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1.
Sci Rep ; 14(1): 19322, 2024 Aug 20.
Article in English | MEDLINE | ID: mdl-39164323

ABSTRACT

The Ili River Valley in Xinjiang, China, is a typical seasonal frozen area where loess landslide disasters have become increasingly common during the freeze-thaw periods in recent years. This study analyzed the macroscopic mechanical strength and microstructure changes of the Ili loess under different freeze-thaw cycles (FTCs) through the post-freeze-thaw triaxial compression test on the unsaturated soil in laboratory. Apart from the scanning electron microscopy (SEM), and the nuclear magnetic resonance (NMR), the macro-micro correlation analysis and the cluster-principal component analysis were applied for the theoretical discussion. The results indicated that the cohesive force of the loess exhibits an initial decreases, followed by the increases, and eventually keep stable after various FTCs, while the internal friction angle showed the opposite developing trend before the final constant. Similar to the strong correlation between the cohesive force and the particle abundance, the internal friction angle is also closely related to the abundance and orientation fractal dimension of the loess particles. However, the principal component analysis results showed that cohesive force strongly correlates with the average maximum pore size and the pore size fractal dimension, for which the internal friction angle most strongly affected by the average maximum particle size. The possible reason is that the extracted principal components represent a class of microscopic parameters with the same or similar change trend, although there may be a certain offset between them. The mechanical deterioration of loess is attributed to the repeated frost heaving force and the migration potential caused by FTCs. The alterations of the microstructure accelerated the deterioration of the macroscopic mechanical properties of the loess, which further widens the understanding of the mechanism behind the deterioration of loess mechanical strength in the Ili River Valley under FTCs, and contributes to the prevention and management of the local landslide disasters.

2.
Data Brief ; 55: 110626, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38993227

ABSTRACT

This publication contains data on geophysical measurements taken in the Szuszalewo wetlands located in northern Poland. The measurements were made using the electrical resistivity imaging (ERI) method. The ERI data was collected during two survey expeditions - March 30th, 31st (two ERI profiles), April 1st (one ERI profile), and May 12th (two prospection lines) 2023. The reason goal was to illustrate the arrangement of geological layers creating this wetland. The data repository contains detailed data descriptions for each survey site. This Electrical Resistivity Imaging (ERI) data from the selected survey sites can be used to perform numerical modeling of groundwater and surface water interaction in this environmentally valuable area, which is, to a certain extent a scientific terra incognita, hydrogeological investigation of hydraulic conductivity and hydrodynamic field, identify geological structure, and characterize engineering properties of the organic soils.

3.
Environ Sci Technol ; 58(26): 11718-11726, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38889109

ABSTRACT

Mountaintop removal coal mining is a source of downstream pollution. Here, we show that mountaintop removal coal mining also pollutes ecosystems downwind. We sampled regional snowpack near the end of winter along a transect of sites located 3-60 km downwind of coal mining in the Elk River valley of British Columbia, Canada. Vast quantities of polycyclic aromatic compounds (PACs), a toxic class of organic contaminants, are emitted and transported atmospherically far from emission sources. Summed PAC (ΣPAC) snowpack concentrations ranged from 29-94,866 ng/L. Snowpack ΣPAC loads, which account for variable snowpack depth, ranged from <10 µg/m2 at sites >50 km southeast of the mines to >1000 µg/m2 at sites in the Elk River valley near mining operations, with one site >15,000 µg/m2. Outside of the Elk River valley, snowpack ΣPAC loads exhibited a clear spatial pattern decreasing away from the mines. The compositional fingerprint of this PAC pollution matches closely with Elk River valley coal. Beyond our study region, modeling results suggest a depositional footprint extending across western Canada and the northwestern United States. These findings carry important implications for receiving ecosystems and for communities located close to mountaintop removal coal mines exposed to air pollution elevated in PACs.


Subject(s)
Coal Mining , Snow , British Columbia , Polycyclic Aromatic Hydrocarbons/analysis , Environmental Monitoring
4.
Sci Total Environ ; 932: 172950, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38703842

ABSTRACT

Increasing demands from agriculture and urbanization have decreased groundwater level and increased salinity worldwide. Better aquifer characterization and soil salinity mapping are important for proactive groundwater management. Airborne electromagnetic (AEM) is a powerful tool for aquifer characterization and salinity delineation. However, AEM needs to be interpreted with caution before being used for groundwater quality analysis. This study introduces a framework that utilizes the AEM data for both lithologic modeling and salinity delineation. A resistivity-to-lithology (R2L) model is developed to interpret AEM resistivity to lithology based a depth-dependent multi-resistivity thresholds. Then, a cokriging method is used to integrate AEM data from two different EM systems to predict resistivity at the aquifer. Finally, a resistivity-to-chloride concentration (R2C) model utilizes the resistivity model to estimate chloride concentrations at sand facies. A deep learning artificial neural network (DL-ANN) model is introduced with a successive bootstrapping approach to estimate total dissolved solids first and then use it together with resistivity data to estimate chloride concentration. The methodology was applied to delineating salinity plumes in the Mississippi River Valley alluvial aquifer (MRVA). This study found that the salinity distribution in MRVA is highly correlated with the Jurassic salt basin, salt domes, faulting, seismicity, and river water quality. The result indicates salinity upconing due to excessive pumping.

5.
Parasit Vectors ; 17(1): 186, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38605395

ABSTRACT

Starting in October 2021, quarterly malacological surveys have been undertaken in Malawi, with the sampling of 12 specified freshwater habitats throughout a calendar year. Each survey monitors the presence of aquatic intermediate snail hosts of medical and veterinary importance. In March 2023, the alien lymnaeid species Pseudosuccinea columella was encountered for the first time in the surveys, in Nsanje District. This species identity was later confirmed upon DNA analysis of mitochondrial ribosomal 16S sequences. In July 2023, P. columella was also noted at single sites within Mangochi and Chikwawa Districts, and again in Nsanje District, with an additional location observed. Of particular importance, our sampled location in Mangochi District was directly connected to Lake Malawi, which expands the species list of invasive molluscs in this lake. While P. columella is a well-known intermediate snail host for human and animal fascioliasis, screening collected snails for trematode cercariae, alongside molecular xenomonitoring, did not yield equivocal evidence of active fluke infection. However, the newly recognized presence of this alien intermediate snail host within Lake Malawi, and along the Shire River Valley, flags a new concern in altered local transmission potential for human and animal fascioliasis.


Subject(s)
Fasciola hepatica , Fascioliasis , Animals , Humans , Fasciola hepatica/genetics , Fascioliasis/veterinary , Malawi , Snails
6.
Sci Total Environ ; 912: 168613, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-37984659

ABSTRACT

The distributions of heavy metals in paddy fields and rice along river valleys were studied to explore the key factors affecting the accumulation of heavy metals in the upstream terraces and downstream plains. Results from 975 sampling sites showed that elevation, growing season and soil organic matter (OM) had significant effects on the content of Cd and Pb in topsoil and rice. The content of Cd (0.47-0.66 mg kg-1) and Pb (49.9-68.6 mg kg-1) in paddy fields with low elevation (30-60 m) in the downstream plains was significantly higher than the content of Cd (0.29-0.38 mg kg-1) and Pb (43.9-56.3 mg kg-1) in the upstream terraces with high altitude (60-90 m). In the double-rice production area, late rice generally produced grains with higher Cd and Pb content than early rice. Soil Cd was positively increased with the content of OM, especially in the downstream plains. When elevation was used for principal component analysis, plains with low elevation were grouped together with high content of total and soluble Cd, OM and Pb in soil, as well as high content of Cd and Pb in late rice. Altitude is one of the key factors affecting Cd content in rice. Although content of Cr (93.7-138.0 mg kg-1) was significantly higher than that of Cd and Pb in soil, content of Cr was lower than that of Cd in rice. These results indicate that paddy fields with elevation of 30-60 m in the downstream plains had high risk to produce late rice with Cd and Pb content exceeding the food safety standard 0.2 mg kg-1, which may be resulted from the driving force of runoff on soil soluble Cd and Pb from terraces to alluvial plains in river valleys.

7.
J Environ Manage ; 351: 119757, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38100863

ABSTRACT

Spatial conflicts of land use (SCLU) arise during land-use change, which causes an imbalance of land-use spatial patterns and negatively affects society, the economy, and ecology. Previous research has focused on identifying and measuring SCLU, with less attention on the negative effects. The incorporation of risk assessment methods to evaluate potential conflict risks has been limited. The current study presents methods for measuring SCLU and assessing potential conflict risks from the ecological environment perspective. The spatial comprehensive conflicts index and potential conflict risk index were used to identify and measure the SCLU and to assess and warn against potential conflict risks, respectively, based on a case study in the Ili River Valley in China. The impacts of terrain restriction and land-use change on the SCLU were explored. Results indicate that (1) the SCLU area in the Ili River Valley decreased by 2,608 km2 from 2010 to 2020, compared to the previous decade, the degree of conflict weakened, and the main body of the SCLU gradually shifted northwest. (2) The potential risk areas cover 20,268 km2 in 2020-2030 and are mainly distributed in the "Khorgas City-Huocheng County-Yining City-Yining County" group of towns, as well as along the Ili-Kunes rivers and in the ecological protection zone in the south of the Ili River Valley, which shows the clustering along the city and distribution along the river in the spatial pattern. (3) Topography had a significant impact on the SCLU, and the main types of land-use change in the severe-conflict zone were the reduction of grassland and the expansion of arable and built-up land. For future conflict mitigation in the Ili River Valley, cautioning against urban sprawl and safeguarding land ecological security is critical. This study systematically investigates and analyzes SCLU across three dimensions: theory, methodology, and application to produce a theoretical and practical framework to identify SCLU and assess potential conflict risks.


Subject(s)
Conservation of Natural Resources , Rivers , Cities , China , Risk Assessment , Ecosystem
8.
Huan Jing Ke Xue ; 44(4): 1899-1910, 2023 Apr 08.
Article in Chinese | MEDLINE | ID: mdl-37040941

ABSTRACT

To explore the characteristics and sources of PM2.5 in the core area of Ili River Valley in spring, a total of 140 PM2.5 samples were collected at six sampling sites during April 20-29, 2021, and 51 chemical components including inorganic elements, water-soluble ions, and carbon components were analyzed. The results showed that ρ(PM2.5) was at a low level during sampling, ranging from 9 µg·m-3 to 35 µg·m-3. Si, Ca, Al, Na, Mg, Fe, and K were the most abundant elements, accounting for 12% of PM2.5, indicating that PM2.5 was affected by the dust sources in spring. The spatial distribution characteristics of elements depended on the surrounding environments of the sampling sites. The new government area was affected by coal-fired sources, so the value of As concentration was high. Yining Municipal Bureau and the Second Water Plant were greatly affected by motor vehicle sources, so the values of Sb and Sn concentration were higher. The enrichment factor results showed that Zn, Ni, Cr, Pb, Cu, and As were mainly emitted from fossil fuel combustion and motor vehicles. The concentration of water-soluble ions accounted for 33.2% of PM2.5. Among them, ρ(SO42-), ρ(NO3-), ρ(Ca2+), and ρ(NH4+) were (2.48±0.57), (1.22±0.75), (1.18±0.49), and (0.98±0.45) µg·m-3, respectively. The higher Ca2+ concentration also reflected the contribution of dust sources. The ratio of n(NO3-)/n(SO42-) was between 0.63 and 0.85, which indicated that the influence of stationary sources was more important than that of mobile sources. Both Yining Municipal Bureau and the Second Water Plant were affected by motor vehicle exhaust; therefore, their n(NO3-)/n(SO42-) ratios were high. Yining County was in a residential area, and therefore its n(NO3-)/n(SO42-) ratio was lower. The average ρ(OC) and ρ(EC) in PM2.5 were 5.12 µg·m-3(4.67-6.25 µg·m-3) and 0.75 µg·m-3(0.51-0.97 µg·m-3), respectively. Yining Municipal Bureau was significantly affected by motor vehicle exhaust from both sides, so the values of OC and EC concentration were slightly higher than those in other sampling sites. The SOC concentration was calculated by the minimum ratio method, and the results showed that the values of SOC concentration in the New Government Area, the Second Water Plant, and Yining Ecological Environment Bureau were higher than those in other sampling sites. The results of the CMB model showed that PM2.5 in this area mainly came from the contribution of secondary particulate matter and dust sources, which accounted for 33.3% and 17.5%, respectively. Secondary organic carbon (16.2%) was the main contribution source of secondary particulate matter.

9.
Environ Sci Pollut Res Int ; 30(8): 20804-20820, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36260229

ABSTRACT

The increase in food needs due to high population growth in Niger has led to the intensification of urban agriculture and the increased use of pesticides. The objective of this study is primarily to assess the polar pesticide contamination (mainly herbicides) of the Niger River and its tributary, the Mekrou River, in Niger, using both grab sampling and POCIS (Polar Organic Chemical Integrative Samplers), and then to evaluate the risk to the aquatic environment. Two water sampling campaigns were carried out during the wet and dry seasons. The polar pesticides were analyzed by liquid chromatography coupled with tandem mass spectrometry, which allowed the identification of compounds with concentrations in the grab samples above the WHO guide values and the EU directive: diuron with 2221 ng/L (EU quality guideline: 200 ng/L), atrazine with 742 ng/L (EU quality guideline: 600 ng/L) and acetochlor with 238 ng/L (EU quality guideline: 100 ng/L). The risk assessment study indicated that diuron and atrazine present a high risk for the aquatic environment during the wet season. The main source of water contamination is the intensive use of pesticides in urban agriculture near the city of Niamey, and the intensive cotton farming in the Benin. Moreover, the surveys (30 producers interviewed) showed that 70% of the pesticides used are not approved by the Interstate Committee for Drought Control in the Sahel (CILSS) and some are prohibited in Niger. The inventory of pesticides sold in the zone showed that active ingredients used by producers are 48% insecticides, 45% herbicides, and 7% fungicides.


Subject(s)
Atrazine , Herbicides , Pesticides , Water Pollutants, Chemical , Pesticides/analysis , Rivers/chemistry , Diuron/analysis , Atrazine/analysis , Niger , Environmental Monitoring/methods , Herbicides/analysis , Water/analysis , Water Pollutants, Chemical/analysis
10.
Huan Jing Ke Xue ; 43(11): 5009-5017, 2022 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-36437073

ABSTRACT

The simultaneous observation and analysis of atmospheric particles on a regional scale is an important approach to developing control strategies for air pollution. To study the spatial distribution characteristics of particulate matter and water-soluble inorganic ions in the Ili Valley Urban agglomeration, PM2.5 and PM10 samples were synchronously collected from July 19 to July 29, 2021 in Yining City and the surrounding three counties, and then nine types of water-soluble inorganic ions (WSIIs) were analyzed. The spatial distribution characteristics, existence form of WSIIs, and influencing factors were discussed in depth. The results showed that the average ρ(PM2.5) and ρ(PM10) in the Ili River Valley urban agglomeration in summer were 23 µg·m-3 and 59 µg·m-3, respectively. The emission of local industrial and mobile sources in Yining City was higher than that of the surrounding three counties, resulting in the highest ρ(PM2.5) in the region (25 µg·m-3). Due to the influence of dust sources and topography, the ρ(PM10) in Yining county was the highest in the region (63 µg·m-3). Huocheng county is located upwind of the region, and these favorable diffusion conditions resulted in the lowest ρ(PM2.5) and ρ(PM10) (20 µg·m-3 and 49 µg·m-3, respectively). The concentrations of WSIIs in PM2.5 and PM10 ranged from 28.2%-29.9% and 16.0%-20.2%, respectively. The four main ions (SO42-, NO3-, NH4+, and Ca2+) accounted for approximately 90% of WSIIs mass concentrations. The concentration order of the four main ions in PM2.5 was SO42->Ca2+>NH4+>NO3- and SO42->Ca2+>NO3->NH4+ in PM10. The results of correlation analysis showed that the similar SO42- concentrations in the four cities were mainly caused by regional transport. Ca2+ was the highest-concentration ion in PM10 of Yining City and Qapqal Xibe Autonomous county, and the proportion of Ca2+ was significantly higher than that in most cities in China, which reflected that the cities in the core area of the Ili Valley were greatly affected by the dust sources. The ratios of n(NO3-)/n(SO42-) in PM2.5 and PM10 were 0.78 and 0.76, respectively, indicating that the influence of stationary sources was greater than that of mobile sources. The ratio of n(NO3-)/n(SO42-) in Yining City>Huocheng county>Yining county>Qapqal Xibe Autonomous county, which was consistent with the motor vehicle populations of the four cities, reflecting that Yining City was affected by motor vehicle sources more than the surrounding three counties. The secondary components mainly existed in the form of (NH4)2SO4, NH4HSO4, and NH4NO3. There was excess ammonia after the reaction between NH4+ and SO42- in each city. NH4NO3 mainly existed in Yining City, which was mainly related to high NO2 in Yining City. The NOR of the four cities were 0.03-0.10 and 0.03-0.16 in PM2.5 and PM10, respectively, and the secondary transformation of NO3- was weak due to the influence of high temperatures in summer. The SOR were 0.21-0.41 and 0.23-0.44, respectively. The SOR of Qapqal Xibe Autonomous county was the highest due to the relatively high humidity, whereas the SOR of Huocheng county was higher than that of the three sites in Yining City due to the influence of regional transportation. The formation mechanisms showed that SO42- in Qapqal Xibe Autonomous county and Yining City were mainly produced by the heterogeneous reaction, and in Yining county it was mainly formed via the homogeneous reaction. However, the formation mechanism in Huocheng county was complex and was affected by both homogeneous and heterogeneous reactions.


Subject(s)
Air Pollutants , Rivers , Air Pollutants/analysis , Water/analysis , Environmental Monitoring/methods , Particulate Matter/analysis , Ions/analysis , Dust/analysis
11.
Heliyon ; 8(6): e09640, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35711997

ABSTRACT

The majority of tallgrass prairie has been lost from North America's Great Plains, but remaining tracts often support significant biodiversity. Despite permanent protections for some remnants, they continue to face anthropogenic threats including habitat fragmentation, invasive species, and climate change. Conservationists have sought to buffer remnants from threats using prairie restoration but limited research has assessed such practices at the landscape-level. We reexamine the flora of Mormon Island, the largest tract of lowland tallgrass prairie remaining in the Central Platte River Valley (CPRV) of Nebraska, USA, nearly 40-years after it was initially inventoried and following widespread restoration. We also conducted preliminary inventories of nearby Shoemaker Island and adjacent off-island habitats using an ecotope-based stratified random sampling approach. We examined change at Mormon Island between 1980-1981 and 2015-2020 and compared it to adjacent conservation lands using a number of vegetation indices. We documented 389 vascular plant species on Mormon Island, 405 on Shoemaker Island, and 337 on off-island habitats from 2015-2020, which represented an increase in native and exotic species richness on Mormon Island compared to 1980-1981 results. Floristic quality index (FQI) values increased at Mormon Island between 1980-1981 and 2015-2020. Paradoxically, the distribution of exotic-invasive species also expanded. Mormon Island from 2015-2020 was more similar to Shoemaker Island and off-island habitats from 2015-2020 than Mormon Island from 1980-1981. Widespread restoration introduced a number of high conservation value species native to Nebraska but novel to the CPRV, which improved FQIs despite increased exotic species invasion. These concurrent trends appear to have driven biological homogenization across the study area. Restoration did not fully buffer Mormon Island from exotic species invasion but it may have partially mitigated the impact considering the persistence of most native species across a 40-year period. We recommend using "local ecotype" seed for restorations to preserve distinctive local communities.

12.
PeerJ ; 10: e13311, 2022.
Article in English | MEDLINE | ID: mdl-35529498

ABSTRACT

Soil nutrients are a vital reference index of soil fertility and are essential in studying spatial variability for the development of land resources. The traditional statistical methods including correlation analysis and geostatistical analysis, were used to explore the spatial variability of nutrients and its influencing factors in the Yili River Valley. The results showed that soil total potassium (STK) had a weak variation, soil organic carbon (SOC), soil total nitrogen (STN) and soil total phosphorus (STP) showed a moderate degree of variation. Correlation analysis showed that SOC had a significant correlation with STN, STP, STK, silt, soil water content (SWC), Cos a and altitude (p < 0.01). In contrast, negative correlations were found between the SOC and sand, soil bulk density (SBD) and pH (p < 0.01), the same as STN. STP had a significant correlation with STK, silt (p < 0.01) and Cos a (p < 0.05), whereas negative correlations were found between the STP, sand and SBD (p < 0.01). STK had a significant correlation with silt, whereas negative correlations were found between the STK, sand and SBD. Ordinary Kriging interpolation showed that the distribution of SOC and STN had a high value in the northeast, northwest and southeast, and a low value in the central and southwest. STP was high in the northwest and southeast and low in the northeast and southwest. STK was high in the northwest and northeast and low in the central and southeast regions. This is helpful for the rational exploitation of land resources in ecological economy development in the Yili River Basin.


Subject(s)
Sand , Soil , Soil/chemistry , Rivers , Carbon , Nutrients , Nitrogen/analysis , Phosphorus
13.
Ecol Evol ; 12(5): e8940, 2022 May.
Article in English | MEDLINE | ID: mdl-35600693

ABSTRACT

Large river valleys (LRVs) are heterogeneous in habitat and rich in biodiversity, but they are largely overlooked in policies that prioritize conservation. Here, we aimed to identify plant diversity hotspots along LRVs based on species richness and spatial phylogenetics, evaluate current conservation effectiveness, determine gaps in the conservation networks, and offer suggestions for prioritizing conservation. We divided the study region into 50 km × 50 km grid cells and determined the distribution patterns of seed plants by studying 124,927 occurrence points belonging to 14,481 species, using different algorithms. We generated phylogenies for the plants using the "V. PhyloMaker" R package, determined spatial phylogenetics, and conducted correlation analyses between different distribution patterns and spatial phylogenetics. We evaluated the effectiveness of current conservation practices and discovered gaps of hotspots within the conservation networks. In the process, we identified 36 grid cells as hotspots (covering 10% of the total area) that contained 83.4% of the species. Fifty-eight percent of the hotspot area falls under the protection of national nature reserves (NNRs) and 83% falls under national and provincial nature reserves (NRs), with 42% of the area identified as conservation gaps of NNRs and 17% of the area as gaps of NRs. The hotspots contained high proportions of endemic and threatened species, as did conservation gaps. Therefore, it is necessary to optimize the layout of current conservation networks, establish micro-nature reserves, conduct targeted conservation priority planning focused on specific plant groups, and promote conservation awareness. Our results show that the conservation of three hotspots in Southwest China, in particular, is likely to positively affect the protection of biodiversity in the LRVs, especially with the participation of the neighboring countries, India, Myanmar, and Laos.

14.
Phytochemistry ; 200: 113185, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35436476

ABSTRACT

The study of floral trait diversity has a long history due to its role in angiosperm diversification. While many studies have focused on visual traits including morphology and color, few have included floral scent despite its importance in pollination. Of the studies that have included floral scent, sampling has been limited and rarely explores variation at the population level. We studied geographic variation in the flowers of Oenothera harringtonii, a rare plant endemic to a vulnerable shortgrass prairie habitat, whose population structure and conservation status are well studied. The self-incompatible flowers of O. harringtonii open at dusk, produce nectar and a strong fragrance, and are pollinated by hawkmoths. We collected floral trait (morphology, scent chemistry and emission rates) data from 650 individuals from 19 wild populations to survey floral variation across the entire range of this species. Similarly, we collected floral data from 49 individuals grown in a greenhouse common garden, to assess whether variation observed in the field is consistent when environment factors (temperature, watering regime, soil) are standardized. We identified 35 floral volatiles representing 5 biosynthetic classes. Population differentiation was stronger for floral scent chemistry than floral morphology. (R)-(-)-linalool was the most important floral trait differentiating populations, exhibiting clinal variation across the distribution of O. harringtonii without any correlated shifts in floral morphology. Populations in the north and west produced (R)-(-)-linalool consistently, those in the east and south largely lacked it, and populations at the center of the distribution were polymorphic. Floral scent emissions in wild populations varied across four years but chemical composition was largely consistent over time. Similarly, volatile emission rates and chemical composition in greenhouse-grown plants were consistent with those of wild populations of origin. Our data set, which represents the most extensive population-level survey of floral scent to date, indicates that such sampling may be needed to capture potentially adaptive geographic variation in wild populations.


Subject(s)
Oenothera biennis , Oenothera , Acyclic Monoterpenes , Flowers/chemistry , Odorants , Pollination
15.
Chemosphere ; 295: 133845, 2022 May.
Article in English | MEDLINE | ID: mdl-35151704

ABSTRACT

Trace elements and water-soluble ions in snow can be used as indicators to reveal natural and anthropogenic emissions. To understand the chemical composition, characteristics of snow and their potential sources in the Ili River Valley (IRV), snow samples were collected from 17 sites in the IRV from December 2018 to March 2019. Inverse distance weighting, enrichment factor (EF) analysis, and backward trajectory modelling were applied to evaluate the spatial distributions and sources of water-soluble ions and dissolved arsenic (As) in snow. The results indicate that Ca2+ and SO42- were the dominant ions, and the concentrations of As ranged from 0.09 to 0.503 µg L-1. High concentrations of As were distributed in the northwest and middle of the IRV, and the concentrations of the major ions were high in the west of the IRV. The strong correlation of As with F-, SO42-, and NO2- demonstrates that As mainly originated from coal-burning and agricultural activities. Principal component analysis showed that the ions originated from a combination of anthropogenic and crustal sources. The EFs showed that K+, SO42-, and Mg2+ were mainly influenced by human activities. Backward trajectory cluster analysis suggested that the chemical composition of snow was affected by soil dust transport from the western air mass, the unique terrain, and local anthropogenic activities. These results provide important scientific insights for atmospheric environmental management and agricultural production within the IRV.


Subject(s)
Air Pollutants , Arsenic , Air Pollutants/analysis , Arsenic/analysis , China , Environmental Monitoring/methods , Humans , Ions/analysis , Rivers , Snow/chemistry , Water/analysis
16.
Environ Sci Pollut Res Int ; 29(29): 44862-44873, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35137318

ABSTRACT

The study covered an urban river valley, strongly transformed due to the transport infrastructure development. The paper evaluates changes in spatial management of the valley section passing through the city centre that occurred during the past two centuries (long-term and short-term phenomena) as well as their effect on selected environmental components. The basic spatial analyses were carried out with the use of specialized software, cartographic materials and photographic and descriptive documentation of the studied area (archival data). The most unfavourable changes in the potential of the valley environment occurred over the past few decades. They are manifested in a considerable deterioration of landscape values as well as the quantity and quality of water resources. Relationship was identified between water quality and intensity of motor vehicle traffic near the river. Despite the progressing urbanisation of the valley, revitalisation procedures can be still carried out and attractive space in the city centre can be created. In order to demonstrate the reasonableness of the presented concept, the paper suggests that urban succession should be incorporated as a term covering time trends and accumulated transformations. It can be helpful in analysing and determining the directions of development in disputable situations.


Subject(s)
Environmental Monitoring , Rivers , Cities , Environmental Monitoring/methods , Poland , Rivers/chemistry , Water Quality
17.
PhytoKeys ; 213: 1-18, 2022.
Article in English | MEDLINE | ID: mdl-36762248

ABSTRACT

A new orchid species, Hemipiliaavisoides, is described from Songpan County and Maoxian County, Sichuan Province, China. Morphologically, H.avisoides is most similar to H.hui, but can be distinguished by the combination of its involute middle lip lobe that is smaller than the lateral lobes, floral bracts that are 5 mm long and are always shorter than the ovary, a leaf that is appressed to the substrate and is adaxially green with white lines along 7-9 principal veins and the subterranean stem with a solitary sheath at its base. The floral morphology of H.avisoides is presented by utilising in vivo micro-CT scanning and 3D visualisation.

18.
Biodivers Data J ; 9: e70975, 2021.
Article in English | MEDLINE | ID: mdl-34539204

ABSTRACT

BACKGROUND: The family Nymphalidae is the largest group of butterflies with high species richeness. Rhinopalpapolynice (Cramer, [1779]), a forest species, was discovered in the mid-stream of the Yuanjiang-Red River Valley of Yunnan Province for the first time, which represents the first record of the genus Rhinopalpa in China. NEW INFORMATION: The species R. polynice (Cramer, [1779]) is the first record of the genus Rhinopalpa from China. The specimen was collected in the mid-stream of the Yuanjiang-Red River Valley of Yunnan Province. The female genitalia are described for the first time.

19.
Data Brief ; 37: 107256, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34377753

ABSTRACT

This study aimed to provide datasets useful for identifying and disentangling any complex patterns in the fine spatial heterogeneity of a common nonpoint source pollutant, nitrate, as well as other related water quality metrics (temperature, dissolved oxygen, pH, and conductivity) in streams of the eastern U.S. We aimed specifically to provide a resource dataset of uniquely high spatial detail for the better understanding of how the rapid appearance or disappearance of this common nutrient at fine scales may relate to other aspects of form and function in these watersheds. To accomplish this, the low-order streams observed in this study extend across environmental gradients in urban and rural land cover, and change from free flowing to impounded water. Study streams were also observed at different levels of steam discharge, both pre and post summer storm events. Four unique 600 m stretches of two low-order creeks in Dutchess County, New York, were observed longitudinally at a fine spatial resolution (20 m). These four 600 m stretches contrasted in land cover from heavily urban channelized streams to mainly rural meandering streams with seasonally active floodplains. Data collection occurred above and below areas where impounded water was input into to the stream via a side tributary to observe the effect of adjacent impoundments, and fine scale water quality was assessed both before and after major storm events to see the influence of wet-period flow path activation on nonpoint source fluxes. Data was organized into a final data table and maps showing how water quality parameters change in regard to land use and land cover, free flowing versus impounded water, and the influence of storm events versus dry periods. Water quality data are also mapped in comparison to thresholds of concern for growth of cyanobacteria - a common constituent of harmful algal blooms in the region. Fine spatial resolution data from this study can be used as a baseline for future studies or modeling efforts at similarly fine scales to better understand why concentrations of nitrate rapidly rise or fall longitudinally at <100 m scales within these forms of streams, and how land cover change and intensified storms due to climate change may further influence water quality dynamics at these uniquely fine scales.

20.
Plant Divers ; 43(3): 181-191, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34195502

ABSTRACT

Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora, ignoring the potential contributions of high habitat/ecosystem heterogeneity. Furthermore, current conservation strategies largely focus on forest ecosystems and/or specific flagship species, ignoring marginal ecosystems, leaving species in these ecosystems at risk. Here, we compared the spatial patterns of biodiversity and the potential drivers of these patterns in the river valley and subnival ecosystems of the Hengduan Mountains region (HDM) in southwestern China. Specifically, we compared spatial patterns of diversity, endemism, and threatened species in these ecosystems based on both traditional measurements and recent phylogenetic approaches. We then examined how those patterns were related to environmental factors and human activity in these same regions. We found that the middle-southern HDM supports the highest diversity and endemism for the river valley and subnival ecosystems; however, the distribution patterns of neo- and paleo-endemism in these two ecosystems differ. Regression models indicate that habitat diversity and paleo-climatic fluctuation are important drivers of diversity and endemism for these two ecosystems. Temperature and precipitation, however, showed different influences on the spatial patterns in different ecosystems. Categorical analysis of neo- and paleo-endemism (CANAPE) indicated that most endemism centers are not covered by current nature reserves. Moreover, the intensity of human activity is highest in the southern and southeastern HDM, which coincides with the distribution patterns of diversity, mixed-endemism and high-priority (and threatened) species. These findings suggest that different floras within a single geographic/floristic region respond differently to environmental factors and show different spatial phylogenetic patterns. We, therefore, recommend that future research into the drivers of biodiversity consider the contributions of various ecosystem types within a single geological region. This study also provides a theoretical basis for protecting habitat diversity. Our work confirms that current conservation efforts are insufficient to protect ecosystem diversity in the river valley and subnival ecosystems of the Hengduan Mountains. Therefore, we recommend the establishment of nature reserves in the regions identified in this study; furthermore, we strongly recommend improving current and establishing new management policies for biodiversity conservation in this region.

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