Levels Of Diversity Research Articles

Unraveling the genetic diversity, seed oil fatty acid constituents and antioxidant activity of different okra (Abelmoschus esculentus (L.) Moench) populations.

Abelmoschus esculentus (L.) Moench is cultivated globally for use as a salad or culinary herb. It has a narrow genetic diversity and is sensitive to heat and drought stress. Therefore, it is very important to detect different chemotypes and genotypes to be applied in its breeding programs. The genetic diversity is equally distributed within and among the populations. Principal coordinates analysis, genetic diversity and polymorphism parameters revealed a high level of within-population diversity for some populations. PhiPT values, genetic differentiation index and total heterozygosity amount explored a high level of genetic differentiation between some populations, with a low average rate of gene flow. Nei's genetic distance and STRUCTURE analysis assigned the populations to two distinct and some intermediate genotype groups. Seed oils were composed of the same unsaturated and saturated fatty acids in a ratio of nearly 2:1. Linoleic and oleic fatty acids were the first and second main unsaturated fatty acids, followed by palmitic acid as a major saturated fatty acid in all populations. Clustering analyses explored the populations classified into two chemotype groups. However, it was not similar to those obtained by the molecular genetic data. 2,2-Diphenyl-1-picrylhydrazyl (DPPH; IC50 μg mL-1) analysis revealed a moderate to weak antioxidant activity for a few populations, which significantly correlated with palmitic acid amount. Environmental factors have a stronger effect on seed oil fatty acids profiles than the genetic structure. The detected genotypes and chemotypes could be used for the development of genetic and chemical diversity, respectively, in this crop. © 2025 Society of Chemical Industry.

Genetic diversity and population structure of ALS-resistant Amaranthus hybridus across Brazil's primary soybean-growing regions.

Resistance to acetolactate synthase (ALS)-inhibiting herbicides has emerged in Amaranthus hybridus populations across Brazil's soybean-growing regions. To gain insights into the evolutionary origins and spread of resistance, this study (1) investigated the ALS inhibitor resistance mechanisms in nine A. hybridus populations and (2) assessed their genetic diversity, structure, and relatedness. Resistance to the ALS inhibitor chlorimuron in A. hybridus was associated with two distinct target-site mutations: Trp-574-Leu and Asp-376-Glu. Population genetics revealed low levels of genetic diversity (HE = 0.00117 to 0.16019; π = 0.00126 to 0.17421) and inbreeding (FIS = 0.0015 to 0.13157). Principal component analysis differentiated A. hybridus by geographical region, while ADMIXTURE analysis revealed population structure with evidence of admixture between genetic clusters in three groups of populations. The results suggest multiple local and independent evolutionary origins of resistance. The spread of resistance is primarily driven by local herbicide selection pressure and gene flow through seed dispersal. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genetic diversity in the American elephantfish (Chimaeriformes: Callorhinchus callorynchus) and among its congeners.

Understanding genetic population structure and connectivity is essential for effective species-specific management and conservation strategies. The American elephantfish Callorhinchus callorynchus is targeted and retained as incidental catch in commercial and recreational fisheries in Chile and Argentina. Its wide-ranging distribution across southern South America may require transnational co-operation to ensure sustainable use, but its current population structure is not known. In this work, we analysed the levels of genetic diversity and differentiation within C. callorynchus in South America using two mitochondrial markers, the control region (CR) and the cytochrome oxidase subunit I gene (CO1). Moreover, we assessed levels of genetic diversity within, and divergence among, the three extant callorhinchids (genus Callorhinchus), a group that exhibits allopatric geographical distributions in the southern hemisphere. Overall, sequence analyses of the mitochondrial CR and the CO1 revealed extremely low levels of sequence variation both within and among Callorhinchus species. Genetic homogeneity was found throughout the range of C. callorynchus coupled to low-frequency haplotype sharing across spatially distant locations in Chile and Argentina, suggesting gene flow along the South American coast. Moreover, our analyses supported a scenario of recent population expansion of the species in South America. Given the absence of dispersive eggs or juvenile stages in chondrichthyans, gene flow is mainly mediated by actively swimming adults. Based on the available data, gene flow in callorhinchids appears to occur along continuous coastal regions, with deep oceanic waters serving as strong barriers. Findings here provide an important baseline for future research on dispersal and gene flow in holocephalans.

Topographic conditions dominate tree species recovery over 15 years post-fire in a temperate Pinus sylvestris forest

BackgroundIntensifying fire regimes and changing climatic conditions raise concerns about the capacity of forests to naturally recover after fire. Linking long-term observations of post-fire natural tree regeneration with the environmental and spatiotemporal context is thus becoming increasingly important to guide restoration efforts worldwide. Especially where fires have been rare, snapshot and short-term monitoring efforts prevail, thereby failing to recognize the post-fire species dynamics and wider community trends. Using multivariate Bayesian and spatial point process modeling, we evaluated the main environmental drivers of post-fire tree species recovery, its compositional and structural components, and species’ spatiotemporal co-occurrence patterns over 15 years post-fire in a Central European Pinus sylvestris forest.ResultsTopography-related conditions and ground cover were the prevalent drivers of tree species responses. In addition to diverse species-specific and size-dependent responses, higher site moisture and moss cover were beneficial for most species, while steep and warm habitats with exposed mineral soil and lack of litter mostly represented harsh conditions. We demonstrate the transition of the Pinus sylvestris forest to early successional broadleaves. Betula pendula seedlings and saplings began to dominate 10 and 5 years after the fire, respectively. Pinus sylvestris seedlings showed a similar abundance to Betula pendula and Populus tremula 5 years after the fire but declined sharply thereafter. We identified synchronized but species-specific patterns of seedling decline and sapling basal area build-up in early successional broadleaves. Fagus sylvatica, Picea abies, and Pinus sylvestris saplings showed synchronized recovery 15 years post-fire.ConclusionsWe highlight the need for a detailed recognition of species-environment relationships, particularly where species with diverse levels of natural recovery are challenged along wide topographic gradients. Our findings also demonstrate that the compositional and structural components of post-fire recovery were shaped by species and wider community dynamics depending on time since fire. Exploring these species’ unique and synchronized trajectories through spatiotemporal co-occurrence patterns is essential for setting realistic expectations of future forest recovery and can also help guide active restoration efforts in various post-disturbance contexts.

Estimating mechanisms linking relative income to self-rated health by multilevel modeling: the moderating role of healthcare access and quality index

Income-health gradients vary in societies with diverse cultures and healthcare access levels, and generalized trust in unknown resources of health services may play a crucial role in these gradients. Multilevel models using a sample of 152,501 respondents from 89 societies are conducted to investigate the mediation effect of generalized trust in the correlation between relative income and self-rated health globally, and the moderating role of healthcare access in the association between relative income and self-rated health. Results show that individuals’ relative income significantly and positively predicts their generalized trust, which in turn significantly and positively predicts their self-rated health. In countries and regions with higher levels of healthcare access and quality, a higher level of relative income is positively correlated with increased self-rated health. This study theoretically contributes to the literature on income-health relationships by capturing medical resource access and individual characteristics. Specific policy recommendations include fostering generalized trust, improving healthcare education, and expanding telemedicine.

Close neighbors, not intruders: investigating the role of tank bromeliads in shaping faunal microbiomes.

Tropical montane cloud forests contain high levels of epiphyte diversity. Epiphytic tank bromeliads play an important role in the functioning of these ecosystems and provide a microhabitat for many species of invertebrates. Microbial ecology theory suggests that the environment serves as a source of microbes for animals, but the contribution of this factor to the composition of an animal microbiome varies. In this study, we examined the extent to which tank bromeliads (Tillandsia multicaulis) serve as a source of microbes for two species of fly larvae in a cloud forest fragment in central Veracruz, Mexico. We used 16S rRNA sequencing to characterize the bacterial communities in the organic matter within bromeliad tanks and in the whole bodies (surface and gut) of larvae from two fly taxa (Austrophorocera sp., Tachinidae, and Copestylum sp., Syrphidae) that inhabit these bromeliads. To assess the contribution of bromeliads to the microbiome of the fly larvae, we conducted fast expectation-maximization microbial source tracking (FEAST) analysis. The bacterial communities in bromeliad tanks were primarily composed of Pseudomonadota, Acidobacteriota, Bacteroidota, Verrucomicrobiota, and Spirochaetota. Similarly, communities of the fly larvae contained Pseudomonadota, Bacteroidota, Bacillota, and Actinomycetota. Bromeliad tanks exhibited the highest bacterial richness, followed by Copestylum and Austrophorocera larvae. Beta diversity analyses indicated that bacterial communities clustered by species. We found a modest contribution of bromeliads to the fly microbiome, with nearly 30% of the larvae microbiome traced to the organic matter deposited in the tanks. Our data suggest that the microbiome of flies, which inhabit tank bromeliads during their larval stage, is nourished to some extent by the bacterial communities present in the organic matter within the tank.

Molecular and acoustic evidence for large-scale underestimation of frog species diversity on New Guinea

Species are fundamental units in biology; however, information on species diversity and distribution remain scarce for most taxonomic groups, especially in tropical rainforests. Such knowledge gaps are particularly acute in amphibians, the most threatened group of vertebrates, in which new species continue to be described at a high rate. Herein, using molecular-based approaches, we provide estimates for species diversity of frogs (Anura) in New Guinea and nearby islands, one of the biologically most diverse regions of the world. We first characterised taxonomic and geographic sampling for all available mitochondrial DNA sequences from native frog species. This led us to identify important molecular sampling gaps in the western half of New Guinea that we partially filled by adding 534 new sequences (16S rRNA). Large territories remain uncharted, particularly in the westernmost part of the central cordillera of New Guinea. Using our 16S rRNA dataset, we then delimited Molecular Operational Taxonomic Units (MOTUs), a subset of which was bioacoustically analysed. From a total of 369 delimited MOTUs, we found that 190 could not be assigned to any taxon. Amongst these, 123 are represented by specimens collected in the western half of New Guinea and 19 were supported as distinct by bioacoustics, confirming that this portion of the island is home to many unrecognised species. Based on the estimated level of undescribed diversity in taxa and areas for which data are available, we extrapolate that New Guinea and neighbouring islands could host 800–1,200 frog species, with only 560 species described to date. We assembled the most comprehensive molecular dataset to date (16S rRNA) for frogs from New Guinea and neighbouring islands. We delimited 190 candidate species, of which 19 are supported by available bioacoustic data. We estimated the actual number of frog species on New Guinea and neighbouring islands to be between 800 and 1,200. Parts of New Guinea exhibit species-diversity levels comparable to similarly sized regions in Amazonia and Madagascar. Most unrecognised frog taxa in the region are likely confined to restricted geographical areas and, thus, likely sensitive to both land use and climate change.

Exploring community knowledge, perceptions, and the impacts of anthrax among farming communities living in game management areas in Zambia: A qualitative study using a hybrid approach.

Anthrax remains a neglected zoonotic disease of critical public and animal health significance in Zambia, particularly in regions with active human-wildlife-livestock interfaces such as the Western, Southern and Eastern provinces of Zambia. This study explores the socio-ecological drivers of anthrax transmission and examines the role of legal and illegal wildlife trade value chains in sustaining outbreaks. Secondly, the study explores the methodology used to investigate community knowledge, perceptions, and the impacts of anthrax through focus group discussions (FGDs) and a hybrid approach combining traditional thematic analysis with artificial intelligence (AI) tools. The research was framed within the interpretivist paradigm, aiming to understand shared experiences and socio-cultural contexts. The study utilized focus groups to encourage interaction and generate rich, collective insights. The hybrid approach allowed for data analysis that combined researcher-led reflexivity with AI-driven thematic analysis. Findings reveal diverse levels of awareness about anthrax, widespread misconceptions, and the influence of cultural beliefs on health behaviours. Communities linked anthrax outbreaks to interactions with wildlife and the illegal game meat trade, highlighting the complex interplay of ecological, economic, and behavioural factors in disease dynamics. Additionally, the study underscores the socioeconomic toll of anthrax, including livestock losses, disrupted livelihoods, and food insecurity, compounded by inadequate public health and veterinary responses. The insights gained from this research emphasize the need for multi-sectoral interventions tailored to the specific needs of these communities.

Design and analysis of optical MIMO communications for 256-QAM for reconfigurable holographic surfaces

Abstract Optical multiple‐input multiple‐output (HMIMO) systems leverage reconfigurable holographic surfaces (RHS) to dynamically shape electromagnetic wavefronts, offering superior beamforming and spectrum utilization for next‐generation 6G networks for 256-QAM. By integrating these surfaces into traditional MIMO architectures, HMIMO systems effectively handle high data rates, low latency, and enhanced energy efficiency – even in millimeter‐wave and terahertz bands. Through MATLAB simulations under Rayleigh and Rician fading models, this research demonstrates that HMIMO systems substantially outperform conventional optical MIMO. In Rayleigh environments, where multipath scattering dominates, Optical HMIMO’s adaptable beamforming mitigates rapid signal fluctuations. Under Rician fading, the strong line‐of‐sight component further boosts beamforming gains and spectral efficiency. The study highlights significant improvements in reliability (outage probability), beamforming gain, and spectral efficiency across diverse antenna configurations and SNR levels, underscoring the scalability and robustness of optical-HMIMO for urban and high‐mobility 6G scenarios.

Demonstration experiment and theoretical model of light interference with small particles

Abstract This paper explores light interference in physics education and offers a teaching-focused approach to its demonstration experiment and modelling. Light interference is a fundamental wave phenomenon that reveals the nature of light through the redistribution of intensity due to wave superposition. The study highlights the need for simple, accessible methods to improve students’ understanding and address common misconceptions about wave optics. The authors present a demonstration experiment using readily available materials: powdered sugar particles on glass plates of varying thicknesses, and a helium–neon laser (λ = 0.6328 μm). This setup enables the observation of interference rings in both reflected and transmitted light, making the phenomenon demonstrable. The theoretical model, grounded in interference principles, provides a comprehensive framework for elucidating the impact of glass thickness and particle radius on ring size. The experimental data demonstrate a correlation between ring size and glass thickness, which is consistent with the predictions of theoretical calculations. From an pedagogical standpoint, the proposed demonstration experiment is uncomplicated, readily accessible, and integrates qualitative and quantitative analysis. It facilitates the development of analytical skills in students by utilising tools such as ImageJ and Mathcad. The implementation of this demonstration experiment can be adaptable to diverse learning levels. It enhances comprehension of the physical nature of the interference phenomenon, stimulates interest in optics, and can be adapted to other powders, including medical powder, talc, and cocoa.

Meanings and values of the craft market: An integrated perspective through service‐dominant logic

AbstractIn an era of increasing digitalization, automation and fast production, craft has experienced a significant revival. Producers and consumers, by interacting at individual, dyadic and group levels, influence the craft market with positive and negative connotations. This generates a complex and dynamic environment, where multiple meanings and values intersect. To fully understand this environment, it is essential to integrate the perspectives of both producers and consumers, considering their diverse viewpoints and levels of engagement. Using Service‐Dominant Logic (S‐D Logic) as a theoretical framework, this paper reviews studies on craft through a multi‐level lens, identifying resources applied by producers and consumers at individual and community levels. These resources interact with institutions generating a complex set of meanings and values across micro, meso and macro levels. Key contrasts arise from these interactions, suggesting areas for future research. These include (a) producers’ affective commitment and personal well‐being versus contemporary market dynamics and economic rewards; (b) authenticity, care and custodianship, opposition to the mass market versus innovation and creativity; (c) collaborative market value, care and custodianship versus creativity and innovation of community members; (d) opposition to mass market, care and custodianship and the risk of craft‐washing. These findings provide a new conceptualization of the craft market by holistically and dynamically integrating producers' and consumers' literature. Furthermore, they offer valuable insights for producers, policymakers and institutions on the importance of considering multiple perspectives when dealing with the opportunities and challenges of this market.

Understanding the Genetic Diversity of Bael for Physicochemical and Nutritional Traits of Fruit in West Bengal

ABSTRACT An investigation was carried out to understand the genotypic diversity of 13 bael (Aegle marmelos L. Correa) genotypes and cultivar based on morphological, phytochemical, and nutritional traits of fruit. Higher level of diversity was recorded for morphological traits of fruit namely fruit weight (364.67–2844.3 g), pulp weight (201.00–2414.00 g), and number of seeds per fruit (85–204.67). Rich diversity was also noticed for phytochemical traits. The highest total soluble solid content was registered in Bael-13 (44.79 ºbrix), whereas ascorbic acid and total carotenoids were maximum in Bael-5 (8.21 and 1362.60 mg/100 g, respectively). Bael-6 was significantly superior for total phenols and total flavonoid content as well as the antidiabetic properties (8.34 mg GAE/100 g, 3.57 mg RE/100 g, and 257.71%, respectively). The maximum level of various plant nutrients was recorded in different genotypes namely iron in Bael-2 (1.2 mg/100 g), zinc in Bael-13 (0.35 mg/100 g), and potassium in Bael-9 (22.24 mg/100 g). Further, principal component analysis revealed that the first two components contributed 86.00% to total variation. This information may be useful for future breeding programs to develop nutraceutical-rich varieties of bael and bioprospecting of nutraceuticals from bael on commercial scale.

Workplace diversity in female-dominated industries and intraindividual identity conflict.

This research paper examines the impact of gender and socioeconomic status (SES) diversity on intraindividual identity conflict within a female-dominated economic sector. The study also evaluates whether this relationship is moderated by gender and SES, as suggested in prior research. A quasi-experimental design was employed with 186 child protection workers as participants. Using vignettes that depicted varying levels of diversity, participants were randomly assigned to different conditions. The degree of dissimilarity was determined by comparing the diversity level described in the vignette with the participants' individual characteristics, and intraindividual identity conflict was subsequently measured. Findings revealed that SES dissimilarity within a workgroup is associated with heightened intraindividual identity conflict. Furthermore, the study confirmed that SES moderates the relationship between diversity and intraindividual identity conflict. This research contributes to the existing body of knowledge on the effects of diversity on group identity conflicts, with a particular focus on intraindividual conflict in feminized occupations. Additionally, the findings on SES diversity underscore the importance of advancing our understanding of socioeconomic or class diversity and expanding the study of diversity beyond the Global North-topics that have been largely overlooked in the literature.

Understanding Low Levels of Participation and Diversity in Economics: A Survey of High School Students

ABSTRACTUsing data from a novel survey of over 4800 students, we examine the low levels of participation and diversity in Economics at Australia's high schools. We find that student demand for Economics as a subject is strongly associated with socio‐educational advantage and sex, even when accounting for sample selection in whether schools offer Economics. Students typically have positive perceptions of economics as a field; however, the perceptions of Economics as a subject tend to be negative. Males compared to females, and students from more socio‐educationally advantaged schools compared to less socio‐educationally advantaged schools have more favorable perceptions of Economics as a subject, which is reflected in a higher likelihood of them choosing to study Economics. Controlling for a greater perceived understanding of what the subject of Economics is about does reduce some of the sex and socio‐educational differences in perceptions, but a gap remains.

Estimation of genetic diversity and population structure of ten scarce Eastern Himalayan Rhododendron species

Ten rare, threatened, and endangered Rhododendron species were collected from different altitudinal ranges starting from 2247masl to 3580masl. of Eastern Himalaya (particularly Darjeeling Hills) were studied by polymerase chain reaction (PCR) using randomly amplified polymorphic DNA sequences (RAPD) to measure the degree of the genetic diversity and relationship among the species which are urgently needed to promote effective conservation and management activities. Initially, 19 decamer oligonucleotide primers were screened on ten samples for unambiguous and reproducible band patterns. Out of nineteen, six decamer oligonucleotide primers finally yielding the best results were selected and used for the analysis of present samples. Mean 61 alleles were amplified by using six primers, among ten samples. Total 126 were unique bands showing an average of 79.43% polymorphism. The Genetic Similarity Coefficient (GS) was ranging from 0.45455 to 0.93827. The present study shows an average low level of genetic diversity (PIC= 0.2096, Hs= 0.979, Ho= 0.986, Ht= 0.985, I= 3.973). The population of Rhododendron shows a negative value of inbreeding coefficients (Fis < 0) indicating heterozygotes produced by the population due to crosses happens in between genetically distant individuals but the value does not support that there is a chance of outbreeding depression and population bottleneck in recent future. Results of AMOVA show that variation among and within populations is 1% and 99% respectively. The mean inbreeding coefficient (Fst) within subpopulations is 0.006. A dendrogram based on RAPD markers using the neighbor-joining cluster analysis method produced from Jaccards estimates using Free Tree software divided nine (out of ten) Rhododendron species into two main sister groups this result also supported by Principal Coordinates Analysis (PCoA). The obtained RAPD analysis results also suggested that some rare, threatened, and endangered species of Rhododendron in the present study could maintain moderate levels of genetic diversity. STRUCTURE assessment (ΔK= 5) showed the selected species distributed distantly from each other and estimated that the R. falconeri genotype is the maximum level of admixture among the ten species. Results of Mantel's test show a positive correlation between geographical distance and genetic similarity or dissimilarity of ten Rhododendron species. Whereas the positive regression analysis value (R²= 0.0809) does not tally for the deep connection between geographical distance and genetic similarity or dissimilarity among the evaluated species. Based on the results, summarized that Rhododendron species of Eastern Himalaya are at a high risk of outcrossing depression, which will lead to a population bottleneck. Therefore, immediate conservation (in-situ and ex-situ) measures have to be taken for these rare, threatened, endangered, economically, and ethno-botanically important Rhododendron species.

Mangrove Vascular Flora Composition, Distribution, and Diversity in Selected Sites of the Coastal Areas of Surigao del Sur, Philippines

Mangrove forests are vital components of coastal ecosystems, particularly in tropical and subtropical regions, where they act as natural barriers against environmental hazards. This study aimed to identify and classify mangrove vascular flora, plants adapted to coastal intertidal zones at the species level, analyze their composition and diversity, assess their zonal distribution, and evaluate their conservation status. The study focused on five municipalities: Hinatuan, Barobo, Lianga, San Agustin, and Cagwait, selected for their diverse mangrove ecosystems. Using a non-destructive belt-transect method, the study identified 32 mangrove species from 13 families, totaling 1,301 individuals. Among the most abundant species were R. mucronata (127) and R. apiculata (110). Several species were found to be near-threatened, including C. decandra, H. littoralis, and A. floridum, while those classified as vulnerable included C. tagal, O. octodonta, and A. rumphiana. Additionally, two species, A. aureum and B. gymnorrhiza, are not yet assessed. While, O. octodonta is classified as endemic, emphasizing the need for conservation efforts. The overall species diversity index was calculated at 3.68, indicating a very high level of diversity. These findings are crucial for participatory resource management, enabling the development of conservation strategies that protect biodiversity while addressing the economic needs of vulnerable coastal communities. The study provides a baseline for future studies and assists local governments in developing effective mangrove preservation strategies while raising community awareness of these critical ecosystems.

Fish Diversity in Lubuk Larangan Indigenous Conservation Area in Nagari Pelangai Kaciak, South Pesisir Regency

Lubuk Larangan is a form of customary conservation area as a form of fish conservation and breeding ground for fish. Diversity in the Lubuk Larangan area can be used as a form of river ecosystem conservation and help identify endangered species and the sustainability of the conservation area. This study aims to determine the level of diversity, uniformity, abundance and dominance of fish in the traditional conservation area of Lubuk Larangan in Nagari Pelangai Kaciak, South Pesisir Regency. This research was conducted in October 2024 using the survey method. The results showed that the fish obtained were 7 species with the highest composition of crisp fish (Tor tambroides) 47%. Diversity index (H') with a value of 1.37 medium category. The uniformity index (E) with a value of 0.7 is included in the high category. The dominance index (C) with a value of 0.32 is included in the low category. From the results obtained, it can be concluded that the indigenous conservation area of Lubuk Larangan in Nagari Pelangai Kaciak has fish diversity in the medium category, which means that the waters are in a stable and supportive condition to be used as a conservation area.

A comprehensive exploration of urban spatial economic vitality through the application of the node-place model

ABSTRACT This study investigates urban economic and tourism spatial vitality through the application of the node-place model across both spatial and temporal scales. Cluster analysis was employed to identify and characterize spatial clusters based on urban spatial vitality and the node-place model. Furthermore, bivariate spatial association was applied to examine the correlation between urban spatial vitality and the node-place model components. The findings reveal that the characteristics of these clusters reflect varying levels of density and diversity in urban development and transportation systems which emphasize urban planning and transportation integrations play a vital role in shaping urban vitality.

Soil microbial legacies and drought mediate diversity-invasibility relationships in non-native communities.

High native species diversity generally suppresses non-native invasions, but many ecosystems are now characterized by non-native assemblages that vary in species diversity. How this non-native species diversity affects subsequent invaders and its environmental dependence remain unclear. We conducted a plant-soil feedback experiment. In the conditioning phase, we created three diversity levels (1, 2, or 4 species) using six non-native species to condition the soil. In the responding phase, we planted these six species individually with soil inocula and exposed them to two watering treatments (well-watered vs drought). Under well-watered conditions, the non-native biomass increased with soil inocula generated by different non-native diversity. This biomass pattern was mainly related to arbuscular mycorrhizal fungal richness which increased with non-native species diversity. However, under drought conditions, the non-native biomass did not depend on soil inocula generated by non-native diversity. Our results reveal the crucial role of soil microbial legacies in driving the positive diversity-invasibility relationships of non-native communities and drought stress can eliminate these positive relationships. These findings provide an explanation for the commonly observed co-occurrence of multiple non-native species in nature, predicting an accelerating accumulation of non-native species in a benign environment, but not in a stressed environment.

Strong Environmental and Genome-Wide Population Differentiation Underpins Adaptation and High Genomic Vulnerability in the Dominant Australian Kelp (Ecklonia radiata).

Ongoing and predicted range loss of kelp forests in response to climatic stressors is pressing marine managers to look into the adaptive capacity of populations to inform conservation strategies. Characterising how adaptive genetic diversity and structure relate to present and future environmental variation represents an emerging approach to quantifying kelp vulnerability to environmental change and identifying populations with genotypes that potentially confer an adaptive advantage in future ocean conditions. The dominant Australian kelp, Ecklonia radiata, was genotyped from 10 locations spanning 2000 km of coastline and a 9.5°C average temperature gradient along the east coast of Australia, a global warming hotspot. ddRAD sequencing generated 10,700 high-quality single nucleotide polymorphisms (SNPs) and characterized levels of neutral and adaptive genomic diversity and structure. The adaptive dataset, reflecting portions of the genome putatively under selection, was used to infer genomic vulnerability by 2050 under the RCP 8.5 scenario. There was strong neutral genetic differentiation between Australia mainland and Tasmanian populations, but only weak genetic structure among mainland populations within the main path of the East Australian Current. Genetic diversity was highest in the center of the range and lowest in the warm-edge population. The adaptive SNP candidates revealed similar genetic structure patterns, with a spread of adaptive alleles across most warm (northern) populations. The lowest, but most unique, adaptive genetic diversity values were found in both warm and cool population edges, suggesting local adaptation but low evolutionary potential. Critically, genomic vulnerability modeling identified high levels of vulnerability to future environmental conditions in Tasmanian populations. Populations of kelp at range edges are unlikely to adapt and keep pace with predicted climate change. Ensuring the persistence of these kelp forests, by boosting resilience to climate change, may require active management strategies with assisted adaptation in warm-edge (northern) populations and assisted gene flow in cool-edge (Tasmania) populations.