Search Results (310)

Understory vegetation, particularly dwarf bamboo, plays a crucial role in regulating forest nutrient cycles by intercepting litter and altering decomposition processes, yet its overall impacts remain understudied and insufficiently quantified. This study employs a combination of field surveys and decomposition bag experiments to investigate how understory dwarf bamboo (Fargesia decurvata) alters the spatial–temporal patterns of leaf litter production and decomposition. We found that the dwarf bamboo intercepted more than 25% of canopy litterfall, altering its spatial distribution and reducing decomposition efficiency in the bamboo crown (BC). Leaf trait-decomposition relationships differed strongly across habitats, being positive for saturated fresh weight (SFW), leaf thickness (LFT), and leaf area (LA) and dry weight (DW) in bamboo habitats but weaker in the bamboo-free habitat (NB). Potassium release was significantly higher in the BC treatment, whereas carbon release showed the opposite trend. In contrast, nitrogen and phosphorus exhibited net enrichment across all treatments, with phosphorus enrichment being slower in BC than in bamboo-covered ground surface (BG) and NB. Our results demonstrate that the understory dwarf bamboo reshapes the spatial distribution of litter and nutrient release dynamics during decomposition, resulting in element-specific nutrient release patterns. These findings provide mechanistic insights into how understory dwarf bamboo mediates nutrient cycling dynamics in forest communities. Full article

Microplastics (MPs) are ubiquitous and persistent contaminants of the marine environment, but a clear understanding of their cycling, fate, and impacts in coastal zones is lacking. In this study, large MPs (1–5 mm) were sampled spatially and temporally from the strandline of a macrotidal, sandy beach (Polzeath) in southwest England. MPs encompassing a diversity of sources were categorised by morphology (foams, nurdles, biobeads, fragments, fibres, films) and quantified by number and mass, with a selection analysed for polymer type. A total of about 17,600 particles of around 350 g in mass were retrieved from 30 samples over a period of five months, with an abundance ranging from 35 and 2048 per m². The space- and time-integrated average mass of MPs on the beach strandline was about 2 kg and was dominated (>90%) by fragments, nurdles, and biobeads of polyethylene or polypropylene construction. Nurdles, biobeads, fragments, and, to a lesser extent, fibres were correlated with strandline seaweed abundance, which itself was correlated with previous storm activity. Relationships with seaweed abundance were also supported by visible associations of these MP morphologies with macroalgal deposits through entanglement and adhesion. These observations, coupled with a lack of MPs below the sand’s surface (50 cm depth), suggest that the majority of MPs are transported from an offshore stock with floating organic debris, resulting in a transitory strandline repository and a habitat enriched with small plastics. Full article

Recognizing Other Effective Area-based Conservation Measures (OECMs) is a critical pathway for achieving the global “30 × 30” biodiversity target. China pioneered the Marine Ecological Redline (MERL) system to safeguard key marine ecosystems, rare and endangered species, and critical habitats through large-scale, legally mandated spatial regulation. However, MERLs have not yet been systematically assessed against OECM criteria. This study evaluates the institutional attributes and ecological effectiveness of MERLs, using the Pearl River Estuary as a case study, and identifies potential OECMs across non-MERL areas in China. The results show that MERLs fully meet OECM criteria, with the Pearl River Estuary MERLs demonstrating marked improvements in water quality, biodiversity recovery, and control of marine development intensity. We provide the first empirical evidence that MERLs function as a nationally led institutional OECM model, which enriches the typology of OECMs and introduces a novel governance pathway for marine biodiversity protection. Furthermore, eight types of non-MERL spatial units were identified as potential marine OECMs. By implementing policy and economic incentive mechanisms and establishing tiered recognition and dynamic identification systems, China can further biodiversity conservation and contribute to the global 30% marine protection goal. Full article

Ship Shoal, a large transgressive sand body on the Louisiana continental shelf, is a critical sediment source for coastal restoration. This study evaluates spatial and temporal variability in sediment grain size, percents organic matter (%OM), and carbonate (%CO₃) across the shoal crest (REF), Caminada Dredge Pit (CAM), and Terrebonne Dredge Pit (TER). Sediment samples were collected between 2020 and 2022 using box cores and analyzed for grain size, %OM, and %CO₃, with temporal and spatial patterns assessed through statistical comparisons, correlation analyses, and random forest regression models. Results show that dredged areas act as sinks for fine-grained, organic-rich sediments, with CAM consistently exhibiting the smallest median grain sizes and highest %OM, while REF maintained coarse, well-sorted sands. Carbonate enrichment reflected long-term depositional regimes, with REF exhibiting the highest %CO₃ due to the absence of dredging disturbance. Grain size and %CO₃ were identified as the strongest predictors of %OM, while %CO₃ was only weakly correlated with other sedimentary variables. Collectively, these findings demonstrate that dredge pits function as persistent repositories, with implications for benthic habitat resilience, sediment management, and coastal restoration planning. Future integration of hydrodynamic modeling with sediment transport and biogeochemical processes is needed to enhance predictive capability for managing dredged environments. Full article

Drought stress severely impacts the survival of Platycrater arguta, an endangered tertiary relict plant. This study investigated the mechanism by which exogenous melatonin enhances drought tolerance in P. arguta seedlings through integrated physiological, transcriptomic, and metabolomic analyses. Under 30% PEG-6000-induced drought, seedlings exhibited leaf wilting, reduced relative water content (RWC: 78.6% vs. 84.8% in controls), and elevated oxidative damage (malondialdehyde increased by 62.94%, H₂O₂ by 83.78%). Exogenous melatonin application, particularly at 100 μM (T3), significantly alleviated drought symptoms, restoring RWC to 83.7%, reducing membrane permeability (relative electrical conductivity 1.38-fold vs. CK vs. 2.55-fold in PEG), and lowering oxidative markers (MDA and H₂O₂ accumulation by 28.33% and 27.84%, respectively). T3 treatment also enhanced osmolyte synthesis, increasing proline content by 90.14% and soluble sugars by 47.25% compared to the controls. Transcriptome sequencing revealed 31,870 differentially expressed genes in T3, predominantly enriched in carbohydrate metabolism, oxidative phosphorylation, and tryptophan metabolism pathways. Metabolomic profiling demonstrated that 100 μM melatonin elevated endogenous melatonin levels 19.62-fold and modulated tryptophan-derived metabolites, including indole derivatives and benzoic acid compounds. These findings indicate that melatonin mitigates drought stress by enhancing antioxidant capacity, osmotic adjustment, and metabolic reprogramming, with 100 μM as the optimal concentration. This study provides critical insights into melatonin-mediated drought resistance mechanisms, offering a theoretical foundation for conserving and restoring P. arguta populations in arid habitats. Full article

Coral reefs, essential yet increasingly threatened marine ecosystems, rely on coral–microbiome symbioses for resilience against environmental stressors. This study investigates host-specific influences on bacterial communities in four Pocillopora species (Pocillopora eydouxi, Pocillopora meandrina, Pocillopora verrucosa, and Pocillopora woodjonesi) from the South China Sea. Using Illumina-based 16S rRNA gene sequencing, we analyzed microbiome structures, identified core taxa, and predicted metabolic functions. Results revealed that bacterial composition differed significantly among coral hosts, despite their shared habitat. P. eydouxi exhibited the highest bacterial richness and Shannon index, contrasting with minimal values in P. woodjonesi. A conserved core microbiome of 32 ASVs (1.1% of total ASVs), dominated by Gammaproteobacteria, was shared across all coral species. Host-specific enrichment of probiotic bacteria (Psychrobacter in P. eydouxi and Exiguobacterium in P. meandrina) and pathogenic taxa (e.g., Acinetobacter) was also observed. Functional prediction indicated conserved metabolic pathways across species, particularly amino acid and carbohydrate metabolism. These findings highlight host phylogeny as one of the primary determinants of microbiome assembly, providing critical insights into coral conservation strategies. Full article

The Príncipe Island is in the Gulf of Guinea, along the Cameroon Volcanic Line (West Africa). It is known worldwide for its biodiversity for whose conservation there is strong national and international consensus. But its geodiversity has played and continues to play a very important role in creating this unique habitat in sub-Saharan Africa, and represents an important asset in promoting local tourism, with a focus on the geological history of this remote island. The purpose of this study is to provide a comprehensive synthesis that is both up-to-date and inclusive, incorporating all the fundamental information and references on the geodiversity and the geological heritage of the Príncipe Island. The geological heritage of Príncipe Island is represented by ten geological heritage sites of different types (volcanological, geomorphological, sedimentological, and stratigraphical), and five viewpoints, whose geoheritage contents make it possible to support a narrative about the geological history of the Cameroon Volcanic Line that is of major relevance for the development of geoeducational resources and potentially appealing to fostering regional geotourism. Príncipe geological heritage sites were inventoried and assessed using the same qualitative methodology previously applied to the geological heritage of São Tomé Island, therefore making it possible to complete the country’s national inventory of geological sites, as well as to enrich the representation of African geoheritage among the world’s list of geological heritage sites. Full article

Assessing the well-being of captive brown bears is essential for responsible species management and meeting European and national animal care standards outside their natural habitats. The present study aims to assess the welfare of captive brown bears in Bulgaria, considering environmental parameters, husbandry procedures, and the psychological and physical condition of the animals. The study was conducted on 28 brown bears in 11 zoos in Bulgaria and 19 bears in Bear Sanctuary Belitsa. A specific questionnaire and interviews were conducted with zoo managers and keepers. The welfare of the bears was evaluated based on their living conditions, husbandry, and physical and psychological well-being. The Nature and Animal Protection Center in Dobrich received the highest rating for the welfare of two brown bears among the zoos in the study. The study identified annual veterinary check-ups and enrichment programmes as areas needing improvement. Full article

Tachypleus tridentatus is a rare and endangered marine organism with considerable scientific and economic value. It has existed on Earth for about 450 million years and its continuation to the present day may be related to its unique immune system. Owing to its drastic population decline, diverse technical approaches are required for its recovery, and the development and growth of its larvae are crucial in this context. Vibrio parahaemolyticus is a common marine pathogen that impairs the healthy growth of marine organisms. The peak period of V. parahaemolyticus occurrence is from May to November, which significantly overlaps with the T. tridentatus spawning period from April to September. However, the response mechanisms of juvenile T. tridentatus to V. parahaemolyticus stress remain unknown. Hence, in this study, we aimed to investigate these response mechanisms through acute toxicity assays, histological observations, and transcriptome analysis. The results showed that the 48 h LD₅₀ of V. parahaemolyticus-infected T. tridentatus larvae was determined to be 1.31 × 10⁸ CFU/g. Histological analysis showed that V. parahaemolyticus damaged the larval tissue. In addition, RNA sequencing (RNA-Seq) identified 2347 differentially expressed genes (DEGs; 1440 upregulated and 907 downregulated genes) and 243 enriched signaling pathways. Functional enrichment analysis revealed the enrichment of immunoregulatory pathways, including the Wnt signaling pathway, ECM-receptor interaction, aminoacyl-tRNA biosynthesis, and Toll and Imd signaling pathways. Seventeen DEGs were randomly selected for real-time RT-PCR (RT-qPCR) validation, and their expression patterns were consistent with those obtained via RNA-Seq. The study of the response mechanism of T. tridentatus larvae to V. parahaemolyticus stress provides scientific references for the protection of T. tridentatus habitats and the recovery of its population size. Full article

Marine litter provides novel habitats for substrate-dependent species, potentially facilitating their expansion under climate change. This study investigated the thermal adaptability and substrate selectivity of the cold-water sea anemone Metridium senile in the Yellow Sea, where rising temperatures and anthropogenic substrates may drive its proliferation. Behavioral experiments revealed diminished adhesion capacity under thermal stress (13 °C and 18 °C), with no substrate preference observed. Transcriptomic analysis identified 175 and 340 differentially expressed genes (DEGs) at 13 °C and 18 °C, respectively, compared with the control (8 °C). These DEGs were enriched in metabolic processes, oxidative stress, and cell homeostasis, with key pathways including dorso-ventral axis formation, ECM–receptor interaction, TGF-β, and Wnt signaling pathways. Notably, 7 regeneration-related, 20 adhesion-related, and 16 collagen-related DEGs were implicated in adaptive responses to heat stress. Our findings elucidate the molecular mechanisms underlying M. senile’s resilience and highlight its potential to exploit human-modified habitats under warming conditions, offering insights into ecological shifts in marine ecosystems. Full article

Longleaf pine forests are economically important habitats that stabilize and enrich the soil and store carbon over long periods. When mixed with oaks, these forests provide an abundance of lichen habitats. The tree canopy lichens promote greater moisture capture and retention and encourage canopy insects. Ground lichens limit some vascular plant germination and growth, promoting a more open and healthy pine community. There is a longstanding mutualistic relationship between longleaf pine habitat and lichens. Longleaf pine habitat has a long history of natural summer burning, which promotes a diverse understory and limits tree densities. Lichen diversity exceeds vascular plant diversity in many mature longleaf pine habitats, yet information on the impacts of prescribed fire on lichen species in these habitats is limited. We assessed lichen diversity and abundance before and after a prescribed ground fire in a longleaf pine/wiregrass habitat near Ocala, Florida. Pre-burn, we found greater lichen abundance and diversity on hardwoods, primarily oak species, than on pines. Post-burn, lichen abundance on hardwoods dropped overall by 28%. Lichen abundance on conifers dropped overall by 94%. Ground lichen species were basically eliminated, with a 99.5% loss. Our study provides insights into retaining lichen diversity after a prescribed burn. Hardwood trees, whether alive or standing dead, help retain lichen biodiversity after burning, whereas conifer trees do not support as many species. Landscapes may need to be actively managed by raking pine needle litter away from ground lichen beds, moistening the ground, or removing some lichen material before the burn and returning it to the site post-fire. Based on these results, we suggest retaining some oaks and conducting burns in a mosaic pattern that retains unburned areas. This will allow for lichens to recover between burns, significantly enhancing biodiversity and the ecological health of these longleaf pine communities. Full article

Tree plantations can help reverse the negative impacts of deforestation and land degradation worldwide, and soil microbial communities play key roles in tree growth and productivity. We studied microbial communities in the bulk soil of five native species monoculture plantations in the Republic of Panamá to assess how bacteria and fungi were affected by soil chemistry and plant identity after seven years of tree growth. Relative to the other species, Terminalia amazonia accumulated over three times the aboveground biomass and had lower mortality. Soil nutrients, especially phosphorus, were low, and we found no differences in soil chemistry across the five plantation types. Similarly, there was no difference in alpha diversity of the soil microbial communities across plantation types, and the bacterial communities showed no compositional variation or enrichment of any individual taxa. However, soil fungal communities differed in T. amazonia plantations as compared to the others, exhibiting enrichment or absence of specific taxa of arbuscular mycorrhizal fungi and putative phytopathogens. Our results suggest that T. amazonia may associate with certain microbial taxa that help it overcome low nutrient availability in these habitats. Consideration of plant–soil–microbe interactions in restoration efforts may facilitate tree growth and help to promote climate resilient forested areas. Full article

Wildlife rescue centres face considerable challenges in promoting animal welfare and enhancing the care and housing conditions of animals under professional supervision. These challenges are further compounded by the diversity of species admitted, each with distinct specific needs. In Colombia and other Latin American countries, primates are among the most frequently rescued and behaviourally complex mammalian taxa, requiring particular attention. In response, this study aimed to assess the content validity of proposed animal welfare indicators for Cebus albifrons through a Delphi consultation process and to develop two species-specific assessment protocols: a daily-use tool for keepers and a comprehensive protocol for professional audits. A panel of 23 experts in primate care and rehabilitation participated in two consultation rounds to evaluate and prioritise the indicators based on their content validity, perceived reliability, and practicality. Indicators were classified as either animal-based (direct measures) or resource- and management-based (indirect measures). After each round, experts received summarised feedback to refine their responses and facilitate consensus building. Of the 39 initially proposed indicators, 28 were validated for inclusion in the extended protocol and 10 selected for the daily-use checklist. Among these, 20 indicators in the extended protocol and 6 in the daily protocol were resource- or management-based—such as adequate food provision, physical enrichment, and habitat dimensions—highlighting their practical applicability and relevance in identifying welfare issues and risk factors. Although these indirect indicators were more numerous, the top-ranked indicators in both protocols were animal-based, including signs of pain, affiliative behaviours, and abnormal repetitive behaviours. These are essential for accurately reflecting the animals’ welfare state and are therefore critical components of welfare assessment in captive non-human primates. This study demonstrates that welfare assessment tools can be effectively tailored to the specific needs of wildlife rescue centres, providing a robust foundation for enhancing welfare practices. These protocols not only offer practical approaches for assessing welfare but also underscore the importance of embedding animal welfare as a priority alongside conservation efforts. Future research should aim to refine these tools further, assess their implementation, and evaluate inter- and intra-observer reliability to ensure consistency across different settings. Full article

The Sanniang Bay (SNB) and Dafeng River Estuary (DFR) in the Northern Beibu Gulf, China, are critical habitats for the Indo-Pacific humpback dolphin (Sousa chinensis). However, whether and how the decreased dissolved oxygen (DO) has happened in bottom seawater remains poorly understood. This study investigated DO depletion and microbial community responses using a multidisciplinary approach. High-resolution spatiotemporal sampling (16 stations across four seasons) was combined with functional annotation of prokaryotic taxa (FAPROTAX) to characterize anaerobic metabolic pathways and quantitative PCR (qPCR) targeting dsrA and dsrB genes to quantify sulfate-reducing bacteria. Partial least-squares path modeling (PLS-PM) was employed to statistically link environmental variables (seawater properties and nutrients) to microbial community structure. Results revealed pronounced bottom DO declining to 5.44 and 7.09 mg L⁻¹, a level approaching sub-optimal state (4.0–4.8 mg L⁻¹) in September. Elevated chlorophyll-a (Chl-a) near the SDH coincided with anaerobic microbial enrichment, including sulfate reducers (dsrA/dsrB abundance: SNB > DFR). PLS-PM identified seawater properties (turbidity, DO, pH) and nitrogen as key drivers of anaerobic taxa distribution. Co-occurrence network analysis further demonstrated distinct microbial modules in SNB (phytoplankton-associated denitrifiers) and DFR (autotrophic sulfur oxidizers, nitrogen fixation, and denitrification). These findings highlight how environmental factors drive decreased DO, reshaping microbial networks and threatening coastal ecosystems. This work underscores the need for regulating aquaculture/agricultural runoff to limit eutrophication-driven hypoxia and temporarily restrict human activities in SNB during peak hypoxia (September–October). Full article

The blue shark (Prionace glauca) is a pelagic species widely distributed in the northwestern Pacific Ocean. The trophic roles of blue sharks across different developmental stages and between sexes remain poorly understood. Fifty-four sharks were sampled (October 2022–March 2024) for precaudal length (PCL) and stable isotope levels (δ¹³C, δ¹⁵N) in the muscle tissue (n = 52). Mean PCL varied based on the month of sampling (p = 0.034), with the smallest individuals occurring in July (143.0 ± 4.3 cm) and the largest in October (178.0 ± 2.6 cm). Stable isotope analysis (δ¹³C and δ¹⁵N) indicated consistent offshore habitat use (δ¹³C: from −20.70 to −18.82‰) and significant nitrogen isotopic differences among life history (δ¹⁵N: from 10.23 to 15.72‰; Kruskal–Wallis test, p = 0.037). The elevated δ¹⁵N values observed in the subadult group (relative to juvenile individuals) are likely due to trophic enrichment associated with morphological development. Females exhibited markedly larger isotopic niches (SEAc = 2.42‰²) than did males (0.57‰²), and niche overlap was greater within each sex (40–52%) than between sexes (<21%). These results revealed sex-specific ecological roles and trophic strategies throughout the life history of P. glauca. Understanding these foraging differences can help with catch reduction and habitat-protection measures in the transboundary pelagic fisheries of the northwestern Pacific. Full article