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1.
Mar Environ Res ; 169: 105391, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34217096

RESUMO

Eutrophication is an increasing problem worldwide and can disrupt ecosystem processes in which macrobenthic bioturbators play an essential role. This study explores how intraspecific variation in body size affects the survival, mobility and impact on sediment organic matter breakdown in enriched sediments of an infaunal bivalve. A mesocosm experiment was conducted in which monocultures and all size combinations of three body sizes (small, medium and large) of the Sydney cockle, Anadara trapezia, were exposed to natural or organically enriched sediments. Results demonstrate that larger body sizes have higher tolerance to enriched conditions and can reduce survival of smaller cockles when grown together. Also, large A. trapezia influenced sediment organic matter breakdown although a direct link to bioturbation activity was not clear. Overall, this study found that intraspecific variation in body size influences survival and performance of bioturbators in eutrophic scenarios.


Assuntos
Bivalves , Cardiidae , Animais , Tamanho Corporal , Ecossistema , Sedimentos Geológicos
2.
Mar Environ Res ; 169: 105404, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34225218

RESUMO

The increase in frequency and intensity of extreme climate events over the last few decades has been leading to profound changes in estuarine and marine ecosystems worldwide, with strong implications for the species inhabiting these ecosystems as well as for the services provided by them. In this study, we analysed the effects of climate variability on the temporal and spatial variations in population dynamics of the green crab Carcinus maenas in the Mondego estuary (Portugal), between 2003 and 2018. In this 15-year period, a greater recruitment of C. maenas was observed during drought periods, periods which was matched by an increase in secondary production. Ontogenic stage segregation was also observed, with juveniles being found mainly in the further upriver areas of the estuary. The estuarine population was mainly composed of the green morphotype, with the orange and red morphotypes present in more downstream areas of the estuary. Redundancy analysis (RDA) showed high spatial and temporal variability of C. maenas in the estuary which was related with environmental changes over the 15-year period. A correlation between C. maenas biological features and several local-scale (salinity and river runoff) and large-scale (North Atlantic Oscillation index and Eastern Atlantic pattern) environmental variables was identified through cumulative sums analysis (CUSUM), indicating a strong environmental control on C. maenas population dynamics. This paper shows the importance of relatively long-term datasets to unravel the effects of extreme weather events due to climate change on key epibenthic estuarine species, and also how they might cope with a changing marine environment.


Assuntos
Braquiúros , Animais , Ecossistema , Estuários , Portugal , Rios
3.
Mar Environ Res ; 169: 105384, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34233256

RESUMO

Experimental benthic dredging was conducted in an unfished, muddy area in the Baltic Proper to mimic the impact of trawling by removing surface sediment, with a focus on benthic biogeochemical processes. Sediment cores were taken on the track and compared to undisturbed controls. Benthic fluxes were immediately affected and an upward shift in pore water DIC profiles was detected. The time needed for the sediment to readjust to a new biogeochemical state seemed to be nutrient-specific. Sediment properties (profiles of chlorophyll, organic carbon and water content) were found to change significantly. Macrofauna was removed completely by the dredge pointing out the potential loss of highly valuable functions that are associated with them. In the Baltic Sea, in areas which were previously the most heavily fished, the frequency of trawling may have left little time for readjustment and potentially kept the seabed in a permanent state of transient biogeochemical cycling.


Assuntos
Ecossistema , Sedimentos Geológicos , Países Bálticos , Carbono , Clorofila
4.
BMC Genomics ; 22(1): 490, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193045

RESUMO

BACKGROUND: Global climate oscillation, as a selection dynamic, is an ecologically important element resulting in global biodiversity. During the glacial geological periods, most organisms suffered detrimental selection pressures (such as food shortage and habitat loss) and went through population declines. However, during the mild interglacial periods, many species re-flourished. These temporal dynamics of effective population sizes (Ne) provide essential information for understanding and predicting evolutionary outcomes during historical and ongoing global climate changes. RESULTS: Using high-quality genome assemblies and corresponding sequencing data, we applied the Pairwise Sequentially Markovian Coalescent (PSMC) method to quantify Ne changes of twelve representative teleost species from approximately 10 million years ago (mya) to 10 thousand years ago (kya). These results revealed multiple rounds of population contraction and expansion in most of the examined teleost species during the Neogene and the Quaternary periods. We observed that 83% (10/12) of the examined teleosts had experienced a drastic decline in Ne before the last glacial period (LGP, 110-12 kya), slightly earlier than the reported pattern of Ne changes in 38 avian species. In comparison with the peaks, almost all of the examined teleosts maintained long-term lower Ne values during the last few million years. This is consistent with increasingly dramatic glaciation during this period. CONCLUSION: In summary, these findings provide a more comprehensive understanding of the historical Ne changes in teleosts. Results presented here could lead to the development of appropriate strategies to protect species in light of ongoing global climate changes.


Assuntos
Variação Genética , Genoma , Evolução Biológica , Mudança Climática , Ecossistema , Densidade Demográfica
5.
Sensors (Basel) ; 21(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208507

RESUMO

Spaceborne imaging spectroscopy, also called hyperspectral remote sensing, has shown huge potential to improve current water colour retrievals and, thereby, the monitoring of inland and coastal water ecosystems. However, the quality of water colour retrievals strongly depends on successful removal of the atmospheric/surface contributions to the radiance measured by satellite sensors. Atmospheric correction (AC) algorithms are specially designed to handle these effects, but are challenged by the hundreds of narrow spectral bands obtained by hyperspectral sensors. In this paper, we investigate the performance of Polymer AC for hyperspectral remote sensing over coastal waters. Polymer is, in nature, a hyperspectral algorithm that has been mostly applied to multispectral satellite data to date. Polymer was applied to data from the Hyperspectral Imager for the Coastal Ocean (HICO), validated against in situ multispectral (AERONET-OC) and hyperspectral radiometric measurements, and its performance was compared against that of the hyperspectral version of NASA's standard AC algorithm, L2gen. The match-up analysis demonstrated very good performance of Polymer in the green spectral region. The mean absolute percentage difference across all the visible bands varied between 16% (green spectral region) and 66% (red spectral region). Compared with L2gen, Polymer remote sensing reflectances presented lower uncertainties, greater data coverage, and higher spectral similarity to in situ measurements. These results demonstrate the potential of Polymer to perform AC on hyperspectral satellite data over coastal waters, thus supporting its application in current and future hyperspectral satellite missions.


Assuntos
Imageamento Hiperespectral , Polímeros , Algoritmos , Ecossistema , Água
6.
Huan Jing Ke Xue ; 42(7): 3156-3165, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212641

RESUMO

Watershed land use patterns combined with hydrological regimes affect riverine nitrogen (N) sources, transformation pathways, and exports, which can affect watershed health and freshwater ecosystem service supply. Understanding how land use and hydrological regimes affect riverine N exports is therefore useful for developing sustainable watershed management strategies. Based on in-situ observations during the period 2010-2017, watershed modeling, geospatial technology, and statistical analysis were coupled in this study to explore the responses of riverine nitrogen exports to watershed land use pattern and hydrological regime in a medium-sized watershed. Results showed that nitrate was the major form of dissolved inorganic N in the Jiulong River watershed; agricultural and urban watersheds had higher N exports and greater temporal variability than those in natural watershed. The seasonal fluctuation for watershed N concentrations and exports was obvious in wet years compared with dry years. Compared with the hydrological regime, the land use pattern had significant effects on N concentrations and exports. This study demonstrated that spatiotemporal variations of riverine nitrogen exports were mainly contributed by the coupled effects of watershed land use pattern and hydrological regime.


Assuntos
Rios , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Nitrogênio/análise , Poluentes Químicos da Água/análise
7.
Huan Jing Ke Xue ; 42(7): 3242-3252, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212650

RESUMO

Changes in the community stability of freshwater phytoplankton not only induce a series of ecological environment problems but also influence freshwater ecosystem service functions. To understand the changes in community stability and its driving factors, phytoplankton and environmental parameters were analyzed at 11 sample sites in Huaxi River, a tributary of the Three Gorges Reservoir, in spring, summer, autumn, and winter. Moreover, the resource use efficiency (RUEPP), phytoplankton richness (S), phytoplankton evenness (J), and community turnover (BC) were also determined. Results showed that a total of 8 phyla, including 103 genera and 380 species, were identified in Huaxi River throughout the year. Among them, 264 species were collected in spring, 181 in summer, 197 in autumn, and 183 in winter. The number of Chlorophyta was the largest, followed by Bacillariophyta, Euglenophyta, and Cyanophyta. The number of species and cell density in S0 site were the smallest, while those in S2 site were the largest. The RUEPP was fluctuated in four seasons, with the maximum in summer and the minimum in autumn. BC was significantly negatively correlated with RUEPP, phytoplankton richness, total phosphorus (TP), orthophosphate (PO43--P), total nitrogen (TN), nitrate (NO3--N), permanganate index, and conductivity (Spc); however, it was significantly positively correlated with phytoplankton evenness and dissolved oxygen (DO). These results suggest that water level regulation in the Three Gorges Reservoir has a significant impact on the structure of phytoplankton community in Huaxi River, which leads to the instability of phytoplankton community and easy replacement, and the degree of community turnover is affected by the combined effect of biological and abiotic factors.


Assuntos
Diatomáceas , Fitoplâncton , China , Ecossistema , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise , Rios , Estações do Ano
8.
Huan Jing Ke Xue ; 42(7): 3442-3450, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212671

RESUMO

Based on Landsat satellite remote sensing images, this study interprets land use changes in the Yangtze River Delta (YRD) region from 2000 to 2018. Combined with changes in nitrogen fertilizer application, the changes in ammonia emissions from farmland ecosystem due changes in land use and nitrogen fertilizer application were further investigated. The results show that along with the rapid urbanization process, the area of cultivated land in the YRD region has gradually decreased from 276269 km2 (49% of total land area) in 2000 to 244001 km2 (44%) in 2018. The effects of changes in land use and nitrogen fertilizer application on ammonia emissions from farmland ecosystems mainly include emissions from soil background and nitrogen fertilizer application. From 2000 to 2018, ammonia emissions due to the application of nitrogen fertilizer decreased from 690 kt·a-1 to 541 kt·a-1 (relative decrease by 22%), while the ammonia emissions from the soil background reduced from 32 kt·a-1 to 29 kt·a-1 (decrease by 9%). During the past 20 years, urbanization in the YRD region has accelerated, and the area of cultivated land and the total amount of nitrogen fertilizer application have significantly reduced, thus resulting in reductions in ammonia emissions from the farmland ecosystem.


Assuntos
Amônia , Ecossistema , Agricultura , Amônia/análise , China , Fertilizantes/análise , Nitrogênio/análise , Rios , Solo
9.
Environ Monit Assess ; 193(8): 462, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34216287

RESUMO

Monitoring degraded areas is essential for evaluation of the quality of the rehabilitation process. In this study, we evaluate how the physical and chemical characteristics of the mixture of iron ore tailings with the soil have affected the soil microbial biomass and activity in areas along the Gualaxo do Norte River after the Fundão Dam disaster. Composite soil samples were collected from areas that were impacted (I) and not impacted (NI) by the tailings. The following attributes were evaluated: chemical element content; soil density, porosity, and texture; microbial biomass carbon; basal respiration; and enzyme activity and density of microbial groups (bacteria, actinobacteria, fungi, arbuscular mycorrhizae, phosphate solubilizers, cellulolytic microorganisms, nitrifiers, ammonifiers, and diazotrophs). According to result, the deposition of tailings increased the pH and the soil available P, Cr, Fe, and Mn content and reduced organic matter. The physical and biological attributes were negatively affected, with increases in the silt content and density of the soil, and reduction in macroporosity and in the microbial biomass and activity of the soil (respiration and enzymes) in the impacted area. However, the impacted areas exhibited greater densities of some microbial groups (cellulolytic microorganisms, nitrifiers, and diazotrophic bacteria). Modifications in the organic matter and silt content are the main attributes associated with deposition of the tailings that affected soil microbial biomass and microbial activity. This may affect erosive conditions and the functionality of the ecosystem, indicating an imbalance in this environment. In contrast, the higher density of some microbial groups in the impacted areas show the high rehabilitation potential of these areas.


Assuntos
Poluentes do Solo , Solo , Ecossistema , Monitoramento Ambiental , Ferro , Microbiologia do Solo , Poluentes do Solo/análise
10.
Environ Monit Assess ; 193(8): 473, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34228211

RESUMO

Radiocaesium and radiostrontium contamination in the 'soil - rhizosphere - plants (aerial parts)' system was monitored in the floodplain ecosystem of the Yenisei River in the near impact zone of the Krasnoyarsk Mining and Chemical Combine (MCC). The monitored system included soil, rhizosphere, and sedge vegetation on islands and the river's east bank. The 137Cs and 90Sr specific activities displayed intricate space and time patterns controlled by the river water level, including the time and duration of floods and their correlation with the sedge vegetation season. The specific activities of both radionuclides, especially 137Cs, were above the background in all years of observation, except in a few cases. The soil-to-plant transfer factor (TF) patterns showed continuous 137Cs and 90Sr influx into the system and annual variations in the shares of their bioavailable and fixed forms, especially for 90Sr. The 90Sr distribution in the 'soil - rhizosphere - plants' system observed in 2014-2016 provides evidence for possible local fallout.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Poluentes Radioativos da Água , Radioisótopos de Césio/análise , Ecossistema , Monitoramento Ambiental , Rizosfera , Rios , Federação Russa , Solo , Poluentes Radioativos do Solo/análise , Radioisótopos de Estrôncio , Poluentes Radioativos da Água/análise
11.
Environ Monit Assess ; 193(8): 475, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34231083

RESUMO

The transient storage model (TSM) is a common approach to assess solute transport and pollution modeling in rivers. Several formulas have been developed to estimate TSM parameters. This study develops a new hybrid optimization algorithm consisting of the dragonfly algorithm and simulated annealing (DA-SA) algorithms. This robust method provides accurate formulas for estimating TSM parameters (e.g., kf, T, [Formula: see text]). A dataset gathered by previous scholars from several rivers in the USA was used to assess the proposed formulas based on several error metrics ([Formula: see text] and [Formula: see text]) and visual indicators. According to the results, DA-SA-based formulas adequately estimated the [Formula: see text] ([Formula: see text], [Formula: see text]), [Formula: see text] ([Formula: see text] [Formula: see text]), and [Formula: see text] ([Formula: see text] [Formula: see text]) parameters. Moreover, the DA-SA-1 showed higher accuracy by improving the RMSE and MAE by 98% compared to the DA and DA-SA-1 as alternatives. The formulas developed in this study significantly outperformed the results of previously proposed models by enhancing the NSE up to 70%. The hybrid DA-SA algorithm method proved highly reliable models to estimate the TSM parameters in the water pollution routing problem, which is vital for reactive solute uptake in advective and transient storage zones of stream ecosystems.


Assuntos
Ecossistema , Rios , Algoritmos , Monitoramento Ambiental , Poluição Ambiental
12.
Cien Saude Colet ; 26(6): 2035-2052, 2021 Jun.
Artigo em Português, Inglês | MEDLINE | ID: mdl-34231717

RESUMO

Technological advances play an undeniable role in strengthening health systems. With regard to digital technologies, information systems and the analysis of health data are playing a growing role in health surveillance and preparing for and responding to disease outbreaks, the theme addressed by this article within the context of the Covid-19 pandemic in the State of Rio Grande do Norte. This study departs from the assumption that digital health interventions can increase Covid-19 response capacity. We developed a technology ecosystem that integrates different information systems to meet the needs outlined in international regulations governing the response to the pandemic. In addition to the main elements of the ecosystem, this article describes the application of this instrument by different institutional actors. The main decision making tool used in the state government's Covid-19 response, the ecosystem is a model for digital health interventions in Brazil's national health service. This experience in Rio Grande do Norte brings together elements that can contribute to studies investigating the resilience of health systems and analyzing health policies in emergency situations.


Assuntos
COVID-19 , Medicina Estatal , Brasil , Ecossistema , Humanos , Pandemias , SARS-CoV-2 , Tecnologia
13.
Sensors (Basel) ; 21(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200730

RESUMO

Today, the Internet of Things (IoT) is pervasive and characterized by the rapid growth of IoT platforms across different application domains, enabling a variety of business models and revenue streams. This opens new opportunities for companies to extend their collaborative networks and develop innovative cross-platform and cross-domain applications. However, the heterogeneity of today's platforms is a major roadblock for mass creation of IoT platform ecosystems, pointing at the current absence of technology enablers for an easy and innovative composition of tools/services from the existing platforms. In this paper, we present the Data Spine, a federated platform enabler that bridges IoT interoperability gaps and enables the creation of an ecosystem of heterogeneous IoT platforms in the manufacturing domain. The Data Spine allows the ecosystem to be extensible to meet the need for incorporating new tools/services and platforms. We present a reference implementation of the Data Spine and a quantitative evaluation to demonstrate adequate performance of the system. The evaluation suggests that the Data Spine provides a multitude of advantages (single sign-on, provision of a low-code development environment to support interoperability and an easy and intuitive creation of cross-platform applications, etc.) over the traditional approach of users joining multiple platforms separately.


Assuntos
Internet das Coisas , Ecossistema , Tecnologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-34205161

RESUMO

Polyvinyl alcohol (PVA) is a water-soluble plastic commercially used in laundry and dish detergent pods (LDPs) for which a complete understanding of its fate in the environment and subsequent consequences is lacking. The objective of this study was to estimate the US nationwide emissions of PVA resulting from domestic use of LDPs, corroborated by a nationwide, online consumer survey and a literature review of its fate within conventional wastewater treatment plants (WWTPs). Peer-reviewed publications focusing on the degradation of PVA in critical processes of WWTPs were shortlisted as a part of the literature review, and subsequent degradation data was extracted and applied to a model with a set of assumptions. Survey and model results estimated that approximately 17,200 ± 5000 metric ton units per year (mtu/yr) of PVA are used from LDPs in the US, with 10,500 ± 3000 mtu/yr reaching WWTPs. Literature review data, when incorporated into our model, resulted in ~61% of PVA ending up in the environment via the sludge route and ~15.7% via the aqueous phase. PVA presence in the environment, regardless of its matrix, is a threat to the ecosystem due to the potential mobilization of heavy metals and other hydrophilic contaminants.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Ecossistema , Álcool de Polivinil , Esgotos , Águas Residuárias , Poluentes Químicos da Água/análise
16.
Science ; 373(6550): 56-60, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34210877

RESUMO

Human activities are changing our environment. Along with climate change and a widespread loss of biodiversity, plastic pollution now plays a predominant role in altering ecosystems globally. Here, we review the occurrence of plastic ingestion by wildlife through evolutionary and ecological lenses and address the fundamental question of why living organisms ingest plastic. We unify evolutionary, ecological, and cognitive approaches under the evolutionary trap theory and identify three main factors that may drive plastic ingestion: (i) the availability of plastics in the environment, (ii) an individual's acceptance threshold, and (iii) the overlap of cues given by natural foods and plastics.


Assuntos
Evolução Biológica , Ingestão de Alimentos , Plásticos/metabolismo , Animais , Biodegradação Ambiental , Ecossistema , Água Doce , Água do Mar
17.
BMC Plant Biol ; 21(1): 325, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229602

RESUMO

BACKGROUND: Plant phylogeographic studies of species in subtropical China have mainly focused on rare and endangered species, whereas few studies have been conducted on taxa with relatively wide distribution, especially polyploid species. We investigated the cytotype and haplotype distribution pattern of the Actinidia chinensis complex, a widespread geographically woody liana with variable ploidy in subtropical China comprising two varieties, with three chloroplast fragments DNA (ndhF-rpl132, rps16-trnQ and trnE-trnT). Macroevolutionary, microevolutionary and niche modeling tools were also combined to disentangle the origin and the demographic history of the species or cytotypes. RESULTS: The ploidy levels of 3338 individuals from 128 populations sampled throughout the species distribution range were estimated with flow cytometry. The widespread cytotypes were diploids followed by tetraploids and hexaploids, whereas triploids and octoploids occurred in a few populations. Thirty-one chloroplast haplotypes were detected. The genetic diversity and genetic structure were found to be high between varieties (or ploidy races) chinensis and deliciosa. Our results revealed that these two varieties inhabit significantly different climatic niche spaces. Ecological niche models (ENMs) indicate that all varieties' ranges contracted during the Last Inter Glacial (LIG), and expanded eastward or northward during the Last Glacial Maximum (LGM). CONCLUSIONS: Pliocene and Plio-Pleistocene climatic fluctuations and vicariance appear to have played key roles in shaping current population structure and historical demography in the A. chinensis complex. The polyploidization process also appears to have played an important role in the historical demography of the complex through improving their adaptability to environmental changes.


Assuntos
Actinidia/classificação , Actinidia/citologia , Cloroplastos/classificação , Filogeografia , Teorema de Bayes , China , DNA de Cloroplastos/genética , Ecossistema , Variação Genética , Genética Populacional , Haplótipos/genética , Método de Monte Carlo , Ploidias
18.
Environ Monit Assess ; 193(8): 482, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34241689

RESUMO

Determination of the water quality monitoring network (WQMN) is a vital stage for surveying ecosystem health. Studies have been done in determining the optimal number and location of sampling points, but seasonality of water quality, especially for heavy metals, has been rarely studied. For the first time, this study proposes a framework to determine the optimal location of sampling points to monitor lead (Pb). This study was conducted for the Karoun River, located in southwestern Iran. First, hydraulic characteristics of the river were simulated by implementing of MIKE11 software as well as water quality(variation of Pb concentration). Nash­Sutcliffe coefficient were 0.91 and 0.91 for discharge calibration and validation, respectively. Second, 16 potential sampling points were proposed using modified Sanders' approach considering seasonality. For a better accuracy in the WQMN layout and a more efficient site selection of sampling points, a 1-km buffer is stretched along the river for determining non-point source pollution sources and prioritizing candidate points. This leads to considering different land uses in the study area, while GIS software has been employed. Seasonal changes and land use have a significant impact on the location of optimal sampling points. The presented framework can be used to improve water quality and support watershed protection efforts.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Hidrodinâmica , Irã (Geográfico) , Metais Pesados/análise , Rios , Poluentes Químicos da Água/análise , Qualidade da Água
19.
Environ Monit Assess ; 193(8): 487, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34245365

RESUMO

The stress on the freshwater resources of the planet earth has led the United Nations to add a goal regarding clean water in sustainable development goals list in order to address the global availability of clean water. The widespread use of fertilizers and industrial effluents caused the groundwater contamination in the Haripur District, Khyber Pakhtunkhwa, Pakistan. To investigate and assess the vulnerability of groundwater to contamination, geographic information system (GIS)-based DRASTIC model has been employed. The DRASTIC index values lie between 88 and 190. The lower the DI value, the lower will be the susceptibility towards pollution and vice versa. The indices were classified into five zones, i.e., low (< 109), medium (110-129), moderate (130-149), high (150-169), and very high vulnerable zones (> 170) on the basis of equal intervals. The low vulnerable zone covers almost 6% of the study area, i.e., 118 km2. Medium vulnerable zone encompasses an area of approximately 23%, i.e., 506 km2. The moderate vulnerable zone is the largest in the district covering almost 965 km2, approximately 45% of the study area. The high and very high vulnerable zone encompasses almost 23% and 3% of the study area which means 506 km2 and 66 km2 respectively. A spatial distribution map was generated for nitrate concentration to validate the DRASTIC indices. The results demonstrate a fair relation between groundwater susceptibility and spatial nitrate distribution. This index map will provide a baseline study for this area to develop the safe zones for groundwater exploitation and controlling the current state of deterioration of environmental norms. The areas of high vulnerability are the firsthand task to improve the current situation of crisis especially in the southern parts such as the Hattar industrial area and its surroundings drained by those effluents. These further need specific tasks to restore and reclaim the polluted ecosystem by using proper technological solutions for disposal of these effluents.


Assuntos
Sistemas de Informação Geográfica , Água Subterrânea , Ecossistema , Monitoramento Ambiental , Paquistão , Poluição da Água/análise
20.
Mycorrhiza ; 31(4): 497-510, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34196799

RESUMO

Ectomycorrhizal symbiosis appears extensively in the Northern Hemisphere, where Mediterranean ecosystems constitute an important ecological area of considerable biodiversity value. Littoral sand dunes are among high-risk habitats, and ectomycorrhizal lifestyle contributes significantly to supporting life in such regions. Mallocybe heimii (Bon) Matheny & Esteve-Rav. (Inocybaceae, Basidiomycota) and the very similar M. arenaria (Bon) Matheny & Esteve-Rav. grow in poor, usually sandy soils, in association with angiosperms or gymnosperms. Basidiomata originally identified under these names were collected from littoral sand dunes of Greece, and their morpho-anatomical characteristics were examined in conjunction with material derived from other European regions. Sequences from basidiomata and root tips corresponding to the nuclear rDNA internal transcribed spacer region (ITS) and large subunit (LSU) were obtained and analyzed. Phylogenetic results demonstrated that material identified as M. heimii or M. arenaria form a single well-supported group, while M. agardhii (N. Lund) Matheny & Esteve-Rav. is confirmed to be distinct from M. arenaria (the latter was initially described as a variety of the former, i.e., I. agardhii var. arenaria Bon). A detailed tree of the genus Mallocybe was generated on the basis of concatenated ITS and LSU sequences, and relationships of selected taxa are discussed in the light of morphological and sequence data. In addition, the first morphotype descriptions of M. heimii ectomycorrhizae with Cistus creticus L. and Pinus halepensis Miller are hereby provided. Both morphotypes exhibited the typical characteristics of Inocybe/Mallocybe ectomycorrhizae; however, differences were noted, the most significant being the presence of clamps on mantle hyphae and the type of anastomoses.


Assuntos
Cistus , Micorrizas , Pinus , Ecossistema , Micorrizas/genética , Filogenia , Areia
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