Aims The rapid fluctuations of climate are increasingly altering the fate of species, exacerbating their vulnerability, leading to the loss of genetic diversity in many species, and even pushing some to the brink of extinction. Relict plants, having survived extreme climate changes since the Cenozoic era, carry a wealth of genetic information related to environmental adaptation. Investigating the genetic basis of their population-level environmental adaptation and their potential to cope with future climate change can provide valuable insights for biodiversity conservation. Methods In this study, restriction site-associated DNA sequencing (RAD-seq) was performed on 122 individuals from 18 populations of Pterocarya hupehensis, which is a Cenozoic relict plant distributed around the Sichuan Basin in China. Then, the ecological adaptation and genetic vulnerability of P. hupehensis were studied by landscape genomics. First, we use a latent factor mixed model (LFMM) and Pcadapt to detect selected sites. Second, a Mantel test based on linear models, redundancy analysis (RDA), gradient forest (GF), and generalized dissimilarity modelling (GDM) were used to investigate the response patterns of genetic variation to environmental gradients. Finally, based on the risk of non-adaptedness (RONA), the vulnerability of the P. hupehensis was predicted for the SSP 245 and SSP585 scenarios in 2090. Important findings A total of 398 single nucleotide polymorphism loci (SNPs) were significantly associated with the six climatic factors (Isothermality, Minimum Temperature of Coldest Month, Temperature Annual Range, Mean Temperature of Wettest Quarter, Precipitation of Wettest Month, and Precipitation Seasonality). In addition, 177 of them were detected as selected SNPs. We found that Precipitation Seasonality was an important climatic factor affecting the genetic variation of P. hupehensis. A significant signal of isolation by environment (IBE) was detected, indicating that environmental factors account for more genetic variation than geographical factors. Under the SSP585 scenario in 2090, the genetic vulnerability of P. hupehensis was higher than that under SSP126 scenario. The Precipitation Seasonality has an important effect on the adaptative ability of the population in the northwest range of P. hupehensis. This study not only provides a theoretical foundation for the management and conservation strategies of vulnerable species in the face of future climate change, but also offers a new case study on how relict plants around Sichuan Basin may respond to future climate change.

Aims In order to understand the geographical distribution of threatened species of genus Epimedium in China, and to provide the basis for resource conservation and utilization. Methods The data of Chinese Virtual Herbarium (CVH), China National Specimen Information Infrastructure (NSII), the Royal Botanic Garden Edinburgh (E), Royal Botanic Gardens, Kew (K), Muséum National d'Histoire Naturelle (P) and Universitat Wien (WU) were used. And the specimens of Herbarium of Institute of Medicinal Botany, Chinese Academy of Medical Sciences (IMD), which is not included in the sharing platform but abundant in Epimedium specimens, were also examined. At the same time, combined with our field investigations and literature review, the specimen information of 25 species and 1 variety of Epimedium in China were systematically collected to verify the specimen identification and geographical distribution, and updated the endangered categories and criteria. Important findings A total of 1017 specimens of 428 numbers were examined, and only 666 specimens of 274 numbers (64.02%) were correctly identified. Nineteen taxa (73.08%) had found new distribution compared with the recorded of Flora of China. However, six species were currently known to be distributed only in the type locality. The three provinces with the highest abundance of threatened species were Sichuan (12 species), Hubei (7 species) and Guizhou (6 species and 1 variety). The endangered categories or criteria of 22 taxa were suggested to be adjusted. Epimedium enshiense B. L. Guo et Hsiao, E. reticulatum C. Y. Wu, E. fangii Stearn and E. elachyphyllum Stearn were suggested to be upgraded to Critically Endangered (CR). The endangered categories of E. flavum Stearn, E. glandulosopilosum H. R. Liang, E. mikinorii Stearn, E. sagittatum var. glabratum Ying, E. truncatum H. R. Liang and E. zhushanense K. F. Wu et S. X. Qian were suggested to be upgraded to Endangered (EN). Epimedium simplicifolium Ying and E. fargesii Franch. were respectively suggested to be downgraded from Critically Endangered (CR) and Endangered (EN) to Vulnerable (VU). For another 10 species, the endangered categories remained unchanged and only the criteria were adjusted. The main reasons for the endangered plants of Epimedium were narrow distribution, habitat decline and population decrease. Errors in the identification of specimens of threatened species of Epimedium were prominent. Most species of this genus were distributed in narrow areas and were highly threatened. Therefore, the protection of species diversity should be paid more attention. The?evaluation of endangered categories and criteria is a dynamic process that requires long-term monitoring and constant updating.

Aims Pinus squamata, is a critically endangered species endemic to China, found only in Qiaojia County, Yunnan Province. It faces significant challenges such as fragile habitats and difficulties in population recovery. Fungal communities play a vital role in the population maintenance and ecological adaptation of endangered plants. However, studies on the fungal community characteristics within the roots and rhizosphere of P. squamata are currently insufficient. Methods This study used in-situ sampling and high-throughput sequencing to analyze the fungal community structures and geographical differentiation patterns of wild and cultivated populations of P. squamata. Additionally, it compared the fungal community structures of Pinus squamata with those of its neighboring plant species. Important findings (1) There are significant differences in the fungal community structures within the roots and rhizosphere between the wild and cultivated populations of P. squamata. The fungal diversity in the wild populations is lower than that of the cultivated population. (2) In the wild populations, the fungal communities differ significantly between individuals in the west-slope and east-slope populations. (3) Ectomycorrhizal (ECM) fungi, such as species from the genera Sebacina, Russula, and Xanthoconium, dominate the root systems of Pinus squamata. Individuals in the west-slope population, which inhabit nutrient-poor soils, exhibit greater dependence on ECM fungi. (4) P. squamata shares some ECM fungi with neighboring tree species, highlighting the cooperative role of mycorrhizal fungal networks in resource sharing and ecological stability. This study reveals both abiotic and biotic factors influencing the fungal communities of P. squamata. Results of this study suggest that conservation efforts should combine inoculation with ectomycorrhizal fungi and improvement of the seedling soil to restore critical ectomycorrhizal networks, thereby promoting the vision of integrated recovery of the “pine-fungus” system.

Cathaya argyrophylla, a National Class I protected Plant and an endemic “living fossil” species in China, has fewer than 2,400 wild individuals. Over the past 40 years, extensive research have been conducted on its biological characteristics, genetic diversity, habitat requirements, and conservation strategies. However, C. argyrophylla wild populations continue to decline, presenting a severe conservation challenge. We reviewed the research progress on C. argyrophylla, analyzing its endangered status from aspects such as growth and reproduction traits, geographical distribution, and population dynamics. Additionally, we conducted surveys of fourteen wild populations in 2023 and found that C. argyrophylla seedlings are scarce, juvenile tree mortality rate is high, and population structure indicates a declining trend. This suggests that natural regeneration of C. argyrophylla is hindered, and the current conservation measures are insufficient to reverse the decline. Although progress has been made in seedling cultivation and ex situ conservation, there is still a significant gap in protecting the species' genetic diversity, which requires urgent attention and improvement. Future research and conservation efforts should integrate multiple disciplines and apply new technologies, particularly high-throughput sequencing for conservation genomics, to reveal the endangerment mechanisms and adaptive potential of C. argyrophylla. Additionally, integration of multi-source remote sensing technologies is necessary to monitor population dynamics and habitat changes, which could provide more accurate data to support conservation of C. argyrophylla.

Aims Nyphaea candida C. Presl, an endangered species endemic to Xinjiang and classified as a National Class II protected plant, faces high risks of extinction and requires urgent conservation efforts. The aim of this study is to reveal its reproductive characteristics and explore factors associated with endangered status from a reproductive biology perspective. Methods This study systematically investigated the flowering phenology, floral morphology, breeding sys-tem, pollination process, and seed germination characteristics of N. candida in natural populations. Important findings The flowering period lasts from May to September, with a single flower lifespan of ap-proximately four days, while the stigma remains receptive for only 1～2 days. Pollinators are mainly syrphid flies, though visitation frequency is low and easily affected by adverse weather conditions such as rain. Ex-perimental data suggest that N. candida follows a mixed mating system, predominantly outcrossing but also self-compatible, and depends on pollinators for successful reproduction. Seed viability is measured at 45.33±4.29%, yet germination rate under natural conditions is low (only 2.67±1.63%), restricted by seed coat barriers. The reproductive process of N. candida faces significant limitations due to its floral characteristics, pollination behavior, and seed germination challenges, notably with limited pollinator availability, low visita-tion frequency, and reduced seed viability. Environmental factors (e.g., rainy weather) further inhibit pollina-tion success, imposing substantial pollination constraints on this species. In unstable pollination environments, N. candida tends to adopt a spontaneous self-pollination strategy, which may lead to inbreeding depression and further increase its risk of endangerment.

Aims Rhododendron liboense was a plant species with extremely small populations which distributed on top of limestone mountains, it has high ornamental and scientific research value. The habitat of it was fragile, and the wild population of it was rare, which urgently needs to be studied for conservation genetics. Methods This study focused on 43 individuals from three populations of R. liboense, using double digest restriction-site associated DNA sequencing technology (ddRAD-seq) to obtain single nucleotide polymorphism (SNP) data. The genetic diversity and structure of R. liboense population were analyzed, and historical population dynamics were inferred. Important findings The results showed that the genetic diversity of R. liboense was low (He = 0.139 62 ± 0.003 32, π = 0.157 64 ± 0.003 83), and the level of genetic differentiation between populations was moderate (FST = 0.075 8), The variation within the population (88.22%) is greater than the variation between populations (11.78%) . Structure analysis, PCA analysis, and cluster analysis were used to divide the three populations of R. liboense into two genetic groups. The analysis of population historical dynamics showed that the effective population size (Ne) of R. liboense had been continuously increasing since the last glacial period, which might be related to the gradual warming of the climate suitable for its survival. Based on the above research results and population status, it was recommended to divide the populations into two management units for on-site conservation, while strengthening research on artificial breeding techniques to assist in the ex-situ conservation and field return of R. liboense.

Aims The IUCN Red List provides basis to biodiversity conservation designation. The Red List Index (RLI) derived from the results of Red List assessment is an indicator for the status of species and specific taxonomic groups at global, national, regional scales. Based on the IUCN global assessment data, this study aims to analyze the RLI of Chinese higher plants. Methods The RLI can be calculated based on either national or global assessment data. Chinese Red List Index based on national assessment data (nRLI) for higher plants has been reported. Following the IUCN assessment framework, through the partition of species Extent of Occurrence (EOO) of China and the rest of the world, this study calculated Chinese higher plant Red List Index based on global assessment data (gRLI). And then compared Chinese higher plant gRLI with the results from the Biodiversity Indicators Partnership (BIP), which relied only on a representative subset of Cycads to calculate a nation’s gRLI. Important findings The Chinese higher plant gRLI, with equal steps method, is 0.9467, 0.9082, and 0.5401 for the source data of IUCN assessments, IUCN and Chinese endemic species assessments, and solely Cycas, respectively. The BIP approach underestimates Chinese gRLI for higher plants, suggesting taxonomical bias. This highlights the importance of utilizing as much reliable data as possible for a more precise result of gRLI. By calculating Chinese higher plant gRLI which is comparable to that of other countries, this study provides essential baseline data to support China's international commitments and conservation efforts for various international conventions about biodiversity.

Abstract Aims In recent years, resources of Glycine soja had decreased dramatically under the human disturbance. This study aimed to reveal the resource recovery and position of Glycine soja in communities on abandoned farmland, evaluate its interspecific association with other species and the stability of the community, as well as provide a theoretical basis for resource conservation and community restoration of Glycine soja . Methods In this paper, quadrat method with 1 m×1 m was used on the herb communities on 3 abandoned farmlands near the river located in the suburbs of Shenyang city. The importance value, ecological niche width and the degree of ecological overlap, interspecific association of the major herbaceous in the communities and the stability of the community were analyzed. Important findings There were 65 species of herbaceous plants belonged to 20 families and 51 genera in the investigated community, among which annual plants accounted for 52.31 %. Glycine soja was the most dominant species in the community, with the highest frequency (97.18 %), coverage (49.75 % in average), importance value (33.28) and niche width (BL=101.92, BS=4.75). The resource use overlap Oik value (0.35) and niche similarity (0.30) between Glycine soja and Artemisia lancea were the largest, and the niche overlap between Glycine soja and Vigna minima was also large (Oik=0.34). χ2 test and AC results showed that there was a significant positive association between Glycine soja and Artemisia lancea, and a very significant negative association between Glycine soja and Humulus scandens. The correlation coefficient showed that Glycine soja had a positive association with Vigna minima, but very significant negative association with Setaria viridis, Persicaria orientalis and Echinochloa crusgalli. The overall niche overlap values of the important plants in the community were low (0~0.35). The VR and W values of the variance ratio test of the total association were 0.87 and 122.16, indicating that there was negative association among the major plants in the community. The results of χ2 test, association coefficient (AC), and Spearman rank correlation coefficient showed that there were mainly negative associations among species. The Euclidean distance between the coordinates of the intersection point and the coordinates of the stable point analyzed by M. Godron method was far, indicating that the community stability was relatively poor. However, the Euclidean distance of the community with a longer period of returning farmland to forest was closer than that of the community with a shorter period, suggesting that community stability increases with longer abandonment times.

Aims Salweenia wardii, a rare and endangered protected plant in China, is a extremely small population in the arid valleys of the Hengduan Mountainous. Ite habitat is fragile and severely fragmented, and systematic research on its community ecological adaptive mechanisms and conservation strategies remains lacking. Methods Based on literature and field sample surveys, we initially delineated the geographical distri-bution range of Salweenia wardii. Utilizing data from 18 survey plots collected between 2023 - 2024, we proposed a preliminary community classification scheme, accompanied by a detailed description of the community structure. Additionally, we also analyzed species composition in conjunction with data from 38 list quadrats obtained during the survey. Important findings The results showed that: (1) Salweenia wardii community was concentrated in Karuo District, Baju County, Luolong County and Chaya County of Chamdo City, and formed dominant communities in Karuo Town, Xiali Township, Qumba Township and Jiba Village, with distribution alti-tudes ranging from (3000) 3083 to 3657 (4400) m. (2) 74 vascular plants belonging to 28 families and 55 genera were recorded, mainly xerophytes in the families of Gramineae, Asteraceae, and Rosaceae. The life forms spectrum, dominated by deciduous shrubs and perennial herbs, along with the floristic charac-teristics featuring the coexistence of pan-tropical and north-temperate components, reflected their adaptive strategies to seasonal droughts and the evolutionary features of transitional zone in the Hengduan Mountains. (3) Based on variations in community structure and species composition, Salweenia wardii alliance could be classified into 6 association groups and 10 associations. (4) The population exhibited low natural regeneration capacity and relied on asexual reproduction for maintaice, necessitating urgent conservation measures. Our fingdings fill the gaps in the taxonomic study of Salweenia wardii and offers scientific basis and practical guidance for regiregional biodiversity conservation and ecosystems resto-ration.