Search Results (145)

In recent years, the homogenization and fragmentation of agricultural landscapes have intensified, leading to a decline in epigaeic arthropods. Landscape heterogeneity is a core factor regulating biodiversity, encompassing two key dimensions: composition heterogeneity and spatial configuration heterogeneity. Both landscape composition and spatial configuration heterogeneity influence the distribution of epigaeic arthropods through independent and joint effects. However, quantitative evidence addressing their relative and combined influences remains limited. This study was conducted across 30 independent landscape units (1 km × 1 km) in Changtu County. Pitfall traps were deployed across different habitat types, with three traps per habitat. The proportion of semi-natural habitats was used as an indicator of landscape compositional heterogeneity, while multiple landscape metrics were used to characterize spatial configuration heterogeneity. The effects of landscape heterogeneity on epigaeic arthropods were evaluated using two response variables: activity density (mean number of individuals captured per trap) and diversity (effective number of species). Variance partitioning analysis (VPA) and Bioenv analysis were applied to explore their individual and joint effects on epigaeic arthropods. The results showed that higher landscape composition heterogeneity was associated with greater activity density of epigaeic arthropods, but no significant correlation was found with arthropod diversity. In terms of landscape spatial configuration, patch density (PD) and landscape division index (DIVISION) constituted the optimal model explaining the activity density of epigaeic arthropods, highlighting the importance of patch structure within landscapes. Furthermore, spatial configurational heterogeneity showed a stronger independent contribution than compositional heterogeneity, although their joint effect accounted for the largest proportion of explained variation. These findings provide a theoretical basis for landscape optimization and biodiversity conservation in intensive agricultural regions of Northeast China. Full article

The water–land classification is fundamental for shoreline extraction and coastal habitat mapping, which is the basis of a comprehensive assessment and ecosystem-based coastal zone management. This study aims to separate water and land for coastal zones by taking advantage of both high-resolution satellite imagery and airborne lidar point clouds. Considering physical principles of optical remote sensing and lidar, we developed a prior knowledge-based localization classification approach that eliminates the need for collecting training sets and handling temporal differences across multiple data sources. Our approach first created the initial classification using the WorldView-2 (WV2) Normalized Difference Water Index. Then, the Connected Components Labeling algorithm was used to create a non-overlapping partition of the working area. The third step involved processing the water blocks using prior land cover knowledge. Finally, we used lidar point clouds to refine the initial water blocks and their neighboring areas. This classification approach showed promising results along Matagorda Bay, Texas, an approximately 2449 km² area that is covered by 26 WV2 images and 1568 lidar tiles. Full article

The Con Dao archipelago hosts the oldest MPA in Vietnam and is recognized as a regional marine biodiversity hotspot. Here, we applied environmental DNA (eDNA) metabarcoding to assess coastal fish diversity across four major habitat types: coral reefs, seagrass beds, mangroves, and a harbour in the Con Dao archipelago. Using MiFish-U 12S primers at eight stations, we detected 282 operational taxonomic units, corresponding to 144 fish taxa. Fish assemblages exhibited strong habitat structuring: community composition differed markedly among habitats, with minimal overlap. Only three species were shared across all habitats. Multivariate analyses confirmed that habitat type, rather than spatial distance among sites, was the primary driver of community differentiation. Mangrove and seagrass supported distinct assemblages that were underrepresented in existing species checklists and MPA management frameworks. Notably, eDNA detected cryptic and non-commercial species overlooked by conventional survey methods. These results substantially expand the known fish diversity of the Con Dao Archipelago and highlight the need to incorporate habitat heterogeneity, particularly non-reef ecosystems, into MPA design and monitoring. Although eDNA metabarcoding is subject to amplification biases and limited taxonomic resolution in reference databases, it offers a powerful complement to traditional surveys for characterizing under-sampled habitats. Full article

Observations suggest that headwater streams have lower species diversity within a site than larger streams, but higher beta diversity, and thus gamma diversity, across a catchment. This pattern of diversity includes taxonomic richness and genetic diversity, as well as a high degree of endemism. I review several mechanisms that potentially contribute to the overall high diversity of freshwater organisms in headwaters, although these mechanisms are interdependent. These include the high numbers of headwater streams, heterogeneity of habitats and resources, founder effects, colonization dynamics, isolation, and strong selection, all leading to diversification of forms. However, riverscape diversity patterns vary across taxonomic and functional groups, highlighting that patterns of diversity are driven by different processes for different organisms. More explicitly structured sampling designs will better address patterns of taxonomic richness and for a broader range of taxa. It will be interesting to find ways to partition the relative importance of different mechanisms in contributing to the variation in diversity among headwaters. The great importance of headwater streams to global biodiversity conservation is clear, but will be more evident when better assessments of diversity patterns across these small systems are available. Full article

Objectives: Our objectives were to develop and validate the habitat model based on low-dose computed tomography (LDCT) for noninvasive prediction of the visceral pleural invasion (VPI) in subpleural nodules with solid component. Methods: A total of 313 patients with subpleural lung adenocarcinoma nodules from three centers were retrospectively enrolled and divided into training (n = 192), validation (n = 82), and external test (n = 39) sets. All patients underwent preoperative LDCT scan. The habitat model was constructed using unsupervised clustering to partition each tumor into three distinct habitats, from which radiomic features were extracted and selected. Its diagnostic performance was compared with a whole-lesion radiomic model and radiological model. Statistical analysis included receiver operating characteristic (ROC) analysis and DeLong test. Results: The habitat model significantly outperformed both the radiomic and radiological models across the validation and external test sets, with areas under the ROC curve of 0.893 and 0.908, respectively (all p < 0.05). In contrast, the radiomic model achieved 0.833 and 0.772, while the radiological model yielded 0.746 and 0.624. The corresponding software tool has been made publicly available to facilitate broader clinical application. Conclusions: The habitat imaging model based on LDCT effectively predicts the VPI in subpleural lung adenocarcinoma by quantifying intratumoral spatial heterogeneity and demonstrates promising diagnostic performance compared to conventional radiomic and radiological methods. This approach offers a noninvasive preoperative tool to assist in risk stratification and guide personalized therapeutic decision-making for subpleural nodules detected during lung cancer screening. Full article

The Mediterranean Sea is a major biodiversity hotspot increasingly affected by biological invasions, climate warming, and habitat degradation. Among the most successful invaders are the rabbitfish species Siganus luridus and Siganus rivulatus, Lessepsian migrants from the Red Sea that are now widespread across the eastern Mediterranean. This study examined how these invasive herbivores influence native herbivore assemblages in shallow coastal habitats around Lipsi Island in the Aegean Sea, Greece. Using Underwater Visual Census (UVC) surveys and in situ feeding observations, we quantified the abundance and grazing activity of invasive rabbitfish relative to that of the native herbivores Sparisoma cretense and Sarpa salpa. Invasive rabbitfish represented approximately 35% of the herbivore assemblages and showed clear habitat and dietary preferences. Significant negative correlations were observed between invasive foraging activity and the feeding rate of the native S. cretense, while no such effect was found for S. salpa. High habitat overlap between S. luridus and S. cretense suggests that this native species may be more susceptible to competition on rocky substrates. Evidence of partial resource partitioning was observed, including increased use of seagrass habitats by S. salpa. These findings highlight how invasive herbivores can restructure native herbivore communities and alter grazing dynamics in eastern Aegean coastal ecosystems. Given the ongoing sea warming and widespread decline of seagrass habitats across the Mediterranean, understanding these competitive interactions is therefore essential for assessing future biodiversity trajectories and informing management strategies. Full article

Hydrological fluctuations drive community dynamics in floodplain lakes, yet their integration into water resource management remains limited. Here, we integrated environmental DNA (eDNA) metabarcoding with hydroacoustic surveys to investigate vertebrate community assembly in China’s largest freshwater lake (Poyang Lake) during the winter dry season. We detected 65 vertebrate species, with Cypriniformes dominating. Beta-diversity partitioning revealed that turnover dominated taxonomic and functional dissimilarity, while phylogenetic beta diversity was characterized by nestedness, which is consistent with environmental filtering. Functional richness declined with water depth, coinciding with hydroacoustic vertical size stratification, indicating niche partitioning along depth gradients. Null model analysis showed stochastic processes (ecological drift) dominated regional assembly (72.97%), whereas joint species distribution modeling attributed explained variation to environmental factors (28.9%, notably water depth) and species associations (29.7%) at local scales. This hierarchical framework, regional stochasticity shaping the species pool and local deterministic filtering structuring communities, reframes environmental flow conceptualization: effective management must preserve the full spectrum of hydrological variability and maintain bathymetrically diverse habitats that support functional niche differentiation. The integrated eDNA-hydroacoustic approach offers a non-invasive, high-resolution toolkit for biological assessment within regulatory water quality frameworks. Full article

Hopea celebica Burck is an endangered dipterocarp endemic to Sulawesi, Indonesia, occurring in two ecologically contrasting habitats: karst and ultrabasic forests. These environments differ markedly in soil composition and topography, potentially driving ecological specialization and genetic divergence. To investigate the genetic variation and genetic structure of this species, we applied newly developed microsatellite (SSR) markers, together with the chloroplast DNA sequences of the trnL–trnF region. Genotypes at 15 SSR loci were determined for 255 individuals collected from six populations covering the range of the species’ distribution across karst and ultrabasic forests. Genetic diversity was consistently higher in karst than in ultrabasic populations. DIYABC and VarEff analyses revealed a historical bottleneck and earlier recovery in the karst populations. Analysis of molecular variance (AMOVA) revealed that 35% of the genetic variation was partitioned between habitat types (F_RT = 0.345, p = 0.001). Bayesian clustering (STRUCTURE), principal coordinate analysis (PCoA), and UPGMA dendrograms consistently showed two distinctive clusters corresponding to habitat type. Chloroplast haplotypes differed between populations in the karst and ultrabasic forests. These results suggest that populations in the karst and ultrabasic forests have undergone a long history of differentiation without migration. The strong habitat-related genetic structure likely reflects ecological isolation and early-stage speciation. We recommend treating the karst and ultrabasic populations as distinct conservation units to preserve the evolutionary potential and adaptive capacity of H. celebica under ongoing environmental change. Full article

Understanding how migratory waterbird species co-vary through time can reveal guild structure and guide monitoring in dynamic coastal wetlands, yet seasonal phenology can inflate simple co-occurrence signals. Here, we used standardized monthly bird counts from Yongan Wetland, Taiwan (36 survey months across two survey blocks: November 2014 and January–August 2015, and October 2016–December 2018) to infer de-seasonalized interspecific associations. We analyzed 50 regularly recorded species and a focal subset of 13 shorebirds and ducks. For each species, we transformed raw counts to monthly anomalies that remove recurrent seasonal patterns, then quantified pairwise Spearman correlations and controlled multiple testing using Benjamini–Hochberg FDR (q ≤ 0.05) to construct association networks. The anomaly-based network revealed strong guild structure: positive links were concentrated within dabbling ducks and within shorebirds, consistent with shared habitat use and foraging regimes, whereas negative links were fewer and suggested potential niche partitioning or spatiotemporal segregation. Robustness analyses (moving-block bootstrap stability, a circular-shift null comparison, and log-transformed anomaly sensitivity) supported that the main network patterns were unlikely to arise from chance alignment. Our framework provides a transparent, time-series–based approach for disentangling phenology from association inference, offering a practical framework for wetland monitoring and hypothesis generation about waterbird community dynamics. Full article

The study used camera traps (2946 trap days, 60 sites) to investigate the diversity, habitat use, and activity rhythms of six sympatric ungulates in a montane ecosystem of southwestern China: tufted deer (Elaphodus cephalophus), Chinese goral (Naemorhedus caudatus), Chinese serow (Naemorhedus griseus), sambar (Rusa unicolor), wild boar (Sus scrofa), and blue sheep (Pseudois nayaur). Relative abundance indices indicated that sambar were most frequent, while blue sheep and Chinese goral were least common. Species showed distinct elevational, slope, and vegetation preferences, suggesting spatial niche segregation. Kernel density estimates revealed predominantly diurnal activity, with bimodal patterns for tufted deer, sambar, and Chinese goral, and unimodal peaks for blue sheep, wild boar, and Chinese serow. Temporal overlap was highest between sambar and tufted deer, and lowest between tufted deer and blue sheep. These results demonstrate spatial and temporal partitioning as key mechanisms enabling ungulate coexistence and underscore the importance of conserving heterogeneous montane habitats. Full article

Kelp transplantation is a nature-based strategy aimed at restoring coastal habitat integrity and marine biodiversity. However, its functional consequences for trophic integration within benthic food webs remain poorly understood. Using δ¹³C and δ¹⁵N stable isotope analyses, we evaluated how Undaria pinnatifida transplantation alters consumer trophic structures and isotopic niche characteristics in Oeyeondo, South Korea. While basal source remained isotopically uniform across sites, the introduction of U. pinnatifida triggered significant isotopic shifts in consumers, reflecting a reorganization of carbon assimilation pathways. At the transplanted site, herbivores exhibited significantly enriched δ¹³C values (−14.7 ± 2.0‰ to −13.2 ± 0.3‰) compared to the control site (−19.3 ± 1.2‰), indicating direct assimilation of kelp-derived carbon. Conversely, grazers showed depleted δ¹³C values (−20.6 ± 0.6‰) reflecting a shift toward alternative benthic resources. Isotopic niche metrics revealed a broader community-level niche width at the transplanted site, driven by increased resource diversity and niche partitioning. These findings demonstrate that kelp transplantation effectively restructures benthic food web dynamics by providing new energy pathways, offering a robust functional framework for evaluating marine forest restoration success. Full article

Land use transformation directly affects the stability and sustainability of regional ecosystems. Clarification of the trade-off/synergy dynamics among ecosystem services (ESs) provides a theoretical foundation to understand the transition of ES interactions from trade-offs to synergies, thereby facilitating the achievement in ecological sustainability in the ecoregion. This study, taking Jiangxi Province, China, as an example, utilized the InVEST model, Theil–Sen estimator, Mann–Kendall test, bivariate spatial autocorrelation, ecosystem service bundles (ESBs), and Random Forest (RF) models to conduct such an ecosystem-focused integrated analysis. According to land use changes from 1980 to 2020, the time-series spatiotemporal patterns of water yield (WY), soil conservation (SC), habitat quality (HQ), and carbon storage (CS) were analyzed. Differences in ES trade-off/synergy relationships and their underlying motivating factors were examined using a 3 km spatial grid framework. Compared with previous studies that mainly focused on typical subregions and of which driver analyses often remained at the individual ES level, this study introduced an explainable RF-SHAP framework based on the cooperative game theory at the grid scale, to quantitatively characterize the relative contributions of every motivating factor to ES trade-off/synergy relationships. The results indicate that from 1980 to 2020, forests and croplands constituted the predominant land use types, taking up 88% of the studied area. Throughout this period, forests, croplands, and grasslands decreased markedly, while built-up areas expanded notably, with a rise of 2876.65 km². Over the same time span, WY increased on average by 0.50% whereas SC, HQ, and CS declined by 0.50%, 0.98%, and 1.30%, respectively. Overall, these ESs demonstrated a geographical distribution characterized by low levels in SC, HQ and CS in the central area and high levels towards the provincial boundary. At the grid scale, the four ESs demonstrated predominantly a synergistic relationship while WY&HQ and WY&SC pairs were characterized by trade-offs. The constraint effect analysis revealed U-shaped relationships for SC&HQ, WY&HQ, and WY&SC, and inverted U-shaped relationships for SC&CS and HQ&CS, with clear threshold effects among these ES pairs. Based on self-organizing maps, the study area is partitioned into six ESBs, and the trade-off/synergy linkages of ESs are affected by the interplay of natural and societal forces. Elevation, slope, and rainfall emerge as the primary driving variables accompanied by population density and proximity to urban centers. These results are anticipated to offer reference to governments for their sustainable management in environmental resources to achieve United Nations Sustainable Development Goal (SDG) 15 (Life on Land: Protect, restore and promote sustainable use of terrestrial ecosystems). The methods used in this paper provide a replicable framework for exploring ES interactions and driving mechanisms in other ecologically sensitive regions in the world. Full article

Anthropogenic disturbance can reshape mammal communities through both long-term habitat modification and short-term direct human presence, yet these disturbance dimensions are often conflated. Using three consecutive years (2017–2019) of camera-trap data from two subtropical forest reserves in Chongqing, China (Jinfoshan and Jinyunshan), we evaluated the differential effects of human modification (HM) and human activity (HA) on mammal taxonomic diversity, functional diversity (MNTD and SES.MNTD), and diel activity patterns. HM and HA were not significantly correlated, indicating that they represent largely independent disturbance components in this system. Regression analyses showed that HM was significantly associated with reduced Shannon–Wiener diversity, while HA primarily influenced community evenness with a non-linear response (initial increase followed by decline at higher disturbance). In contrast, functional diversity metrics (MNTD and SES.MNTD) did not exhibit significant relationships with either HM or HA across the observed gradients, suggesting relative stability of trait dispersion at the community level. Activity analyses revealed guild-specific behavioral strategies: herbivores retained a predominantly crepuscular pattern but reduced activity during periods of high human presence, whereas omnivores displayed stronger temporal niche partitioning, becoming more nocturnal under higher disturbance intensity, particularly in Jinyunshan. Together, these results demonstrate that distinct disturbance types can affect mammal communities through different pathways and that integrating multidimensional diversity metrics with behavioral analyses can improve conservation planning in human-dominated landscapes. Full article

Submerged aquatic macrophytes and their microbiomes can help mitigate eutrophication, yet how microbial communities and functions differ across specific plant-associated and surrounding niches remains unclear. Here, we profiled bacterial community composition (16S rRNA gene sequencing) and quantified nitrogen and phosphorus cycling genes (narG, nirK, nirS, nosZ, phoD by qPCR) across eight distinct compartments associated with the submerged macrophyte Hydrilla verticillata in a eutrophic freshwater wetland. The niches spanned open water, bulk sediment, rhizosphere, and plant phyllosphere (leaf/stem surfaces) and endosphere (leaf/stem/root interiors). Alpha diversity differed significantly among niches: sediments (non-rhizosphere and rhizosphere) exhibited the highest Operational Taxonomic Unit (OTU) richness and diversity, whereas leaf-associated niches (phyllosphere and endosphere) had the lowest. Beta diversity showed clear separation by niche, indicating strong habitat filtering. Community composition also varied markedly: the water column was dominated by Bacteroidota (~51% of sequences), plant-associated communities were enriched in Pseudomonadota (43–90%), and sediment niches were dominated by Firmicutes (23~48%). Functional gene abundances showed pronounced niche partitioning. Nitrate/nitrite reduction genes (narG, nirK, nirS) were most enriched on leaf phyllosphere, with narG abundance equally high in the water, whereas the N₂O reductase gene nosZ peaked in sediment niches. The alkaline phosphatase gene phoD had its highest copy numbers in leaf biofilms, with significantly lower levels in internal plant tissues. Overall, neutral processes explained ~61% of community variation, but deterministic assembly was evident in the well-connected water and leaf surface niches. These findings reveal strong niche differentiation in plant-associated microbiomes and suggest that compartmentalized microbial functional capacity within the H. verticillata holobiont enhances nitrogen removal and phosphorus cycling in eutrophic waters. Full article

The whiting, Merlangius merlangus, is a key cold-temperate demersal species in the Black Sea, yet information on its essential habitats and demographic structure remains limited for effective regional management. This study combined fishery-independent bottom trawl surveys with in situ hydrographic observations to identify autumn hotspots of recruits and adults along the southern Black Sea and to assess their relationships with environmental gradients. A stratified random survey (10–125 m) was conducted in autumn 2024, with data collected from 66 hauls. The population showed a strong female bias, with females comprising 67.9% of individuals (F:M = 2.12:1), significantly deviating from a 1:1 sex ratio. Length–weight relationships indicated positive allometric growth in females (b = 3.16), isometric growth in males (b = 3.03), and overall positive allometry for the combined population (b = 3.15). The relative condition factor (Kn) was close to unity (1.01 ± 0.10), suggesting stable body condition during the survey period. Generalized Additive Models with a Tweedie distribution revealed that depth–temperature interactions were the primary drivers of distribution for both recruits and adults, explaining 74.7% and 69.5% of deviance, respectively. Recruits concentrated at 40–75 m within 10–15 °C, while adults extended beyond 100 m, associated with the upper Cold Intermediate Layer. These findings highlight hydrographically dynamic nursery and feeding habitats, underscoring the need for adaptive, habitat-based spatial management of this shared Black Sea stock. Full article