PLANTS, PEOPLE, PLANET

Climatic and biogeographic variables are often used as a proxy for tree genetic diversity, but local factors can also influence it. We propose that woodland age, presence of ancient trees, and population size could impact genetic diversity. Using the RBG Kew UK National Tree Seed Project as a study case, we examined how these factors are accounted for during seed collection. We found 42% of tree seed collections come from ancient woodlands and that 8.4% overlap with ancient trees. Sampled forest patches size ranges from few individuals to several thousand. We then carried out a pilot to examine the role of population size on functional traits variation, testing the relationship between population size and seed germination and seedling thermal stress sensitivity in three populations of the Betula pubescens Ehrh. complex. We found that seeds and seedlings from larger populations showed higher fitness and stress resistance. Our results highlight the importance of local factors to predict variation in functional traits, relevant for tree resilience. Existing seed collections of native species stored in conservation seed banks offer a valuable resource to explore these factors and improve our understanding of genetic diversity in tree populations, with implications for biodiversity conservation and forestry production.

(1) BackgroundSaffron crocus (Crocus sativus) is the source of saffron, the most expensive spice in the world. It evolved about 3000 years ago as a sterile triploid clone in Greece. Since then, saffron has spread across the globe, where regionally distinct practices of saffron cultivation have developed. Despite differences in morpho-physiological traits, genetic variability is low, if present at all. Here, we aim to resolve chromosomal and sequence-associated variability across saffron crocus cultivars from the crops main cultivation areas in Africa, Asia and Europe. (2) MethodsWe used genome-wide DNA polymorphisms obtained through genotyping-by-sequencing (GBS) of 33 saffron and 14 closely related Crocus accessions, which we place into a phylogenetic context. For karyotyping, we compare nine saffron accessions by multi-color fluorescent in situ hybridisation (FISH) with repetitive DNA probes. (3) Key resultsPhylogenetic analyses confirmed the single origin and clonal nature of all saffron accessions. We detected slight DNA differences among saffron crocus genotypes, which were minor compared with those in wild C. cartwrightianus populations. Still, the Iranian saffron accessions form a genetically very narrow group that differs from the other proveniences in population genetic analyses. However, chromosomes of some saffron accessions display variable FISH signals, likely resulting from gains and losses of tandemly repeated DNA. (4) Main conclusionsBased on the high genetic identity and small karyotypic differences, we confirm the clonal origin of the saffron accessions. Nevertheless, as we detected small and regional chromosomal variability, we conclude that at least four somaclonal saffron lineages emerged after saffrons origin. Societal Impact StatementFor millennia, many cultures developed cultivation practices and regional crop varieties. A notable case is saffron, the worlds most expensive spice that is harvested from stigmas of saffron crocus. This flower crop arose 3000 years ago in a singular genome triplication event and since then spread clonally across the globe. By identifying genetic and chromosomal variability in clonal saffron accessions, we highlight regional diversity, support the preservation of traditional knowledge, and underscore the risk of relying on only one clonal lineage. This informs strategies for saffron cultivation, linking cultural heritage with modern genomics to address biodiversity, evolution, and food security.

Belemia belongs to Nyctaginaceae and comprises two species of delicate vines. Both species are endemic to Brazil. Belemia fucsioides, the type species, described in 1981, occurs in a restricted area of the Atlantic Forest in southeastern Brazil. Belemia cordata, described in 2020, is known from only two records from the same area in the Cerrado of northern Brazil. Here, we describe the taxonomic history of Belemia and provide the first synopsis for the genus. We include species description, distribution map, identification key, and anatomical data. We used field observations over the past decade and modeled anthropogenic changes in the species range to conduct a conservation assessment in accordance with the IUCN Red List criteria. Conservation assessments indicate significant concerns for Belemia, classified as either endangered (B. fucsioides) or critically endangered (B. cordata). The species are threatened primarily by habitat loss to land used for agriculture, forestry, and livestock production. This study contributes to ongoing initiatives exploring plant diversity in the Neotropics and supports efforts to identify threats to biodiversity.

Forest regeneration depends not only on how many seeds trees produce, but on the physiological quality of those seeds. Yet while climate-driven shifts in seed quantity and masting have received sustained attention, the parallel question of whether climate change degrades seed quality remains poorly resolved. Using a nationwide dataset of seed mass and viability in European beech (Fagus sylvatica L.) collected between 1996 and 2024 (13,349 seed lots from 381 forest districts across Poland), with climate-quality analyses focused on 5,374 freshly harvested seed lots from 353 districts (2004-2023), we asked whether the two components of seed quality respond to different seasonal climatic windows, and whether harvest-year climate also shapes seed performance during long-term cold storage. Seed mass and seed viability were only weakly correlated (Spearmans {rho} = 0.15), acting as two independent dimensions of seed quality. Both revealed substantial temporal variation over the study period, but along distinct trajectories. Seed mass declined markedly between segmented-regression breakpoints in 2009 and 2019, more steeply at higher latitudes, coinciding spatially and temporally with the masting breakdown reported at the species northeastern range margin. Climatic associations were correspondingly divergent. Viability was positively associated with previous summer temperature, consistent with temperature-cued flower initiation, and negatively with spring temperature in the harvest year, plausibly reflecting thermal disruption of early embryogenesis. Seed mass showed no significant association with any seasonal climatic predictor, indicating control by slower or unmeasured processes. Storage duration progressively reduced viability, and this decline was further modulated by climate during seed development, with seeds developing under climatically suboptimal conditions losing viability faster. These results expose a hidden decoupling between seed quantity and seed quality under contemporary climate change, with direct consequences for forest regeneration and for ex situ conservation strategies that assume mast-year seeds will remain viable for decades.

Banana (Musa spp.) is a vital staple food and cash crop cultivated in over 140 countries, providing nourishment and livelihoods to more than 400 million people worldwide. In this context, Bhimkol (Musa balbisiana, BB genome), a diploid banana variety native to Northeast India holds significant nutritional and commercial value. Its high iron and nutrient content have already been commercially validated through products like Bhimvita and Bhimshakti, which utilize fresh fruit pulp as nutrient-rich food for infants. However, Bhimkol fruits typically contain 100-150 seeds, an undesirable trait for product development. The manual removal of these seeds significantly increases production time and labour costs. Furthermore, because bananas are recalcitrant to traditional breeding, there is a constant need for rapid in vitro transformation protocols. To address these challenges, as a proof of concept, our research aims to knockout the INNER NO OUTER (INO) gene, which is responsible for ovule development. Using CRISPR/Cas12a technology, we established an efficient and reproducible in vitro regeneration and transformation system using Embryogenic Cell Suspensions (ECS). The resulting CRISPR-edited plantlets exhibited various mutations, including insertions and deletions (INDELs) within the targeted INO gene. These INDELs resulted in frameshift mutations that triggered premature stop codons. While these genetic changes are expected to render the banana seedless, phenotypic verification is currently underway to confirm the absence of seeds in mature fruit. Significance StatementDespite its superior nutritional profile, the commercial viability of the Bhimkol banana (Musa balbisiana) is restricted due to abundance of seeds (100-150 per fruit). This study employs CRISPR/Cas12a-mediated knockout the INNER NO OUTER (INO) gene in Bhimkol and expected to develop seedless fruits. The resulting plantlets exhibit targeted indels that trigger frameshift mutations, effectively disrupting ovule developmental INO gene.

Growth kinematics and soil mechanics are key to explain how roots overcome the mechanical resistance of soil, yet few studies are linking these two factors. Formulas for cone penetration tests are typically used to infer the friction experienced by roots, but these fail to consider how growth affects the external forces applied on the root. This study formalised how expansive growth in the root apical meristem can reduce soil friction, and applied the framework to analyse the growth strategy of 6 plant species. The results of the analysis revealed trade-offs between reducing frictions, maintaining a desired growth trajectory and elongation rate. A shorter elongation zone can reduce the fraction of the mechanical energy lost to friction, but this is done at the expense of the elongation rate. A sharper tip or increased radius can help roots maintain the elongation rate at no energetic cost, but these strategies come with the cost of growth instability (tortuous roots) and decrease in specific root length respectively. During establishment, root strategies may therefore occupy a 2-dimensional trait space in which the mechanical efficiency of growth is balanced against the explorative-exploitative trade-off. HighlightsGrowth and form of root tips explain how plants overcome mechanical resistance from the soil Trade-offs link the energy lost by friction, growth stability and elongation rate of roots Larger roots allow faster growth independently of these trade-offs New framework formalises plants strategies to acquire soil resources

A global nuclear war could inject soot into the stratosphere, blocking sunlight and causing rapid cooling. Assessments of the resulting agricultural collapse rely on crop models never validated under such conditions. We grew wheat, canola, and potato in growth chambers simulating the light and temperature of an extreme nuclear winter at tropical and temperate sites. In the tropical chamber (18-20 {degrees}C, 200 mol m-2 s-1 PAR), all three crops produced viable yields. Wheat yielded 2.1-2.3 t/ha (n=3 well-watered, n=3 water-stressed pots), 60% of the global average, and single-pot observations of canola and potato suggested biological yields comparable to global averages. In the temperate chamber simulating nuclear winter irradiance (60-360 mol m-2 s-1), wheat stems collapsed under their own weight. Although hand-harvesting recovered 0.6-2.8 t/ha of grain, mechanical field harvest of a flat canopy would recover substantially less. This failure mode was not observed in a higher-light control chamber and is not captured by existing crop models, which may therefore overestimate temperate cereal production under nuclear winter. Canola produced comparable yields under both temperate light regimes without lodging. Empirical screening of additional staples is needed to identify which remain viable under nuclear winter.

AO_SCPLOWBSTRACTC_SCPLOWO_LIAirborne imaging spectroscopy enables species-level classification in hyperdiverse tropical forests, but accuracy varies enormously among species. We asked which ecological and evolutionary attributes make a tropical tree species spectrally separable. C_LIO_LIUsing 3,256 field-verified crowns spanning 169 species in a hyperdiverse moist forest in French Guiana, we tested seven hypothesised determinants of classification accuracy at species, pairwise, and individual-crown scales using random forest, beta regression, elastic net, and binomial GLMM analyses. C_LIO_LIPhenological regularity - the strength and consistency of seasonal leaf-cycling - was the single strongest predictor of separability, emerging as the top-ranked variable across all analyses. The presence of congeneric species in the classification pool also reduced accuracy, while broader phylogenetic isolation contributed in multivariate models. At the crown level, crown area was the strongest predictor of correct classification, while liana infestation reduced odds of correct identification by 38%. Leaf chemical traits did not predict separability. C_LIO_LIIt is the consistency of a species ecological signal - its phenological rhythm, spatial sampling, and freedom from canopy contamination - rather than any single functional trait, that determines whether it can be reliably mapped from imaging spectroscopy. C_LI

Two threatened new species of Podostemaceae belonging to the genus Inversodicraea, I. joulei and I. lebbiei, both from the Republic of Sierra Leone, are described and illustrated. A first record in Sierra Leone of the genus Lestestuella is also reported. Inversodicraea is the most species-rich genus of Podostemaceae in Africa and now comprises 38 species. Inversodicraea joulei is easily recognised because it has a persistent spine distally on the median rib of each fruit valve, and scattered, membranous scale-leaves with broadly rounded apices, while Inversodicraea lebbiei is distinct in having narrowly triangular robust scale-leaves which are inrolled, spreading distally, and completely covering the stem, arranged in five ranks. Inversodicraea joulei is known from a single location with three sites while I. lebbiei is known from two locations each with one site. Using the latest IUCN Red List guidance, Inversodicraea joulei is assessed as Critically Endangered and I. lebbiei is assessed as Endangered, due to threats from dam construction projects, agricultural practices and mining activities, resulting in high levels of siltation on rocks in the fast-flowing rivers where these species grow.

Crop improvement can enhance food security, but side effects, such as trade-offs between valuable agronomic traits, are common. Likewise, fertilisation helps ensure high yields, but can devalue mutualisms with soil microbes that would otherwise be essential for nutrient acquisition. If the need for nutritional mutualisms is reduced in crops, mutualisms could be disrupted by selection relaxation or allocation trade-offs. Thus, crops could achieve high yields in spite of, or because of, disruption of nutritional mutualisms. Alternatively, the highest-yielding plants might flourish because they maximise nutrient acquisition from both symbionts and the soil. Here, enhanced mutualism could evolve over the course of agricultural crop improvement. To investigate whether high yields in cultivars and wild accessions are negatively or positively genetically correlated with outcomes in the legume-rhizobia mutualism, we measured whether yield and symbiosis traits trade-off or are positively genetically correlated among cultivars and wild accessions. We also tested whether this relationship differs between accessions released before or after 1950. We measured genetic correlations between yield and mutualism traits in 87 domesticated pea (Pisum sativum) accessions in a common garden agricultural field across three years. Seed yield and N2 fixation (%Ndfa) were positively genetically correlated. While N fixation was more strongly predictive of yield in the pre-1950 accessions than the post-1950 accessions, the underlying positive genetic correlation between the traits did not differ between the groups. The positive genetic correlation between yield and N2 fixation indicates that selection to increase yields has maintained or increased the benefits of the rhizobial mutualism in pea. Our findings predict that breeding to increase yield may continue to produce pea cultivars that get a greater proportion of their N from rhizobia, enhancing symbiotic mutualism and reducing the proportion of N supplied by fertilisation.

Urban environments typically experience higher temperatures than surrounding natural landscapes, making urban vegetation crucial for cooling local areas and improving the health of city residents. Impervious urban surfaces limit the absorption and retention of precipitation, potentially limiting tree water access and threatening long-term survival. Here, we measured tree physiology and growth of Lophostemon confertus (Queensland brush box) trees to investigate how a passive irrigation system that stores stormwater affected the performance of young, establishing trees in a hot and dry suburb of western Sydney, Australia. During the 2024-2025 austral summer, three years after planting, the local climate was periodically hot and dry, with a total of 16 days above 35 {degrees}C. Irrigated L. confertus trees had higher water availability (i.e., higher predawn leaf water potential,{Psi} pre), lower water stress (i.e., higher midday leaf water potential,{Psi} mid, more frequently above turgor loss point), greater stomatal conductance (gs) on hot and dry summer days, and reduced leaf temperatures (Tleaf), compared to control trees. No significant differences in growth rates were observed between irrigated and control trees during the first three establishment years, but irrigated trees had greater crown survival during the hot, dry summer. Our results suggest passive irrigation may mitigate periods of short-term heat and drought stress in urban trees by increasing water access to support transpiration that prevents leaves from overheating, improving tree health. Higher tree transpiration may lead to greater ecosystem services by increasing cooling benefits, contributing to mitigation of urban heat island effects.

PremiseCentaurea melitensis (Asteraceae) is a problematic invader of grasslands globally, but little is known about its genetic makeup. Here we develop a reference genome to facilitate studies of its invasion history, genetic variation, and evolution. MethodsInbred offspring of a single individual of C. melitensis from its invasion of California, USA were used for flow cytometry to estimate genome size, and for genomic DNA extraction. DNA was sequenced with PacBio HiFi technology (yield = 85.7Gb). The genome was assembled with Hifiasm and annotated with BRAKER3. GENESPACE was used to compare gene order (synteny) with three other species within the subfamily Cichorioideae. ResultsWe estimated a mean genome size of 795.0 Mbp for C. melitensis, and our assembly totaled 696.6 Mbp in 48 contigs (N50 = 55.6 Mbp; BUSCO = 98%), with annotation of 25,157 protein-encoding genes. This included four telomere-to-telomere putative chromosomes, nine additional chromosome arms terminated by telomeric repeats, and a complete chloroplast genome. Synteny varied markedly across the genus and subfamily, suggesting a dynamic history of structural variation in the lineage of C. melitensis. DiscussionWe provide a highly complete and contiguous genome assembly to facilitate the further study of genomic variation in C. melitensis.

Common bean (Phaseolus vulgaris) is an important crop in Canada and globally. Like other legumes, common bean (Phaseolus vulgaris) establishes symbiotic interactions with nitrogen fixing bacteria called rhizobia. However, nitrogen fixation by rhizobia in association with common bean is often suboptimal, constraining its productivity and necessitating the application of nitrogen fertilizer. To support the development of high-performing, locally adapted rhizobial inoculants for Ontario common bean growers, we isolated 216 common bean-nodulating rhizobia from southern Ontario soils using a nodule trapping approach with four common bean cultivars. Whole genome sequencing followed by phylogenomic analyses of the 216 rhizobial isolates revealed substantial diversity, assigning them to 11 Rhizobium species, including two novel species. Nearly all isolates belong to the symbiovar phaseoli, spanning the nodC {gamma}-a, {gamma}-b, and alleles, with four isolates belonging to the symbiovar gallica. Soil origin had a significant impact on the species-level community composition recovered during the nodule trapping experiments, indicative of biogeographical structuring of common bean-nodulating rhizobia across southern Ontario. In contrast, host trapping cultivar had only a minor influence of the recovered Rhizobium population diversity. Greenhouse assays demonstrated that one of the novel Rhizobium species exhibited the highest average symbiotic effectiveness, although high-quality isolates were found across multiple species. Together, these results revealed a diverse and genomically variable Rhizobium community capable of forming effective symbioses with common bean in southern Ontario soils. Importantly, our genome-sequenced Rhizobium collection will serve as a valuable resource for identifying competitive and high-quality strains for the development of inoculants tailored to Ontario common bean production. IMPORTANCECommon bean is a globally important food crop, yet its productivity is often limited by suboptimal nitrogen fixation, forcing growers to rely on synthetic fertilizers. Consequently, identifying high-performing, locally adapted inoculant strains is essential for reducing dependence on synthetic nitrogen fertilizers and improving the sustainability of temperate agroecosystems. Our study provides a genome-sequenced collection of common bean-nodulating Rhizobium from southern Ontario, revealing substantial species and genomic diversity across sampling locations. Greenhouse studies allowed us to identify multiple isolates, including isolates from a novel Rhizobium species, that consistently fix nitrogen with, and enhance the growth of, common bean plants. Our findings highlight strong biogeographical structuring of rhizobial communities and demonstrate that Ontario soils already harbour strains with high symbiotic potential. In addition, our Rhizobium collection represents a foundational resource to support future inoculant development and enables future work on the ecology, evolution, and applied optimization of legume-rhizobium symbioses.

O_LIBackground and Aims: Chemodiversity is a fitness-relevant trait shaped by genetics, environment, and their interaction. Populus trichocarpa naturally inhabits broad climatic gradients and shows extensive variation in specialised metabolism. We investigated whether provenance and climate of origin imprint leaf chemodiversity and class-level relationships under common-garden conditions, and how these patterns relate to gene expression. C_LIO_LIMethods: Leaves from 87 P. trichocarpa genotypes representing 22 provenances from the west coast of North America growing in a common garden were profiled by untargeted FT-ICR-MS (1030 features) and targeted LC-MS/MS. A subset of 41 genotypes was subject to RNA-seq analyses. We tested whether provenance influenced multivariate patterns and whether metabolomic differences were related to geographic and climatic distance, where chemodiversity was quantified as Functional Hill Diversity. C_LIO_LIKey Results: P. trichocarpa metabolomes differed among origins despite shared growth conditions and showed distance-decay with both geography and climate. North-south extremes were well separated, and within-drainage samples shared high similarity. Flavonoid and isoprenoid pools strongly co-varied across individuals, whereas isoprene synthase activity did not predict total isoprenoids. Transcriptomes showed within-pathway coherence but limited overall provenance separation. C_LIO_LIConclusions: Leaf chemistry in P. trichocarpa retains signatures of geographic origin even under common-garden conditions. Coordinated investment in flavonoids and isoprenoids, together with among-origin differences in functional chemodiversity, reveals provenance-linked chemical fingerprints that complement genomic and metabolic trait data for climate-informed deployment. C_LI

The fully mycoheterotrophic, non-photosynthetic Afrothismia fonensis Cheek & G.Delhaye sp. nov. (Afrothismiaceae), is described and illustrated from two sites in submontane forest in or adjacent to the Pic de Fon Foret Classee, Simandou Range, Republic of Guinea. This is the first record of the genus and family in West Africa west of Nigeria. The new species is remarkable for its small size, and for being unique in the genus in the entirely connate intertepaline lobes (in other species of the genus they are free or only partly united) and the longitudinal ridges on the outer perianth tube (unknown in other species). The provisional extinction risk assessment for Afrothismia fonensis is Critically Endangered (CR B1ab (iii)+2ab(iii)+D1) using the IUCN 2012 categories and criteria, due to less than 50 individuals being recorded, and due to the both the very small range and the immediate threats from foraging by red river hogs, trampling by cattle and from de-watering of the adjacent Oueleba iron-ore body where mining began in 2025. It should be noted that mitigation actions are expected to adequately address the risks associated with mining activities, and direct impacts to both areas of Afrothismia fonensis habitat have been fully avoided through relocation of planned infrastructure. We review the importance of the Boyboyba forest, Simandou range, as the West African centre of diversity for non-photosynthetic heteromycotrophs. This new discovery is examined in the context of other recently discovered range extensions to Guinea of Central African genera and families.

BackgroundA structural governance failure sits at the intersection of international biodiversity law and the digital genomics revolution. The Convention on Biological Diversity (CBD) and the Nagoya Protocol on Access and Benefit-Sharing (ABS) were designed to ensure that countries of biological origin share equitably in commercial benefits from their genetic resources. Critically, these instruments apply exclusively to non-human genetic resources: plants, animals, fungi, and microbiota. Human genetic resources are deliberately excluded from the CBD and Nagoya ABS framework and are governed separately through bioethics instruments, including the World Health Organization (WHO) framework and the Declaration of Helsinki. This study focuses on non-human digital sequence information (DSI), nucleotide and protein sequence data derived from non-human organisms deposited in open-access databases, which underpins industries generating over USD 1.56 trillion in annual revenue. Africa, hosting approximately 25% of global terrestrial species and nine of the worlds 36 biodiversity hotspots, provides a disproportionate share of the genetic resources from which non-human DSI is derived, yet receives negligible monetary returns because digitisation severs the traceability chain that ABS governance requires. Human genomic data is presented here solely as a secondary indicator of Africas broader infrastructure; it does not constitute the legal basis for Africas modelled allocation share under the Cali Fund. ObjectivesThis study systematically characterises (i) Africas non-human biodiversity endowment as the basis for Cali Fund claims; (ii) ABS governance readiness across 54 African Union (AU) member states; (iii) the commercial trajectories of non-human DSI-dependent industries and projected Cali Fund benefit-sharing flows; and (iv) Africas human genomic representation as a secondary infrastructure indicator, explicitly distinguished from the non-human DSI benefit-sharing argument. MethodsA structured evidence synthesis was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 reporting elements, where applicable to a secondary data analysis design. Literature was searched across PubMed, Scopus, Web of Science, Google Scholar, and official repositories of the CBD, Food and Agriculture Organization of the United Nations (FAO), International Union for Conservation of Nature (IUCN), and United Nations Environment Programme (UNEP). The search was restricted to January 2022 - April 2026 to capture post-Kunming-Montreal Global Biodiversity Framework (KMGBF) literature. A total of 412 records were identified before screening; 34 peer-reviewed articles and 19 institutional documents met all inclusion criteria. Quantitative Cali Fund scenario modelling used the United Nations Environment Programme World Conservation Monitoring Centre (UNEP-WCMC) and KPMG (2024) non-human DSI sector revenue baseline (CBD/WGDSI/2/2/Add.2). The 12.5% net profit margin is a cross-sector proxy from that study; actual margins vary by sector. Africas modelled allocation share (20-25%) is the authors analytical construct based on Africas non-human species richness and hotspot share; it is not an internationally agreed formula. ResultsAfricas non-human biodiversity endowment is exceptional: 25% of terrestrial species, nine of 36 biodiversity hotspots, and the worlds second-largest tropical forest system. Non-human DSI from African genetic resources is a critical input to industries generating USD 1.56 trillion annually, yet Africa contributes a marginal and unmeasured fraction of International Nucleotide Sequence Database Collaboration (INSDC) sequences. As a secondary indicator, 94.48% of genome-wide association study (GWAS) participants as of 2024 were of European ancestry (Corpas et al., 2025); this human genomic data is presented for contextual illustration only and is not the basis for Africas Cali Fund modelled allocation share. Zero African Union member states have enacted legislation explicitly covering non-human DSI in their ABS framework. Africas modelled allocation share ranges from USD 312 million (Scenario A, 20% weight) to USD 5.83 billion (Scenario C, 25% weight) annually. ConclusionsAfrica is among the most biologically rich continents on Earth for non-human life, yet structurally excluded from the benefit-sharing framework the CBD intended to create. The Cali Fund represents the first mechanism capable of correcting this at scale. Realising Africas modelled allocation share requires urgent legislative reform, institutional capacity investment, sequencing infrastructure development, and a coordinated African position at COP17 scheduled in Yerevan, October 2026.

Habitat fragmentation disrupts metapopulation dynamics by altering environmental conditions and constraining demographic processes critical for persistence and recruitment. In the dry Afromontane forests of northern Ethiopia, we investigated how natural and anthropogenic drivers affect seedlings, saplings, and mature tree dynamics of Olea europaea subsp. cuspidata across 34 patches. We used dynamic occurrence models to quantify effects of patch area, altitude, browsing, and disturbance. Our results indicate that high disturbance reduces seedling occurrence probability lower disturbance sites has seedling in 30% of survey plots, high disturbance would bring this down to 10% (median = -1.322, 95% CI: -2.703 to -0.283). Disturbance makes seedling less likely to persist, while large patch size help seedling persists (median = -0.93, 9 5 % CrI -1.87 - -0.02). For mature individuals, disturbance was the only significant predictor of occurrence probability, suggesting greater resistance to environmental and spatial variability compared to earlier life stages. These findings emphasize that while mature trees display resilience, the successful regeneration of Olea europaea is constrained by disturbance, but current level of browsing is not a threat. Management strategies for conservation should prioritise reducing disturbance through community engagement and forest stewardship to enhance regeneration potential and ensure long-term population viability.

Recovery debt (RD) quantifies the interim deficit of biodiversity and function during the recovery process after disturbance. Unlike typical recovery indices derived from data on experimental-control comparisons, RD further considers the target (reference) biodiversity level, modelling the rate at which it is approached over time. However, the application of the RD approach to active restoration has not been explicitly implemented to date. Here, we extend the RD framework to evaluate active ecological restoration in agricultural systems, defining the onset of recovery as the shift from intensive to wildlife-friendly management. We applied this approach to assess short-term pollinator recovery in 14 olive groves across a gradient of farming intensification and landscape complexity in southern Spain. Restoration actions included adopting low-intensity ground cover management and actively restoring field margins. At one, three, and five years post-restoration, we assessed community responses by quantifying bee abundance, species richness, plant-bee network properties, and flower visitation rates. Reference systems were defined by olive groves in complex landscapes with low-intensity herb cover management and organic farming practices. Following restoration, the RD of bee abundance decreased from 71% to 55%. We found no significant effects of pre-intervention agricultural management on RD. Instead, across sites, the reduction of the RD (i.e., recovery) of bee abundance, richness, network connectance and flower visitation rate was strongly mediated by the availability of high-quality semi-natural areas in the surrounding landscape and by the ecological contrast created by restoration interventions at both the farm and floral patch levels. RD for other network metrics showed no significant pattern of variation. Our study demonstrates that wildlife-friendly management and targeted habitat restoration can rapidly reduce recovery debt for bee abundance and function in permanent agroecosystems. However, the recovery of more complex interaction-network properties likely requires longer timescales.

Plants, as structural elements of habitats, contribute greatly to the maintenance of local biodiversity through their biological interactions. In this study we explore whether their rarity, according to Rabinowitzs (1981) three criteria, is related to the richness and diversity of arthropods and other plants they are associated to, in a gypsum-rich steppe. We first analysed whether the geographic abundance and ecological specialisation of 32 characteristic and dominant plant species are related to the diversity (richness and phylogenetic diversity (MPD)) and degree of local specialisation of arthropods associated with them (1,694 taxa). Then, we focused on a non endemic and non specialized plant in the study area (Krascheninnikovia ceratoides) to explore the effect of population size on two types of interactions: aerial arthropods and plant facilitation. Results indicate that: 1) plant species abundance (geographical range) is not related to the richness or MPD of communities of associated arthropods, 2) plant species ecological specialization (edaphic endemisms or gypsophiles) do not contribute differentially to the maintenance of singular arthropod communities, and 3) the community of aerial arthropods and plants interacting with K. ceratoides in a small population are not necessarily less diverse than those in patches of similar size in a large population. Results also revealed that the two plant species with fewer interactions (one rare, one widespread) do show the highest singularity in their interactions with arthropods. Our study illustrates the important contribution of rare plants to the conservation of local biodiversity.

Pennycress (Thlaspi arvense L.) is an intermediate winter oilseed crop that has only recently been domesticated for agronomic use. Improving agronomic traits requires sources of genetic variation, and mutagenesis is frequently used to help overcome the limitations of natural populations. We investigate the impact of Ethyl methanesulfonate (EMS) on genetically effective cells (GECs) to characterize the intra-individual genetic variation of EMS mutagenesis in pennycress. We identified that pennycress contains at least 4 GECs which, when treated with EMS, create unique mutations across different branches within the same individual plant. We then propagated the M2 plants for whole genome sequencing, providing extensive characterization of the EMS mutation profile and developing a gene index as a resource for future reverse genetic screenings. Article SummaryPennycress is an emerging winter oil seed crop in the American Midwest. Domestication efforts have advanced rapidly through a combination of genetic techniques. One of the most successful methods has been the use of a mutant gene index, a large collection of pennycress seed where new genetic variation has been created through Ethyl methanesulfonate (EMS). EMS mutations are not uniform however, and a single treated seed can have wide genetic variation within the resulting plant. We investigate the role of genetically effective cells on EMS variation, and present the full EMS population as a resource for further pennycress domestication efforts.