Search Results (412)

Cowpea (Vigna unguiculata L. Walp.) is an important legume crop contributing to food and nutritional security. However, its systematic evaluation for yield and adaptability, particularly in the Middle-Lower Yangtze River region of China, remains insufficient. In this study, conducted in Jiangxi Province across two seasons (April and August 2024), a comprehensive analytic hierarchy process (AHP) model evaluated 139 Chinese cowpea accessions based on 18 agronomic traits. The evaluation showed coefficients of variation for 11 quantitative traits ranged from 5.18% to 49.42%, with single pod weight and pod length exhibiting the highest variation. Shannon–Wiener index analysis indicated pod width and SPAD (Soil Plant Analysis Development) were the most diverse traits (H’ = 1.04 and 1.01). Based on the AHP model, 139 accessions were classified into four grades. Notably, Grade I accessions demonstrated high comprehensive scores, comprising three cultivars: ‘Changde Baipi Doujiao’, ‘Guilin Changjiangdou’, and ‘Guangrao Wuyuemang’. These exhibit promising performance under field conditions and high yield potential, making them worthy of further regional testing. Cluster and principal component analyses revealed natural groupings and variation patterns within the germplasm resources. This study provides a practical, preliminary decision-support tool for yield and field adaptation evaluation. Full article

The salinization of natural grasslands is a growing global concern. The Songnen Plain in northeastern China represents a typical soda–saline grassland region, yet an integrated understanding of how salinization reshapes plant, soil, and microbial components in this ecosystem remains limited. In this study, we investigated plant community characteristics, soil physicochemical properties, and soil microbial communities across a salinity gradient (from non-saline to extremely severe saline) using field surveys, laboratory analyses, and structural equation modeling (SEM). Our results showed that vegetation species diversity, the Shannon–Wiener index, and Simpson’s index all decreased from mild to severe salinization. Soil nutrient indicators, including total nitrogen (TN), total phosphorus (TP), and total potassium (TK), significantly decreased with increasing salinity. SEM revealed that plant community diversity had a significant positive effect on soil microorganisms, whereas soil properties, particularly available potassium (AK) and electrical conductivity (EC), exerted significant negative effects on microbial diversity. Together, these results provide an integrated view of how salinization restructures plant–soil–microbe interactions across the Songnen Plain grasslands. These findings improve understanding of saline–alkali grassland degradation from a plant–soil–microbe perspective and provide a theoretical basis for ecosystem restoration in this region. Full article

Winter barley (Hordeum vulgare L.) is an important crop used for feed, food, malting, and bioethanol production. Recent research indicates that the seed mycobiome significantly influences seed health and usability, affecting its potential applications. This study examined the fungal species present in seven barley cultivars grown under two agrotechnical regimes. Fungal species were classified according to their effects on seeds and plants, and biodiversity indices were calculated for each group. Enhanced agrotechnical practices increased yields and improved grain quality. Higher DON concentrations were observed in low-yield treatments. Mycological analysis revealed that field fungi, particularly Fusarium, dominated the grain mycobiome and were associated with infection and reduced seed quality. High Dominance (Y), Margalef, and Shannon–Wiener indices for quality-deteriorating fungi correlated with lower yields, while the Dominance index (λ) for these fungi was negatively correlated with grain protein content. The prevalence of specific fungi on seeds depends on storage conditions and fungal adaptations, which may result in complementary consortia. Understanding these interactions can support the development of effective seed storage strategies and inform material classification and future use decisions. Full article

Dongping Lake is a regulating lake where hydrodynamic alteration and heterogeneous inputs may reshape phytoplankton communities; this study aimed to characterize eukaryotic phytoplankton, assess water quality and identify key environmental drivers. In September 2025, eukaryotic phytoplankton were profiled using 18S rDNA V9 eDNA metabarcoding across 18 sites, and community–environment relationships were evaluated using diversity indices, principal coordinates analysis (PCoA), Spearman correlations and redundancy analysis (RDA). This study detected 101 eukaryotic phytoplankton species. Bacillariophyta dominated read abundance at 55.08%, followed by Cryptophyta at 22.20%, whereas species richness was highest in Chlorophyta with 40 species. Site richness ranged from 26 to 63, peaking at sampling sites D17 and D18 and reaching a minimum at sampling site D15; Cryptophyta dominated reads only at sampling site D6. Nine dominant species were identified. Mean diversity values were Shannon-Wiener diversity index (H) 3.45, Pielou evenness index (J) 0.92, Margalef richness index (D) 4.40 and Chao1 richness estimator 44.72, and overall water quality was assessed as slightly polluted, with sampling site D12 or D15 reaching moderate pollution under specific indices. Dominant-species responses were differentiated; for example, Stephanodiscus hantzschii was negatively correlated with NH₄⁺ and TN, and Ceratium hirundinella was positively correlated with salinity but negatively correlated with NH₄⁺. RDA ranked key drivers as salinity > NO₂⁻ > TN > NH₄⁺ > TP > DO > temperature. Salinity and nitrogen-form gradients were closely associated with spatial community differentiation and dominant-species shifts, supporting targeted monitoring and management. Full article

In the conducted study, the structure of weed communities and their dynamics were assessed and compared in relation to plantation age and the species of energy crop. Weed diversity within the stands of the investigated energy crops was evaluated in three-year cycles, from 2006 to 2024. The assessment of weed diversity in the stands of the studied energy crops was conducted in three-year cycles, i.e., in the first year of cultivation (2006—the year of plantation establishment), the fourth year of cultivation (2009), the seventh year of cultivation (2012), the tenth year of cultivation (2015), the thirteenth year of cultivation (2018), the sixteenth year of cultivation (2021), and the nineteenth year of cultivation (2024). The species composition of weed communities and the abundance of individual weed species were determined. The diversity and dominance patterns of weed communities occurring in Salix viminalis, Miscanthus × giganteus, and Phalaris arundinacea were described using two indices: the Shannon–Wiener diversity index and the Simpson dominance index. As a result of the conducted observations, it was found that weed abundance, species diversity, and weed infestation dynamics depended on the energy crop species and the age of the plantation. Greater interannual variability was observed in weed abundance, whereas species richness remained relatively more stable between years. The highest species diversity was recorded in the Salix viminalis plantation, where a total of 53 weed species were identified. In contrast, considerably fewer taxa were found in Miscanthus × giganteus (42 species) and Phalaris arundinacea (41 species). Moreover, it was found that regardless of the energy crop species, segetal weeds dominated during the first years of cultivation, i.e., E. crus-galli, A. spica-venti, A. retroflexus, Ch. album, M. inodora, and V. arvensis. In subsequent years of cultivation, however, the dominant species were ruderal weeds, such as A. vulgaris, T. officinale, and U. dioica, as well as invasive species, e.g., S. canadensis and S. gigantea. In subsequent years, ruderal species became dominant. The Shannon–Wiener diversity and Simpson dominance indices indicated differences in species richness and the relative abundance of individual weed species. The highest values of the Shannon–Wiener diversity index and the lowest values of the Simpson dominance index were recorded in weed communities of Salix viminalis plantations aged 7–16 years after establishment. In contrast, the highest Simpson index values, indicating dominance by one or a few weed species, were observed in the first year of cultivation regardless of the energy crop species, as well as in the 19-year-old Miscanthus × giganteus plantation. Full article

Low-count positron emission tomography (PET) is inherently affected by Poisson-dominated noise, which degrades image contrast, structural delineation, and quantitative reliability. This study systematically evaluated residual learning-based deep neural networks to investigate the influence of residual block depth on PET image restoration performance under low-count conditions. We employed a physically controlled striatum phantom, fabricated using 3D printing technology, to ensure reproducible acquisition conditions and controlled physical variability. PET images were acquired using a clinical PET/computed tomography (CT) system with list-mode acquisition. Low-count images reconstructed from short-duration acquisition were paired with high-count reference images reconstructed from extended acquisitions. We compared conventional filtering techniques, including median, Wiener, and modified median Wiener filters, with residual network (ResNet)-based models incorporating 8, 16, and 32 residual blocks. Image quality was quantitatively assessed using contrast-to-noise ratio (CNR), coefficient of variation (COV), line profile analysis, universal quality index (UQI), and perceptual image patch similarity (LPIPS). The results demonstrated that ResNet-based restorations substantially outperformed conventional filtering techniques in contrast recovery, signal stability, and structural preservation. The ResNet-16 model achieved the most balanced performance, yielding the highest CNR (9.02) and lowest COV (0.105), while also demonstrating superior structural and perceptual similarity, as indicated by UQI (0.9224) and LPIPS (0.0174), relative to the high-count reference images. Deeper network configurations exhibited diminishing returns and reduced structural consistencies. These findings indicate that an intermediate residual block depth is optimal for low-count PET image restoration and highlight the importance of architectural optimization in deep learning-based PET image enhancement with phantom-based evaluation frameworks. Full article

The succession of plant communities and soil-driven mechanisms triggered by wetland degradation are central issues in global ecology. To investigate the effects of Deyeuxia purpurea wetland degradation on plant community characteristics and its key soil regulatory factors, this study selected D. purpurea wetlands with different degradation degrees in the Sanjiang Plain as research objects and analyzed the characteristics of plant communities, soils, and their relationships. The results indicated that wetland degradation was significantly associated with turnover in plant community composition, with hydrophytic species progressively replaced by mesophytic and xerophytic species. As degradation intensified, Simpson’s diversity index, the Shannon–Wiener index, Pielou’s evenness index, and Patrick’s richness index all increased significantly. The non-degraded wetland exhibited significantly higher aboveground, belowground, and total biomass than the degraded wetlands. Aboveground and total biomass showed a significant negative correlation with the diversity index. Soil pH, water content (WC), total phosphorus (TP), dissolved organic nitrogen (DON), and ammonium nitrogen (NH₄⁺-N) were key factors associated with changes in plant community diversity and biomass. Partial least squares path modeling (PLS-PM) and variance partitioning analysis (VPA) further quantified potential association pathways, showing that wetland degradation exerted both direct and indirect effects on key soil physicochemical factors and plant community characteristics. Specifically, wetland degradation was directly associated with decreases in soil pH, WC, and TP, while positively affecting soil dissolved organic nitrogen (DON) and plant diversity. It also indirectly influenced plant species composition and biomass through changes in soil pH, WC, DON, and TP. TP was negatively correlated with plant diversity and biomass, whereas ammonium nitrogen had a direct positive effect on species composition. Dissolved organic nitrogen directly negatively affected species composition. Overall, this study systematically elucidates plant community response patterns and the synergistic driving mechanisms of multiple soil factors during D. purpurea wetland degradation, providing an important scientific basis for wetland conservation and ecological restoration in the Sanjiang Plain. Full article

Zelenci is a limnocrene spring in the South-Eastern Alps, attractive for its unique structure and known among researchers for its high diatom diversity. Our aim was to assess how abiotic factors influence the structure of diatom communities in different habitats and to compare the trophic status over 10 years of investigation. Four sampling sites were chosen: two for tychoplankton and two for epipelon. Achnanthidium minutissimum was the most abundant species in both habitats, while Navicula was the most diverse genus (17 species). Planktonic diatoms dominated plankton samples, while the motile ecological type dominated the epipelon. Of all diatom taxa, 23.5% had some endangerment status. Key factors influencing the Shannon–Wiener diversity index were water level, temperature, and concentration of NH₄⁺. The most important abiotic factors for the tychoplankton community were temperature and NH₄⁺, while the most important abiotic factors influencing the structure of epipelon communities were water level, NH₄⁺, pH, and dissolved oxygen concentration. Trophic index revealed increasing inflow of nutrients to the spring; 10 years ago, they were oligotrophic to oligo-mesotrophic, whereas in the present, they are predominantly eu-mesotrophic to eutrophic, indicating human pressure from the catchment area. Full article

This study evaluates the ecological impact of Robinia pseudoacacia L. (black locust) invasion on native chestnut (Castanea sativa Mill.) groves on Mount Amiata (Central Italy), focusing on both plant and macrofungal community dynamics. Surveys were conducted over a three-year period (2022–2024) across 16 plots to assess shifts in taxonomic alpha diversity, species richness, and trophic guild structure. Our results demonstrate that while R. pseudoacacia stands exhibit a higher Shannon–Wiener index for plants, native chestnut groves host significantly greater species richness and higher taxonomic distinctiveness across both biological groups. A major shift in fungal functional structure was observed with chestnut-dominated plots characterized by a predominance of ectomycorrhizal species (58.3%), whereas invaded stands were heavily dominated by saprotrophic fungi (73.4%). Non-metric Multidimensional Scaling (NMDS) further confirmed a clear separation in community composition between the two forest types, indicating that R. pseudoacacia invasion leads to a homogenization of the forest biota and a potential decline in ecosystem health, as evidenced by the sharp reduction in mycorrhizal diversity. These findings highlight the importance of monitoring macrofungal communities as sensitive bioindicators of the ecological degradation caused by invasive woody species. Full article

Environmental DNA metabarcoding has proven to be a powerful tool for monitoring fish diversity, and has been widely used in both freshwater and marine ecosystems. Fish diversity is a critical indicator to assess ecosystem function and its health. In this study, we took 12 samples from four areas (Area 1 (LS1) is the edge of the seagrass field adjacent to oyster reefs; Area 3 (LS3) is the edge of the seagrass field adjacent to coral reefs; Area 2 (LS2) is situated between LS1 and LS3 where there is dense seagrass distribution around the sampling sites; and Area 4 (LS4) is located between LS1 and LS3; we sample in the places at least 4 m by 4 m on the beach where no seaweed is present, each with three replicates) from Li’an Bay to detect fish diversity across multi-habitat seagrass areas based on the environmental DNA metabarcoding. A total of 312 Amplicon Sequence Variants (ASVs) were detected from 12 samples, and 58 fish species were annotated, representing 21 orders, 32 families and 48 generas. In general, the mean of Simpson and Pielou’s evenness indices followed the pattern LS1 > LS4 > LS2 > LS3, while the mean of Shannon–Wiener Diversity Index is LS4 > LS1 > LS2 > LS3. A total of 35 functional entities were observed among the four areas, with functional redundancy (FR) values of 0.800, 0.657, 0.542, and 0.7 for LS1, LS2, LS3, and LS4, respectively. All FR values were below 1.5, suggesting low ecological niche overlap among species within each area. These findings provide fundamental insights into the ecological health and stability of seagrass beds in Li’an Bay and offer a scientific basis for future ecological restoration efforts. Full article

Grassland degradation is a critical ecological problem worldwide that threatens ecosystem integrity and functional services. Although previous studies have documented the drivers of climate change, overgrazing, and anthropogenic perturbation, research concerning the impact of invasive alien plants on grassland ecosystems remains limited. The present study, integrating pairwise field investigation of Ageratina adenophora invasion and non-invasion plots across heterogeneous grassland types (tropical grasslands [TG]; tropical shrub-grasslands [TS]; warm-temperate grasslands [WG]; and warm-temperate shrub-grasslands [WS]) and A. adenophora indigenous plants phytotoxicity bioassay, aims to assess the invasibility and resilience of heterogeneous grassland landscapes to A. adenophora invasion. The field investigation demonstrated the greater vulnerability of TG and TS to A. adenophora invasion, whereas WG and WS possessed higher resilience. In addition, regression analysis revealed significant reductions of the Shannon–Wiener index and the Pielou index as the A. adenophora’s important value reached the threshold 0.36. Bioassay showed that A. adenophora aqueous extracts inhibit seed germination and seedling growth of recipient plants, with Saccharum arundinaceum exhibiting the highest tolerance to A. adenophora stress. In summary, our findings not only highlight the flora communities’ dynamics and invasibility of diverse grasslands driven by A. adenophora invasion in subtropical regions but also verify S. arundinaceum’s potential for A. adenophora replacement management. Full article

High-altitude mine wastelands in Southwest China present formidable challenges for ecological rehabilitation due to extreme climatic stressors and multi-element contamination. Ecological restoration is closely related to soil environment. However, the mechanism by which parent material-induced heterogeneity governs spontaneous vegetation succession is still poorly understood. We established 36 plots (216 quadrats) to investigate the soil physical and chemical properties and vegetation restoration of propylite, porphyry and siltstone in the Xifanping Copper Mine, Sichuan Province. Furthermore, fifteen metal/metalloid elements (Au, Ag, Mo, W, Cu, Pb, Zn, Hg, As, U, Se, Cr, Sn, Ti, Total Fe₂O₃), soil pollution and vegetation structure were evaluated. The study area exhibited severe composite pollution (mean Nemerow integrated pollution index = 8.09), primarily driven by Au, Ag, Mo, W, and Cu. Vegetation surveys identified 34 vascular plant species from 12 families. Propylite-derived substrates supported significantly higher species richness, Shannon–Wiener diversity, and soil organic matter than porphyry and siltstone. Redundancy analysis (RDA) identified soil organic matter (SOM) and bulk density (BD) as dominant environmental filters, with SOM explaining 14.03% of community variance (p < 0.01). Two native pioneers, Potentilla supina and Cynoglossum wallichii, were identified as specialized uranium (U) accumulators with bioconcentration factors of 13.39 and 4.49, respectively. Lithological inheritance dictates early successional trajectories by influencing edaphic structure and nutrient bioavailability. The identified U-accumulating species provide a valuable genetic resource for implementing Assisted Natural Regeneration (ANR) and developing sustainable phytoremediation strategies in contaminated alpine ecosystems. Full article

This study provides the first comprehensive structural and diversity assessment of the Stanului Forest ecosystem since the last taxonomic survey conducted in 1987. The paper analyses the structural indices of biocoenosis and vegetation diversity in the Stanului Forest ecosystem (Gemărtălui Valley), in the hilly area of Oltenia (Romania), in Dolj County. Primary data were obtained using randomised sampling with frame squares, which ensured the random selection of sampling units and standardisation of the data collection process. The number of samples was equal (10) across all vegetation categories studied. The sampling area was 1 m² for herbaceous species and 100 m² for woody species. Structural indices (frequency, constancy, dominance index, index of relative significance, etc.), diversity indices (Shannon–Wiener, Gleason, Simpson), and statistical analyses were used to interpret the data. The results showed that from a taxonomic perspective, 5 families of woody species and 15 families of herbaceous species were identified. The presence of the invasive species (Robinia pseudoacacia) can negatively influence the ecological functions of the existing plant community. The species Quercus frainetto and Carpinus betulus accounted for 55.16% of the woody layer dominance. In the herbaceous layer, Carex sylvatica and Schedonorus giganteus recorded the highest dominance values. The Shannon–Wiener diversity index was 0.53 in the woody layer and 0.50 in the herbaceous layer. Full article

Martagon Lily, Lilium martagon, belongs to geophytes inhabiting mainly forest communities in temperate regions of Europe and Asia and it is considered as a rare and endangered species in many regions. The presented investigations were conducted in three populations, occurring in forest habitats in Southern Poland: Wolski Forest (population 1), Mount Chełm (population 2), and Hrabeński Forest (population 3). At each site, 10 phytosociological relevés covering an area of 100 m² were taken. For each phytosociological relevé, the Shannon–Wiener, Pielou, and Simpson indices, as well as the number of species, were calculated. The detailed field studies were conducted in permanent study patches measuring 20 m × 20 m. The measurements of habitat conditions (e.g., number of species, soil moisture, light intensity at ground level, height of plant cover) were carried out in 2018. The observations of the abundance and developmental structure of stems, as well as selected traits (e.g., height, number and dimensions of leaves, number of flowers) were conducted in 2018–2023. The analysis of phytosociological relevés showed that the study sites in Wolski Forest and Mount Chełm were located in the Tilio cordatae–Carpinetum betuli oak-hornbeam forest association, while the study site in Hrabeński Forest was situated in the Dentario glandulosae–Fagetum mountain beech forest association. The statistical analysis confirmed that the greatest Shannon and Simpson index values, number of species, soil humidity, light intensity at ground level, and height of plant cover were recorded in Hrabeński forest. The greatest number of Lilium martagon stems and a lack of juvenile stems was found in population 3, while in less abundant populations—1 and 2—juvenile, immature, virginile, and generative stems were found. The statistical analysis showed that the highest immature and virginile stems with the greatest number of whorl leaves, as well as the substantial height of generative stems and number of whorl leaves observed in population 3, might be the result of growing in conditions of lateral shading provided by adjacent plants. The lowest height of immature and virginile stems recorded in population 1 and generative stems noticed in population 2 might be caused by them being overshaded by the canopy of surrounding trees. Moreover, the obtained results suggest the favourable impact of weather conditions during the meteorological spring and summer of 2019 on the growth of Lilium martagon stems. Nevertheless, the lack of a unified trend in the studied populations indicates the occurrence of site-specific temporal variability of individual traits. Considering the obtained results, it can be concluded that population 3 presents a much better state and prospects for persistence in the occupied site than populations 1 and 2. At the same time, it should be pointed out that further long-term observations of populations of Lilium martagon located in different habitat conditions are still strongly desired. Full article

To investigate the long-term effects of climate change on biological communities, our primary aim was to identify the most reliable indicators among available biodiversity, dominance, and evenness indices. We examined three distinct response types to climate change, represented by three taxonomic groups: Aculeata (Hymenoptera), Syrphidae (Diptera), and nocturnal macrolepidoptera (Lepidoptera). Using faunistic datasets derived from our own 3–5 decades of field surveys, we calculated 12 key indices with the vegan package in R 4.2.1. The robustness of these indices was assessed through 1000-fold bootstrap simulations and pairwise correlation analyses. Our results revealed that the Gini–Simpson, Simpson diversity, McIntosh diversity, and McIntosh evenness indices consistently demonstrated high temporal stability and strong correlations across all three climate response types. Therefore, we recommend these indices as primary climate indicators. In contrast, Chao1 estimates, Margalef Index, Menhinick Index, and the Shannon–Wiener diversity index are suitable only for analyzing specific response patterns. Meanwhile, the Berger–Parker, Buzas–Gibson indices, and Hill numbers showed high variability or limited ecological responsiveness, making them unreliable for tracking climate change impacts. Our findings underscore that selecting biodiversity indices must be tailored to the research question and the characteristics of the ecosystem in order to ensure valid and informative ecological analysis. Full article