closely resembled that of conserved remnants. Conversely, restoration plantings and agroforests exhibited high compositional overlap across sites, reducing overall species richness. Our findings underscore the wide variation in biodiversity outcomes among and within reforestation methods, emphasizing that goals and strategies must align with local conditions to maximize benefits in complex tropical landscapes
From demand deficit to development strategy: Navigating mini-grid viability in a fragile context
No full textInternational audienceFour in five people without access to electricity live in Sub-Saharan Africa, where mini-grids are seen as a key solution. Yet investment remains constrained by low and unpredictable demand, especially in fragile settings. We study electricity demand in North Kivu (Democratic Republic of Congo), using pre-grid census and survey data combined with six years of post-connection consumption records. Five key findings emerge: (i) demand is highly heterogeneous across and within localities, with pockets of low uptake; (ii) pre-grid covariates explain some variation but have limited predictive power for realized connection and consumption; (iii) SMEs consume far more per connection than households while making up a small share of connections; (iv) consumption rises after connection and then plateaus, indicating slow movement up the energy ladder; (v) conflict shocks temporarily depress consumption, but usage rebounds, highlighting resilience in the face of insecurity. We further examine how an integrated, demand-building strategy by the local operator can partially mitigate these challenges. The case highlights that mini-grid viability in fragile settings may depend less on improved demand forecasting and more on the capacity to build and coordinate demand alongside infrastructure, with implications for policy design, risk-sharing finance, and the role of public and donor support
Changes in phenology mediate vertebrate population responses to temperature globally
No full textInternational audiencePhenotypic responses to climate affect individual fitness, but the extent to which this translates into effects on population dynamics remains poorly understood. We assemble 213 time series on phenotypes and population sizes of wild vertebrates globally and match them with local climate data. Our meta-analysis shows that morphological traits are mostly climate insensitive. However, phenology is earlier in warmer-than-average years, which contributes positively to population growth in most species. At lower latitudes, temperature has weaker effects on phenology but stronger direct negative effects on population growth, likely because these populations are less capable of tracking climate via plasticity. Variation in the phenology-mediated effect of temperature on population growth cannot be explained by latitude, generation time, migratory mode, or diet. This suggests that simple relationships between species characteristics and population responses to warming may not occur in nature. Instead, we may need to embrace ecological complexity by considering local-scale predictors that capture intra-specific variation
Does Working from Home Pollute? The Environmental Effects of Wfh
No full textInternational audienceWork-from-home (WFH) arrangements experienced an unprecedented boom since the Covid-19 crisis, raising questions about their environmental impact. This study investigates the causal effect of WFH on PM2.5 concentrations, the most harmful air pollutant globally, using high-resolution pollution data and employment records from France. We find that WFH contributes to higher PM2.5 levels, particularly in areas with a high prevalence of home-based workers. Our analysis reveals that residential emissions outweigh the reduction in transport-related pollution, leading to a net increase in air pollution. These findings highlight the need for policymakers to address the environmental challenges associated with the growing prevalence of WFH, particularly through energy efficiency improvements and cleaner residential heating technologies
Stimulation de la voie des phénylpropanoïdes par application de phénylalanine chez la fraise et la tomate pour le contrôle de Botrytis cinerea
No full textInternational audienceLa fraise (Fragaria × ananassa) et la tomate (Solanum lycopersicum) sont deux cultures économiquement importantes sensibles au champignon Botrytis cinerea, responsable de la pourriture grise au champ et sur les fruits lors du stockage post-récolte. Face aux enjeux environnementaux et sanitaires liés à l’usage des fongicides de synthèse, stimuler les défenses des plantes via la voie des phénylpropanoïdes apparaît comme une alternative prometteuse (Ramaroson et al., 2022). Cette voie métabolique débute par la conversion de la phénylalanine (Phe) en acide trans-cinnamique via l’enzyme phénylalanine ammonia-lyase (PAL). Les composés phénoliques produits, notamment les flavonoïdes, stilbènes ou acides phénoliques, contribuent à la résistance aux pathogènes via des fonctions antioxydantes, structurelles et de signalisation (Saini et al., 2024). Des travaux récents montrent que l’application exogène de Phe peut induire une résistance accrue des plantes à des infections fongiques. L’application préventive d’une solution de 4,1 mM de Phe confère une résistance à B. cinerea sur feuilles détachées de tomate (Oliva et al., 2020). Sur fraise, des pulvérisations de 10 mM en pré- ou post-récolte diminuent la sensibilité des fruits sans affecter leur qualité (Pons et al., 2025). L’effet de la Phe semble indirect, via l’induction de métabolites de défense par la plante (Oliva et al., 2020), et son efficacité accrue proche de la récolte pourrait s’expliquer par une métabolisation rapide de la Phe en composés actifs (Kumar Patel et al., 2020). L’étude vise à (1) explorer l’effet de différents paramètres sur l’efficacité de la protection induite par la pulvérisation de Phe contre B. cinerea (dose, moment d’application, génotype de la plante, souches de l’agent pathogène) sur fraise et tomate, (2) développer une compréhension fine de la métabolisation de la Phe dans ces conditions, et (3) évaluer l’impact de ce traitement sur la qualité et la conservation des fruits
La gestion de l’eau : défi majeur pour l’humanité, nouvel enjeu de recherche sur l’innovation
No full textInternational audienceLa gestion de l’eau est devenue un enjeu majeur pour l’innovation, du fait de la pression anthropique croissante sur cette ressource, accentuée par le changement climatique. Elle constitue un domaine particulier d’innovation car l’eau est un bien commun, qui circule sur la planète, qui est nécessaire à la vie et à tous les secteurs économiques, et dont la gestion combine étroitement des dimensions technologiques, organisationnelles, institutionnelles et sociales. L’article précise ces enjeux et appelle à un renforcement des échanges entre « Water Studies » et « Innovation Studies », l’objectif qui a motivé le forum innovation 2023 « innover pour une gestion durable et concertée de l’eau ». Après une synthèse des fronts possibles de recherche entre ces deux communautés, l’article introduit les articles de ce numéro spécial d’ Innovations , en montrant leurs contributions complémentaires pour une analyse des innovations dans des situations contrastées de gestion de l’eau sur la planète
Lighting up the underground: Enhancing growth-ring detection in grassland subshrubs using autofluorescence and histochemistry
No full textInternational audienceHighlights: • Autofluorescence is a useful tool to identify rings and cell types in shrubby wood. • FASGA staining improved contrast between fibers and parenchyma, aiding ring limits. • Mäule staining highlighted ring boundaries based on lignin type (S/G) differences. • Underground organs had high starch reserves, indicating energy storage for resprout.Abstract: Growth rings in woody plants form in response to seasonal variation in the environment and are fundamental to dendrochronological studies, but estimating plant ages—especially in underexplored growth forms such as forbs, shrubs and subshrubs from grasslands—remains challenging. Here, we address a knowledge gap in the anatomy and histochemistry of subshrubs from natural Cerrado grasslands and evaluate their potential for dendrochronological applications. We studied underground woody organs of Jacaranda decurrens, Lippia lupulina, and Mandevilla longiflora, collected at the Santa Bárbara Ecological Station (Brazil). We used autofluorescence microscopy and a suite of histochemical tests targeting structural and non-structural compounds. Autofluorescence allowed spatial assessment of wood tissues without staining, and improved growth-ring visualization. FASGA staining increased contrast between fibers and parenchyma, facilitating tissue discrimination and growth-ring delimitation, while Mäule staining highlighted differences in cell-wall composition and guaiacyl/syringyl (G/S) ratios throughout growth-ring formation. Starch was consistently detected in parenchymatic cells of all species (lowest in J. decurrens, intermediate in L. lupulina, highest in M. longiflora), and its spatial association with parenchyma aided growth-ring identification. Combining fluorescence and histochemical approaches provides complementary insights into the anatomy and chemistry of underground organs and advances dendrochronological studies in grassland ecosystems
Bulletin de veille du réseau d'écotoxicologie terrestre et aquatique N°79
No full textINRAE, réseau ECOTOX → A paraîtreBulletin de veill
Polyploidy modulates the adaptation to water deficit in citrus scion/rootstock associations evaluated under controlled pot condition and relates to specific changes in root and leaf transcriptome
No full textData availability: The RNA-seq data underlying this article are available in Gene Expression Omnibus (GEO) database at: https://www.ncbi.nlm.nih.gov/geo, and can be accessed with the project accession number: GSE255759.International audienceHighlights: • Tetraploid rootstocks with triploid scions enhance drought tolerance in pots. • In pots, 4x rootstocks better regulate water loss under drought conditions. • ABA levels under stress are higher in 4× than in 2× rootstocks. • DEGs involved in transport, stress response and protective barrier formation. • Polyploidy shows strong potential to improve citrus drought resilience.Abstract: Citrus, one of the world's most important crops, is facing significant challenges due to drought events. Previous studies have demonstrated that tetraploid rootstocks may exhibit greater tolerance to abiotic stresses than their diploid counterparts. The effects of combining a tetraploid rootstock with a triploid scion under water deficit conditions have not been thoroughly explored. A water deficit experiment was conducted under controlled pot conditions using four citrus scion/rootstock combinations: diploid and tetraploid Swingle citrumelo rootstocks grafted with diploid Mexican lime and triploid Persian lime. Physiological, biochemical, and transcriptomic analyses under controlled pot condition revealed that tetraploid rootstocks exhibited significantly improved performance under drought stress, with an even greater effect when the scion was the triploid Persian lime. In that condition, the improved resilience was associated with reduced water consumption, higher photosynthesis, increased stomatal conductance and transpiration under water stress conditions. Elevated abscisic acid levels and stronger antioxidant activity in polyploid rootstocks further contributed to the stress response. Transcriptomic data revealed distinct gene expression changes in roots and leaves, influenced by organ ploidy and rootstock-scion interactions. Taken together our results provide insights into drought adaptation mechanisms including osmotic adjustment, oxidative stress protection, sustained photosynthesis, antioxidant enzyme activity and enhanced synthesis of protective barriers. These findings underscore ploidy's role at both rootstock and scion levels in shaping the plant's response to water deficit, revealing useful interactions between rootstock and scion influencing drought resilience
Large-scale genome-wide association study of 398,238 women unveils seven novel loci associated with high-grade serous epithelial ovarian cancer risk
No full textInternational audienceABSTRACT Background Nineteen genomic regions have been associated with high-grade serous ovarian cancer (HGSOC). We used data from the Ovarian Cancer Association Consortium (OCAC), Consortium of Investigators of Modifiers of BRCA1 / BRCA2 (CIMBA), UK Biobank (UKBB), and FinnGen to identify novel HGSOC susceptibility loci and develop polygenic scores (PGS). Methods We analyzed >22 million variants for 398,238 women. Associations were assessed separately by consortium and meta-analysed. OCAC and CIMBA data were used to develop PGS which were trained on FinnGen data and validated in UKBB and BioBank Japan Results Eight novel variants were associated with HGSOC risk. An interesting discovery biologically was finding that TP53 3’-UTR SNP rs78378222 was associated with HGSOC (per T allele relative risk (RR)=1.44, 95%CI:1.28-1.62, P=1.76×10 -9 ). The optimal PGS included 64,518 variants and was associated with an odds ratio of 1.46 (95%CI:1.37-1.54) per standard deviation in the UKBB validation (AUROC curve=0.61, 95%CI:0.59-0.62). Conclusions This study represents the largest GWAS for HGSOC to date. The results highlight that improvements in imputation reference panels and increased sample sizes can identify HGSOC associated variants that previously went undetected, resulting in improved PGS. The use of updated PGS in cancer risk prediction algorithms will then improve personalized risk prediction for HGSOC