Search Results (1,590)

Trophic ecology is an important aspect to consider when studying interactions between species, especially in ecologically similar species. We studied the trophic ecology of three sympatric insectivorous lizards in a dune system in the Eastern Iberian Peninsula: Acanthodactylus erythrurus, Psammodromus algirus and Psammodromus edwardsianus. We obtained a total of 485 faecal samples and found 18 different prey groups. The trophic niche breath analysis showed that A. erythrurus was the most specialised species of the three. We also considered two different habitat types and, interestingly, both Psammodromus species had wider trophic niches in the more extreme habitat type where arthropod diversity is expected to be lower. Trophic niche overlaps were especially low between P. algirus and A. erythrurus, indicating resource partitioning, and higher between both Psammodromus species in the suboptimal habitat type. Our results lead to the conclusion that environmental stress could favour trophic generalism (increased trophic niche breadth). This is a very interesting result, especially in the context of climate change and habitat alteration. Full article

Ammopiptanthus nanus is an endangered evergreen shrub endemic to the western Tianshan Mountains. Genetic diversity and population structure of this species were assessed using single-nucleotide polymorphism (SNP) loci identified via double-digest restriction site-associated DNA (ddRAD) sequencing. In this study, a total of 42 individuals were sampled from seven populations located in valley habitats across the western Tianshan Mountains. A low level of genetic diversity (mean H_E = 0.09) and strong interpopulation genetic differentiation (mean F_ST = 0.4832) were observed in the species, indicating substantial genetic structuring among populations. Population structure analyses using Admixture analysis, principal coordinate analysis (PCA), and maximum likelihood trees yielded congruent patterns, supporting four genetically distinct groups within the western Tianshan Mountains. Genetic drift and inbreeding, likely induced by habitat fragmentation, appear to be primarily responsible for the low genetic diversity, while restricted gene flow probably shaped the pronounced genetic structure. Based on our findings, we recommend specific conservation strategies for A. nanus aimed at maintaining genetic diversity and facilitating gene flow. Full article

Environmental DNA (eDNA) detection has emerged as a powerful, non-invasive tool for identifying aquatic organisms, particularly those that are rare, elusive, or invasive. Dreissena polymorpha (zebra mussel) is an invasive bivalve posing ecological and economic threats to North American freshwater systems. In April 2021, zebra mussels were discovered attached to a boat destined for Lake Sidney Lanier in North Georgia—a high-use recreational reservoir with no prior reports of infestation. To determine whether D. polymorpha had been introduced, we implemented a biomonitoring protocol leveraging eDNA collection and PCR-based detection. Sampling was conducted during summer 2022 across high-risk marina sites and potential habitats. Positive controls from the Tennessee River yielded expected results, while Lake Lanier samples showed no evidence of zebra mussel DNA. Our results validate using eDNA methodology for proactive biomonitoring and highlight the importance of molecular surveillance and community outreach to prevent the establishment of invasive species in vulnerable aquatic systems. This study demonstrates the utility of a scalable, replicable early detection framework that can be adopted by educational institutions, natural resource agencies, and community groups to mitigate the risk of biological invasions. Full article

The species of the Bufonidae family exhibit a great diversity of habitats, diurnal or nocturnal habits, a complex evolutionary history, and a wide distribution, which makes this group suitable for morphological studies. In this work, we aimed to identify the existence of morphological patterns related to the habitat use and diurnal or nocturnal habits of Bufonidae in the Brazilian Amazon. To achieve this, we studied the morphological measurements of 210 specimens from three zoological collections and characterized the type of habitat and diurnality/nocturnality of the species. The morphological patterns and habitat use were investigated through principal component analysis (PCA) and multiple correspondence analysis (MCA), respectively. The evaluation of the relationships between morphological variation, habitat use, and diurnality/nocturnality was performed via redundancy analysis (RDA). Accordingly, Amazonian bufonids were divided into three morphological groups associated with different vegetation types and environments, demonstrating that body size is closely linked to diurnal or nocturnal life habits and habitat. Species with large body sizes are associated to anthropized areas, while intermediate and smaller species are associated with primary forests. Full article

Humans have been using lipids for many centuries; these are oils found in plants, particularly in seeds. However, relatively recently, it has become clear that lipids are the primary metabolites of any living organism. Fatty acids (FAs) are a structural component of lipids, and their role in building the framework of the lipid bilayer cannot be overstated. They participate in maintaining homeostasis by controlling membrane permeability. Changes in the FA composition of lipid bilayers can modulate the transition of the membrane from a liquid crystalline to a gel-like state. Thus, knowledge of a plant’s FA profile can aid in understanding the physiological mechanisms underlying their interaction with the environment and the ways in which they adapt to various stress factors. Throughout the colonization of terrestrial habitats, plants evolved, and new phylogenetic groups appeared; at present, some features of the FA composition of their individual representatives are known. However, the overall change in the composition of lipid FAs during the evolution of higher plants is still not understood. Our analysis of the literature showed that the FA diversity tends to decrease from mosses to angiosperms, mainly due to a reduction in polyunsaturated very-long-chain FAs, while the average acyl chain length remains unchanged. It is important to recognize the trends in this process in order to understand the adaptive capabilities of higher plants. This knowledge can be useful not only from a fundamental point of view, but also in practical human activities. Full article

Our study addresses how large-scale hydrological alterations shape zooplankton biodiversity in floodplain ecosystems, which are highly sensitive to changes in river connectivity. Following the operation of the Gabčíkovo hydroelectric power plant in the Danube inland delta, we examined the long-term responses of crustacean zooplankton communities, as these organisms are key indicators of hydromorphological disturbance. Based on previous evidence that river regulation often reduces habitat heterogeneity, we hypothesized that hydrological alterations in the Danube riverscape would promote increasing taxonomic and functional homogenization within sites, while simultaneously enhancing differentiation between sites over the past three decades. A total of 121 planktonic crustacean species were recorded across six monitored sites between 1991 and 2020, comprising 49 copepods and 72 cladocerans. Communities showed rising species richness, especially during the first decade of the hydropower plant’s operation. While overall richness increased, dam-induced hydromorphological changes triggered habitat-specific community shifts. In the main channel and adjacent parapotamal arm, taxonomic and functional homogenization occurred, dominated by resilient tychoplanktonic species with a gathering or secondary filter-feeding strategy. In contrast, isolated side arms experienced gradual eutrophication, favoring euplanktonic and primary filter-feeding taxa. The observed taxonomic and functional convergence within both habitat groups reflects the loss of connectivity and the cessation of artificial flooding. Full article

Investigating the compositional characteristics of rhizosphere soil bacterial communities of Chinese seabuckthorn across different distribution areas and their relationship with habitat factors holds significant value for the development and utilization of characteristic medicinal plant resources in the Qinghai–Tibet Plateau. This study targeted rhizosphere soil from 12 distribution areas of Chinese seabuckthorn on the Qinghai–Tibet Plateau. By integrating measurements of soil and climatic parameters with high-throughput sequencing and redundancy analysis (RDA), the research systematically elucidated the characteristics of rhizosphere bacterial communities and their environmental driving mechanisms. The results revealed that rhizosphere bacterial communities of Chinese seabuckthorn across all 12 distribution areas were dominated by Proteobacteria, Acidobacteriota, and Actinobacteriota. Among them, the R2 habitat exhibited the highest amplicon sequence variant counts (3496), while R1, R8, R9, and R12 habitats showed significantly lower counts. α/β diversity analysis revealed that Shannon, Ace, and Chao1 indices in R2 and R7 habitats were significantly higher than those in R1 and R8. Regarding community aggregation patterns, soil bacterial communities in R1, R9, and R12 habitats exhibited the highest aggregation, while those in R2 and R11 habitats showed relatively lower aggregation. Functional prediction demonstrated that Metabolism dominated across all distribution areas (50.40–52.02%), with the R11 habitat exhibiting exceptionally high metabolic function abundance (>9300). Clustering analysis partitioned the 12 habitats into two distinct groups: one comprising R2, R6, R7, R9, R10, and R11, and the other containing the remaining six habitats. Redundancy analysis (RDA) further clarified that habitat factors, including altitude, soil water content (SWC), east longitude (EAST), and pH, were key drivers shaping bacterial community structure. This study underscores the pivotal regulatory role of environmental factors in shaping rhizosphere microbial diversity, community structure, and functional profiles of Chinese seabuckthorn, thereby providing a valuable scientific foundation for the sustainable development of characteristic medicinal plant resources on the Qinghai–Tibet Plateau. Full article

Integrated aquaculture, centered around polyculture involving multiple species, is a typical practice for the sustainable development of the aquaculture industry, capable of enhancing resource utilization efficiency, environmental stability, and overall productivity through establishing symbiotic interactions among species. This study employed multi-amplicon high-throughput sequencing to assess the ecological impacts of two polyculture methods involving river crabs on sediment bacteria, fungi, and protists. One method involved polyculturing river crabs with mandarin fish, silver carp, and the stone moroko (SPC), and the other involved polyculturing river crabs with only mandarin fish and silver carp (SMC). The results showed that, compared to the SMC group, the SPC group remarkably increased the Chao1 index of bacterial communities in pond sediment and decreased the Pielou_J index of protists. The relative abundances of all fungal phyla and most dominant bacterial and protistan phyla (top 10 in relative abundance) in the SPC group were considerably different from those in the SMC group. In the co-occurrence networks of bacterial, fungal, and protistan communities, the numbers of edges and nodes were higher in the SPC group than in the SMC group, and the habitat niche breadth of bacterial community was also notably increased in the SPC group. The levels of total carbon (TC), total nitrogen (TN), and phosphates within pond sediment in the SPC group were obviously lower than those in the SMC group, and were significantly correlated with the microbial communities, with TC being identified as the primary contributor driving changes in the microbial communities. All the findings collectively demonstrate that the polyculture of river crabs with mandarin fish, silver carp, and the stone moroko enhances the stability of bacterial, fungal, and protistan communities in sediment and enhances resource utilization efficiency in aquaculture, thereby preventing the environmental risks associated with excessive nutrient accumulation in sediment. Polyculture systems integrating river crabs with mandarin fish, silver carp, and the stone moroko represent a sustainable aquaculture model with significant ecological benefits. Full article

Biodiversity conservation in South Korea faces increasing challenges from alien plant invasions. These invasions threaten endemic species uniquely adapted to specialized habitats, making it crucial to understand their ecological interactions. This study quantitatively compared the species composition, ecological niches, and species turnover patterns of alien and endemic plants in South Korea using data from the National Ecosystem Survey. Non-metric multidimensional scaling (NMDS) and multi-response permutation procedure (MRPP) analyses revealed significant compositional heterogeneity between groups. Kernel density estimation (KDE) revealed niche overlap in water-related factors (precipitation, water yield), but clear separation in topographic and climatic variables (altitude, slope, temperature). Alien plants exhibited broader niche breadths, confirming their ecological generalist traits, whereas endemic species displayed narrower niches confined to specialized habitats. Zeta diversity analysis indicated slower species turnover in alien species, suggesting niche assimilation and habitat homogenization. Both groups fit a power-law model, emphasizing deterministic environmental filtering. These findings highlight the ecological risks posed by alien species to stability of endemic plant communities and underscore the importance of targeted, science-based management strategies. Full article

Impatiens parviflora DC. occurs in various plant communities. Its occurrence has been confirmed in Poland across 13 natural habitats protected under the Habitats Directive. The aim of our work is to determine the differences between the plots with and without I. parviflora in terms of the species richness and ecological conditions of the 9180* habitat-type forest. Using data from 315 plots on which a phytosociological relevés was carried out, we analyzed the geographical variability, the Shannon-Winner index and the indicator species for old forests. Flora diversity was represented using the DCA, and the IndVal index was calculated to determine the species that best characterize the differentiated groups. The highest percentage of monitoring plots with I. parviflora is located in the Sudetes Mountains (67.7%) and the lowest in the Bieszczady Mountains (7.5%). Plots with I. parviflora were characterized by significantly lower tree cover, a higher number of tree species in the stand, a lower height of both the understory and herb layer and a lower number of old forest species. Impatiens parviflora does not affect the total number of species in the understorey but is associated with a lower proportion of species typical of old forests. The presence of I. parviflora also correlates with a higher proportion of young trees in the understorey, suggesting a link with successional processes and habitat disturbance. The spread of I. parviflora is limited by shade-loving trees such as Abies alba Mill. and Fagus sylvatica L. The diversity of the distribution of I. parviflora depends on local conditions, so conservation efforts should take into account the local ecological context. Full article

The Doce River basin is the largest river system in southeastern Brazil. Over the last century, the Doce River has been undergoing a serious process of degradation, culminating in a huge environmental disaster due to Fundão tailing dam bursting in Mariana (Minas Gerais) and causing severe damage to biodiversity and local human communities. Near its mouth, the Doce River harbors an extensive lake area, with over ninety lakes on coastal lowlands. These lakes are of fluvial origin and connected to each other and to the main Doce River by small tributary streams. In this area, one of the main sources of impact on the fish fauna is the presence of non-native fish species. We compared richness, taxonomic diversity, beta diversity, species composition and proportion of non-native species in lakes and streams, and related these variables to each other and to environmental variables. We used the indicator species index (IndVal) to identify species associated with each type of environment. We used multivariate analyses to test the influence of stream habitat on the fish fauna in streams and Generalized Linear Models (GLMs) to test the influence of distance to lakes on the proportion of non-native species in streams, and the influence of this proportion on total and native fish richness and diversity. The results showed that some non-native species originating from lentic environments have adapted to the lakes and are spread throughout the internal lake system. In streams, there are proportionally fewer non-native fish and their distribution is more fragmented, as some stretches do not provide the conditions for the establishment of some of these species, making them potential refuges for native ichthyofauna. As the streams move away from the lakes, the proportion of non-native species tends to decrease. In streams, the richness and diversity of native species are affected by the proportion of non-native species, but not in lakes. The native vegetation in the landscape showed no potential for reducing the invasion of non-native species. The depth and width of the streams are directly related to the proportion of non-native species within the streams and are structural characteristics that should be considered in strategies for the conservation of the fish fauna. Full article

Background: Glioblastoma (GBM) is a highly aggressive and heterogeneous primary malignancy of the central nervous system, with a median overall survival (OS) of approximately 15 months. Achieving accurate and generalizable OS prediction across multi-center settings is essential for clinical application. Methods: We propose a Personalized Habitat-aware Survival Prediction Network (PHSP-Net) that integrates multiparametric MRI with an adaptive habitat partitioning strategy. The network combines deep convolutional feature extraction and interpretable visualization modules to perform patient-specific subregional segmentation and survival prediction. A total of 1084 patients with histologically confirmed WHO grade IV GBM from four centers (UPENN-GBM, UCSF-PDGM, LUMIERE and TCGA-GBM) were included. PHSP-Net was compared with conventional radiomics, habitat imaging models and ResNet10, with independent validation on two external cohorts. Results: PHSP-Net achieved an AUROC of 0.795 (95% CI: 0.731–0.852) in the internal validation set, and 0.707 and 0.726 in the LUMIERE and TCGA-GBM external test sets, respectively—outperforming both comparison models. Kaplan–Meier analysis revealed significant OS differences between predicted high- and low-risk groups (log-rank p < 0.05). Visualization analysis indicated that necrotic-region habitats were key prognostic indicators. Conclusions: PHSP-Net demonstrates high predictive accuracy, robust cross-center generalization and improved interpretability in multi-center GBM cohorts. By enabling personalized habitat visualization, it offers a promising non-invasive tool for prognostic assessment and individualized clinical decision making in GBM. Full article

Wild animals are an essential component of natural ecosystems, and the accurate identification of wildlife targets plays a critical role in ecological conservation and species monitoring. However, the effectiveness of conventional object detection algorithms is often limited by the challenges posed by complex outdoor environments, small target sizes, and group occlusions. To address these issues, this study constructs a dataset comprising over 8000 images of 10 protected wildlife species and investigates effective detection methods for wildlife in natural habitats. We propose a novel deep learning-based detection framework, YOLO-WildASM, which incorporates three key improvements to the YOLOv8 architecture: a P2 detection layer for small objects, a multi-head self-attention (MHSA) mechanism, and a bidirectional feature pyramid network (BiFPN). Experimental results demonstrate that YOLO-WildASM significantly outperforms YOLOv8 and other state-of-the-art models on the custom wildlife dataset, achieving a mAP50 of 94.1%, which is 2.8% higher than the baseline model and superior to the latest YOLOv12 model (92.2%). Furthermore, ablation and generalization experiments validate the model’s enhanced performance and adaptability in multi-scale wildlife detection tasks. The proposed deep learning-based detection framework provides an efficient and robust solution for wildlife monitoring and ecological conservation in complex natural ecosystems. Full article

Evolutionary processes involving sustainability are here expressed in units of classical mechanics, where newly evolved traits are distance, segments of evolutionary trees are time, and species as entire character sets are mass. Data arranged on a morphological evolutionary tree (caulogram) allow precise calculations of evolutionary velocity, acceleration, momentum and force, with force interpretable as resistance to environmental change. Stem-taxon trees of species of the moss family Streptotrichaceae and Pottiaceae tribe Pleuroweisieae were developed as sets of minimally monophyletic genera, and annotated with numbers of newly evolved traits per species. Calculations provided evidence that precise and comparative measures of the results of sustainable evolutionary processes may be calculated, and, as directly derived from expressed traits, are also accurate and informative about processes leading to resilience across multiple extinction events. The two groups evidenced similar, gradual evolutionary rates, implying that similar evolutionary processes occur across 110 my for Streptotrichaceae and 66 my for Pleuroweisieae, although habitats differ. Extension of sets of new traits per species into the past imply origination of the oldest extinct recognizable progenitors near the Permian–Triassic extinction event, when a cut-off in all data imply a complete over-haul of the character set for both groups, i.e., a major change in evolutionary mass. Speciation occurs in bursts. Extinction is gradual, the negative of acceleration. The rates of origination of genera over time for both groups are nearly the same as those previously proposed for genera of extinct horses. Plateaus in graphs of species per genus imply ancient quadratic patterns of speciation. The combination of process-governed stability through stasis of morphological traits, and of resilience as the ability to survive multiple extinction events has apparently little changed, and both contribute to sustainability over geologic time. Full article

Background/Objectives: We evaluated eukaryotic diversity in two cores obtained from abyssal sediments collected at depths of 4280 m and 4444 m in the equatorial Atlantic, between the Fernando de Noronha and São Pedro and São Paulo archipelagos, using a DNA metabarcoding approach applied to environmental DNA (eDNA) samples. Results: In total, we detected 248,905 DNA reads that were assigned to 65 amplicon sequence variants (ASVs) in the two core sediments (176,073 DNA reads and 59 ASVs were detected in sediment obtained at 4280 m depth, and 72,832 DNA reads and 14 ASVs were detected in the core at 4444 m). These represented three Kingdoms and five phyla: Fungi (Ascomycota and Basidiomycota), Viridiplantae (Chlorophyta and Streptophyta) and Chromista (Ciliophora), in rank abundance order. Ascomycota was the dominant phylum, followed by Basidiomycota. Didymella sp., Cladosporium sp., Scopulariopsis sp., Alternaria eichhorniae, Curvularia sp., Hortaea werneckii, Penicillium sp. (Ascomycota) and Malassezia globosa (Basidiomycota) were the most abundant taxa. Pseudochlorella pyrenoidosa (Chlorophyta) was the most abundant representative of Viridiplantae detected, and Spirotrachelostyla tani (Ciliophora) was the only Chromista detected, both present as minor components of the assigned eukaryotic diversity and only in the 4280 m core. The eukaryotic assemblages displayed moderate diversity indices, and those from the deeper core (4444 m depth) displayed the highest diversity values. Few assigned taxa were present in both samples. The two cores differed in their geological characteristics, consistent with their location in different depositional basins. The core obtained at 4280 m depth, located further north and more isolated from the adjacent continent by two fracture zones, appears to receive less terrigenous sediment input. In contrast, the core obtained at 4444 m depth is under greater continental influence and receives more terrigenous input from the continent. These geological and geographic differences may contribute to the varying eukaryotic eDNA diversities found. Results: Our metabarcoding study revealed the presence of a sediment eukaryotic community dominated by fungi. This included assigned ASVs representing groups with different ecological roles, such as cosmopolitan and phytopathogenic members and extremophiles, some of which may be able to survive and function in the polyextreme deep-sea abyssal conditions. Abyssal sediments present a potential habitat for studying organisms at the edge of viable conditions for life on Earth. eDNA metabarcoding provides a promising technique for detecting cryptic and uncultured biodiversity compared to traditional approaches, opening avenues for further ecological, evolutionary and biotechnological studies. Full article