Sampling Sites Research Articles

Modelling of the trade-off between the deep soil moisture and vegetation restoration in the hilly area of the Loess Plateau, China

Excessive depletion of soil moisture by artificial forests in the vegetation restoration areas of the Loess Plateau has attracted widespread attention. To assess potential risks of soil moisture deficit, we needed on-site vegetation and soil sampling data, as well as UAV images from the Chaigou Watershed for three-dimensional analysis, combining both sampling and raster data. Three-dimensional surfaces for assessment of trade-off were established innovatively by the local regression and interpolation methods. The results indicated that soil moisture benefits at 20–40 cm depth are lower than at 0–20 cm due to infiltration and surface disturbance. In some areas of the Chaigou Watershed, grass and shrub-grass vegetation are facing risks of soil moisture deficit based on trade-off values (RSMD) and multiparameter evaluations. Analysis of deep soil water content variability revealed the moisture decreases significantly with the deepening of the soil layer in some plots. R (Richness), H (Shannon’s Diversity), Margalef, COHESION, and CONTAG were applicable in interpolation and fitted with the local regression model (R2 > 0.6) corresponding to the trade-off, but SPLIT was proven to be inapplicable in this study area. The zero trade-off inflection points were 6 %–8 %, while the trend inflection points were 7.5 %–9 % for soil moisture and vegetation indices of vegetation and landscape in typical sampling sites of the Chaigou Watershed. Three-dimensional fitting model is more comprehensive and effective in assessing deep soil moisture conditions and grass plots on shady slopes generally had the best trade-off status in this region.

A potential bioaerosol source from kitchen chimneys in restaurants

Bioaerosols are ubiquitous and have a substantial impact on the atmosphere and human health. Despite the identification of numerous bioaerosol emission sources, the contribution of anthropogenic sources remains inadequately understood. In kitchens, oil stains accumulated at the vent may discharge microorganisms into the environment with airflow, potentially discharging bioaerosol pollution. This putative anthropogenic source of bioaerosols has been long ignored. To investigated whether kitchen chimneys can be a potential source for bioaerosols, air samples, oil stains from in/out chimneys, and surface sand samples were collected near several commercial restaurants. PCoA showed that sampling sites significantly impacted microbiomes, whereas SourceTracker analysis led to the finding that waste grease significantly contributed to bioaerosol composition. Both findings agree with the kitchen chimney as a source of microbes in bioaerosols in the surrounding environment. Furthermore, despite the low biodiversity, a high proportion of stress-tolerant and potential pathogenic bacteria and fungi were found in residual culinary grease, which may escape into the air causing potential risks to human beings. These results led to the proposal that airborne microbiota can originate from cooking waste grease. Immediate actions should be taken into account to enhance disinfection and sterilization aimed at fume vents.

IT IS SNOWING MICROPLASTICS IN WESTERN SIBERIA

The atmosphere is an important transport medium for polymeric anthropogenic particles such as microplastics (MPs). The analysis of particles deposited on the snowpack enables monitoring the abundance and transport of MPs and semi-synthetic fibers. In the current study, the abundance of MPs and man-made textile fibers in deposited snow in Western Siberia, Russia, was investigated in a large area ranging from the Altai Mountains (52°01"N) to the Arctic Circle (66°30"N). Rayon fibers accounted for 44 % of all detected particles, while the remaining 66 % were MPs made of PET, PA, PC, PP and other plastics. The highest number of MPs and fibers per unit area was 2,817 ± 915 items m-2 with an estimated daily deposition rate of 25.8 items m-2 d-1. The maximum calculated mass particle load was 4,444 ± 1,530 mg m-2 or 34.9 ± 12 mg L-1 of melted snow. Particle concentrations in snow were generally higher in the southern parts of Western Siberia but did not significantly correlate with population density. The Lagrangian dispersion model FLEXPART was used to estimate the geographical patterns of potential sources of the fibers detected in the snow in Western Siberia. Our analysis shows that particles can reach the sampling sites via both short-range and long-range atmospheric transport, including the possibility of cross-border transport for the smaller particle sizes.

Functional traits mediate the elevational patterns of functional diversity and community structure of mosses in a tropical mountain area

Functional diversity refers to the value, range, and distribution of functional traits within a community, such as the morphological, physiological and behavioral characteristics of species that determine the role a species plays in an ecosystem. Assessing the drivers of elevational pattern of functional diversity is crucial to predict the effects of global change on functional diversity and community structure. In our research, we collected mosses species data from 65 sampling sites and measured 11 functional traits that are related to their ecological functions. We applied double canonical correspondence analysis (DCCA) to analyze species responses to environmental conditions based on their traits. We applied generalized additive models with a Gaussian function of variance to determine the elevational patterns of functional trait composition, diversity and community structure. We applied and compared boosted regression trees (BRT) without considering functional traits and piecewise structural equation modelling (SEM) mediated with functional traits to relate environmental variables with functional diversity and functional community structure, respectively. We found the first DCCA axis accounted for the largest dissimilarities between the two groups of species and correlated mainly with the water-utilization traits. Although both functional diversity and community structure displayed negatively skewed pattern along the elevational gradient, habitat complexity and climatic variables contributed differently to their respective patterns. The SEM approach consistently outperformed the BRT approach in explaining the variations in both functional diversity and community structure. Our findings highlight the important role of functional traits in mediating the relationship between the environment and functional diversity metrics. Both biotic and abiotic processes play a significant role in shaping the community assemblages, with environmental variables having distinct impacts. Traits related to structure maintenance, water absorption, cell hydration, and nutrient acquisition were found to be key drivers of functional diversity, while water-utilization traits were mainly responsible for regulating functional community structure.

Relationship Between Aquatic Factors and Sulfide and Ferrous Iron in Black Bloom in Lakes: A Case Study of a Eutrophic Lake in Eastern China

Black bloom is a very serious water pollution phenomenon in eutrophic lakes, with Fe(II) and S(−II) being the key limiting factors for this problem. In this paper, three different machine learning methods, namely, Random Forest (RF), Gaussian Mixture Model (GMM), and Bayesian Network (BN), were used to explore the complex interactions among Fe(II), S(−II), and other aquatic factors in the estuary of Chaohu Lake to better characterize and monitor water degradation by black bloom. The results of RF showed that total nitrogen (TN), ammonia, total phosphorous (TP), suspended sediment concentration (SSC), and oxidation–reduction potential (ORP), which were chosen from 11 factors, had the most important relationships with Fe(II) and S(−II). The 69 sampling sites were divided in three groups identified as worst, worse, and bad according to the observed values of seven factors using the GMM. Then, the BN model was applied to three observation groups. The results showed that the structures of the interaction networks were different between the groups. S(−II) controlled only SSC production in the bad and worse group sites, while SSC was determined by both S(−II) and Fe(II) in the worst group. Ammonia and TN exhibited the most direct importance for S(−II) and Fe(II) production in all observation groups. According to the indications from the BNs, potential management strategies for different water pollution conditions were developed. Finally, the threshold values of Fe(II), S(−II), TP, ammonia, TN, SSC, and ORP, which were 0.80 mg/L, 0.04 mg/L, 0.45 mg/L, 3.44 mg/L, 4.15 mg/L, 55 mg/L, and 135 mv, respectively, were determined on the basis of the BN models. These values will be helpful to develop accurate strategies of oxygenation to quickly eliminate black bloom in the lake.

Plant-Parasitic and Free-Living Nematode Community Associated with Oak Tree of Magoebaskloof Mountains, Limpopo Province, South Africa

A study was conducted in the mountains of Magoebaskloof, Limpopo Province, where oak trees grow along the banks of the Broederstroom River. This study revealed that 22 nematode genera were associated with oak trees (Quercus robur). The most frequently occurring nematodes were Aphelenchus sp. (100%) and Plectus sp. (100%), followed by Helicotylenchus sp. (90%). This study examined the relationship between nematodes and the physicochemical properties of the soil using Pearson correlation. It uncovered that the organic matter content (OMC) had a negative correlation with the number of Panagrolaimus sp. (r = −0.770) and Hemicycliophora sp. (r = −0.674). Conversely, the sand percentage positively correlated (r = 0.695) with the number of Hemicycliophora sp. The clay content of the soil showed a positive correlation (r = 0.617) with the number of Ditylenchus. Soil pH demonstrated a significant negative correlation with Acrobeloides sp. (r = −0.877). The canonical correspondence analysis (CCA) explained 63.3% of the relationship between nematodes and soil physicochemical properties. The CCA results indicated that Ditylenchus exhibited a positive correlation with OMC, while the Panagrolaimus and Hemicycliophora species showed a negative correlation with OMC. The results indicated that none of the soil sample sites were under stress. The soil food web analysis revealed that most soil samples were nutrient-enriched with a low C/N ratio. In conclusion, this study revealed that oak trees harbor a high diversity of plant-parasitic and free-living nematodes. The results suggest that soil nematodes, particularly free-living bacterivores, such as Panagrolaimus, can indicate organic matter content in the soil.

Physical, Chemical And Bacteriological Indicators Of Well Water Around A Necropolis Located In The Urban Area Of The Municipality Of Paraíso Do Tocantins

During the months of September 2023 to July 2024, groundwater samples were collected at 10 sampling sites, distributed in the Sector Oeste neighborhood, in the city of Paraíso do Tocantins, state of Tocantins, with the aim of assessing the quality of groundwater captured in tube wells potentially used for human consumption. For all the groundwater samples, the physicochemical parameters ammonia, chloride, apparent color, hardness, nitrate, nitrite, pH, turbidity and microbiological total and thermotolerant coliforms were analyzed. Based on these results and in order to better understand the physicochemical behavior of these waters, principal component analysis (PCA) was used to carry out a more complete evaluation of the original data. The physicochemical and microbiological parameters assessed in the groundwater collected showed that 90% of the wells had pH values below those recommended in Ordinance GM/MS No. 888/2021 and the presence of total and thermotolerant coliforms in all the water samples from the wells analyzed, which is in disagreement with the legislation. In addition, the PCA explained 49.84% of the total variance of the data, making it possible to assess the degree of similarity between the samples. It is important to have more reliable monitoring and assessment of groundwater in cemetery areas and prior knowledge of the chemical composition of this water, as this is the only way to assess whether any parameter is altered, even if its concentration is equal to or lower than that considered naturally occurring by current legislation.

Benthic foraminifera as bio-indicators of natural and anthropogenic conditions in Roscoff Aber Bay (Brittany, France).

Living benthic foraminifera, known as environmental bio-indicators of both natural and anthropogenic conditions in marine environments, were investigated in the coastal environment of Roscoff Aber Bay (Brittany, France). Eight sampling sites subject to natural variations (freshwater inputs, tides) and/or anthropogenic impacts (pollution, eutrophication) were studied over four seasons in 2021-2022 (November, February, May, August). We sought to understand the spatial distribution of foraminiferal populations within and between sampling sites over the different seasons and to identify sensitive species and those tolerant to anthropogenic impacts. To this end, sedimentary and biogeochemical characteristics of the sediments were examined by measuring grain size, temperature, oxygen, salinity, pH, environmental pigment concentration (chl a and phaeopigments), total organic carbon (TOC), isotopic ratios of carbon (δ13C), nitrogen (δ15N) and sulfide (δ34S), and chl a fluorescence. Considering these parameters as potential driving factors, four environments were distinguished among the sampling sites: open water, terrestrial, oligotrophic and eutrophic. These showed an increasing gradient of organic supply as well as very different microbial activities, highlighted by carbon and sulfide isotopic ratios. Foraminiferal population study revealed the dominant species characterising these main environments. The lowest abundance but highest diversity of foraminifera was found in the harbour site, associated with the dominance of Haynesina germanica, suggesting this species is tolerant to eutrophic environments and anthropogenic impacts. Open water was dominated by Ammonia beccarii and Elphidium crispum, while Quinqueloculina seminula was the most abundant species in the site with the greatest terrestrial influence. Interestingly, the observed organic enrichment of the harbour due to anthropogenic activities (fisheries, waste deposits, etc.) does not seem to significantly affect foraminiferal diversity. Overall, the benthic foraminiferal species in Roscoff Aber Bay appear to be an excellent proxy for marine environmental conditions under various natural and anthropogenic influences.

Industrial Assessment of Mudstone Deposits of Gercus Formation as a Raw Material for Bricks Industry in Erbil Governorate, Northern Iraq

This paper evaluates the mudstone deposits' physical, chemical, and mineralogical properties and the possibility of use as a raw material to manufacture building bricks. Four sites are selected from the Gercus Formation in Shaqlawa district and the samples are tested. The mudstone samples are analyzed to define the grain size, Atterberg limits, chemical, physical and mechanical characteristics of the clay bricks. The grain size analysis of the mudstone samples showed they contained a high percentage of clay and silt and a low percentage of sand. The chemical analysis showed that silica (SiO2) was the major component in the mudstones. XRD analysis showed the presence of non-clay minerals i.e. calcite, quartz, albite and clay minerals of illite, palygorskite and chlorite. Raw samples of all studied sites were treated to prepare brick samples without addition, and others with 10% standard sand added. The results showed that the bricks prepared from the B to B10 and C to C10 stations have varying water absorption and compressive strength, while the efflorescence has light salts. All these properties are within the requirements of the Iraqi specification for brick manufacturing. The sample sites A, D, A10, and D10 are not compatible with the Iraqi standard in terms of absorption and compression.

Diversity Patterns of Bacteria in the Root Zone of Davidia involucrata Along an Altitudinal Gradient

Davidia involucrata has an ancient origin, representing a remnant from the paleotropical flora that thrived during the Tertiary period. Altitudinal gradient acts as a natural testing ground for studying climate change, and research on the distribution patterns of microorganisms along altitudinal gradients is crucial in understanding the adaptability of D. involucrata to climate change. In our study, we examined sample sites ranging from 1600 to 2200 m in elevation, which are part of the primary habitat zone for Davidia involucrata within the Xuebaoding National Nature Reserve. In 2021, field surveys were conducted across four altitudinal gradients (1600 m, 1800 m, 2000 m and 2200 m) of the D. involucrata distribution in the nature reserve. The sampling plots were set in each altitudinal gradient, and three representative and healthy mature trees were selected as sample trees for each plot. Rhizosphere soils were used to test the soil stoichiometry characteristics and root zone microbial communities. Our findings indicated pronounced differences in soil total carbon (TC) and total phosphorus (TP) content and C:P and N:P ratios between the four altitude sites (p < 0.05). Analysis of the bacterial communities revealed higher richness (PD and Chao1 indexes) at ASL2000 and ASL2200 (high altitude) compared to ASL1600 and ASL2000 (low altitude) (p < 0.05). Non-metric multidimensional scaling analysis demonstrated a distinct clustering of bacterial communities between the high and low altitudes (p < 0.01). At the phylum level, Proteobacteria and Acidobacteria were predominant at high altitudes, while Actinobacteria and Chloroflexi dominated at low altitudes. The core microbiome, shared among all altitudes, comprised 377 genes. The analysis of differential abundance revealed notable disparities in the prevalence of certain bacterial genera with altitude, with Arthrobacter and Acidothermus experiencing the most pronounced shifts (p < 0.05). This confirmed that environmental factors significantly influenced bacterial community structure and abundance. Spearman’s rank correlations revealed that both Chao1 and PD indices were positively correlated with elevation, TC, and TN, with Chao1 showing stronger relationships. Both indices were negatively correlated with MAT, while only Chao1 exhibited a significant negative correlation with pH. Linear regression analysis further confirmed the significant associations between Chao1 index and elevation, TN, MAT, and pH. Furthermore, redundancy analysis demonstrated that altitude (ASL) and TN were the primary factors shaping soil bacterial community composition, explaining 21.32% and 30.70% of the variance, respectively. Altitude significantly influenced microbial community structure (p = 0.003). Distinct microbial taxa showed specific associations with environmental gradients, suggesting niche specialization in response to soil conditions. These findings suggest that altitude influences soil nutrient characteristics and microbial community composition in the D. involucrata habitat, offering insights into the ecological factors affecting this endangered species.

Low pharmaceutical pollution of epibenthic organisms from Admiralty Bay, Antarctica (King George Island, South Shetland Islands)

The presence of medicinal products has been reported in the Antarctic marine environment but still little is known about the bioaccumulation of these compounds. This study was set up to detect and quantify pharmaceutical residues in benthic biota from Admiralty Bay, King George Island (South Shetland Islands, Antarctica). Pharmaceuticals and stimulants were analysed using LC-MS/MS in dominant epibenthic macroorganisms that were collected at eight nearshore sublittoral sites (water depth 3–30 m) by a SCUBA diving team during austral summer (February 2023). Out of 22 analytes, only the stimulant caffeine (CAF) and the antiepileptic carbamazepine (CBZ) have been identified in the macrobenthic algae and invertebrates indicating a relatively low contamination level of the bay. The analytes were detected predominantly in the northern part of the bay (Mackellar Inlet and Martel Inlet) which reflects likely their elevated environmental concentrations in this area and suggests that local research stations represent the main source of pharmaceutical contamination. Irrespective of the sampling site, both compounds were found almost exclusively in brown and red macroalgae highlighting their potential for uptake and accumulation of CAF and CBZ. This study provided the first evidence of the presence of medicinal substances in the Antarctic macrobenthic organisms and can serve as a baseline for environmental risk assessment.

Insights into the seasonal variation, distribution, composition and dynamics of microplastics in the Ganga River ecosystem of Varanasi City, Uttar Pradesh, India.

The current study explores the seasonal dynamics of microplastic (MP) pollution in the Ganga River of Varanasi City, Uttar Pradesh, India, focusing on water and sediment samples collected during pre-monsoon and post-monsoon periods. The analysis shows significant variations in MP occurrence, shape dynamics, color distribution, and size composition across diverse sampling sites. During the pre-monsoon season, MP concentrations ranged from 17 to 36 particles/L in water samples and 160 to 312 particles/kg in sediment, indicating a moderate to high level of contamination. Post-monsoon sampling showed higher MP concentrations at most sites, indicating the influence of seasonal hydrological changes on MP distribution. Shifts in MP shape dynamics were observed between seasons, with films, foams, fragments, and filaments showing variable distributions. Similarly, color variations in MPs exhibited site-specific patterns, with white, brown, blue, and other colors being predominant. These findings highlight the diverse sources and compositions of MPs in the river ecosystem, highlighting the complexity of MP pollution dynamics. Polymer-type distributions further elucidated the composition of MPs, with notable contributions from polyethylene terephthalate, rayon, polyester, and polyvinyl chloride. PCA analysis revealed significant shifts in particle size and shape distribution between pre-monsoon and post-monsoon periods in both water and sediment samples, with post-monsoon samples showing an increase in larger particles and filaments. These changes highlighted key factors driving the variance in microplastic contamination across different sites. The prevalence of these polymers features diverse sources of MP pollution, including textiles, packaging materials, and industrial waste. Ongoing monitoring and research are crucial to understanding its sources, distribution, and impact on river ecosystems, essential for protecting aquatic biodiversity and human health.

Effect of rhizosphere soil microbial communities and environmental factors on growth and the active ingredients of Angelica sinensis in Gansu Province, China.

The growth and accumulation of active ingredients of Angelica sinensis were affected by rhizosphere soil microbial communities and soil environmental factors. However, the correlationship between growth and active ingredients and soil biotic and abiotic factors is still unclear. This study explored rhizosphere soil microbial community structures, soil physicochemical properties, enzyme activities, and their effects on the growth and active ingredient contents of A. sinensis in three principal cropping areas. Results indicated that the growth indices, ligustilide, ferulic acid contents, and soil environmental factors varied in cropping areas. Pearson correlation analysis revealed that the growth of A. sinensis was affected by organic matter, total nitrogen, total phosphorus, and available phosphorus; ferulic acid and ligustilide accumulation were related to soil catalase and alkaline phosphatase activities, respectively. Illumina MiSeq sequencing showed that the genera Mortierella and Conocybe were the dominant fungal communities, and Sphingomonas, Pseudomonas, Bryobacter, and Lysobacter were the main bacterial communities associated with the rhizosphere soil. Kruskal-Wallis one-way ANOVA and Spearman correlation conjoint analysis demonstrated a significant positive correlation (p < 0.001) among the composition of the rhizosphere microbial communities at all three sampling sites. The growth and active ingredient accumulation of A. sinensis not only was significantly susceptible to the bacterial communities of Sphingomonas, Epicoccum, Marivita,Muribaculum, and Gemmatimonas but also were significantly influenced by the fungal communities of Inocybe, Septoria, Tetracladium, and Mortierella (p < 0.05). Our findings provide a scientific basis for understanding the relationship between the growth and active ingredients in A. sinensis and their corresponding rhizosphere soil microbial communities, soil physicochemical properties, and enzyme activities.

Multivariate Analysis of Water Quality in the Seybouse River: Implications for Pollution Management

ABSTRACTHeavy metal contamination in water bodies is a pervasive and persistent environmental challenge in many parts of the world, especially in developing countries. This study investigates the use of multivariate analysis methods for monitoring variations in water quality along a spatial gradient and for the interpretation of pollution levels at different sampling sites. We assessed the water quality of the Seybouse River and identified possible sources of pollution using three complementary multivariate analysis techniques (PCA, NMDS, and K‐means clustering). The results indicate a longitudinal gradient in water quality associated with industrial and agricultural activities in the middle and lower Seybouse River. Physico‐chemical and heavy metal analyses show high water turbidity with elevated concentrations of iron and chromium. We show that the contamination stems from four different sources, which can be categorized into different pollution levels. Our results suggest that complementary multivariate methods are a robust approach to identifying and categorizing significant sources of pollution in rivers, enabling the development of future successful water quality management strategies based on water pollution levels. This study highlights the importance of monitoring water quality and taking effective measures to control and mitigate pollution from various sources to ensure the safety of the environment and human health.

Effect of soil and community factors on the yield and medicinal quality of Artemisia argyi growth at different altitudes of the Funiu mountain.

Altitude and ecological factors significantly influence plant growth and the accumulation of secondary metabolites. However, current research on the impact of altitude and ecological factors on the yield and medicinal quality of Artemisia argyi (A. argyi) is limited. This study established sampling sites in wild populations of A. argyi across seven altitude ranges on Funiu Mountain. We quantified the yield, output rate of moxa, and key medicinal ingredients. Additionally, we analyzed the response of yield and medicinal quality of wild A. argyi populations to various ecological factors at different altitudes. The results showed that wild populations of A. argyi exhibited higher yields and medicinal quality at altitudes below 500 m. Yield was positively correlated with higher soil total nitrogen (TN) content and lower soil total phosphorus (TP) content, while the improvements in medicinal quality were positively associated with higher population density and lower contents of both soil TN and TP. The variation in soil C/N, C/P, and N/P ratios across different altitudes was substantial, affecting soil mineralization and subsequently influencing the absorption of mineral elements by A. argyi. Notably, the phosphorus content in leaves and stems was negatively correlated with yield and medicinal quality, respectively. In contrast, the accumulation of nitrogen, phosphorus, and potassium in leaves was positively correlated with yield. The differences in the primary medicinal ingredients between the leaves and stems of A. argyi were maximum at altitudes below 500 m. The contents of neochlorogenic acid and cryptochlorogenic acid in both leaves and stems showed a significant positive correlation. In the principal component analysis, the primary medicinal ingredients from the leaves contributed more significantly to the overall quality than those from stems. These results suggest that A. argyi is best suited for cultivation at altitudes below 500 m. Population density and the soil's TN and TP contents play a crucial role in determining the yield and medicinal quality of A. argyi. Futhermore, the medicinal quality of A. argyi is more indicative of the main medicinal ingredients found in the leaves, while the stems also serve as a key organ for accumulating flavonoids and phenolic acids.

Population structure of Desmophyllum pertusum found along the United States eastern continental margin

ObjectiveThe connectivity and genetic structuring of populations throughout a region influence a species’ resilience and probability of recovery from anthropogenic impacts. By gaining a comprehensive understanding of population connectivity, more effective management can be prioritized. To assess the connectivity and population genetic structure of a common cold-water coral species, Desmophyllum pertusum (Lophelia pertusa), we performed Restriction-site Associated DNA Sequencing (RADseq) on individuals from nine sites ranging from submarine canyons off New England to the southeastern coast of the United States (SEUS) and the Gulf of Mexico (GOM). Fifty-seven individuals and 3,180 single-nucleotide polymorphisms (SNPs) were used to assess genetic differentiation.ResultsHigh connectivity exists among populations along the SEUS, yet these populations were differentiated from those to the north off New England and in Norfolk Canyon along the North Atlantic coast of the United States, as well as those in the GOM. Interestingly, Norfolk Canyon, located just north of North Carolina, and GOM populations exhibited low levels of genetic differentiation, corroborating previous microsatellite analyses and signifying gene flow between these populations. Increasing sample sizes from existing populations and including additional sampling sites over a larger geographic range would help define potential source populations and reveal fine-scale connectivity patterns among D. pertusum populations.

High atmospheric dissolved organic nitrogen deposition in southeast Tibet

Nitrogen deposition has been highlighted in the last decades because it was considered as one control factor of global change. The Yarlung Tsangpo Grand Canyon acts as a major passage of monsoonal moisture transport from the Bay of Bengal into the Tibetan Plateau. However, the characteristics of nitrogen(N) deposition in this area are still unclear. Here, we established five N deposition monitoring sites and quantification the bulk N deposition fluxes from 2200 to 4600m above sea level in southeast Tibet. Results showed that the average precipitation amount of the five sites was 1127.7 mm. The dissolved organic nitrogen (DON) was the dominant species, and the deposition flux was 16.80 kg N ha−1 yr−1. The averaged NH4+-N deposition flux was 4.92 kg N ha−1 yr−1, whereas the NO3−-N deposition flux was 1.49 kg N ha−1 yr−1. In addition, the deposition fluxes of TDN, DON and NH4+-N were all significantly positive to precipitation amounts at all five sampling sites. However, the deposition flux of NO3−-N was significantly correlated with precipitation amount in the remote environment, and there was no correlation between precipitation amounts and NO3−-N deposition fluxes in human concentrated areas. TDN, DON and NH4+-N deposition were all concentrated in the plant growing season at all five sampling sites. In conclusion, the atmospheric TDN deposition flux in the Yarlung Zangbo Grand Canyon in southeast Tibet is mainly controlled by precipitation, and DON was the dominant species, followed by NH4+-N, and NO3−-N contribution was limited.

What Matters for an occurrenceID and What Is an occurrenceID That Matters?

In the Darwin Core data standard (Darwin Core Maintenance Group 2023), the concept of dwc:Occurrence (Wieczorek et al. 2012) in ecological data presents a data model construct not commonly found in data management practices used by ecological data collectors. We frequently encounter raw data without an Occurrence table. For example, the concept of Occurrence can be represented as a cell, where the rows represent sampling sites, the columns represent species, and the value of each cell indicates the count of the species at a specific site. A value in a cell in such a matrix can be interpreted as x number of individuals of species y occurred at sampling site z. While data providers tend to track data on tangible individual components (e.g., species, location, sample), generating "Occurrence records" typically requires pivoting and/or joining tables associated to these components. Maintaining a stable and persistent occurrenceID for an Occurrence record created through data transformation is not an easy task. This is especially true for long-term monitoring datasets, where the underlying tables used to generate Occurrence records are continuously updated. Additionally, most ecological data collectors are focused on the primary use of the data, not on the long term integration and accessibility of the data. The Occurrence concept is only required in data exchange format but not needed in ecological data management practices. The disconnect between the practical data management needs of data collectors and the abstractions required for data exchange raises challenges, particularly with an increasing expectation for globally unique and persistent occurrenceIDs. This presentation will explore the difficulties of creating and managing occurrenceIDs for data providers and managers, especially those who manage data using basic systems such as spreadsheets and simple relational databases. Maintaining stability and persistence of identifiers for inherently artificial constructs like Occurrences within the original, component-based data structure can pose significant challenges. We will explore why meaningful identifiers for occurrenceIDs are often preferred by data providers. We will unpack different use cases and delve into how and why occurrenceIDs were constructed for each use case. Through this discussion, we hope to spark a conversation that informs future data modeling efforts and addresses the inherent artificiality of Occurrences.

Differential relative catchability of wild‐ and hatchery‐origin steelhead in the Deschutes River, Oregon

AbstractObjectiveWe assessed the relative proportions of wild‐ and hatchery‐origin summer steelhead Oncorhynchus mykiss caught by sport anglers in the Deschutes River, Oregon. Our objective was to evaluate if steelhead of wild or hatchery origin were equally or disproportionately captured by sport anglers relative to the overall run composition.MethodsWe conducted access‐based angler creel surveys of the Deschutes River steelhead fishery during 2000–2019 and 2021 to observe reported catch of wild and hatchery steelhead. We collated fishery‐independent hatchery‐wild composition data from three locations (two dams and one fish trap) bounding the fishery area we creel sampled. We then used a series of mixed‐effect logistic regression models fit to compare angler catch of wild‐ and hatchery‐origin steelhead relative to their composition at the fishery‐independent sampling locations.ResultThe best‐fit model suggests that anglers were more than twice as likely to observe a wild steelhead in their catch as compared with the chance of the fishery‐dependent sampling sites to observe a wild steelhead. Across all years, wild steelhead were 27–31% of the stock composition at the fishery‐independent sampling sites yet averaged 65% of angler catch.ConclusionDisproportionately high encounter rates of wild‐origin summer steelhead suggest that any adverse impacts associated with catch‐and‐release fishing may be magnified by this effect. We explore some potential mechanisms that could account for this difference and hypothesize that a difference in catchability between wild and hatchery steelhead is the most likely mechanism driving the observed patterns. Regardless of the mechanism, annual catch of wild steelhead is proportionally greater than expectations, given wild steelhead run size compared with that of hatchery steelhead.

Source rock and petrophysical evaluation of the Late Cretaceous Haymana Formation, Haymana Basin, Central Anatolia, Turkey

This study investigates the petroleum potential of the mudstones of the Late Cretaceous Haymana Formation in the Haymana Basin, Turkey. Lithofacies, pore structure, and source rock characteristics of the mudstones are examined using stratigraphical, sedimentological, petrophysical, and organic geochemical methods along four stratigraphic sections and other sampling sites. The depositional model presents a facies distribution within a submarine fan system. According to bulk mineralogy, the identified lithofacies are mixed mudstone, mixed siliceous mudstone, marl, mixed carbonate mudstone, argillaceous/siliceous mudstone, and clay-rich siliceous mudstone. XRD and mercury intrusion measurements suggest that the macropores (&gt; 50 nm) of the mudstones formed by dissolution of calcite, while mesopores (2 nm-50 nm) developed around the clay/quartz/feldspar. Of the analysed samples, no lithofacies class is distinct with any specific range of porosity or permeability, which suggests a strong heterogeneity in pore throat size, mineral content, and grain size. The black shale from the northwest of the basin with 1.19% TOC, 0.07 mg/g S 1 , 1.01 mg/g S 2 , and 441°C T max is a relatively more mature source rock although it still exhibits poor petroleum potential. Overall, the TOC values (avg. 0.38%) of the mudstones suggest organic-poor rock characteristics for the Haymana Formation in the studied parts of the Haymana Basin.