Ecological Implications Research Articles

High energetic cost of color change in octopuses

For many animals, color change is a critical adaptive mechanism believed to carry a substantial energetic cost. Yet, no study to date has directly measured the energy expenditure associated with this process. We examined the metabolic cost of color change in octopuses by measuring oxygen consumption in samples of excised octopus skin during periods of chromatophore expansion and contraction and then modeled metabolic demand over the whole octopus as a function of octopus mass. The metabolic demand of the fully activated chromatophore system is nearly as great as an octopus’s resting metabolic rate. This high metabolic cost carries ecological and evolutionary implications, including selective pressures in octopuses that may influence the adoption of nocturnal lifestyles, the use of dens, the reduction of the chromatophore system in deep-sea species, and metabolic trade-offs associated with foraging.

Molecular and morphoanatomical characterization of Urocystis heteropogonis sp. nov.: a novel smut fungus infecting Heteropogon contortus.

A new species of smut fungus, Urocystis heteropogonis, was discovered infecting Heteropogon contortus in Shawar Valley, Swat district, Khyber Pakhtunkhwa, Pakistan. The study aimed to characterize this fungus based on its morpho-anatomical and molecular features and clarify its phylogenetic position within the genus Urocystis. Urocystis heteropogonis was identified as a novel species, distinct from other Urocystis species. Morphologically, it is characterized by larger spore balls (14-69 × 11-45μm) and central spores that are 14-28 × 11-20μm in size, with each spore containing1-8 central spores. The spore walls measure 0.9-2.5μm in thickness and the species differs in infection patterns compared to other Urocystis species. Phylogenetic analysis based on the ITS and LSU regions of nuclear ribosomal DNA (nrDNA) further confirmed the novelty of the species, placing it within a distinct clade alongside U. agropyri, U. occulta, U. piptatheri, and U. tritici. The discovery of Urocystis heteropogonis adds to the diversity of smut fungi infecting grasses and highlights the need for further research into its ecological and agricultural implications. Future studies should focus on the disease's spread, management, and potential impact on host populations.

Corporate engagement in mitigating plastic pollution: examining voluntary initiatives and EU regulations

Plastic pollution has emerged as a critical global environmental challenge, with far-reaching ecological, economic, and social implications. This article addresses the fragmented nature of the current literature on plastic pollution regulations and their impact on the corporate sector and aims to bridge this gap by providing a comprehensive analysis of the current EU regulatory framework and corporate voluntary self-regulatory initiatives relevant to plastic pollution. Examining voluntary initiatives – including corporate social responsibility (CSR) programs and the emerging concept of plastic credits – in terms of their potential to tackle plastic pollution and promote environmental sustainability, the article presents novel insights on how different regulatory mechanisms and voluntary self-regulatory initiatives engage the corporate sector in mitigating plastic pollution. While highlighting the importance of collaborative efforts between regulatory bodies and businesses, the study critically evaluates the challenges and limitations of current approaches. It addresses concerns about the efficacy and transparency of CSR initiatives, with particular attention to the issue of greenwashing and its potential legal implications. By synthesizing diverse sources, this article emphasizes the need to combine stringent regulatory frameworks with responsible business practices to engage the corporate sector in preventing and mitigating plastic pollution, specifically within the context of the European Union’s pioneering environmental policy. Ultimately, the study suggests that the most effective long-term solution lies in reducing plastic production altogether while acknowledging the role of transitional measures in the interim.

A full genome assembly reveals drought stress effects on gene expression and metabolite profiles in blackcurrant (Ribes nigrum L.)

Abstract Blackcurrant (Ribes nigrum L., family Grossulariaceae) is a perennial shrub that is widely cultivated for its edible berries. These are rich in antioxidants, vitamin C and anthocyanins, making them a valuable ingredient in the food and beverage industry. However, prolonged periods of drought during the fruiting season lead to drought stress, which has serious ecological and agricultural implications, inhibiting blackcurrant growth and reducing yields. To facilitate the analysis of underlying molecular processes, we present the first high-quality chromosome-scale and partially haplotype-resolved assembly of the blackcurrant genome (cv. Rosenthals Langtraubige), also the first in the family Grossulariaceae. We used this genomic reference to analyze the transcriptomic response of blackcurrant leaves and roots to drought stress, revealing differentially expressed genes with diverse functions, including those encoding the transcription factors bZIP, bHLH, MYB and WRKY, and tyrosine kinase-like kinases such as PERK and DUF26. Gene expression was correlated with the abundance of primary metabolites, revealing 14 with significant differences between stressed leaves and controls indicating a metabolic response to drought stress. Amino acids such as proline were more abundant under stress conditions, whereas organic acids were depleted. The genomic and transcriptomic data from this study can be used to develop more robust blackcurrant cultivars that thrive under drought stress conditions.

Altitudinal variations in forensically relevant dipterans in Trentino Region (Italy): implications for PMI estimation and forensic ecology.

This study investigates the populations of dipterans in the southeastern Prealps of Trentino, Italy, along an altitudinal gradient that exceeds 1000m. The study is important because dipterans play a significant role in crime scene analysis by helping to determine the post-mortem interval (PMI) and understand corpse relocation dynamics. Nine aerial traps were used across three sites from May to November 2023, and a total of 17,876 individuals from diverse species were captured. Statistical analyses revealed significant differences in dipteran populations across sites and exposure levels. The study identified relationships between species and environmental factors such as altitude, temperature, and sunlight exposure using Canonical Correspondence Analysis (CCA). Results demonstrated that species composition varied with environmental conditions, offering insights into potential shifts due to climate change. The presence of specific species was notably affected by temperature fluctuations, which could impact their usefulness in PMI estimation. Continuous monitoring is crucial to track dipteran population dynamics amidst changing environmental conditions. Such knowledge is important for improving accuracy in PMI estimations and enhancing forensic investigations. In conclusion, ongoing research is pivotal in adapting forensic entomological analyses to evolving ecological contexts, ensuring their reliability in forensic science applications. This study highlights the dynamic nature of dipteran ecology within forensic contexts and emphasises the need for further investigation to observe shifting population dynamics under climate change impacts.

Genetic potential for aerobic respiration and denitrification in globally distributed respiratory endosymbionts

The endosymbiont Candidatus Azoamicus ciliaticola was proposed to generate ATP for its eukaryotic host, an anaerobic ciliate of the Plagiopylea class, fulfilling a function analogous to mitochondria in other eukaryotic cells. The discovery of this respiratory endosymbiosis has major implications for both evolutionary history and ecology of microbial eukaryotes. However, with only a single species described, knowledge of its environmental distribution and diversity is limited. Here we report four complete, circular metagenome assembled genomes (cMAGs) representing respiratory endosymbionts inhabiting groundwater in California, Ohio, and Germany. These cMAGs form two lineages comprising a monophyletic clade within the uncharacterized gammaproteobacterial order UBA6186, enabling evolutionary analysis of their key protein complexes. Strikingly, all four cMAGs encode a cytochrome cbb3 oxidase, which indicates that these endosymbionts have the capacity for aerobic respiration. Accordingly, we detect these respiratory endosymbionts in diverse habitats worldwide, thus further expanding the ecological scope of this respiratory symbiosis.

Pre-emergence herbicides used in urban and agricultural settings: dissipation and ecological implications

Herbicides are widely recognized as the most cost-effective solution for weed control, but their extensive use in both urban and agricultural settings raise serious concerns about nontarget effects. We assessed the possible hazards associated with pre-emergence herbicides such as dimethenamid–P, metazachlor, and pyroxasulfone, which are frequently applied in both urban and agricultural soils. The dissipation rate constant values (k day−1: 0.010–0.024) were positively linked to total organic carbon (TOC), silt, clay, soil pH, and Al and Fe oxides, but negatively correlated with sand content. In contrast, half-life values (DT50: 29–69 days) of the herbicides showed negative correlations with TOC, clay, silt, soil pH, and Fe and Al oxides, while sand content showed a positive impact. The selected herbicides showed minimal impact on soil dehydrogenase activity (DHA). Mostly, soils with higher organic matter (OM) content exhibited increased DHA levels, highlighting the role of OM in influencing this soil enzyme across different soils. Assessment of environmental indicators like groundwater ubiquity score (GUS:1.69–6.30) and leachability index (LIX: 0.23–0.97) suggested that the herbicides might reach groundwater, posing potential risks to nontarget biota and food safety. Human non-cancer risk evaluation, in terms of hazard quotient (HQ < 1) and hazard index (HI < 1), suggests minimal or no risks from exposure to soil containing herbicide residues at 50% of the initial concentrations. Our data thus help the stakeholders and regulatory agencies while applying these pre-emergence herbicides in soils and safeguarding human and environmental health.

Potentially toxic elements (PTEs) in the invasive Asian clam (Corbicula fluminea) from polluted urban river areas of Bangladesh and evaluation of human health risk.

The invasive Asian clam species, Corbicula fluminea, has significant ecological and societal implications at both local and international levels due to its nutritional aspects. C. fluminea from four urban rivers in Bangladesh exhibited negative allometric growth and degree of contamination with potentially toxic elements (PTEs), which posed a concern to human health based on the AAS and USEPA risk models. The highest mean concentration of PTEs followed a decreasing order: Zn (155.08 ± 4.98mg/kg) > Cu (53.96 ± 7.61mg/kg) > Mn (14.29 ± 3.25mg/kg) > Cd (2.23 ± 0.10mg/kg) > Pb (1.64 ± 0.14mg/kg) > As (1.51 ± 0.45mg/kg) > Ni (1.25 ± 0.27mg/kg) > Cr (0.65 ± 0.02mg/kg) in C. fluminea and raising safety concerns. With the exception of Cr and Mn, all element levels were exceeded safety guideline value (SGV) (mg/kg. ww) and exhibited a strong positive correlation (p < 0.05) among the sites. The target hazard quotient of Mn is THQ > 1, and As showed a non-carcinogenic risk in children at OBR, BR, and MR site. The hazard index (HI > 1) value at the BR and MR sites indicated a public health risk associated with the clam. The target cancer risk (TCR) values for As, Cd, and Ni showed that consuming clams posed a carcinogenic risk to human health. These findings suggest that eating these clams may put consumers at significant risk for health issues related to As, Cd, Ni, and Mn exposure. The study emphasizes the need for strict monitoring and preventative measures to reduce the health risks posed by PTEs contamination in clams.

Unravelling intermediate migration patterns in gull hybrids: insights from ring re-encounters

Hybridization is a common phenomenon in birds, particularly between closely related species, when reproductive isolation mechanisms are insufficiently developed. Hybrids differ from the parental species in genetic, morphological, and behavioural traits. However, the migration patterns of hybrids have been scarcely studied. Examining hybrid migration behaviour is essential as it may reveal their role as a “gene bridge” between species and enhance our understanding of speciation mechanisms and the genetics of migration. Most research focuses on tracking the migration of long-distance migrants, but the effect of hybridization on migration is poorly understood also in short-distance migrants. The study aimed to verify whether the migratory movements of interspecific hybrids between the Herring (Larus argentatus) and the Caspian Gull (L. cachinnans) are intermediate, as predicted by the genetic basis of migration. Migration patterns, based on distance and direction, were determined from re-encounter data of individuals ringed in Poland, for over 20 years (2002–2023). These included both allopatric (parental species) and sympatric (both parental species and hybrids) populations. The results indicated that large gull hybrids exhibit an intermediate migration patterns, similarly to other hybridizing species. Unlike many cases where intermediacy may select against hybrids, the absence of significant environmental barriers along gulls’ migration routes and their wide wintering range likely mitigates selective pressures. This finding underscores the need for further investigation into the ecological implications of hybrid migration patterns. By using bird re-encounter data, we demonstrated that it provides a sufficient basis for analysing migration patterns and detecting intermediacy, even in within-continental and short-distance migrants.

Host trees partially explain the complex bacterial communities of two threatened saproxylic beetles.

Microorganisms are integral to ecosystem functioning and host adaptation, yet the understanding of microbiomes in diverse beetle taxa remains limited. We conducted a comprehensive study to investigate the microbial composition of two red flat bark beetle species, Cucujus haematodes and C. cinnaberinus, and assessed the influence of host taxonomic relatedness and host tree species on their microbiomes. We sampled 67 larvae of two Cucujus taxa taken from 11 host tree species. 16S rRNA V4 fragment sequencing revealed distinct microbial communities associated with each Cucujus species, with host tree species significantly influencing microbiome composition. Alpha and beta diversity metrics indicated significant differences between microbial communities in both beetle and host tree species. Principal component analysis indicated distinct clustering based on host tree species but not for beetle species. This overlap could be attributed to the similar ecology of both Cucujus species. The detection of various bacteria, among which some have already been reported in saproxylophagous beetles, suggests that the red flat bark beetles ingest the bacteria via foraging on other wood-dwelling invertebrates. Our findings show the complex interplay between host taxonomy, microhabitat and microbial composition in Cucujus, providing insights into their ecological roles and conservation implications. This research helps to fill the gap in understanding the microbial dynamics of saproxylic beetles, sheds light on factors shaping their microbiomes and highlights the importance of considering both host species and environmental conditions when studying insect-microbe interactions in forest ecosystems.

Effect of a tropical cyclone on the pelagic ecosystem of a continental shelf

AbstractThis study aimed to comprehend the effects of Typhoon Maria on the pelagic ecosystem in the southern East China Sea. Shipboard measurements were conducted at eight sampling stations before (2–4 d) and after (3–6 d) the typhoon, which enabled the evaluation of the potential impacts of the typhoon on this pelagic ecosystem, with particular focus on carbon dynamics. Following the typhoon's passage, there was a slight drop in sea surface temperature. The response of the variables to the typhoon, however, exhibited variations at different sampling stations. For further analysis, t‐tests compared variables, while type II regression assessed the linear correlation between two variables. Overall, during the post‐typhoon period, concentrations of nitrate, chlorophyll a, primary production, bacterial biomass and production, plankton community respiration, and abundance of large phytoplankton (&gt; 2 μm) and the relative abundance of picophytoplankton among larger‐sized picoeukaryotes were higher compared to the pre‐typhoon period. The mean value of fugacity of CO2 was similar to or slightly lower than pre‐typhoon period. Although the typhoon‐induced vigorous primary production might have absorbed a significant amount of CO2, the decrease in fugacity of CO2 could have been offset by the plankton community respiration. The findings suggest that the typhoon enhanced physical disturbance and increased water column mixing, which, in turn, augmented nutrient availability and promoted plankton growth in the shallow water column. Overall, this study sheds light on the complex interactions between typhoons and marine ecosystems and highlights the importance of further investigating these phenomena to better understand their ecological implications.

Genetic Diversity and Ecogeographical Niche Overlap Among Hybridising Ox-Eye Daisies (Leucanthemum, Asteraceae) in the Carpathian Mountains: The Impact of Anthropogenic Disturbances.

Climate change and human influence are transforming mountain ecosystems, significantly impacting species distributions and biodiversity. Among these changes, the upward migration of lowland species into mountain regions stands out. This study examines the ecogeographical niche overlap and genetic diversity among three Leucanthemum species distributed along an altitudinal gradient in the Carpathian Mountains: the lowland L. ircutianum (4x), the montane L. rotundifolium (2x) and the alpine L. gaudinii (2x). By genotyping over 600 individuals using SNP analysis, followed by principal coordinate analysis (PCoA), Neighbour-Net Network and Structure clustering, we reveal not just distinct genetic groups but also hybridisation across all species, suggesting the potential for triple hybrids. Genetic admixture is further supported by environmental background and niche overlap analyses that reveal substantial overlap among species, particularly in line with their vertical distribution. Climate envelope plots indicate a likely reduction in available habitat for mountainous species due to climate change, leading to an increase in competition and an intensification of hybridisation. Anthropogenic influences are further intensifying these hybridisation trends. Among the studied species, L. gaudinii is most at risk of overwhelming hybridisation, whereas L. ircutianum may experience habitat expansion. By providing a comprehensive genetic and ecological overview, our research highlights the significance of hybridisation in biodiversity conservation and the challenges posed by environmental changes and anthropogenic activities in mountain environments. This study not only contributes to the understanding of genetic diversity in the Carpathians but also underscores the broader implications for molecular ecology and conservation strategies in mountain ecosystems.

Seasonal occurrence and ecological risk assessment of polycyclic aromatic hydrocarbons in the sediments and water in the left-bank canals of Indus River, Pakistan.

This study investigated a pressing environmental concern: the presence, distribution, sources, and ecological implications of sixteen polycyclic aromatic hydrocarbons (PAHs) in the left-bank canals of Kotri barrage-Akram, Pinyari, and Phuleli of the Indus River in Pakistan. These vital waterways, crucial for industrial, domestic, and agricultural activities, are experiencing contamination threats from anthropogenic sources, particularly PAHs. The study collected three water and two sediment samples from each canal in pre-monsoon and post-monsoon seasons. Then the EPA's liquid-liquid extraction method and gas chromatography determined the concentrations of PAHs. The findings of this study reveal alarming contamination levels, with pre-monsoon concentrations ranging from 22.256 to 836.455ng/L in water and 1,459.941 to 43,179.243ng/g in sediments. The post-monsoon concentrations ranged from 60.352 to 5663.058ng/L in water and 2976.770 to 15,238.335ng/g in sediments. The diagnostic ratios and principal component analysis (PCA) identified multiple sources of contamination, including industrial and domestic wastewater discharge, solid waste burning, vehicular emissions, biomass combustion, and petroleum residues. Furthermore, the assessment of the toxic equivalency factor (TEF) underscored the heightened carcinogenic potential of certain PAHs, notably benzo(a)pyrene and benzo(a)anthracene. Thus, the high levels of PAH contamination pose severe health risks to both human populations and aquatic ecosystems, emphasizing the urgency of addressing this issue. Stricter regulations governing industrial and domestic waste discharge, advocacy for cleaner fuel technologies, and the implementation of effective waste management practices must be initiated as crucial strategies in safeguarding the environmental integrity of the left-bank canals and the health of the surrounding communities.

Origin and ontogeny of the xylopodium in Cerrado legumes: Role of the hypocotyl and ecological significance

Bud-bearing underground organs play a role on plant persistence in different fire-prone ecosystems worldwide, but their origin, development and anatomical features are still a matter of inquiry. The xylopodium, for instance, seem to originate from the hypocotyl or primary root, or both, usually associated with tuberous roots. Because this structure is commonly found in legumes across the Brazilian savannas (Cerrado), understanding its formation is important for unveiling its relevance for post-fire resprouting. Here we aimed to investigate the role of the hypocotyl on the development of six Cerrado legume shrubs, as well as histochemical features and ecological implications from seedlings to adult plants in this frequently-burned ecosystem. Seeds of the six study species were collected in central Brazil, set to germinate and cultivated until the stages of four, six, nine, and twelve months. At each stage, the region correspondent to the hypocotyl was delimited and anatomical and histochemical analyses performed. Over time, the hypocotyl region underwent a tuberization process, during which the cortex was progressively replaced by the formation of secondary xylem through intense cambial activity. Before the twelve-month-old stage, all species presented buds, mainly cotyledonary, and reacted to starch, phenols and pectins. Early hypocotyl tuberization drives the formation of the xylopodium from seedlings to adulthood, and the presence of buds and the accumulation of reserves during its formation is a fundamental process driving species’ persistence after fire.

Mycorrhizal specialization toward each distinct Oliveonia fungus in two closely related photosynthetic Dactylostalix orchids

Abstract Although rhizoctonias from Ceratobasidiaceae, Tulasnellaceae and Serendipitaceae are typical orchid mycobionts, orchid mycorrhizal fungi exhibit vast taxonomic and ecological diversity. This diversity stems from the high specificity of orchid mycorrhizal associations and the remarkable diversity of over 28,000 orchid species. The subtribe Calypsoinae is particularly notable for its diverse mycorrhizal partnerships, including rhizoctonias, ectomycorrhizal and saprotrophic non‐rhizoctonia fungi. However, the mycobionts within certain Calypsoinae lineages, such as the genus Dactylostalix, remain understudied. This study explores the physiological ecology of two photosynthetic Calypsoinae species, Dactylostalix ringens and Dactylostalix uniflora, to gain insight into potentially novel associations and their ecological implications. We analysed the mycorrhizal communities of both Dactylostalix species using high‐throughput ITS metabarcoding of root samples collected from multiple locations. Additionally, we measured the natural abundances of 13C and 15N isotopes in the leaves of the two Dactylostalix species and their co‐occurring autotrophic reference plants, as well as in fungal pelotons isolated from D. ringens, to assess the potential for partial mycoheterotrophy. Our findings revealed that D. ringens and D. uniflora form specialized mycorrhizal associations predominantly with distinct lineages of Oliveonia (Oliveoniaceae, Auriculariales), even in sympatric populations. Stable isotope analysis showed that both Dactylostalix species exhibited conflicting isotopic signals: elevated δ15N values, supporting partial mycoheterotrophy, but lower δ13C values compared to autotrophic plants, suggesting autotrophy. Peloton samples from D. ringens displayed only modest 13C enrichment relative to autotrophic references. These conflicting isotopic signals make it difficult to precisely determine whether both Dactylostalix species are autotrophic or partially mycoheterotrophic. Intriguingly, the 13C and 15N signatures of Dactylostalix species and their pelotons resemble those of many rhizoctonia‐associated orchids. This isotopic evidence implies a niche overlap with endophytic tendencies between rhizoctonias and Oliveonia, suggesting that potential endophytic traits may have facilitated the recruitment of Oliveonia as novel mycorrhizal partners. Furthermore, the mycorrhizal segregation between D. ringens and D. uniflora likely promotes their sympatric coexistence and may contribute to reproductive isolation through ecological specialization. Read the free Plain Language Summary for this article on the Journal blog.

Diaspore Dimorphism, Awn Hygroscopicity and Adaptive Significance in a Winter Annual Bromus tectorum (Poaceae).

Bromus tectorum, a winter annual plant, produces dimorphic diaspores: complex diaspores with multi-awns and simple diaspores with one awn. However, there is no information available about the role of awns and the germination characteristics of dimorphic diaspores. Dispersal germination and awns hygroscopicity of the dimorphic diaspores were assessed. The complex diaspore with multi-awns can easily be dispersed long distances from the mother plant by mammals. The simple diaspores with one awn are tightly attached to the mother plant. Caryopses from the two types of diaspores exhibited non-deep physiological dormancy at maturity, which can be released by dry storage and GA3 treatment. The awns have hygroscopic activity and can move in response to changes in moisture, moving the complex diaspore (the seed) into the soil. The seedling emergence from complex diaspores was significantly higher than those from simple diaspores at all burial depths. Germination of caryopses on the soil surface was poor. The optimal planting depth for both types of diaspores' emergence is 1-2 cm. The distinct characteristics of dimorphic diaspores and the beneficial influence of hygroscopic awns on dispersal, germination, and seedling establishment have significant ecological implications for B. tectorum's successful reproduction in unpredictable cold deserts.

Zinc oxide nanomaterials: Safeguarding food quality and sustainability.

In this era, where food safety and sustainability are paramount concerns, the utilization of zinc oxide (ZnO) nanoparticles (NPs) is a promising solution to enhance the safety, quality, and sustainability of food products. ZnO NPs in the food industry have evolved significantly over time, reflecting advancements in synthesizing methods, antimicrobial activities, and risk assessment considerations for human health and the environment. This comprehensive review delves into the historical trajectory, current applications, and prospects of ZnO NPs in food-related contexts. Synthesizing methods, ranging from solvothermal and solgel techniques to laser ablation and microfluidic reactors, have facilitated the production of ZnO NPs with tailored properties suited for diverse food applications. The remarkable antimicrobial activity of ZnO NPs against a wide spectrum of pathogens has garnered attention for their potential to enhance food safety and extend shelf-life. Furthermore, comprehensive risk assessment methodologies have been employed to evaluate the potential impacts of ZnO NPs on human health and the environment, regarding toxicity, migration, and ecological implications. By navigating the intricate interplay between synthesis methods, antimicrobial efficacy, inhibitory mechanisms, and risk assessment protocols, by elucidating the multifaceted role of ZnO NPs in shaping the past, present, and future of the food industry, this review offers valuable insights and promising avenues for researchers, policymakers, and industry stakeholders to enhance food safety, quality, and sustainability.

Fasciola hepatica and Fasciola hybrid form co-existence in yak from Tibet of China: application of rDNA internal transcribed spacer.

Fasciolosis is a parasitic disease affecting humans and livestock, caused by digenean trematodes of the genus Fasciola, primarily F. hepatica and F. gigantica. This study investigates the coexistence of these species and their hybrids in yaks from Tibet, China. We analyzed the nuclear rDNA internal transcribed spacer (ITS) regions, including ITS1 and ITS2, through Sanger sequencing and Next-Generation Sequencing (NGS) to assess single-nucleotide polymorphisms (SNPs). Our results reveal that one specimen (NM008B) is identical to pure F. hepatica, while another (NM008A) contains genetic information from both F. hepatica and F. gigantica, indicating potential hybridization or introgression. The morphological analysis reveals that the collected adult F. hepatica specimens exhibit distinct characteristics, while the hybrid specimens display "intermediate" features of F. hepatica and F. gigantica. This study is the first to document the coexistence of F. hepatica and hybrid Fasciola forms in a single yak. The findings underscore the complexities of hybridization dynamics and the necessity for advanced molecular techniques in accurately identifying Fasciola species. Future research should focus on mitochondrial DNA and other nuclear gene analysis to further elucidate the nature of these hybrids and their ecological implications.

Non-native palm affects arthropod communities and litter decomposition in an ongoing biome shift

The emergence of novel ecosystems, characterized by shifts in species composition and interactions, abiotic conditions and altered ecosystem functioning, is a major and inevitable challenge to contemporary ecosystem management. This study examines the ecological implications of Trachycarpus fortunei, a non-native evergreen palm, currently involved in a biome shift from deciduous temperate forest to evergreen laurophyllous forest in the Southern European Alps. Specifically, we investigated the effects of T. fortunei encroachment in peri-urban forests on flying and ground-dwelling arthropod communities as well as on leaf-litter decomposition. We found that the presence of T. fortunei altered arthropod community composition, mostly by reducing the number of herbivore species. This effect was likely driven by the lower quality of palm leaves as a food source compared to deciduous, dicotyledonous tree leaves and by a lower plant richness in the herb and shrub layer. Furthermore, we observed higher rates of leaf-litter decomposition associated with increasing abundance of young palm trees, which was not explained by predictors commonly associated with litter decomposition (i.e., detritivore abundance, litter depth and air temperature). Hence, the slow decay of palm leaves appears to be counterbalanced by the favourable conditions for litter decomposition within dense palm stands. Overall, our findings indicate that high densities of the non-native palm species (T. fortunei) impacts herbivore arthropod communities in the Southern European Alps, providing first evidence of possible effects on ecosystem functioning of this ongoing biome shift. These outcomes are integral components of the broader process of laurophyllisation in the study region, a phenomenon linked to climate warming and land use change, encompassing both native and non-native species.

Mercury speciation in environmental samples associated with artisanal small-scale gold mines using a novel solid-phase extraction approach to sample collection and preservation

In artisanal small-scale gold mines (ASGM), mercury (Hg) is known to pollute nearby river waters and sediments where it can be methylated to the highly bioavailable methylmercury (MeHg). The assessment of Hg speciation in water samples has been challenging for many years, with recommended procedures often not adequately allowing for analysis of samples in a suitable timeframe. Using a novel solid-phase extraction (SPE) method for sampling and preservation of Hg species, representative speciation data can be safely and easily collected and retained for up to 4-weeks (MeHg = 115 ± 8% refrigerated and 109 ± 13% unrefrigerated storage; Hg2+ = 100 ± 14% refrigerated and 94 ± 12% unrefrigerated storage). Concentrations of MeHg in environmental water samples and drinking water were below detection limit across two ASGM sites in western Kenya and concentrations of Hg2+ were below drinking water guidelines; however, drinking water sources contribute 20–30% of the tolerable weekly intake of Hg, indicating a need to minimise exposure of Hg from dietary sources to prevent Hg poisoning. Sediments from receiving rivers at ASGM sites showed total Hg concentrations above guideline limits (0.08–1.84 mg kg−1 total Hg) along the length of the river; however, MeHg concentrations fluctuated dependent on the stagnation of the river due to damns and ponds (5.9 ± 14.3 µg kg−1 MeHg). The findings show that SPE can be used as a robust sample collection and preservation approach for Hg speciation, which can better inform mitigation measures, understand ecological and human health implications, and improve environmental monitoring.