Key Species Research Articles

Parasites disrupt a keystone mutualism that underpins the structure, functioning, and resilience of a coastal ecosystem

AbstractParasites can alter the traits or densities of mutualistic partners, potentially destabilizing mutualistic associations that underpin the structure, functioning, and stability of entire ecosystems. Despite the potentially wide‐ranging consequences of such disruptions, no studies have directly manipulated parasite prevalence and/or intensity in a mutualistic partner, nor quantified the resulting community‐level effects. Here, we investigated the effects of a common trematode parasite (Cercaria opaca) on the strength of a keystone facultative mutualism in western Atlantic salt marshes between the foundational marsh cordgrass, Spartina alterniflora, and the ribbed mussel, Geukensia demissa. Cordgrass increases mussel survivorship and growth through shading, while mussels enhance cordgrass growth by producing nutrient‐rich biodeposits. This mutualistic association also creates conditions that enhance biodiversity and ecosystem functioning, and mediates the ability of foundational plants to resist and recover from extreme drought. We used lab and field assays to show how increasing infection with trematode metacercariae negatively influenced mussel biodeposit production, as well as the strength of mussel shells and byssal attachments. By conducting a field manipulation using experimentally infected mussels, we demonstrated that the mutualistic benefits of mussels to cordgrass growth decreased with increasing trematode infection intensity—a pattern likely generated by reduced mussel biodeposition and enhanced mortality. Additionally, increasing parasite loads in mussels led to predictable decreases in the abundances of benthic invertebrates, as well as in key ecosystem characteristics and process rates (i.e., redox potential and sediment accretion). Finally, a survey of five North Carolina salt marshes demonstrated that infection with C. opaca was most common in mussels in areas experiencing cordgrass die‐off due to drought, and that infection intensity decreased with distance from die‐off areas. Because the mussel–cordgrass mutualism underpins marsh ecosystem resilience to drought‐associated die‐off, our results suggest that parasitism may depress recovery from these disturbances. Although this is the first experimental demonstration of parasites indirectly altering community structure and functioning by undermining an ecologically influential mutualism, this type of relationship could be common in nature, given that parasites frequently infect influential mutualists.

Climatic and disturbances influence on tree-rings of Larix gmelinii in the southeast coastal area

The vast region of North East Asia is covered by primary mixed conifer-broadleaved forests which include a range of different tree species. A key factor in the dynamics of these ecosystems is wind disturbance. According to reports, this factor will be increasingly important as a result of the poleward migration of tropical cyclones, a characteristic of which is strong wind. At the same time, global climate change may reduce the recovery potency of some species and lead to new combinations of species. Gmelin Larch is one of the key early succession species in the north of the region. In the southeastern part of its range (Russian Far East), this species has not been widely studied by dendroclimatologists and there are no dendroecological studies available. This study shows how the seasonal growth of Larix gmelinii responds to changes in climate, specifically to variations in precipitation and temperature. The study has established that these trees are more affected by rising temperatures than by consistent precipitation levels, provided there is no shortage of water. Interestingly, after the 1970s there was a change in the climate sensitivity of Larix gmelinii in June (the month with the strongest correlation). It went from a negative correlation with temperature to a positive correlation with precipitation. By using tree ring data, we were able to reconstruct the past history of forest disturbance. The peaks in this chronology coincide with those in earlier published dendroecological reconstructions for other species. They indicate that the radial growth of larch is sensitive to canopy changes. We recorded two release peaks in the 1960s and 2000s, during the period of meteorological observations. We attributed the first peak to the most powerful tropical cyclone Emma (1956). We assume also that the second peak reflects the recent intensification of tropical cyclones in the region. In our opinion, the change in microclimate as a result of disturbance has altered the relationship to climate in such a way that disturbance may cause tree growth to be dependent on precipitation. At the same time, such low correlations do not support a conclusion about the strong negative influence of the current climate on the trees.

Addressing offshore wind farms compatibilities and conflicts with marine conservation through the application of modelled benchmarking scenarios

Offshore wind power generation structures are scheduled for development in the Canary Islands, potentially resulting in spatial overlap with various maritime activities, particularly fishing. It is crucial to point out that some areas that are considered suitable for installing these structures are in protected zones that are part of the Natura 2000 network, and do not have any prior environmental impact assessments. The research delved into the efficacy of utilizing Ecopath with Ecosim software to examine the consequences of implementing this technology in the study area, employing an ecosystem-based approach. To address this question, simulations were executed by assessing three distinct scenarios. The results suggest that there would be changes in the distribution of keystone species such as top predators, alongside a conspicuous decline in the abundance and catches of target species of the fishery. The Ecospace model holds the potential to forecast the impacts of offshore wind installations; however, crucial factors must be carefully considered, such as the lack of information. Notwithstanding the constraints, research like this demonstrates the efficacy of spatial ecosystem modelling in exploring this issue.

Specialists regulate microbial network and community assembly in subtropical seagrass sediments under differing land use conditions

Microorganisms in the sediment play a pivotal role in the functioning and stability of seagrass ecosystems and their dynamics are influenced by the nutrient acquisition strategies of host plants. While the distinct impacts of microbial generalists and specialists on community dynamics are recognized, their distribution patterns and ecological roles within seagrass ecosystems remain largely unexplored. To address this issue, we conducted an analysis of community assembly processes and co-occurrence relationships of both microbial generalists and specialists within sediment profiles (0–100 cm) from seagrass habitats subjected to differing land use conditions. The results revealed that seagrasses in Yifeng Estuary experienced the large proportion of cultivated land and exhibited higher organic carbon content in the 0–20 cm surface sediment layer. Nitrogen-cycling bacteria were predominantly associated with seagrasses from Yifeng Estuary, whereas Vibrio spp. was more prevalent in seagrasses from Liusha Bay. Notably, seagrass Halophia beccarii (YHB) in Yifeng Estuary harbored higher niche breadths for both microbial generalist and specialist compared to Halodule uninervis (LHU) and Halophia ovalis (LHO) from Liusha Bay. Stochastic processes were pivotal in shaping seagrass sediment microbial communities, with a higher immigration rate observed in YHB, suggesting greater microbial turnover in this area. Additionally, YHB sediment presented lower drift and higher dispersal limitation among generalists compared to LHU and LHO, whereas the pattern was reversed among specialists. Specialists were found to play a crucial role in shaping microbial interactions within YHB sediment, with genera Halioglobus identified as keystone species in the network. The specialists were further found to significantly influence microbial β-diversity in seagrass sediment directly. Overall, our findings illustrated how microbial generalists and specialists were distributed in seagrass sediments in response to land use changes and provided new insights into the potential roles of microbial regulation in degraded seagrass ecosystems.

Carbohydrate accumulation patterns in mangrove and halophytic plant species under seasonal variation

This study investigates the impact of carbohydrate accumulation in mangrove and halophytic plants on their response to abiotic stress. Using soil analysis and FT-IR spectroscopy, key species (Sueda nudiflora, Aeluropus lagopoides, Avicennia marina) were examined for seasonal changes in sugar content (reducing sugars, total soluble sugars, starch). The elevated carbohydrate levels may serve as an indication of the plant’s ability to adapt to different environmental conditions throughout the year. This accumulation enables plants to adapt to variations in their environment, assuring their survival and functionality during periods of environmental fluctuation. Halophytic plants’ sugar content peaked during the monsoon, suggesting biotic adaptations. The mangrove Avicennia marina had year-round sugar levels. PCA and Hierarchical Cluster Analysis revealed sugar accumulation trends across species and seasons. Partial Least Squares (PLS) analysis revealed correlations between soil characteristics and sugar content, suggesting plant-microbe interactions. K-means clustering and correlation analysis of FT-IR data revealed sugar composition and resource allocation trade-offs. These findings shed light on the role of carbohydrate metabolism in enabling coastal plants to endure stress. Gaining insight into these mechanisms can enhance sustainable agriculture in challenging environments and shed light on plant adaptations to evolving environmental conditions, especially biotic interactions.

Mediterranean octocoral populations exposed to marine heatwaves are less resilient to disturbances.

The effects of climate change are now more pervasive than ever. Marine ecosystems have been particularly impacted by climate change, with marine heatwaves (MHWs) being a strong driver of mass mortality events. Even in the most optimistic greenhouse gas emission scenarios, MHWs will continue to increase in frequency, intensity and duration. For this reason, understanding the resilience of marine species to the increase of MHWs is crucial to predicting their viability under future climatic conditions. In this study, we explored the consequences of MHWs on the resilience (the ability of a population to resist and recover after a disturbance) of a Mediterranean key octocoral species, Paramuricea clavata, to further disturbances to their population structure. To quantify P. clavata's capacity to resist and recover from future disturbances, we used demographic information collected from 1999 to 2022, from two different sites in the NW Mediterranean Sea to calculate the transient dynamics of their populations. Our results showed that the differences in the dynamics of populations exposed and those not exposed to MHWs were driven mostly by differences in mean survivorship and growth. We also showed that after MHWs P. clavata populations had lower resistance and slower rates of recovery than those not exposed to MHWs. Populations exposed to MHWs had lower resistance elasticity to most demographic processes compared to unexposed populations. In contrast, the only demographic process showing some differences when comparing the speed of recovery elasticity values between populations exposed and unexposed to MHWs was stasis. Finally, under scenarios of increasing frequency of MHWs, the extinction of P. clavata populations will accelerate and their capacity to resist and recover after further disturbances will be hampered. Overall, these findings confirm that future climatic conditions will make octocoral populations even more vulnerable to further disturbances. These results highlight the importance of limiting local impacts on marine ecosystems to dampen the consequences of climate change.

The latest Carboniferous-earliest Permian palynological assemblage from the Sauce Grande Formation, Claromecó Basin, Argentina: Implications for the local palynostratigraphic scheme and correlations in Western Gondwana

The Sauce Grande Formation of the Ventania System and Claromecó Basin, east-central Argentina, is a geological unit of glaciomarine origin showing evidence of the glaciation that affected the supercontinent of Gondwana during the late Paleozoic. The age of this unit was previously determined from scarce and poorly preserved fossils, but mainly from radiometric dating and the fossil content of the overlying geological units. This study presents a palynological assemblage obtained from the Sauce Grande Formation in the PANG 0002 borehole, drilled in the Upper Paleozoic Claromecó Basin. Based on the identification of key species, such as Converrucosisporites confluens, Pakhapites ovatus, P. fusus, Vittatina spp., and Weylandites magmus, an age no older than Gzhelian is inferred for the interval studied. The inferred age allows us to relate the glaciomarine deposits of the Sauce Grande Formation to the last episode of the late Paleozoic Ice Age. The palynological assemblage of the Sauce Grande Formation is correlated with the Converrucosisporites confluens-Vittatina vittifera (CV) Biozone of the Claromecó Basin. Based on updated information and new correlations of the CV Biozone with palynostratigraphic schemes established in neighboring basins (Chacoparaná, Paraná, and central-western Argentina), its age is adjusted to the Gzhelian-late Artinskian interval, encompassing the Carboniferous-Permian boundary. This new information contributes to refining the current biostratigraphic scheme of the late Paleozoic Claromecó Basin.

Rare bacterial and fungal taxa respond strongly to combined inorganic and organic fertilization under short-term conditions

Soil microbial communities play a crucial role in driving multiple ecosystem functions. Although numerous studies have investigated the effects of fertilization on the entire soil microbial community, the responses of abundant (relative abundance ≥ 1 % in all samples, or ≥ 1 % in some samples but never < 0.01 % in any samples) and rare (relative abundance < 0.01% in all samples, or < 0.01% in some samples but never≥ 1% in any samples) microbial taxa, as along with their relative contributions to ecosystem functions in agricultural soils under combined organic and inorganic fertilization, have been less explored. Here, a field experiment revealed that rare bacterial and fungal taxa were more sensitive to short-term fertilization than abundant taxa. The combined application of inorganic and organic fertilizers maintained the alpha-diversity of rare bacterial taxa and enhanced the alpha-diversity of rare fungal taxa. The significant impact of fertilization on the bacterial community was primarily induced by alterations in soil pH (decreased from 6.01 to 5.46), total phosphorus (0.32 – 0.37 g/kg), available phosphorus (1.24 – 4.76 mg/kg), and available potassium (41.11 – 58.78 mg/kg), whereas the fungal community was less influenced by fertilization. The dissimilarity of both abundant (Mantel r = 0.38, P = 0.001) and rare (Mantel r = 0.26, P = 0.014) bacterial taxa exhibited positive relationships with ecosystem multifunctionality. Additionally, ecosystem multifunctionality was positively associated with the relative abundance of specific genera and keystone species, particularly rare bacterial taxa (e.g., Melioribacter, Aquisphaera, Sunxiuqinia, Methylobacterium, and Thermosporothrix), the abundant fungal genus Achroiostachys, and rare fungal taxa (e.g., Paraphelidium, Pseudallescheria, Scutellinia, Niesslia, Tilletia, Coprinopsis, Poaceascoma, Entrophospora sp., Acremonium persicinum, Hydropisphaera erubescens, and Rozellomycota sp.) (ρ = 0.52–0.75, P < 0.05). A partial least-squares path model indicated that soil nutrients (path coefficient = 0.83, p = 0.001) and microbial beta-diversity (path coefficient = 0.18, p = 0.049) exerted primary direct and positive effects on ecosystem multifunctionality, with soil nutrients also indirectly influencing ecosystem multifunctionality through microbial beta-diversity. Collectively, these findings underscore the significant response of rare, rather than abundant, microbial taxa and their contributions to ecosystem multifunctionality. This highlights the potential of appropriately combined inorganic and organic fertilizers, which promote rare microbial taxa, to enhance the multifunctionality of agricultural ecosystems.

The Fate of a Polygenic Phenotype Within the Genomic Landscapes of Introgression in the European Seabass Hybrid Zone.

Unraveling the evolutionary mechanisms and consequences of hybridization is a major concern in biology. Many studies have documented the interplay between recombination and selection in modulating the genomic landscape of introgression, but few have considered how associations with phenotype may affect this landscape. Here, we use the European seabass (Dicentrarchus labrax), a key species in marine aquaculture that undergoes natural hybridization, to determine how selection on phenotype modulates the introgression landscape between Atlantic and Mediterranean lineages. We use a high-density single nucleotide polymorphism array to assess individual local ancestry along the genome and improve the mapping of muscle fat content, a polygenic trait that is divergent between lineages. Taking into account variation in recombination rates, we reveal a purging of Atlantic ancestry in the admixed Mediterranean populations. While Atlantic individuals had higher muscle fat content, we observed that genomic regions associated with this trait in Mediterranean populations displayed reduced introgression of Atlantic ancestry. These results emphasize how selection against maladapted alleles shapes the genomic landscape of introgression.

Thermophilic Hemicellulases Secreted by Microbial Consortia Selected from an Anaerobic Digester.

The rise of agro-industrial activities over recent decades has exponentially increased lignocellulose biomasses (LCB) production. LCB serves as a cost-effective source for fermentable sugars and other renewable chemicals. This study explores the use of microbial consortia, particularly thermophilic consortia, for LCB deconstruction. Thermophiles produce stable enzymes that retain activity under industrial conditions, presenting a promising approach for LCB conversion. This research focused on two microbial consortia (i.e., microbiomes) that were analyzed for enzyme production using a cheap medium, i.e., a mixture of spent mushroom substrate (SMS) and digestate. The secreted xylanolytic enzymes were characterized in terms of temperature and pH optima, thermal stability, and hydrolysis products from LCB-derived polysaccharides. These enzymes showed optimal activity aligning with common biorefinery conditions and outperformed a formulated enzyme mixture in thermostability tests in the digestate. Phylogenetic and genomic analyses highlighted the genetic diversity and metabolic potential of these microbiomes. Bacillus licheniformis was identified as a key species, with two distinct strains contributing to enzyme production. The presence of specific glycoside hydrolases involved in the cellulose and hemicellulose degradation underscores these consortia's capacity for efficient LCB conversion. These findings highlight the potential of thermophilic microbiomes, isolated from an industrial environment, as a robust source of robust enzymes, paving the way for more sustainable and cost-effective bioconversion processes in biofuel and biochemical production and other biotechnological applications.

Visible-light-driven Z-scheme ZnTe/WO3 heterojunction for simultaneous elimination of tetracycline and Cu(II)

Z-Scheme heterojunction photocatalysts can effectively suppress the recombination of charge carriers while maintaining high redox capacity. In this study, ZnTe/WO3 (ZW) Z-scheme heterojunction photocatalysts were synthesized using a hydrothermal method, and a series of photocatalytic materials were prepared for the simultaneous removal of tetracycline (TC) and Cu(II) from water. The physicochemical and photoelectrochemical properties of the catalytic materials were characterized through various methods, including SEM, XRD, XPS, and others. The experimental results indicate that the ZW-10 % composite material exhibits the most significant removal efficiency for pollutants. Within 150 min of visible light irradiation, the removal rates for TC and Cu(II) reach 73.8 % and 73.3 %, respectively, representing a substantial improvement compared to individual ZnTe and WO3. Free radical capture experiments and electron spin resonance analysis reveal that ·O2− and ·OH are the key reactive species responsible for TC oxidation, while electrons (e−) dominate the reduction of Cu(II).

Pathology of tissue loss in three key gorgonian species in the Mediterranean Sea

The Mediterranean is known for its marine biodiversity, especially gorgonian forests. Unfortunately, these are experiencing rapid declines due to climate change, manifested by repeated marine heat waves resulting in mass mortality events since the early 1990 s. To better understand why gorgonians are declining, more systematic approaches to investigate the exact causes are needed, and pathology may aid in this goal.We described gross and microscopic pathology of tissue loss in three key gorgonian species in the Mediterranean region, Paramuricea clavata, Eunicella cavolini, and Leptogorgia sarmentosa, that were all experiencing various degrees of acute to subacute tissue loss characterized by exposed axial skeleton sometimes partly colonized by epibionts and thinning of adjacent tissues. The most significant variety of lesions was seen in P. clavata followed by L. sarmentosa and E. cavolini. For all species, dissociation of gastrodermal cells was the dominant microscopic lesion followed by necrosis of the gastrodermis. Ciliates invading gastrodermis and associated with necrosis of polyps were seen only in E. cavolini. Epidermal tissue loss was seen only in L. sarmentosa, while P. clavata was distinguished by a prominent inflammatory response and unidentified dark round structures within the tentacle epidermis and gastrodermis with no host response. Further work to understand the cause of death in gorgonians is needed, particularly to elucidate the role of ciliates and environmental co-factors or infectious agents not visible on light microscopy, as well as applications of additional tools such as cytology.

Site-based climate-smart tree species selection for forestation under climate change

Global climate change threatens ecosystem functions and resilience, prompting large-scale planting initiatives to mitigate its impacts. To ensure new plantations are adaptive to future climates, it is crucial to consider climate mismatches resulting from climate change when selecting tree species. However, current research is all species-based, which is not effective for species selection across species at specific plantation sites. Our research developed a novel site-based approach that can identify optimal tree species for specific planting sites under projected future climates. We evaluated the feasibility and effectiveness of this method across 10 representative sites in diverse climatic zones in China based on climate niche projections for 100 key tree species. Our findings demonstrated the necessity and effectiveness of this approach, which can select a suit of suitable tree species tailored for any potential planting site across China under different climate change scenarios. For instance, at Tibet Dongjiu Forest farm, Aibes densa and Quercus pannosa currently showed high suitability scores above 0.8 (on a scale of 0–1). However, by the 2080s, Aibes densa's suitability was projected to drop to 0.25, while Quercus pannosa was expected to maintain its suitability. Conversely, Quercus aquifolioides currently had a low suitability of 0.08, but it was projected to increase to 0.74 by the 2080s. These findings demonstrate the importance of using this approach to avoid selecting the wrong species or overlooking potentially suitable species. In addition, our simulation analysis suggests that a dataset of 40–50 species is necessary to ensure that most planting sites can identify 2–3 suitable species. This advancement significantly enhances the precision and effectiveness of tree species selection strategies for local practitioners, offering vital insights for forestry, conservation, and ecological restoration projects. These results highlight the tremendous potential and practical applicability of our site-based approach in enhancing forestry adaptation and ecological functions in response to global climate change.

Role of CD34 in calcification of human aortic valve interstitial cells from patients with aortic valve stenosis

Various osteogenic factors are involved in ectopic human aortic valve calcification; however, the key cell species involved in calcification remains unclear. In a previous study, we reported that mesenchymal stem (CD73, 90, 105) and endothelial (VEGFR2) cell markers are positive in almost all human aortic valve interstitial cells (HAVICs) obtained from a patient with calcified aortic valve stenosis (CAVS). Further, CD34-negative HAVICs are highly sensitive to calcification stimulations. Here, we aimed to pathophysiologically clarify the role of CD34 in HAVICs obtained from individual patients with severe CAVS. A DNA microarray between CD34-positive and CD34-negative HAVICs, separated by fluorescence-activated cell sorting, indicated that tenascin X (TNX) mRNA expression significantly decreased in CD34-negative cells. Furthermore, the inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β significantly downregulated CD34 expression in HAVICs. TGF-β, a key cytokine of endothelial-mesenchymal transition, did not affect HAVIC calcification. CD34 overexpression strongly inhibited TNF-α- and IL-1β-induced calcification and maintained TNX mRNA expression. These results suggest one possibility that CD34 is an inhibitory regulator of valve calcification. Furthermore, TNF-α- and IL-1β-induced CD34 downregulation in HAVICs contributes to HAVIC calcification by downregulating TNX protein expression.

Depositional environment and stratigraphic framework of the NS- 1 well, Coastal Swamp Depobelt, Niger Delta Basin: a foraminiferal perspective

A comprehensive analysis of 102 ditch-cutting samples from the NS-1 well in Leuma Field, Coastal Swamp Depobelt, Niger Delta Basin, covering depths from 4730 ft to 7790 ft, is presented. Lithologic descriptions revealed eleven lithostratigraphic sub-units within the transitional-paralic sequence of the Agbada Formation, comprising alternating sandstone and shale. The foraminiferal analysis identified 58 species: 14 planktonic, 26 calcareous benthic and 18 agglutinated benthic. Key planktonic index species such as Globigerinoides sp. and Globorotaliacontinuosa indicates a Middle to Late Miocene age. The biozonation correlates with the Blow (1969) Scheme (N7- N9/N10/N11) placing the intervals within the Middle Miocene to Late Miocene epochs. The depositional environment transitioned from Coastal Deltaic to Inner Neritic and Middle Neritic, suggesting a shallow marine setting influenced by a warm, humid climate. The presence of calcareous foraminifera supports a shallow marine deposition above the carbonate compensation depth. This study provides valuable insights into the sedimentological, stratigraphic, and paleoenvironmental history of the NS-1 well during the Miocene.

Development of germline progenitors in larval queen honeybee ovaries.

Honeybees (Apis mellifera) are a keystone species for managed pollination and the production of hive products. Eusociality in honeybees leads to much of the reproduction in a hive driven by the queen. Queen bees have two large active ovaries that can produce large numbers of eggs if conditions are appropriate. These ovaries are also active throughout the long lives of these insects, up to 5 years in some cases. Recent studies have indicated that the germline precursors of the adult honeybee queen ovary are organized into 8-cell clusters, joined together by a polyfusome; a cytoplasmic bridge. To understand the origin of these clusters, and trace the development of the honeybee queen ovary, we examined the cell types and regionalization of the developing larval and pupal queen ovaries. We used established (nanos and castor), and novel (odd skipped) gene expression markers to determine regions of the developing ovary. Primordial germline cells develop in the honeybee embryo and are organized into ovary structures before the embryo hatches. The ovary is regionalized by larval stage 3 into terminal filaments and germaria. At this stage, clusters of germline cells in the germaria are joined by fusomes and are dividing synchronously. The origin of the 8-cell clusters in the adult germarium is therefore during larval stages. On emergence, the queen ovary has terminal filaments and germaria but has not yet developed any vitellaria, which are produced after the queen embarks on a nuptial flight. The lack of germaria, and the storing of germline progenitors as clusters, may be adaptions for queen bees to endure the metabolic demands of a nuptial flight, as well as rapidly lay large numbers of eggs to establish a hive.

Diversity pattern of Symplocos tree species in China under climate change scenarios: Toward conservation planning

Symplocos, a genus rich in endemic and keystone species in China's subtropical forests, plays a vital role in maintaining biodiversity. Climate change impacts on Symplocos trees affect ecosystem composition, dynamics, and functions. This study delves into the potential ramifications of climate change on the distribution and richness of Symplocos species across China under different climatic conditions. A comprehensive analysis was conducted using occurrence records of 29 species of Symplocos, focusing on habitat suitability modeling and spatial analysis, to demonstrate the possible effects of climate change on the distribution and diversity patterns of Symplocos species in China. Environmental data, including bioclimatic variables, were collected, and the future climate scenarios were projected using the combined average of the two global climate models. Four modeling algorithms were applied in an ensemble species distribution models to assess the distribution of Symplocos species and decipher the pattern of species richness and endemism. The results indicate high accuracy and performance of the models with a mean AUC of 0.94 and TSS of 0.77, particularly the random forest. The analysis identified key bioclimatic variables influencing Symplocos species distribution, with precipitation patterns (precipitation of driest month and precipitation of warmest quarter) and temperature variability (temperature mean diurnal range) playing significant roles. Predictions suggest a reduction in Symplocos species richness over the next six decades, particularly in southern and southwestern China, with potential gains in other regions. Overall, this study highlights the vulnerability of Symplocos species to climate change and underscores the importance of proactive conservation efforts and forest plantations to mitigate future loss in Symplocos species diversity.

Estimating common whelk (Buccinum undatum) abundance using baited remote underwater video (BRUV)

Abstract Baited static gear fisheries targeting benthic invertebrates have expanded at a global scale. While improvements have been made in the monitoring and management of these fisheries, reliable survey methods for stock assessments of many key species are lacking. In this study we examine the viability of a baited remote underwater video (BRUV) system for obtaining abundance indices for a data-limited stock (common whelk, Buccinum undatum), and compare this method to catch per unit effort (CPUE) from commercial fishing. BRUVs capable of collecting 15 hours of timelapse footage were deployed on pot strings in two distinct whelk fishing sites, with replication over a spring-neap tidal cycle. Three potential BRUV metrics—the maximum (MaxN) and mean (MeanN) abundance and time of first arrival (T1)—were calculated for each deployment, and significant linear relationships were identified between MaxN, MeanN, and CPUE across sites. Temporal variability in BRUV indices driven by tidal dynamics was minimal, although results suggest high current speeds may reduce abundance estimates, and a potential method for predicting density on the seabed using arrival rates is also demonstrated. BRUVs are a valuable tool in developing stock assessment surveys for static gear fisheries.

In Situ Fourier Transform Infrared Investigation on the Low-Level Carbon Dioxide Conversion over a Nickel/Titanium Dioxide Catalyst.

Efficiently converting atmospheric carbon dioxide (CO2) is crucial for sustainable human development. In this study, we conducted systematic in situ Fourier transform infrared tests to examine how hydrogen (H2) partial pressure affects the conversion of low-level CO2 (around 400 ppm) using nickel/titanium dioxide (Ni/TiO2). Results show that increasing H2 partial pressure significantly increases surface monodentate formate species, leading to enhanced methane (CH4) production at both 250 and 400 °C. Conversely, on Ni's surface, the key species are formyls and bidentate formate at 250 °C, but these decrease significantly at 400 °C. These findings indicate that low-level CO2 is more easily converted to CH4 over Ni/TiO2 than Ni, regardless of temperature. Additionally, the strong Ni-TiO2 interaction gives Ni/TiO2 an advantage in converting low CO2 concentrations, with excellent durability even at 400 °C. This study enhances our understanding of direct CO2 conversion and aids in the development of advanced CO2 emission reduction technologies.

Cocatalyst Embedded Ce-BDC-CeO2 S-Scheme Heterojunction Hollowed-Out Octahedrons With Rich Defects for Efficient CO2 Photoreduction.

Constructing heterojunction photocatalysts with optimized architecture and components is an effective strategy for enhancing CO2 photoreduction by promoting photogenerated carrier separation, visible light absorption, and CO2 adsorption. Herein, defect-rich photocatalysts (Ni2P@Ce-BDC-CeO2 HOOs) with S-scheme heterojunction and hollowed-out octahedral architecture are prepared by decomposing Ce-BDC octahedrons embedded with Ni2P nanoparticles and subsequent lactic acid etching for CO2 photoreduction. The hollowed-out octahedral architecture with multistage pores (micropores, mesopores, and macropores) and oxygen vacancy defects are simultaneously produced during the preparation process. The S-scheme heterojunction boosts the quick transfer and separation of photoinduced charges. The formed hollowed-out multi-stage pore structure is favorable for the adsorption and diffusion of CO2 molecules and gaseous products. As expected, the optimized photocatalyst exhibits excellent performance, producing CO with a yield of 61.6µmolh-1g-1, which is four times higher than that of the original Ce-BDC octahedrons. The X-ray photoelectron spectroscopy, scanning Kelvin probe, and electron spin resonance spectroscopy characterizations confirm the S-schematic charge-transfer route. The key intermediate species during the CO2 photoreduction process are detected by in situ Fourier transform infrared spectroscopy to support the proposed mechanism for CO2 photoreduction. This work presents a synthetic strategy for excellent catalysts with potential prospects in photocatalytic applications.