Northern Sites Research Articles

Deep north atlantic circulation strength: Glacial-interglacial variability over the last 400,000 years

Most of the high-resolution studies investigating the past variability of the deep North Atlantic circulation are focused on recent timescales, but little is known for periods older than the last glacial period. Based on magnetic, elemental and physical grain-size proxies of three pairs of sediment cores located South of Iceland, we reconstructed the past changes in grain-size and basaltic-derived grain concentration over the last 400 ka (1 ka = 1000 years). The source and grain-size proxies exhibit highly similar variations between the three sites, suggesting they are affected by the same regional process. Persistently lower concentrations and finer grain-sizes recorded in the southernmost and deeper site compared to the northern sites indicate a North to South gradient that is consistent with the southward transport of sediments from a northern basaltic source by a deep current. Therefore, we interpret changes recorded by the ensemble of proxies at the three sites as past variations in the ISOW intensity. These new results show persistent influence, over the entire 400 ka, of a southward deep-water flow in the subpolar North Atlantic, from 1800 to 2800 m water depth. The “off mode” of deep Atlantic circulation during Heinrich events suggested by many studies is therefore questioned. This study extends the previous observations made for the 20–65 ka period over the last 400 ka. Our results also show that the three studied sites are bathed by a deep-water mass formed in the Nordic Seas, during both glacial and interglacial periods, suggesting that the present-day convection areas were still active during glacial periods. Our ISOW intensity records are highly similar to those of deep-water ventilation. We propose that the strength of overflows in the North Atlantic regulates the volume of North Atlantic Deep Water (NADW) and its southward transport in the Atlantic basin. Therefore, the Southern source waters may only act as an opportunistic component of the deep Atlantic circulation, invading or retreating depending on the NADW strength.

Wildfire Impacts for Temperature Index Snowpack Model Parameters

ABSTRACTStreamflow derived from snowmelt is a key source of water for communities and agricultural producers in the western U.S. As wildfires become larger and more frequent in the West (due in part to climate change), it is increasingly important to understand their potential impacts on snowpack. Temperature‐index models remain widely used to simulate snowpack in post‐wildfire assessments due to their low data requirements. However, there is limited information on how the key parameters of such models change due to wildfires. The objectives of this study are to (1) quantify the observed changes in the melt‐rate function and the rain‐snow temperature threshold due to wildfires and (2) develop methods to adjust the melt‐rate function and rain‐snow temperature threshold (or Px Temperature) to simulate the potential impacts of wildfires on snowpack. To accomplish these goals, snow water equivalent data from 42 SNOTEL sites that have been impacted by wildfire are used to estimate the changes in the melt‐rate functions and Px Temperatures between the pre‐and post‐wildfire periods. Then, general linear models (GLMs) are developed to estimate the changes in the model parameters based on readily available topographic, climatic, and land cover information. The results indicate that late season melt‐rates typically increase after a wildfire for sites in northern and central ecoregions of the western U.S. Px Temperature also changes for many sites, but the direction and magnitude of change is highly variable between sites. Nearly all the GLMs can estimate the observed parameter changes better than simply using the average observed changes. However, substantial variation in the parameter values is not explained by the GLMs.

Subalpine fir response to drought in northern British Columbia, Canada

Abstract As global warming continues, drought severity and duration are expected to increase in many areas of the world, necessitating a thorough understanding of how trees react to severe drought periods. In this study, we used dendrochronological analyses to determine the response of subalpine fir [Abies lasiocarpa (Hook.) Nutt.] to historical drought events on sites along a latitudinal interval of 500 km in the Rocky Mountains in northern British Columbia, Canada. We used the ClimateBC Climate Moisture Deficit index to approximate drought conditions at the sites and to identify common drought years across sites. We then compared wood densities across the time series to temperature, precipitation, and climate moisture indices for the locations studied to determine relationships between subalpine fir wood densities and climate in this region. We demonstrated that subalpine fir wood density was often negatively correlated to spring and summer temperatures and that these stands are responsive to drought events in the short term. We found that the latitudinal difference between stands was not as pronounced as expected; however, northern sites had a stronger climate response and more frequent drought years than southern sites. This cautiously suggests that the impacts of climate change may be more intensely felt in forests at more northern latitudes. If droughts continue to become more frequent in northern British Columbia, as is predicted with changing climates, we might expect less carbon sequestration and lower wood strength in subalpine fir trees from this region.

Variable preservation of the 1991 Hudson tephra in small lakes and on land

Volcanic ash (tephra) preserved in terrestrial environments and lake sediments contains information about volcanic processes and can be used to infer eruptive parameters and frequency of past eruptions, contributing to the understanding of volcanic hazards. However, tephra deposits can undergo transformation from their initial fallout sedimentation to being preserved as a tephra layer in the sedimentary record. The process is likely to be different in lakes and in terrestrial (soil) sequences. Here we compare the thickness, mass loading and grain size of tephra layers from the 1991 eruption of Cerro Hudson, Chile, from small lakes and adjacent terrestrial settings to measurements of the tephra made shortly after the eruption. We analysed samples from 35 cores in total from six small lakes (<0.25 km2), located 76 and 109 km from the volcano in two contrasting climatic areas (cool and humid northern site, and warm and dry southern site), and made 73 measurements of tephra thickness and 11 measurements of grain size in adjacent terrestrial areas. The major element geochemistry of our samples confirmed they were from the 1991 Hudson eruption. We found that some of the measured characteristics of the preserved tephra layers were comparable to those recorded in 1991 shortly after initial deposition, but that there was considerable variability within and between locations. This variability was not predictable and lake sediments did not preserve a notably more accurate record of the fallout than terrestrial sites. However, in aggregate the characteristics of the preserved tephra was similar to those recorded at the time of deposition, suggesting that, for palaeotephra research, a sampling strategy involving a wide range of environments is more robust than one that relies on a single sedimentary record or a single type of sedimentary environment.

Economic evaluation of corn relative maturity hybrids in corn–pennycress–soybean rotations

AbstractThis manuscript is a follow‐up of previously published results that presented findings on pennycress (Thlaspi arvense L.) establishment and agronomics in response to previous corn (Zea mays L.) relative maturity (CRM) hybrids grown for grain and silage in the corn–pennycress–soybean [Glycine max (L.)] rotations. In this manuscript, we compared the economics of grain corn–pennycress–soybean rotations (grain rotation) with silage corn–pennycress–soybean rotations (silage rotation). The treatments were CRM hybrids ranging from 76 to 95 days (full season) at northern sites (Morris and Rosemount, MN) and 95 to 113 days (full season) at southern sites (Lexington, IL, and Custar, OH). Full‐season corn harvested for silage was included as a control treatment representing optimum conditions for sowing pennycress. A partial budget procedure was used for economic analysis. The results showed that the annualized net benefits (ANBs) ranged from $315 to $945 ha−1. The silage rotation produced greater ANBs than the grain rotation at all sites due to increased pennycress seed yield. In the grain rotation, the 105 days in the south, 95 days corn at Morris, and 86 days corn at Rosemount resulted in minimal ANB losses compared with silage rotation. Among grain corn treatments, some of the early CRM hybrids resulted in greater ANBs (up to 40%) than the full season hybrid. Results demonstrate potential to integrate pennycress into a grain rotation using early CRM hybrids. In addition, valuing the diverse ecosystem benefits that pennycress offers as a cash cover crop during the offseason between corn and soybean rotation may help to attract growers.

ESTIMATION OF NITRIC ACID GAS DRY DEPOSITION IN VIET NAM

This article uses dry deposition calculating method to estimate Nitric acid (HNO3) gas dry deposition and analyze, evaluate trend of HNO3 gas dry deposition in recent years. The results present that HNO3 gas concentration is from 0.02 to 0.83 ppb and Yen Bai site has the highest HNO3 gas emission in 2020 and 2021. High HNO3 gas emission focuses on summer and spring at Northern’s sites. HNO3 gas emission at Southern sites is lower than that of Northern ones. HNO3 gas dry deposition is from 6.63 kg/ha/year to 10.26 kg/ha/year and the highest HNO3 gas dry deposition value is in 2021. Ha Noi site has the highest HNO3 gas dry deposition value in 2019, 2020, and 2022 while Yen Bai site is in 2021 and 2023. HNO3 gas dry deposition value at Southern sites is lower than Northern sites. The highest monthly HNO3 gas dry deposition is from June to August at Yen Bai site in 2021 and May in 2020. Annual average HNO3 gas dry deposition of 2021 is higher than other years. HNO3 gas dry deposition in recent years has an increasing trend.

Detailed analysis of local climate at the CTAO-North site on La Palma from 20 yr of MAGIC weather station data

ABSTRACT The Observatorio del Roque de los Muchachos will host the northern site of the Cherenkov Telescope Array Observatory (CTAO), in an area about 200 m below the mountain rim, where the optical telescopes are located. The site currently hosts the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, which have gathered a unique series of 20 yr of weather data. We use advanced profile-likelihood methods to determine seasonal cycles, the occurrence of weather extremes, weather downtime, and long-term trends correctly taking into account data gaps. The fractality of the weather data is investigated by means of multifractal detrended fluctuation analysis. The data are published according to the Findable, Accessible, Interoperable, and Reusable (FAIR) principles. We find that the behaviour of wind and relative humidity show significant differences compared to the mountain rim. We observe an increase in temperature of $0.55\pm 0.07\mathrm{(stat.)}\pm 0.07\mathrm{(syst.)}$$^{\circ }$C decade−1, the diurnal temperature range of $0.13\pm 0.04\mathrm{(stat.)}\pm 0.02\mathrm{(syst.)}$$^{\circ }$C decade−1 (accompanied by an increase of seasonal oscillation amplitude of $\Delta C_m=0.29\pm 0.10\mathrm{(stat.)}\pm 0.04\mathrm{(syst.)}$$^{\circ }$C decade−1), and relative humidity of $4.0\pm 0.4\mathrm{(stat.)}\pm 1.1\mathrm{(syst.)}$ per cent decade−1, and a decrease in trade wind speeds of $0.85\pm 0.12\mathrm{(stat.)}\pm 0.07\mathrm{(syst.)}$ (km h−1) decade−1. The occurrence of extreme weather, such as tropical storms and long rains, remains constant over time. We find a significant correlation of temperature with the North Atlantic Oscillation Index and multifractal behaviour of the data. The site shows a weather-related downtime of 18.5 per cent–20.5 per cent, depending on the wind gust limits employed. No hints are found of a degradation of weather downtime under the assumption of a linear evolution of environmental parameters over time.

Modelling of atmospheric concentrations of fungal spores: a 2-year simulation over France using CHIMERE

Abstract. Fungal spore organic aerosol emissions have been recognised as a significant source of particulate matter as PM10; however, they are not widely considered in current air quality models. In this work, we have implemented the parameterisation of fungal spore organic aerosol (OA) emissions introduced by Heald and Spracklen (2009) (H&S) and further modified by Hoose et al. (2010) in the CHIMERE regional chemistry-transport model. This simple parameterisation is based on two variables, leaf area index (LAI) and specific humidity. We have validated the geographical and temporal representativeness of this parameterisation on a large scale by using yearly polyol observations and primary biogenic organic aerosol factors from positive matrix factorisation (PMF) analysis at 11 French measurement sites. For a group of sites in northern and eastern France, the seasonal variation of fungal spore emissions, displaying large summer and small winter values, is correctly depicted. However, the H&S parameterisation fails to capture fungal spore concentrations for a smaller group of Mediterranean sites with less data availability in terms of both absolute values and seasonal variability, leading to strong negative biases, especially during the autumn and winter seasons. Two years of CHIMERE simulations with the H&S parameterisation have shown a significant contribution of fungal spore OA to PM10 mass, which is lower than 10 % during winter and reaches up to 20 % during summer in high-emission zones, especially over large forested areas. In terms of contributions to organic matter (OM) concentrations, the simulated fungal spore contribution in autumn is as high as 40 % and reaches at most 30 % of the OM for the other seasons. As a conclusion, the fungal spore OA contribution to the total OM concentrations is shown to be substantial enough to be considered a major PM10 fraction and should then be included in state-of-the-art chemistry-transport models.

Dating and Interpreting Landscapes of Livestock Herding: Excavation of a Hut Site and Enclosure in Southwestern Ireland

ABSTRACT Grazing livestock in uplands was a widespread practice in late Medieval and early modern Europe, but there can be uncertainty about the date and function of archaeological sites associated with herding. This paper reviews fieldwork on such sites in northern and northwestern Europe and reports on the excavation of a hut and enclosure in the mountains of southwestern Ireland. The hut was found to have been built in the 16th or 17th centuries a.d. and was probably used to oversee dairy animals (likely cows). The enclosure was dated to the early 18th or early–mid-19th century a.d. and is more likely associated with goat milking. The excavations demonstrate that construction dates can be obtained for pastoral sites in uplands of northwestern Europe. Furthermore, with careful reading of features in the surrounding landscape and consideration of documentary and ethnographic evidence, fieldwork can help determine the nature of pastoral economies over time.

Anthropogenic and environmental risk factors of salmonid predation in a tidal freshwater delta

Abstract Water diversions that support agricultural and municipal use result in fish mortality through entrainment and impingement. Additionally, this infrastructure may attract both predators and prey fishes, thereby increasing predation rates and prey mortality near these anthropogenic contact points. The Sacramento–San Joaquin Delta (the Delta) in California's Central Valley is a tidal freshwater ecosystem that exports large volumes of water for municipal and agricultural use while at the same time providing valuable migratory and rearing habitat for imperilled fishes. Emigrating juvenile salmonids experience high mortality in the Delta, with predation by non‐native fishes contributing substantially. Therefore, this study had three main objectives. First, we determined if small water diversions aggregated piscivorous fishes like other similar structures in freshwater ecosystems. Second, we determined how small diversions may influence juvenile salmon predation risk in conjunction with other known predation risk factors (e.g. predator abundance, temperature and depth). Third, we assessed the predator assemblage, abundance and distribution to determine the likely predator composition in objectives one and two. Throughout the spring of 2021, we used ARIS (adaptive resolution imaging sonar; Sound Metrics) sonars to compare piscivore abundance at 30 water diversions in the north Delta to shorelines adjacent to diversions that did not contain these structures. We used predation event recorders (PERs) to assess the predation risk juvenile salmonids were exposed to, with linear distance (m) from diversions, and other predation risk factors in the north Delta. Finally, we used a boat electrofishing survey to determine the piscivore assemblage and compare spatial trends in black bass (Micropterus spp.) CPUE and relative abundance throughout these waterways. Piscivore abundance was greater near small water diversions than at adjacent shorelines and the predation risk of juvenile salmonids increased with diversion proximity. Additionally, predation risk increased with increasing piscivore abundance and decreasing water depth. The north Delta predator assemblage was dominated by black basses (Micropterus spp.), which likely drove the negative relationship of predation risk with water depth, given habitat requirements of these species. Furthermore, increasing smallmouth (Micropterus dolomieu) and spotted bass (Micropterus punctulatus) abundance in our northern study sites may have weakened temperature effects on predation, given metabolic requirements of these species. Our work demonstrated that small water diversions are likely to increase mortality of endangered salmonids, and that the north Delta predator assemblage was different than recorded by previous work in this system, changing predation risk factors. Although more work is needed to determine the population level impacts of diversions, the ubiquitous distribution of these structures warrants management solutions to reduce mortality from this source. These results indicate that in addition to entrainment and impingement, water diversions may increase mortality of small‐bodied fishes by attracting predators and elevating predation risk. Given the continual human demand for freshwater, predator–prey interactions should be considered along with entrainment and impingement when assessing intake infrastructure mitigation, especially when diversions co‐occur along migratory routes and essential habitat of imperilled fishes.

Megacity solid waste disposal suitability mapping in Dhaka, Bangladesh: an integrated approach using remote sensing, GIS and statistics.

Selecting suitable Megacity Solid Waste Disposal (MSWD) sites is a challenging task in densely populated deltas of developing countries, exacerbated by limited public awareness about waste management. One of the major environmental concerns in Dhaka City, the world's densest megacity, is the presence of dumps close to surface water bodies resources. This study employed the Geographic Information System (GIS)-Analytic Hierarchy Process (AHP) framework to integrate geomorphological (slope and flow accumulation), geological (lithological and lineament), hydrogeological (depth to groundwater table and surface waterbody), socioeconomic (Land use land cover, distance to settlement, road, and airport), and climatological (wind direction) determinants, coupled by land-use and hydro-environmental analyses, to map optimal dumps (MSWDO) sites. The resulting preliminary (MSWDP) map revealed 15 potential landfill areas, covering approximately 5237 hectares (ha). Combining statistical analysis of restricted areas (settlements, water bodies, land use) with AHP-based ratings, the MSWDO map revealed two optimal locations (2285ha). Additionally, the hydro-environmental analysis confirmed the unsuitability of northern sites due to shallow groundwater (< 5.43m) and thin clay, leaving 11 options excluded. Sites 12 (Zone A, 2255ha) and 15 (Zone B, 30ha), with deeper groundwater tables and thicker clay layers, emerged as optimal choices for minimizing environmental risks and ensuring effective long-term waste disposal. This study successfully integrates remote sensing, geospatial data, and GIS-AHP modeling to facilitate the development of sustainable landfill strategies in similar South Asian delta megacities. Such an approach provides valuable insights for policymakers to implement cost-effective and sustainable waste management plans, potentially minimizing the environmental risks to achieve Sustainable Development Goals (SDGs) 6, 11, 13, and 15.

Developing genomic tools to assist turnip rape [Brassica rapa (L.) subsp.oleifera (DC.) Metzg.] breeding

IntroductionTurnip rape is recognized as an oilseed crop contributing to environmentally sustainable agriculture via integration into crop rotation systems. Despite its various advantages, the crop’s cultivation has declined globally due to a relatively low productivity, giving way to other crops. The use of genomic tools could enhance the breeding process and accelerate genetic gains. Therefore, the present research investigated 170 turnip rape accessions representing its global gene pool to identify SNP markers associated nine phenological and agro-morphological traits and estimate the genomic breeding values (GEBVs) of the germplasm through GWAS and genomic prediction analyses, respectively.MethodsField trials were conducted at two sites in northern and southern Sweden to obtain the phenotypic data while genotyping was conducted via the genotyping-by-sequencing (GBS) method. The traits studied include days to flowering (DTF) and maturity (DTM), plant height (PH), seed yield (YLD), thousand seed weight (TSW), silique length (SL), number of siliques (NS), number of seeds per silique (SS), and pod shattering resistance (PSHR).Results and conclusionAnalysis of variance revealed substantial variation among accessions, with significant genotype-by-environment interaction for most traits. A total of 25, 17, 16, 14, 7, 5, 3, and 3 MTAs were identified for TSW, DTF, PH, PSHR, SL, YLD, SS and DTM, respectively. An 80%–20% training-test set genomic prediction analysis was conducted using the ridge regression – BLUP (RR-BLUP) model. The accuracy of genomic prediction for most traits was high, indicating that these tools may assist turnip rape breeders in accelerating genetic gains. The study highlights the potential of genomic tools to significantly advance breeding programs for turnip rape by identifying pivotal SNP markers and effectively estimating genomic breeding values. Future breeding perspectives should focus on leveraging these genomic insights to enhance agronomic traits and productivity, thereby reinstating turnip rape as a competitive and sustainable crop in Sweden and broader global agriculture.

Trend of SO2 Gas Dry Deposition in Vietnam

This research used the calculating method of dry deposition to estimate SO2 dry deposition value and evaluate its trend in 5 recent years. The results indicate that SO2 emission at Northern sites is more changing than Southern ones in months by affecting meteorology and weather. Summer and autumn seasons have SO2 emitted concentrations higher than other seasons in 2019, 2020, and 2022 year at Yen Bai, Hoa Binh, and Ha Noi stations. The 2021 year has the highest SO2 dry deposition and the 2019 year has the lowest SO2 dry deposition in 5 recent years. The Hanoi site has the highest SO2 dry deposition value from 2019 to 2022 year. Hoa Binh site has the highest SO2 dry deposition at 2.45 kg/ha/year in 2023. High SO2 dry deposition occurs normally in the summer and autumn (from April to August). Southern sites have lower SO2 dry deposition amounts with not much change than the Northern sites of Vietnam. The increasing trend of SO2 dry deposition happened from 1999 to 2023 year and it increases sharply from 1999 to 2021. Therefore, SO2 dry deposition will have a light-increasing trend in the future.

Ground‐Observed Snow Albedo Changes During Rain‐On‐Snow Events in Northern Alaska

AbstractRain‐on‐snow (ROS) events occur when rain falls on snowpack and can have substantial ecological and social impacts. During ROS events, liquid water in the snowpack can decrease the surface albedo, which contributes to the positive snow‐albedo feedback and further accelerates snowmelt. In a warming climate, the frequency and spatial coverage of ROS events are projected to increase in the high‐latitude regions, especially in northern Alaska. Multi‐year ground observations at two northern Alaska sites are utilized to evaluate 59 ROS events from 2012 to 2022. Results show that ROS events lead to dramatic snow albedo changes with a mean decline of −0.04 per day, which is considerably larger than the multi‐year mean of −0.005 in May and −0.008 in June. A snow albedo model is used to simulate the daily snow albedo changes due to snowpack liquid water content. The simulated impact of liquid water content accounts for only 10% of the observed snow albedo changes. In addition, composite synoptic conditions from reanalysis products reveal different moisture sources for ROS events. ROS events in May are associated with anomalous high pressure systems over the site and meridional transport of warm and moist air from lower latitudes. While the June synoptic conditions for ROS events show little deviation from the climatological mean and suggest local moisture contributions. ROS events in June show comparable snow albedo changes as in May despite the difference in moisture sources, which implies a prolonged impact of ROS events on rapid snow deterioration during late spring.

Temperature dependence of feeding activity in the invasive freshwater snail Pomacea canaliculata: implications for its response to climate warming

AbstractPomacea canaliculata, a freshwater snail native to South America, has become widely naturalised in many countries, causing serious damage to agricultural and native ecosystems. Although climate warming is likely to expand the distribution of this species, limited information exists regarding its impact on feeding activities. In this study, we examined the effects of temperature on the feeding activity of this species and estimated the impact of climate warming on its feeding potential. The feeding activity was determined by measuring the amount of standard food (Japanese mustard spinach, komatsuna) ingested at different temperatures. It tended to increase from 15 to 25 °C but became almost stable from 25 to 35 °C. The respiration rate determined by the O2 consumption rate, showed a similar response to temperature. Based on these findings, we constructed a simple model to estimate the relative feeding activity using climatic data recorded at meteorological stations throughout the Japanese Archipelago. The model estimated that, with warming of + 2 °C, annual feeding potential (relative value) increased by 21.1% at the present northern distribution limit of this species. The effect of warming on percentage increase in feeding potential was estimated to be smaller at the southern distribution limit (9.9%), although the absolute feeding potential was larger than that at the northern sites. The model also suggested that if this species expanded its northern distribution range as a result of climate warming, it would have a high feeding potential comparable to that of the southern regions.

Long-term measurements of aerosol composition at rural background sites in France: Sources, seasonality and mass closure of PM2.5

Fine particulate matter (PM2.5) was monitored at five rural background locations in France from 2012 to 2021. Annual PM2.5 ranged from 5 to 15 μg m−3, all sites repeatedly exceeding the 2021 annual World Health Organization guideline. Chemical speciation including organic and elemental carbon (OC, EC), secondary inorganic aerosols (SIA: NO3−, SO42−, NH4+) and other major water-soluble ions (Cl−, Na+, Mg2+, Ca2+, K+) were monitored on 24-h filters covering 14% of the year. A source apportionment of OM was undertaken based on fine potassium and using representative ratios for domestic biomass burning (BB) and fossil fuel (FF) emissions. The latter dominated the EC fraction (55–60%) while BB was the main primary source of OM (27–54%). The average mass balance of PM2.5 at the French rural background atmospheric sites was: secondary organic aerosol (18–35%), BB (17–27%), non-sea-salt sulphate (12–17%), nitrate (6–22%), ammonium (7–11%), FF (4–6%), mineral dust (3–9%) and sea salt (1–2%). Secondary aerosols were the main component of PM2.5 through all seasons, with SIA dominating in spring episodes. The contribution of OM to PM2.5 was larger at the southern sites whereas the contribution of SIA was larger at the northern sites. The mean OC/EC ratio and the good correlations between OC, EC, and fine potassium suggested that BB was the main primary source contributing to carbonaceous aerosols, 27–54% to total OM depending on the site; and also, to PM2.5 (17–27%). Stronger regulations of OM sources including BB, nitrate from combustion, and ammonium from agricultural sources are needed to reduce PM2.5 at rural background sites on an annual and episodic basis, respectively.

Structure and diversity patterns of coralligenous cliffs across three ecoregions in the Central‐Western Mediterranean Sea

AbstractAimCoralligenous reefs are the main marine bioconstructions in terms of spatial distribution within the Mediterranean basin. Two distinct reef morphologies can be distinguished based on the surface and topographical features of the seafloor: cliffs developing vertical slopes and banks found on gently steep or horizontal bottoms. Despite their importance for monitoring and conservation efforts, observations regarding the variability of biogeographical patterns are scarce. Here, we aimed to assess the differences in the composition and structure of these cliffs across ecoregions and estimate the relative role of abiotic environmental features, geographic location, and connectivity in shaping diversity patterns.LocationThe study was carried out in the Central‐Western Mediterranean Sea. Samples were collected at 65 sites across the Algero‐Provençal Basin, the Ionian Sea and the Tyrrhenian Sea.MethodsWe assessed the composition and structure of coralligenous cliffs through photographic samplings collected by scuba divers. Patterns in α‐ and β‐diversity were associated with 9 abiotic environmental variables, latitudinal and longitudinal gradients, and connectivity measures using Generalized Additive (GAM) and Conditional Autoregressive (CAR) models.ResultsCoralligenous cliffs were primarily composed of algae and displayed a high degree of variability. The Partition Around Medoids (PAM) clustering method successfully delineated seven distinct clusters with a non‐uniform distribution within the studied ecoregions. The α‐diversity increased in eastern and northern sites and with phosphate concentration, while decreased with temperature, chlorophyll and nitrates concentration. β‐diversity at the site level increased with temperature, while it was negatively affected by northward current speed and chlorophyll concentration. Moveover, β‐diversity increased within connected sites.Main ConclusionsCoralligenous cliff diversity responds both to the physico‐chemical features of the habitat and between‐habitats connectivity. However, our findings suggest that small‐scale abiotic and biotic processes could contribute to explaining the variability observed. These findings can significantly enhance the monitoring and conservation efforts of this Mediterranean endemic ecosystem.

Environmental factors have stronger effects than biotic processes in patterns of intertidal populations along the southeast coast of Brazil

Rocky shore communities are shaped by complex interactions among environmental drivers and a range of biological processes. Here, we investigated the importance of abiotic and biotic drivers on the population structure of key rocky intertidal species at 62 sites, spanning ∼50% of the Brazilian rocky shoreline (i.e., ∼500 km). Large-scale population patterns were generally explained by differences in ocean temperature and wave exposure. For the gastropod species Lottia subrugosa, differences at smaller scales (i.e., 0.1–1 km) were better explained by other abiotic influences such as freshwater discharge and substrate roughness. Based on the general population patterns of intertidal species identified, three main oceanographic groups were observed: a cold-oligotrophic grouping at northern sites (Lakes sub-region), a eutrophic group associated with large estuaries and urban zones (Santos and Guanabara bays); and a transitional warm-water group found between the two more productive areas. Larger individuals of Stramonita brasiliensis, L. subrugosa and Echinolittorina lineolata were generally found in the cold-oligotrophic system (i.e., upwelling region), while small suspension feeders dominate the warm-eutrophic systems. Evidence of bottom-up regulation was not observed, and top-down regulation effects were only observed between the whelk S. brasiliensis and its mussel prey Pernaperna. Environmental drivers as compared to biotic interactions, therefore, play a key role determining the population structure of multiple intertidal species, across a range of spatial scales along the SW Atlantic shores.

Spatial Dynamics of Demersal Fish Assemblages off the Korean Coast in the East Sea.

This study assessed variations in demersal fish assemblages with respect to the study site and water depth. Seasonal samplings from May 2018 to March 2019 were conducted along the northern (Ayajin, Goseong) and southern (Hupo, Uljin) sites of the East Sea off the Korean coast, using commercial gill nets. Samples were collected at depths of ~50, ~80, ~150 m across the study sites, with concurrent monitoring of water column structures. A total of 73 species and 6250 specimens were collected. Distinctive fish species compositions were observed according to the study site and depth. Although Glyptocephalus stelleri was the most abundant fish species in both Ayajin and Hupo, Gadus macrocephalus, Icelus cataphractus, and Alcichthys elongatus were most predominant in Ayajin, whereas Cleisthenes pinetorum, Hippoglossoides dubius, and Gymnocanthus herzensteini were more prevalent in Hupo. In terms of depth layer, in Ayajin, G. stelleri dominated in both intermediate and deeper layers, with Hemilepidotus gilberti, A. elongatus, Enophrys diceraus common in shallower depths. Conversely, in Hupo, G. stelleri, C. pinetorum, and A. nadeshnyi dominated across all depth layers, whereas Dasycottus setiger and G. herzensteini dominated in deeper and shallower depths, respectively. Significant influences of the study site and water depth on fish assemblage structures were observed due to variations in water temperature at the seasonal thermocline boundary.

Judean Reception of the Elisha Narratives

Abstract Scholars have noted scribal attempts to undermine Elisha’s prophetic reputation in his promise to the Shunammite woman (2 Kgs 4:8–17). However, these readings fail to adequately consider the intertextual links between Elisha’s promise and Yahweh’s promise to Abraham (Gen 18:1–15): Why did the scribes link Elisha’s promise with Yahweh’s promise, especially when the narrative is largely hostile against Elisha? Paying attention to the possible context in Achaemenid Yehud, this article proposes a new interpretation of Elisha’s promise: It highlights scribal efforts to subjugate and silence Bethel, a northern Israelite cultic site believed to be the repository for Elisha traditions during this period. And it argues that the Judean scribes deliberately linked Elisha’s promise with Yahweh’s promise, as an “antithetical parallelism” to support their attempts to stigmatise Bethel’s traditions by pointing readers toward Elisha’s human weaknesses and limitations in his prophetic career.