Search Results (100)

Species composition is an important indicator for the condition, functioning, and ecosystem service provision of salt marshes, making the mapping of species composition valuable for their management. Previous studies have demonstrated that the combined use of unoccupied aerial vehicle (UAV)-mounted multispectral cameras and machine learning (ML) can provide effective mapping of vegetation communities in these habitats. However, to date, these studies have predominantly focused on relatively species-poor salt marshes in North America. There has been no published testing of these combined UAV-ML methods in the salt marshes of northwestern Europe, which contain different often more diverse assemblages. Consequently, this study investigated whether applying recent methodological advances can accurately map National Vegetation Classification communities in three locations in the United Kingdom, each comprising two salt marsh sites, one established and one restored. Sites consisted of a mix of established and restored salt marshes of different ages, enabling a complementary assessment of how these methods perform in communities at different stages of development. The applied random forest ML models were found to produce highly accurate maps of salt marsh vegetation communities, with a mean overall accuracy of 94.7%. No relationship was found between the age of restoration sites and the accuracy of the classifications, showing these methods may be applied at a range of stages of community development and offer wider applicability for saltmarsh management and monitoring. The findings of this study demonstrate that advances in the combined use of drones and machine learning provide a readily transferrable method for mapping standardised vegetation communities in both established and restored northwestern European salt marshes and therefore likely other salt marshes globally. Consequently, this study demonstrates that both researchers and practitioners may confidently use these methods to create improved assessments of both marsh condition and function. Full article

The hypersaline soils of the Odiel Saltmarshes Natural Area in Southwest Spain harbor highly diverse microbial communities adapted to extreme conditions. However, their genomic diversity remains largely unexplored. In addition to high salinity, these soils are contaminated with heavy metals, creating a hostile environment of great interest for studying extremophilic microorganisms and their metabolic adaptations. This study aims to characterize the uncovered prokaryotic taxa as Candidatus species inhabiting the hypersaline soils of the Odiel Saltmarshes, based on their metagenomic assembled genomic sequences. The reconstructed genomes were assessed for quality based on completeness and contamination thresholds and subsequently taxonomically classified. Comparative genomic analysis of six high-quality MAGs revealed key metabolic traits related to survival under extreme salinity and heavy metal conditions. The findings provide new insights about microbial diversity of hypersaline environments and expand the catalog of known prokaryotic genomes. Detailed characterization of six novel Candidatus taxa highlights the unique adaptations of these microorganisms, enhancing our understanding of life in extreme habitats. Full article

Saltmarshes have emerged as important sinks for microplastic (MP) pollution, yet little is known about the long-term accumulation and retention mechanisms of MPs in these environments. This study presents the first chronological record of MPs in Mediterranean saltmarsh sediments, using sediment cores dated via a combination of AMS radiocarbon (¹⁴C) and radionuclide (²¹⁰Pb, ¹³⁷Cs, ²⁴¹Am) from two saltmarshes located on the Adriatic Sea coast of Croatia (Blace and Jadrtovac). MPs were extracted and analysed across core depths and assessed in relation to geochemical parameters (organic matter (OM), carbonates, organic carbon (C-org), total nitrogen (TN), phosphorus (P) forms’ content, and grain size distribution). Results show that MPs first appear in sediments dated to 1950 in Jadrtovac and post-1960 in Blace, with concentrations increasing markedly in more recent surface layers. Jadrtovac exhibited higher MP concentrations (up to 0.5 MPs g⁻¹), dominated by fibres (86%) associated with urban and maritime sources, while Blace showed lower concentrations, dominated by fragments (60%), likely from localised sources such as agriculture or single-use packaging. Polymer analysis confirmed contrasting source profiles, with rayon and cellophane dominating in Jadrtovac, and polypropylene and olefin in Blace. MPs positively correlated with OM, C-org, P, TN and sand content, and negatively with clay and carbonate content. Principal component analysis (PCA) confirmed that MPs were associated with organic-rich, sandy sediments. These findings demonstrate that OM composition and sediment texture significantly influence MP retention and highlight the role of saltmarshes as long-term archives of plastic pollution in low-energy coastal settings. Full article

Although the central focus of ecology has long been the relationship between biodiversity and ecosystem functioning, this relationship has rarely been explored in species-poor communities such as salt marshes, which have the potential to shed new light on this debate. We conducted two microcosm experiments, each testing a different environmental variable (salinity or disturbance) and its interaction with the plant community’s richness and species composition, using all possible combinations of the three sedge species found in the pioneer plant community in the Yangtze River Estuary. The relationships between diversity and productivity were weak and non-significant, possibly due to intense competition among the sedges. Species composition played a more important role in determining productivity. Moreover, biodiversity effects were found to be environment-dependent. Salinity stress increased the selection effect, while disturbance tended to increase both selection and complementarity effects. Interestingly, the correlation between biodiversity and stability was non-linear and presented different patterns in the salinity and disturbance experiments. Our results show that species-poor systems with low functional group diversity may exhibit weak relationships between biodiversity and ecosystem functioning during the establishment phase under controlled experimental conditions. In this ecosystem, species richness rarely impacted biomass, which was instead primarily driven by species composition and environmental conditions. Full article

The Sacred Ibis Threskiornis aethiopicus is an invasive alien species (IAS) that has become established in many European countries. Because of its invasive status and its frequent interactions with native species, understanding the behavioural tolerance of this species to human disturbance is relevant for both conservation and management. Here, we analysed Flight Initiation Distances (FID) of T. aethiopicus recorded between 2012 and 2025 across the northern Adriatic coast. The dataset (n = 72) included approaches on foot and by boat in six habitat types (artificial saltmarshes, farmlands, brackish ponds, freshwater wetlands, saltmarshes, tidal flats). Mean FID was 41 m (SD = ± 24); it was affected mainly by group size, whereas habitat, season and approach mode had no clear effect. A cross-species analysis of mean FID versus body mass indicated that, for its size, T. aethiopicus has a much shorter FID than expected from the allometric relationship observed in 20 other waterbirds species for which FID was also collected (n = 1505) at the same sites. The results suggest partial habituation to anthropized environments and a limited flight response compared to native species. These findings may support management actions aimed at monitoring and controlling the expansion of the species while mitigating disturbance to native assemblages. Full article

This essay highlights how, in lieu of a supportive community, Toni Morrison’s artistic daughter-protagonist, Sula, creates her own safe space within her liberated imagination through self-mothering. Thematic motifs of creative identity, the social role of the artist, and revolutionary self-care are relevant not only to Sula but to how Morrison herself conceived of transformative, safe spaces for Black women writers through her work as a writer and editor. In addition to discussing Sula, I briefly expound on Morrison’s novels, Beloved, Song of Solomon, Tar Baby, Paradise, and Bluest Eye, showing how audacious self-preservation undergirds the moral, political, and social dimensions of art, leading to personal and communal good. Reflecting on how Morrison flourished as a writer and editor after her divorce, while being the single parent to two young boys, I explicate Morrison’s understanding of motherwork as a complement to her artistic life, instructive of the ways in which carework, including self-care, helps artists and communities thrive. Morrison praised self-mothering in her unconventional artistic characters to reveal how female community and self-love are essential to sustain Black women artists. Full article

Coastal saltmarsh wetlands play a pivotal role in global carbon and nitrogen cycling, yet the vertical distribution characteristics of sediment carbon and nitrogen and their regulatory mechanisms remain uncertain. Microbial biomass carbon (MBC) and nitrogen (MBN) serve as critical indicators of ecosystem functioning, representing the most labile organic fractions that directly mediate biogeochemical processes in coastal wetlands. We investigated Yalu River Estuary coastal wetlands in the northern Yellow Sea. Sediment cores (0–100 cm depth) were collected and stratified into 20-cm intervals to analyse physicochemical properties and carbon–nitrogen indicators, enabling quantitative assessment of vertical distribution patterns and environmental drivers. The key findings are as follows: (1) Both microbial biomass carbon (MBC) and nitrogen (MBN) exhibited significant depth-dependent decreases, with MBC decreasing sharply by 45% (90.42 to 60.06 mg/kg) in the 40–60 cm layer and MBN decreasing by 50% (7.50 to 3.72 mg/kg) in the 80–100 cm layer. Total carbon (TC) peaked in the 40–60 cm layer (6.49 g/kg), whereas total nitrogen (TN) continuously decreased (from 0.51 (surface) to 0.24 g/kg (bottom)). (2) Depth-specific controls were identified: Surface layers (0–20 cm) were governed by tidal scouring (causing TC loss) and pH buffering; subsurface layers (20–40 cm) were constrained by moisture content (MC) and bulk density (BD), with partial mitigation by labile TC; and deeper layers (40–100 cm) were dominated by chemical factors exhibiting TN limitation and high electrical conductivity (EC). Understanding these microbial biomass dynamics is particularly crucial for predicting how coastal wetlands will respond to climate change and anthropogenic disturbances, as MBC and MBN serve as sensitive early-warning indicators of ecosystem health. Notably, MBC and MBN in northern Yellow Sea coastal wetlands are regulated primarily by physical—biological interactions in surface sediments and chemical stressors in deeper layers, providing crucial theoretical foundations for precise wetland carbon sink assessment and sustainable ecosystem management. Full article

This paper investigates whether carbon payments are sufficient to entice private landholders to invest in the rehabilitation and protection of coastal wetlands as a nature-based climate solution. Ecologically intact coastal wetlands, such as mangroves and saltmarshes, are capable of sequestering and storing large amounts of carbon. Reinstating ecological functionality of degraded coastal wetlands may be achieved by installing conservation fences that exclude hard-hoofed domestic and feral animals. This research integrates ecological, technical and economic data to ascertain whether conservation fencing could represent a financially viable investment for coastal landholders in the Australian context, if restored wetlands attracted carbon payments. Data gleaned through literature review and expert interviews about technical fencing requirements, contemporary costs and potential blue carbon income are consolidated into scenarios and tested using cost–benefit analysis. Payback periods are calculated using deterministic parameters. Risk-based cost–benefit analysis accounts for uncertainty of ecological and price parameters; it provides probability distributions of benefit–cost ratios assuming an expert-agreed economic lifespan of conservation fences. The results demonstrate that the payback period and benefit–cost ratio are highly sensitive to wetlands’ carbon sequestration capacity, fencing costs and the carbon price going forward. In general, carbon payments on their own are likely insufficient to entice private landholders to protect coastal wetlands through conservation fencing, except in circumstances where restored wetlands achieve high additional carbon sequestration rates. Policy measures that reduce up-front costs and risk and remuneration of multiple ecosystem services provided by restored wetlands are required to upscale blue carbon solutions using conservation fencing. The research findings bear relevance for other conservation and land-use contexts that use fencing to achieve sustainability goals and generate payments for ecosystem services. Full article

This study presents a comprehensive economic valuation of UK saltmarsh habitats, utilising a benefit transfer approach. The core of this research underscored the necessity for consistency in the selection of primary studies for meta-regression models (MRMs) to mitigate potential inaccuracies. A commodity-consistent, methodology-consistent meta-regression model was established based on the existing literature that only used the stated preference methods for saltmarsh valuation in the UK. This research is distinct in its concentration on UK-based studies, aiming to provide a valuation that is not only more reflective of the region-specific importance of these habitats but also contributes to the formulation of more informed policies. The results from the unweighted Ordinary Least Squares (OLS) model, which accounted for approximately 61% of the variance in LnWTPHA (logarithm of per hectare willingness to pay), were particularly revealing. These findings suggest a higher valuation for saltmarshes when a spectrum of benefits is presented for valuation purposes. Incorporating the economic valuation derived from this research, the estimated existence value of saltmarsh habitats in the UK stands at GBP 991 per hectare per year. These findings offer region-specific insights critical for formulating effective conservation strategies, emphasising balanced approaches that consider diverse saltmarsh sizes and socio-economic factors. The study’s UK-focused, consistent methodology and commodity and variable analysis provide policymakers and environmental managers with robust tools to ensure sustainable preservation of saltmarsh habitats. Full article

Marsh vegetation dampens wave energy, providing protection to coastal communities from storms. A new modeling framework was applied to study wave height evolution over the saltmarsh bordering Newbury, MA. A regional Delft3D hydrodynamic model generated wind driver waves in the open water portions of the study area, which were then one-way coupled with an analytical model, the Marsh Transect Wave Attenuation (MTWA) model, which tracked wave evolution along select transects throughout the marsh. Field observations of vegetation and wave height evolution were used to calibrate MTWA. Seven scenarios were run covering a range of possible future management and environmental conditions, in addition to projected sea level rise. Results underscore the importance of vegetation and elevation to wave attenuation. Full article

Sea level rise is an escalating threat to saltmarsh ecosystems as increased inundation can lead to decreased biomass, lowered productivity, and plant death. Another potential stressor is elevated nitrogen often brought into coastal regions via freshwater diversions. Nitrogen has a controversial impact on belowground biomass, potentially affecting saltmarsh stability. In this study, we examined the effects of inundation and nitrogen on common saltmarsh plants (Spartina alterniflora and Spartina patens) placed within two marsh organs (a collection of PVC pipes at different levels, the varied elevation levels expose the plants to different inundation amounts) located in the Pascagoula River, Mississippi, USA, with six rows and eight replicates in each row. We randomly fertilized four replicates in each row with 25 g/m² of NH4⁺-N every two-three weeks during the growing season in 2021 and 2022. We concurrently collected vegetative traits such as plant height and leaf count to better understand strategies saltmarshes utilize to maximize survival or growth. We harvested half of the vegetation in Year 1 and the remaining in Year 2 to evaluate the impact of inundation and nitrogen on above- and belowground biomass at different temporal scales. We developed Bayesian models that show inundation had a largely positive impact on S. alterniflora and a mostly negative impact S. patens, suggesting that S. alterniflora will adapt better to increasing inundation than S. patens. Additionally, fertilized plants from both species had higher aboveground biomass than non-fertilized plants for both years, with nitrogen addition only showing impact on belowground biomass in the long term. Our results highlight the importance of long-term study to facilitate more-informed restoration and conservation efforts in coastal wetlands while accounting for climate change and sea level rise. Full article

Haloarchaea, a group of extremophilic archaea, thrive in hypersaline environments characterized not only by high salinity but also by other extreme conditions, such as intense UV radiation, high osmotic pressure, heavy metal contamination, oxidative stress, and fluctuating temperatures. This study investigates the environmental adaptation strategies of species of two genera, Haloarcula and Natrinema, the second and third largest haloarchaeal genera, respectively, after Halorubrum. Comparative genomic analyses were conducted on 48 species from both genera to elucidate their genomic diversity, metabolic potential, and stress-tolerance mechanisms. The genomes revealed diverse metabolic pathways, including rhodopsin-mediated phototrophy, nitrogen assimilation, and thiamine biosynthesis, which support their survival and adaptation to extreme conditions. The analysis identified mechanisms for oxidative stress mitigation, DNA repair, “salt-in” and “salt-out” osmoregulatory strategies, adaptations to temperature shifts and heavy metal exposure, and immune defense. Experimental validation of four representative species, Haloarcula terrestris S1AR25-5A^T, Haloarcula saliterrae S1CR25-12^T, Haloarcula onubensis S3CR25-11^T, and Natrinema salsiterrestre S1CR25-10^T, isolated from the heavy-metal-rich hypersaline soils in the Odiel Saltmarshes (Huelva, Spain), demonstrated their tolerance, especially to arsenic, corroborating genomic predictions. This study advances our understanding of the resilience of haloarchaea under poly-extreme conditions and underscores their ecological significance and promise for biotechnological applications, such as the bioremediation of heavy-metal-polluted environments and the production of valuable biomolecules. Full article

The Fauzderhat coast of Chattogram (Bangladesh) is increasingly affected anthropogenic pressures, necessitating an understanding of its ecological conditions to inform effective ecosystem management. Despite this urgency, the local succession patterns and environmental impacts on macrobenthic communities remain poorly understood. This study examines the saltmarsh bed macrobenthos in Fauzderhat, documenting 81,724 individuals from 54 species. These include ten families and twenty-two species of annelids, ten and twelve species of arthropods, and ten and eleven species of mollusks, as well as six and nine species from different phyla. Seasonality showed significantly different patterns of changes, with the number of species and abundance peaking during the monsoon (53 species) and post-monsoon (21,969) conditions, respectively, and being lowest in the post-monsoon condition (39 species) and winter (18,265 individuals). Species richness, diversity, and evenness were significantly higher in monsoon and lower in post-monsoon conditions, with the differences being only significant in the former. Cluster analysis and line graphs indicated that average species abundance was lowest post-monsoon, increased through the winter and pre-monsoon conditions, then declined again during monsoon conditions. SIMPER analysis revealed the highest dissimilarity between pre-monsoon and post-monsoon conditions while winter and post-monsoon conditions showed the lowest dissimilarity of microbenthic assemblages. Correlation coefficients showed the macrobenthos were positively correlated with soil salinity, dissolved oxygen, and pH, while they were negatively correlated with sand, Inundation Period, and nutrients. CCA showed that monsoon conditions (higher water temperature, inundation period, and tidal height) created unfavorable environments for most species, except for several species. Conversely, winter favored species like M. oligobranchia. Post-monsoon nutrient levels increased stress, reducing species presence, while pre-monsoon conditions supported balanced diversity. Full article

Roots and rhizomes play diverse roles in the response of coastal wetland ecosystems to climate change through hydrobiogeomorphic and biogeochemical processes. The accumulation of living and dead belowground biomass contributes significantly to surface elevation gain, redox status through root oxygen loss and exudates, and plant transport of greenhouse gases to the atmosphere. Yet, responses of belowground biomass to global climate stressors are difficult to measure and remain poorly understood. Here, we report on the response of individual components of belowground biomass to 12 years of CO₂ enrichment in a temperate tidal marsh. In both a community initially dominated by the C₃ species Schoenoplectus americanus and another initially dominated by the C₄ species Spartina patens, elevated CO₂ increased total belowground biomass and subtly altered depth distributions of some components. In the Spartina community, this effect was the result of the direct effects of CO₂ on plant biomass allocation, while any direct response in the Schoenoplectus community was difficult to detect because of changes in the relative abundance of C₃ versus C₄ species. In the Schoenoplectus community, belowground biomass was positively related to S. americanus stem density. Compared to the C₄ community, the Schoenoplectus community had higher root and rhizome biomass and deeper rhizomes. These results highlight the importance of community composition and plant functional traits in understanding ecosystem- and community-scale responses to elevated CO₂ and their potential impacts on marsh elevation. Full article

The study of marine and terrestrial palynomorphs in fluviomarine environments has been successfully used in combination with different geophysical approaches to understand high-resolution relative sea-level oscillations and to reconstruct the environmental changes affecting estuaries and adjacent inland ecosystems. However, erosion during the postglacial marine transgression frequently causes sedimentary discontinuities or may lead to the redeposition of ancient upland sediments, including secondary, recycled and rebedded pollen. Therefore, a robust seismic and chronological control of the sedimentary facies is essential. In addition, studies of modern pollen sedimentation and its relationship to contemporaneous vegetation are valuable for obtaining a more realistic interpretation of the sedimentary evidence. To explore the significance of the experimental evidence obtained and to support the interpretation of sedimentary records from the same basin, we analysed a large set of modern pollen data from the Ría de Vigo (NW Iberia). The pollen samples derived from different sedimentary environments were compared with the local and regional vegetation cover. Pollen evidence from the various limnetic systems studied allows the identification of major vegetation types in the basin. However, in all the cases, the reconstructed relative pollen contributions of each vegetation unit are often distorted by the overrepresentation of certain anemophilous pollen types, the underrepresentation of some entomophilous species, and the specific taphonomy of each site of sedimentation. The ability of the seabed pollen evidence to represent the modern deciduous and alluvial forests, as well as the saltmarsh vegetation onshore, increases in the shallowest points of the ria (shallower than −10 m). Conversely, pastures and crops are better represented at intermediate depths (shallower than −30 m), while scrubland vegetation is better represented in samples at more than 20 m below modern sea level. It is concluded that shallow seabed pollen can provide information on the main elements of the modern vegetation cover of the emerged basin, including the main elements of the vegetation cover. However, the selection of the most suitable subtidal sites for coring, combined with pollen data from several environmental contexts, is critical for achieving an accurate reconstruction of the changing conditions of the emerged basin over time. Full article