Search Results (80)

Long-term changes in land-use and water quality degradation are key pressures on riverine ecosystems, yet their effects on the functional structure of fish assemblages remain insufficiently quantified. We conducted a decadal assessment of fish assemblages in four rivers experiencing rapid land-use transformation in Guangxi, China—the Zuojiang (ZY), Youjiang (YJ), Yujiang (YuJ), and Guijiang (GJ) rivers. Species-level functional traits describing body shape, vertical habitat position, feeding guild, trophic level, and maximum total length were used to calculate multiple functional diversity indices related to environmental variables using redundancy analysis and random forest models. Over the decade from 2013 to 2023, impervious surface and bare land increased significantly, while forest, shrubland, and grassland declined, coinciding with marked deterioration in water quality, including higher chlorophyll-a and lower dissolved oxygen concentrations (p < 0.05). Fish abundance and species richness decreased, and formerly dominant benthic cyprinids and loaches were replaced by tolerant and invasive taxa such as Oreochromis niloticus and Tilapia zillii. NMDS and PERMANOVA indicated a significant shift in community composition between 2013 and 2023 (R² = 0.14, p < 0.001), with fish assemblages shifting toward small-bodied, pelagic, omnivorous, and laterally compressed species. Functional richness declined, whereas functional evenness and functional dispersion increased, indicating functional simplification and homogenization. Multivariate and machine learning models consistently identified increasing impervious cover and declining dissolved oxygen as the strongest predictors of these changes. Our results demonstrate that land-use intensification and water quality deterioration are associated with reduced functional integrity in Guangxi rivers and highlight the value of trait-based indicators for monitoring and managing biodiversity in rapidly urbanizing catchments. Full article

Seasonal hydrology reshapes large-river food webs by altering habitat connectivity and basal resource availability. Trophic baselines from before the 2021 Yangtze ten-year fishing ban are now valuable because monitoring has shifted from fish abundance alone toward food-web function and ecological recovery. We analysed carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotopes of fish and the baseline bivalve Corbicula fluminea collected in March (dry season) and August (wet season) 2016 from the Jingjiang section of the lower Yangtze River. In the dry season, 100 individuals of 27 species were analysed; species mean δ¹³C ranged from −30.52‰ (Micropercops swinhonis) to −21.19‰ (Aristichthys nobilis) and δ¹⁵N from 6.30‰ (Hypophthalmichthys molitrix) to 14.90‰ (Lophiogobius ocellicauda). In the wet season, 187 individuals of 47 species were analysed; species mean δ¹³C ranged from −32.07‰ (Pseudobrama simoni) to −20.84‰ (Salanx ariakensis) and δ¹⁵N from 6.27‰ (Misgurnus anguillicaudatus) to 14.87‰ (Saurogobio gymnocheilus). Among 24 shared species, δ¹³C differed significantly between seasons (paired t = 4.30, p < 0.001), but δ¹⁵N did not (t = 1.52, p = 0.143). Mean trophic level fell from 3.07 to 2.74 (t = 3.85, p < 0.001). This decline remained significant in a trophic-enrichment-factor sensitivity analysis using 2.5–4.0‰. Community-wide carbon range (CR), nitrogen range (NR), total convex-hull area (TA), mean nearest-neighbour distance (NND), and the standard deviation of nearest-neighbour distance (SDNND) showed larger wet-season CR (9.08 vs. 7.51), slightly larger NR, TA and NND, and lower SDNND. Seasonal hydrology thus mainly altered basal carbon pathways and relative trophic positions rather than reorganising feeding guilds. The dataset provides a pre-ban isotopic baseline for assessing whether post-ban recovery in the lower Yangtze includes restoration of trophic structure and energy-flow pathways. Full article

Introduction: The physical characteristics of microplastics (MPs), particularly their size and color, closely resemble natural food prey for several marine organisms, leading to active or accidental ingestion by marine species, including fish larvae. Despite growing concern, the occurrence of MPs in wild fish during early developmental stages remains insufficiently documented, and laboratory studies report inconsistent results. Given their key ecological role in marine food webs and their economic relevance, the health and survival of fish larvae are critical for maintaining fish populations. Objective: This study aimed to investigate MPs’ presence throughout the larval developmental stages and assess whether MP contamination profiles (concentration, color, type, and size) differ between species. Methodology: MPs were analyzed in the larval stages of two fish species with distinct ecological niches: the European sardine (Sardina pilchardus), a marine migratory species, and the common goby (Pomatoschistus microps), an estuarine resident species. Samples were collected from the Douro Estuary (NW Portugal) over one year, covering different developmental stages. Results: MPs were detected in both species at all developmental stages observed, including the yolk-sac stage (where the feeding of larvae is endogenous), indicating contamination at a stage when the mouth is not yet functional. Sardina pilchardus showed a higher abundance of transparent nylon fibers of 0.5 mm, and Pomatoschistus microps transparent polypropylene fibers of size 0.4 mm. Moreover, MP contamination did not vary between species or throughout the developmental stages, showing similar levels and profiles of MPs contamination. Conclusions: These findings provide new evidence that MP contamination begins at the earliest developmental stages of the fish, from hatching onwards. The results further suggest that MP uptake in fish larvae is primarily driven by environmental availability rather than fish larvae’s preferences or ecological guild, physical characteristics, or even the ontogenetic developmental stage. Full article

Woody plants in managed and natural ecosystems are increasingly exposed to arthropod pest pressure, posing challenges for sustainable plant protection. This study evaluates trunk injection as a pest management strategy in woody species, with emphasis on plant-mediated processes shaping interactions between host plants and herbivorous arthropods. Two experimental systems were investigated: a greenhouse experiment with Gleditsia triacanthos and a field experiment with Quercus petraea. Systemic active ingredients (acetamiprid and abamectin) were applied using both experimental and professional injection devices, and their effectiveness was assessed against Tetranychus urticae and a complex of foliar-feeding insects. In the greenhouse experiment, trunk injection reduced T. urticae populations compared with untreated controls and soil drench treatments, with reductions of 55.6–58.4% for larvae, 65.7–67.5% for eggs, and 28.7% for adults, although foliar application achieved higher suppression (up to 81.2% for eggs). In the field experiment, treatments reduced leaf discoloration (from 16.3% in control to 1.45–3.80%) and skeletonization (from 15.1% to 9.95–12.7%), with more moderate effects on defoliation. Differences among feeding guilds suggest that responses to systemically distributed compounds depend on feeding behavior and canopy position. Both pressurized and non-pressurized methods enabled uptake and translocation of active compounds within plant tissues. Localized injuries were observed at injection points, including internal necrosis. Overall, trunk injection represents a viable approach for pest management in woody plants, highlighting the role of plant-mediated processes in shaping treatment outcomes under contrasting conditions. Full article

Reducing enteric methane emissions from ruminants has emerged as a critical environmental priority in the face of global climate change, given the substantial contribution of methane to agricultural greenhouse gas outputs. This study evaluated the potential of spearmint essential oil (SEO) to reduce methane production and enhance energy utilization efficiency using an in vitro rumen fermentation system. The experiment comprised a control (CON, no additive), three SEO doses (L-SEO: 100 mg/L; M-SEO: 200 mg/L; H-SEO: 400 mg/L), and a commercial essential oil blend (AGL: 150 mg/L). Results indicated that M-SEO and H-SEO significantly reduced methane production at 24 h from 58.11 mL/g DM in CON to 47.93 and 46.58 mL/g DM, respectively (p < 0.001), corresponding to reductions of 17.5% and 19.8%. Furthermore, M-SEO increased total volatile fatty acid concentration from 48.41 to 58.10 mmol/L and elevated the molar proportion of propionate, while significantly enhancing microbial crude protein production (p < 0.001). Microbial community analysis revealed that M-SEO increased bacterial alpha-diversity (Shannon index) (p = 0.001) and significantly enriched specific functional guilds, particularly the propionate-producing genus Succiniclasticum and the butyrate-producing genus Butyrivibrio. Interestingly, the abundance of dominant methanogens (Methanobrevibacter) was not reduced, suggesting a metabolic inhibition mechanism rather than a biocidal effect. Functional prediction analysis further supported this, indicating a downregulation of pathways associated with methanogenesis, including key enzymes such as methyl-coenzyme M reductase. In conclusion, SEO supplementation at 200 mg/L effectively reduced methane production by redirecting metabolic hydrogen toward propionate formation, without affecting overall fermentation. Therefore, the current study indicated that SEO could serve as a sustainable feed additive for mitigating enteric methane emissions in ruminants. Full article

Arthropod pest species represent a serious threat to agriculture and forestry. Canada is no exception, with over 1200 recorded pest species. Although a consolidated dataset would benefit research, management, and policy, information on these species has never been compiled into a unitary database. This publication merges available information to create a dataset for the agroforest pest insects of Canada and updates the taxonomy for these records based on the Catalog of Life and GBIF. Each species record includes (1) their global distribution, (2) feeding guild for adults and larval stages (when available), (3) host plant data (when available) and (4) identifiers to obtain DNA barcodes from the Barcode of Life Data Systems (when available). Full article

Crop residues can harbor pathogens, making winter sanitation essential for sustainable viticulture. The grass–sheep–grape system could improve vineyard health through microbial optimization. To evaluate this, we assessed the effects of sheep feeding on fallen leaves on the occurrence of grape diseases through greenhouse experiments and used high-throughput-sequencing to compare microbial communities in grape fallen leaves and sheep feces, aiming to determine whether winter grazing reduces residue-borne pathogens. The results revealed that sheep grazing in vineyards significantly reduces the occurrence of grape leaf and cluster diseases, as well as a fundamental difference in microbial structures between leaves and feces, with no fungal taxa detected in the feces. The number of shared bacterial OTUs was minimal, while feces contained significantly more unique bacterial OTUs than fallen leaves. Additionally, bacterial diversity was significantly higher in feces than in fallen leaves. Sheep feces harbored a substantial number of highly efficient cellulose-degrading anaerobic bacteria, which may enhance organic matter conversion efficiency, and promote nutrient cycling in vineyards. Moreover, the grazing process directly reduced several pathogenic fungi associated with grape leaf, fruit, and root diseases. Functional analysis further indicated that fecal bacterial communities were primarily enriched in core metabolic and genetic processing functions, while leaf microbes were more involved in microbial interactions and secondary metabolism. More importantly, no function guilds of plant pathogenic fungi were present in feces. Overall, winter sheep grazing in vineyards can remove fallen leaves, not only reducing the risk of pathogen transmission but also potentially introducing beneficial bacterial communities. This study provides a feasible strategy for organic vineyard management in winter, and offers important insights for promoting sustainable vineyard production. Full article

Bats (Chiroptera) provide critical ecosystem services, including pest suppression, pollination, and seed dispersal. Understanding their dietary ecology is essential for conservation management yet has historically been constrained by methodological limitations. This review synthesizes advances in bat dietary analysis over the past several decades, from traditional morphological and stable isotope approaches to the revolutionary DNA metabarcoding techniques that now dominate the field. We systematically evaluate the strengths and limitations of each methodological approach and examine how molecular methods have transformed our understanding of bat trophic ecology. Research progress across major feeding guilds—insectivorous, frugivorous, nectarivorous, carnivorous, and sanguivorous bats—is examined, with emphasis on recent discoveries enabled by molecular techniques. We discuss ecological and conservation applications, including ecosystem service quantification, food web construction, and responses to environmental change. Finally, we identify priority directions for future research, including long-read sequencing technologies, multi-method integration, reference database expansion, and One Health applications. This synthesis provides guidance for researchers selecting appropriate analytical approaches and highlights the critical role of dietary studies in bat conservation amid accelerating global change. Full article

Although marine forest restoration projects have been widely implemented along the Korean coast, most evaluations have relied on simple structural indicators such as seaweed coverage or biomass, leaving functional responses of benthic macrofaunal communities largely unexplored. This study examined the effects of marine forest restoration on the functional structure of macrozoobenthic communities at development sites along Korea’s eastern coast in 2021 and 2024. Seaweed biomass increased significantly in 2024 compared to that in 2021, and this increase in seaweed biomass showed a clear positive correlation with increases in species number, density, and biomass of macrozoobenthos. Changes in feeding types of macrozoobenthic communities were remarkable, with grazer density increasing most sharply, followed by carnivores, omnivores, and suspension feeders. Red algal biomass was also positively correlated with suspension feeders and grazers, suggesting that seaweed mediated habitat and secondary food-web structures beyond providing simple food resources. These results indicate that seaweed habitat restoration plays an important role in recovering the functional diversity and feeding guild composition of macrozoobenthic communities and demonstrates the potential of using both species and functional diversity indicators to evaluate the effectiveness of marine forest restoration projects in Korea. Full article

The Yangtze River Estuary is one of the most productive estuarine ecosystems in the western Pacific, supporting diverse fish communities that sustain ecosystem functioning. This study investigated the seasonal patterns and community structure of intertidal fish assemblages to provide a baseline for future habitat assessments. Seasonal surveys conducted from May to December 2024 recorded 47 fish species belonging to 10 orders, 18 families, and 37 genera. Cyprinidae contributed the highest proportion of species (42.55%). Dominant species identified by the index of relative importance-including Cynoglossus gracilis, Coilia nasus, and Lateolabrax japonicus—characterized the seasonal assemblage structure. The assemblages were dominated by sedentary species (82.98%), and demersal fishes accounted for 48.94% of the species. Carnivorous taxa (57.45%) dominated the trophic guilds. Diversity indices indicated moderate diversity (H′: 1.797–2.441; C: 0.788–0.892; D: 1.724–4.770; J′: 0.6318–0.8642). Similarity analysis based on Jaccard’s index (Cj) showed the highest overlap between spring and summer (Cj = 0.5000) and the lowest between spring and winter (Cj = 0.1714); spring–autumn and summer–autumn were approximately 0.30, indicating moderate overlap. ABC curves yielded slightly negative W values in spring and summer and positive values in autumn and winter (W = −0.066 to 0.276), indicating moderately disturbed assemblages in spring–summer and less disturbed communities in autumn–winter. Overall, the study provides a seasonal baseline of intertidal fish assemblages in nearshore waters of the southern branch of the Yangtze River Estuary, which can provide useful ecological context for future assessments of nursery and feeding habitats of juvenile Chinese sturgeon (Acipenser sinensis). Full article

Elucidating the relationship between changes in insect assemblage structure and diversity and the number of years of ecological restoration will help us evaluate the effectiveness of ecological restoration. Our objective is to investigate the response of the structure and diversity of insect communities in the ecological restoration area of Yimin Surface Mine in Inner Mongolia to different restoration years (1 year, 4 years, 7 years) by monitoring in 2018, 2021, and 2024. A total of 1282 insect specimens were collected using sweep-netting methods, representing 70 species from 46 families across 8 orders. The results demonstrated that as restoration progressed, insect taxa significantly increased from 25 to 55 species (p < 0.01), with key functional groups (Coleoptera and Lepidoptera) showing marked richness enhancement. α-diversity indices (Shannon–Wiener and Margalef) significantly increased, while the Simpson dominance index decreased, indicating a more homogeneous species distribution. β-diversity analysis revealed reduced compositional dissimilarity among plots during later restoration stages, reflecting enhanced assemblage stability. The trophic structure shifted from phytophagous dominance to stabilized proportions across all feeding guilds, signaling food web maturation and ecosystem development. Overall, local ecological restoration projects had a significantly positive effect on insect survival and biodiversity development. Our research addresses a gap in faunal assemblage studies of coal mine rehabilitation zones. Full article

Parks serve as vital components of green infrastructure within urban ecosystems, providing recreational opportunities that not only enhance human well-being but also support bird diversity. However, the shared use of park spaces by both humans and birds inevitably leads to spatial overlap and natural competition between the two groups. Consequently, addressing the diverse needs of both groups and balancing the ecosystem services provided to each has become an urgent and critical issue. In this study, we conducted bird and social surveys in an urban park and employed the SolVES and MaxEnt models to investigate the spatial patterns of cultural ecosystem services (CES), supporting ecosystem services (SES), and bird plumage color CES in the park. We then analyzed the trade-offs and synergies between different ecosystem service relationship pairs, as well as the factors influencing them, using bivariate spatial autocorrelation and geographical detectors analyses. Our results indicated a synergistic relationship between the recreational value of park CES and both park SES and bird plumage color CES. High-coverage vegetation areas along main roads promoted synergy, benefiting visitors’ appreciation of cultural services, bird roosting, and the supply of plumage color CES. Meanwhile, trade-offs were observed between the aesthetic value of park CES, park SES, and bird plumage color CES, primarily in fitness plazas where noise levels exceeded 70 dB. In contrast, visitors reacted more strongly to disturbances than birds. Furthermore, the colonization of colorful insectivorous birds enhanced the visual aesthetic value while simultaneously increasing the number of bird-feeding guilds and strengthening ecosystem stability. Our study suggests that planting tall trees, especially along park boundaries, expanding the perimeter green separation zone, and incorporating micro-water landscapes will help improve both avian CES and provide a more pleasant environment for visitors in parks. Full article

There are few studies on the extent to which waterfowl select plant food compared with what is available in wetland ecosystems. We used a new dataset on the presence of seeds in the alimentary canal or feces to identify flowering plant species whose seeds are ingested by North American ducks or geese. These data are a proxy for dispersal interactions because an important fraction of ingested seeds survives gut passage and is dispersed by endozoochory. We compared the plant traits of species whose seeds were ingested with those of species on the U.S. Department of Agriculture National Wetland Plants List (NWPL). Using a global dataset on plant form and function and chi-squared tests, we compared four categorical traits (moisture requirements, growth form, plant height, and seed mass) between species whose seeds are ingested by North American ducks and geese with the NWPL. Our analyses identified significant differences between the trait distributions of plants whose seeds were ingested by waterfowl guilds and those of the NWPL. Geese and ducks (except whistling ducks) ingested more aquatic and semiaquatic plant species than expected from the NWPL. All guilds except sea ducks ingested more herbaceous graminoids and fewer shrubs or trees than expected. Diving ducks interacted with fewer of the taller plants (>5 m) than expected, but otherwise plant height distributions did not differ from those expected. All waterfowl guilds ingested more species of intermediate seed size (1–10 mg) and fewer species of the smallest (<0.1 mg) or largest (>100 mg) size categories than expected. These results help to explain the role of the long-distance dispersal of seeds by migratory waterfowl in plant biogeography and how plant distributions are likely to respond to global change. Full article

Freshwater macroinvertebrates, often used as indicators of environmental quality for freshwater ecosystems, may be compromised by microplastics (MPs). We investigated MPs occurring in benthic filter feeder, predator, and grazer macroinvertebrates collected from the catchment-independent but adjacent Olifants and Sabie rivers of Kruger National Park as duplicates. We counted 369 MPs in 376 organisms (1.0 n/organism) with a mean of 8.8 n/organism, 8.5 n/organism, and 0.16 n/organism in filter feeders, predators, and grazers, respectively. Based on MP colour, size, and morphotype, significant differences in proportional compositions between predatorial macroinvertebrates and all other macroinvertebrates in both rivers preclude predatorial macroinvertebrates as a proxy indicator for the other macroinvertebrates. Proportional compositions of MP characteristics in macroinvertebrates differed in all respects between the two adjacent rivers, except for one aspect. Microplastic morphotypes occurred in equal proportions in macroinvertebrates of both rivers, suggesting biological selection based on morphotype but not MP colour or size. We found little evidence of trophic transfer between feeding guilds. Of the six polymer types observed (n = 50), butyl and chlorobutyl dominated. Waste mismanagement, single-use plastics, inefficient wastewater treatment plants, mining, and road transportation may be the major MP pollution sources that need mitigation. Microplastics in freshwater ecosystems of nature conservation areas need more attention due to high biodiversity that may be exposed. Full article

Plant-growth-promoting rhizobacteria (PGPR) influence soil fertility, plant growth, tolerance to abiotic stress, resistance to herbivorous insects, and plant interactions with other organisms. While the effects of PGPR on plant growth, fruit yield, and induced defense responses have been extensively studied, the consistent positive outcomes have fueled rapid expansion in this research field. To evaluate PGPR impacts on plant growth and interactions with phytophagous insects, we conducted a systematic meta-analysis using publications from electronic databases (e.g., PubMed, Web of Science) that reported PGPR effects on plants and insects. Effects were categorized by plant family, PGPR genus, insect feeding guild, and insect–host specialization. Our analysis revealed that PGPR generally enhanced plant growth across most plant families; however, the magnitude and direction of these effects varied significantly among PGPR genera, indicating genus-specific interactions with host plants. When assessing PGPR-mediated reductions in phytophagous insects, we found that Pseudomonas, Rhizobium, and Bacillus exhibited the weakest negative effects on insect populations. PGPR significantly reduced both monophagous and polyphagous insects, with the most pronounced negative impacts on sucking insects (e.g., aphids, whiteflies). This study highlights critical patterns in PGPR-mediated plant growth promotion across taxa and the related differential effects on phytophagous insect activity. These insights advance our understanding of PGPR applications in agroecological production systems, particularly for integrated pest management and sustainable crop productivity. Full article