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Sub-Antarctic giant kelp (Macrocystis pyrifera) forests have remained relatively wild and far from anthropogenic pressures. However, they are increasingly exposed to multiple stressors that might affect kelp forest persistence. The urban impact of a coastal city, Ushuaia (54° S 68° W), in the Beagle Channel, Argentina, on giant kelp forest environments was evaluated in this study and implications on morphological variability were explored. Seasonal samplings were conducted from 2019 to 2021 in two contrasting sites: an urban site directly exposed to coastal discharges, and a non-urban site. Our results indicate that the combination of coastal discharges, kelp canopy and low wave exposure increases light attenuation inside kelp forests, promoting coastal darkening. Additionally, and based on the present results, we present the first record of algal turf in the Beagle Channel. We further propose the Kelp Structure Index to describe the effect of environmental conditions on kelp structure, which highlights an increased blade surface in sites with urban impacts. These results suggest that giant kelp shows high plasticity in morphological traits under varying environmental conditions, particularly in environments exposed to coastal darkening effects. However, the presence of turf indicates that urban pressures might be severely limiting kelp forest health. [ABSTRACT FROM AUTHOR]

Since 2020, the Pampas ecoregion, a highly productive area of Argentina, has endured its most severe drought in the past century. Our understanding of the impact of droughts on physicochemical changes in lotic environments remains limited, and this knowledge gap becomes even more pronounced when considering the concurrent urbanisation and industrialisation that alter land-use patterns and pose threats to water quality. This study aims to analyse, on a short-term basis, how hydrodynamics and physicochemical characteristics of streams, exposed to different land uses, are affected by drought. During the winter of 2022, we conducted three samplings in streams within the Samborombón River basin. We selected three streams influenced by rural land use and three influenced by urban development. Our data collection encompassed meteorological information, the multivariate El Niño Southern Oscillation (ENSO) index and the Palmer drought severity index. We measured hydrological and physicochemical variables at each sampling site. Our analysis identified an extreme drought period coinciding with 'La Niña' conditions during the sampling period. The annual accumulated precipitation for this period was notably lower, at 622 mm, compared with the historical average (1958–2022) of 1006 mm for this region. Hydrological variables exhibited significant differences between urban and rural streams. Urban streams maintained a consistent water flow, while rural streams were predominantly characterised by disconnected pools. Additionally, urban streams exhibited significantly greater Secchi depth and higher nutrient concentrations, whereas rural streams displayed elevated pH, conductivity and turbidity levels. These findings underscore the crucial role of urban effluents in sustaining a base flow during extreme drought conditions. However, this base flow is associated with poorer water quality, disrupting the natural chemical and hydrological dynamics of the region during drought events. [ABSTRACT FROM AUTHOR]

The input of trace elements from a small urban river (Las River, Toulon, France) located on the northern Mediterranean coast was studied during both base flow and flood events. A 2-year monitoring period of water flow and suspended particulate matter (SPM) showed a typical Mediterranean hydrological regime: a strong increase in water flow and SPM during short flood periods. During the flood event, an up to 2-fold increase in dissolved trace element (DTM) concentrations and particulate trace element content in SPM (PTM) was observed compared to the baseline discharge. The enrichment factor of elements in the SPM ranges from low or moderate for Co, Ni and Cr (1.0–4.7) to extremely high for Cd (157). However, the enrichment factors decrease from base flow to flood, indicating a dilution effect with a large yield of weathering particles with higher particle size. The most significant total trace element loading occurred during flood, ranging from 78% for As and Ni to 91% for Pb, while PTM loading during flood ranged from 35% for As to 77% for Pb. The specific dissolved fluxes during the flood are significantly higher for Pb, Cu and Zn than in the surrounding rivers, indicating specificity in the catchment (lithology). This study shows the importance of monitoring the transport of pollutants through small urban rivers and their potential impact on the coastal region, especially when they enter small and closed bays, as a receiving pool. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess urbanization effects on microbial communities from low-order streams. Artificial substrata were placed upstream (control) and downstream (urban) of the cities of the selected streams. Photosynthetic parameters derived from chlorophyll-a fluorescence were measured using a Pulse of Amplitude Modulated Fluorometer, and the bacterial biofilm and bacterioplankton were counted by microscopy after staining with 4′,6-diamidino-2-phenylindole. We found higher bacterial biofilm biomass together with higher concentration of nutrients in urban reaches. The biofilm total density of bacteria was negatively correlated with the humic acid concentration, while the bacterioplankton total density was positively correlated with soluble reactive phosphorus and nitrite concentration. Autotrophic Index reflected the predominance of heterotrophs in the three streams. The concentration of chlorophyll-a, the minimum fluorescence, and the other photosynthetic parameters showed variations between the streams. These would respond to environmental factors at local scale not included in this study and may be influenced by the low development of autotrophic biomass at least in two of the streams studied. The bacterial morphotypes Small rod, Large rod, and Vibrio shaped (large) allowed the differentiation of urban reaches and would be useful as indicators of urbanization effects in both biofilm and bacterioplankton of lowland streams. [ABSTRACT FROM AUTHOR]

Despite the implications of winter precipitation for socioeconomic activities and transportation services, the influence of cities on winter precipitation is less studied compared to that on summer precipitation. Here we investigated the statistical relations between precipitation, temperature, and impervious surface fraction in 12 major cities across the contiguous United States. The results showed negative correlations between snowfall intensity and impervious surface fraction. The correlations depend on latitude and the distance to complex terrain features (water bodies or topography), with stronger correlations for inland cities than coastal/lakeside cities. We further selected Kansas City for modeling analyses based on the Weather Research and Forecasting model. Simulation results indicated that the heating effect of urban land occurs in the near-surface atmosphere during the precipitation period, leading to changes of different hydrometers and an overall tendency of reducing snowfall but increasing rainfall. • Statistical analyses quantifying the influence of urbanization on winter precipitation across 12 U.S. cities over 10 years. • Modeling simulation elucidating the physical processes through which urban land influences winter precipitation. • Snow only, rain only and mixed precipitation eventsand a season-long simulation conducted over Kansas City. • The urban-induced temperature results in reduced snowfall and increased rainfall especially during mixed-precipitation event. [ABSTRACT FROM AUTHOR]

The unrestrained and constant inflow of tourists to some cities can provoke the discomfort of residents. The term ‘overtourism’ describes a condition in which the limits are exceeded to the point that regular everyday urban life suffers. The quantity of visitors and resulting crowds create burdens on the functioning of some city services, and they simultaneously result in a deterioration in the quality of sightseeing. This paper gives a review of the academic literature concerning this issue, especially studies concentrating on cruising and alternative short-term renting. Major complaints raised by locals on the negative impact of tourism are not only about overcrowding, but also include the serious social and economic questions of the endangerment of rights. In order to regulate and mitigate conflicts, preserve identity and allow decent urban life in all its aspects, city governments are forced to introduce some limitations and rules in the sphere of tourism, and also with regard to the real-estate market and urban planning. The level of measures and policies required depend on the type of problem, size of the city and dispersion of the attractions.

The development of urbanization has a negative impact on aquatic environments, making them the final receptors for a variety of anthropic substances, many of which lead to eutrophication. In Ushuaia (Tierra del Fuego), the Arroyo Buena Esperanza (ABE) has been subjected to these impacts. Its water quality decreases as the stream crosses the urban zone and discharges into Bahía Encerrada (BE). However, it is unknown whether its waters are toxic to the biota. We evaluated the water quality of the ABE all along its path through the urban zone and at its mouth in the BE through the effect on survival (48 hours) and growth (21 days) of Daphnia magna. Acute and chronic bioassays were conducted with D. magna neonates exposed to waters from four sites of the ABE: one with no urban impact, one with intermediate impact, and two with high impact. Water quality decreased as the stream crosses the urban zone, finding high values of ammonia, phosphates, particulate organic matter, total suspended solids and coliform bacteria; caused by the contribution of untreated sewage effluents. The survival of D. magna at 48 hours was close to 100%, which indicates the absence of acute toxicity of the water. The individual biomass varied according to the site and the time tested, increasing gradually but not evenly between sites. The organisms exposed to the most impacted sites presented higher biomass and growth rate in comparison to the sites with the least impact. This is linked to the poorer water quality of the impacted sites. The growth of D. magna was an environmental diagnostic tool with high applicability for the detection of sublethal effects of the waters of Fuegian streams, which adequately complements the environmental monitoring. [ABSTRACT FROM AUTHOR]

The Beirut port explosion caused substantial damages, not only for the city, but also for the country's economy. The explosion caused 207 deaths and more than 6.500 people were injured. Also, around 300,000 people lost their homes and the physical damages costs are estimated to $4.6 billion. The economy and the architecture of the city was severely affected and not only the Lebanese people felt the negative impact of this event. It is estimated that foreigners from 22 countries were affected by the blast, especially the Bangladeshi nationals. In this respect, the present research aims to present the Beirut Port explosion and its effects on the citizens' lives and its negative impact on the city's economy and architecture. In the end, conclusions regarding the causes of this tragic event are drawn and a series of recommendations regarding the rebuilding of the city and its development, are presented. [ABSTRACT FROM AUTHOR]

Urban areas are vulnerable to climate and weather extremes, including severe convective events. However, large cities can themselves intensify such events, although the magnitude of this intensification remains uncertain. In this study, we quantify the influence of Moscow on severe convective events by using simulations with the convection-permitting COSMO-CLM model with 1-km resolution for multiple summers for 2007–2016 and analyzing the difference between simulations with and without the urban canopy parameterization (URB and noURB, respectively). We found a significant difference between these simulations for extreme precipitation and wind characteristics. Within the city boundary, the difference is about 20% for 30 mm daily precipitation events and 70% for 50 mm events. Strong wind events are twice as frequent in the URB simulation. The urban canopy significantly increases the magnitude and variability of extreme quantiles for vertical velocities. We found more than a 50% increase in compound events with both wind and precipitation exceeding their 0.99 quantiles and in events with the 2–5 km updraft helicity exceeding critical values, which serve as a good proxy for mesocyclone formation. Our findings may help to refine the population bias and can be used to specify the predicted changes in convective hazards in mid-latitude cities. • High-resolution simulations show significant impact of Moscow on convective events. • Intense daily precipitation increases over Moscow and downwind northeastern areas. • The city leads to a 50% increase in compound extreme wind and precipitation events. • Moscow significantly raises updraft helicity and vertical velocity in the city limits. • Population bias in convective reports for large cities is likely smaller than thought. [ABSTRACT FROM AUTHOR]

In early 2017 high particulate matter (PM) levels were observed across mid-Europe, including Austria. Here we characterize PM pollution in the city of Graz during January to March 2017, a period with substantial exceedances (34 days) of the European Union (EU) PM10 short time limit value. This study evaluates whether the observed exceedances can be attributed to the accumulation of pollutants emitted by local sources or to a larger scale pollution episode including transport. The analyses are based on the ratios of PM10 concentrations determined at an urban and background site, and the analyses of chemical composition of PM2.5 samples (i.e., water soluble ions, organic and elemental carbon, anhydro-sugars, humic-like substances, aluminum, and polycyclic aromatic hydrocarbons). Source apportionment was realized using a macro-tracer model. Overall, the combination of different approaches (PM10 ratios, chemical composition, and macro-tracer derived source apportionment) enabled a conclusive identification of time periods characterized by the accumulation of emissions from local sources or regional pollution episodes. [ABSTRACT FROM AUTHOR]

Hydrometeorological impacts due to urbanization for cities close to complex terrain are poorly understood due to the complexities of terrain‐related circulation and urban perturbations of atmospheric flow. In this study, we examine urban impacts on extreme monsoon rainfall and the resultant flooding over central Arizona based on high‐resolution atmospheric and hydrological model simulations. Strong positive rainfall anomalies at the urban‐rural interface downwind of the city are mainly related to dynamic effects (increased surface roughness) on convective outflow boundaries. Urban‐related thermodynamic disturbances slightly increase rain rates over the downtown core of Phoenix. Contrasting rainfall anomalies for two consecutive storm episodes highlight the importance of flow regime analysis in understanding urban impacts on extreme rainfall in complex terrain. Urban‐induced rainfall anomalies result in amplification of flood peak magnitudes by as much as a factor of 2 for Phoenix watersheds. Our results highlight the urban impacts on regional flood hydrology through land‐atmosphere interactions. Key Points: Contrasting rainfall anomalies for two consecutive storm episodes in the Phoenix metropolitan region show a strong dependence on flow regimeThe dynamic perturbation to terrain‐related circulations dominates urban‐induced rainfall anomalies in complex terrainThe impacts of urban‐induced rainfall anomalies on flood response are assessed through hydrological modeling experiments [ABSTRACT FROM AUTHOR]

In early 2017 high particulate matter (PM) levels were observed across mid-Europe, including Austria. Here we characterize PM pollution in the city of Graz during January to March 2017, a period with substantial exceedances (34 days) of the European Union (EU) PM10 short time limit value. This study evaluates whether the observed exceedances can be attributed to the accumulation of pollutants emitted by local sources or to a larger scale pollution episode including transport. The analyses are based on the ratios of PM10 concentrations determined at an urban and background site, and the analyses of chemical composition of PM2.5 samples (i.e., water soluble ions, organic and elemental carbon, anhydro-sugars, humic-like substances, aluminum, and polycyclic aromatic hydrocarbons). Source apportionment was realized using a macro-tracer model. Overall, the combination of different approaches (PM10 ratios, chemical composition, and macro-tracer derived source apportionment) enabled a conclusive identification of time periods characterized by the accumulation of emissions from local sources or regional pollution episodes.

ABSTRACT This study evaluated gills and liver of Astyanax bifasciatus as histological biomarkers for biomonitoring of streams along areas with different land uses. The fish were collected by electrofishing in six streams in the basin of the lower Iguaçu River. The objective was to correlate the presence and degree of histopathological alterations of gills and liver with the environmental variables among streams along different land uses. The low frequency of histopathological alterations found in fish from the forest streams suggested normal organ functioning. In fish from the rural and urban streams, the histopathological alterations occurred were in higher frequency, indicated light to moderate damage in gills and liver of fish from the rural streams, and moderate to severe damage in liver of fish from urban streams. The histopathological alterations in gills (lamellar aneurysm) and livers (vascular congestion) verified in impacted streams were significantly more frequent and severe. It was possible to distinguish streams along different land uses, suggesting that these histopathological alterations can be used as biomarkers for biomonitoring studies. The health integrity of fish from streams in forest areas further reinforces the importance of maintaining preservation areas in basins under intensive land use.

The question of how much cities are the sources of their own air pollution is not only theoretical as it is critical to the design of effective strategies for urban air quality planning. In this work, we assess the validity of the commonly used incremental approach to estimate the likely impact of cities on their air pollution. With the incremental approach, the city impact (i.e. the concentration change generated by the city emissions) is estimated as the concentration difference between a rural background and an urban background location, also known as the urban increment. We show that the city impact is in reality made up of the urban increment and two additional components and consequently two assumptions need to be fulfilled for the urban increment to be representative of the urban impact. The first assumption is that the rural background location is not influenced by emissions from within the city whereas the second requires that background concentration levels, obtained with zero city emissions, are equal at both locations. Because the urban impact is not measurable, the SHERPA modelling approach, based on a full air quality modelling system, is used in this work to assess the validity of these assumptions for some European cities. Results indicate that for PM 2.5 , these two assumptions are far from being fulfilled for many large or medium city sizes. For this type of cities, urban increments are largely underestimating city impacts. Although results are in better agreement for NO 2 , similar issues are met. In many situations the incremental approach is therefore not an adequate estimate of the urban impact on air pollution. This poses issues in terms of interpretation when these increments are used to define strategic options in terms of air quality planning. We finally illustrate the interest of comparing modelled and measured increments to improve our confidence in the model results. [ABSTRACT FROM AUTHOR]

This study evaluated gills and liver of Astyanax bifasciatus as histological biomarkers for biomonitoring of streams along areas with different land uses. The fish were collected by electrofishing in six streams in the basin of the lower Iguaçu River. The objective was to correlate the presence and degree of histopathological alterations of gills and liver with the environmental variables among streams along different land uses. The low frequency of histopathological alterations found in fish from the forest streams suggested normal organ functioning. In fish from the rural and urban streams, the histopathological alterations occurred were in higher frequency, indicated light to moderate damage in gills and liver of fish from the rural streams, and moderate to severe damage in liver of fish from urban streams. The histopathological alterations in gills (lamellar aneurysm) and livers (vascular congestion) verified in impacted streams were significantly more frequent and severe. It was possible to distinguish streams along different land uses, suggesting that these histopathological alterations can be used as biomarkers for biomonitoring studies. The health integrity of fish from streams in forest areas further reinforces the importance of maintaining preservation areas in basins under intensive land use. [ABSTRACT FROM AUTHOR]

Industrialization in developing countries associated with urban growth results in a number of economic benefits, especially in small or medium-sized cities, but leads to a number of environmental and public health consequences. This problem is further aggravated when adequate infrastructure is lacking to monitor the environmental impacts left by industries and refineries. In this study, a new protocol was designed combining biomonitoring and geostatistics to evaluate the possible effects of shale industry emissions on human health and wellbeing. Futhermore, the traditional and expensive air quality method based on PM2.5 measuring was also used to validate the low-cost geostatistical approach. Chemical analysis was performed using Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF) to measure inorganic elements in tree bark and shale retorted samples in São Mateus do Sul city, Southern Brazil. Fe, S, and Si were considered potential pollutants in the study area. Distribution maps of element concentrations were generated from the dataset and used to estimate the spatial behavior of Fe, S, and Si and the range from their hot spot(s), highlighting the regions sorrounding the shale refinery. This evidence was also demonstrated in the measurements of PM2.5 concentrations, which are in agreement with the information obtained from the biomonitoring and geostatistical model. Factor and descriptive analyses performed on the concentrations of tree bark contaminants suggest that Fe, S, and Si might be used as indicators of industrial emissions. The number of cases of respiratory diseases obtained from local basic health unit were used to assess a possible correlation between shale refinery emissions and cases of repiratory disease. These data are public and may be accessed on the website of the the Brazilian Ministry of Health. Significant associations were found between the health data and refinery activities. The combination of the spatial characterization of air pollution and clinical health data revealed that adverse effects were significant for individuals over 38 years of age. These results also suggest that a protocol designed to monitor urban air quality may be an effective and low-cost strategy in environmentally contaminated cities, especially in low- and middle-income countries.

Industrialization in developing countries associated with urban growth results in a number of economic benefits, especially in small or medium-sized cities, but leads to a number of environmental and public health consequences. This problem is further aggravated when adequate infrastructure is lacking to monitor the environmental impacts left by industries and refineries. In this study, a new protocol was designed combining biomonitoring and geostatistics to evaluate the possible effects of shale industry emissions on human health and wellbeing. Futhermore, the traditional and expensive air quality method based on PM2:5 measuring was also used to validate the low-cost geostatistical approach. Chemical analysis was performed using Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF) to measure inorganic elements in tree bark and shale retorted samples in São Mateus do Sul city, Southern Brazil. Fe, S, and Si were considered potential pollutants in the study area. Distribution maps of element concentrations were generated from the dataset and used to estimate the spatial behavior of Fe, S, and Si and the range from their hot spot(s), highlighting the regions sorrounding the shale refinery. This evidence was also demonstrated in the measurements of PM2:5 concentrations, which are in agreement with the information obtained from the biomonitoring and geostatistical model. Factor and descriptive analyses performed on the concentrations of tree bark contaminants suggest that Fe, S, and Si might be used as indicators of industrial emissions. The number of cases of respiratory diseases obtained from local basic health unit were used to assess a possible correlation between shale refinery emissions and cases of repiratory disease. These data are public and may be accessed on the website of the the Brazilian Ministry of Health. Significant associations were found between the health data and refinery activities. The combination of the spatial characterization of air pollution and clinical health data revealed that adverse effects were significant for individuals over 38 years of age. These results also suggest that a protocol designed to monitor urban air quality may be an effective and low-cost strategy in environmentally contaminated cities, especially in low- and middle-income countries. [ABSTRACT FROM AUTHOR]

This study aims to evaluate how the urban impact (depletion, litter, agriculture, livestock, etc.) changes the riparian forest and water quality of the Lanceiro River, located in the tourist area of Cha cara do Forte, rural area of Caçapava do Sul. For this purpose, it was collected and analyzed the water and the riparian forest from three points of the river, including its tributaries. From the perception that the object of study percolates an area of tourism and urbanization, it was verified that along the river the accumulation of pollutants and contribute to the degradation of the riparian forest and the quality of the water. [ABSTRACT FROM AUTHOR]

Urban facilities have historically played a fundamental role as spaces that allow citizens to exercise their right over the city. How do architecture and urbanism actually contribute to guarantee this right? How do the facilities give an advantage to the construction of the city and citizens through better environmental integration? In some cities in the country the development of new and important facilities, constructed by improving already existing infrastructure, has led to the reduction of an accumulated “social debt”. However, there are still many challenges to be faced on the road to strengthening the processes of social inclusion and to achieving the optimal functioning of these spaces in relation to their environment.

Assemblages of aquatic and edaphic insects in three streams in Central Amazonia were used to evaluate the impact on one of the streams (Cururu) caused by an oil spill that occurred in August 1999. The Cururu stream had already been impacted by domestic sewage. These three streams were evaluated during four different periods of the regional hydrological cycle (falling-, low-, rising- and high-water), from September 2000 to May 2001. An Eckman dredge, an aquatic entomological net and a manual auger were used to collect insects, which were used to estimate the taxonomic richness (at the family level) and insect density in each stream. Anoxic and eutrophic conditions were determined in each stream based on the mean concentration of dissolved oxygen, total nitrogen and phosphorus. Richness and abundance of insect fauna were higher in the Cristalino stream (not impacted) than in the Bom Jardim stream (impacted by domestic sewage) and in the Cururu stream, with the exception of samples collected along the stream banks (littoral fauna). The mean dissolved oxygen was lower in the Cururu stream than in the other two, while the mean concentrations of total nitrogen and phosphorus were higher. These elements showed intermediate values in the Bom Jardim stream, while the opposite pattern was observed in the Cristalino stream, with higher concentrations of dissolved oxygen and lower concentrations of total nitrogen and phosphorus. The concentrations of these variables reflect the modifications resulting from anthropogenic eutrophication caused by the discharge of domestic sewage into Bom Jardim and Cururu and by the oil spill in Cururu, which negatively affected the richness and abundance of insects in these streams.As assembléias de insetos aquáticos e edáficos de três igarapés da Amazônia Central foram utilizadas para avaliar o impacto sofrido por um deles (igarapé Cururu), após um vazamento de óleo derivado de petróleo, ocorrido em agosto de 1999. O igarapé Cururu já era impactado pelo despejo de esgoto doméstico. A avaliação desses sistemas foi realizada em quatro diferentes períodos do ciclo hidrológico da região (vazante, seca, enchente e cheia), entre setembro de 2000 e maio de 2001. Os insetos foram coletados com draga Eckman, rede entomológica aquática e trado, e utilizados para estimar a riqueza taxonômica (nível de família) e a densidade de insetos em cada sistema. Os efeitos de anóxia e os efeitos da eutroficação foram mensurados pelas médias de concentração de oxigênio dissolvido, nitrogênio total e fósforo total, estimadas nos três sistemas. A riqueza e abundância da fauna de insetos foram maiores no igarapé Cristalino (não impactado) do que nos igarapés Bom Jardim (impactado pelo despejo de esgoto) e Cururu, com exceção das amostragens de insetos litorâneos. A concentração do oxigênio dissolvido no igarapé Cururu foi menor do que nos outros dois sistemas, enquanto as concentrações de nitrogênio total e fósforo total no igarapé Cururu foram maiores. Esses elementos tiveram valores inversos no igarapé Cristalino e intermediários no igarapé Bom Jardim. As concentrações de oxigênio dissolvido, nitrogênio total e fósforo total refletem as modificações provocadas pela eutroficação antropogênica nos sistemas Bom Jardim e Cururu. Isso ocorreu devido à liberação de efluentes domésticos pelas comunidades locais e pelo óleo introduzido no igarapé Cururu, influenciando negativamente a riqueza e abundância de insetos nesses igarapés.

The relationship between biodiversity and ecosystem functioning has been intensely debated and researched in recent times. It is generally agreed that there is redundancy of species in ecosystems such that loss of species does not necessarily result in change in the functioning of the ecosystem in which they occur. However the state of our knowledge does not allow prediction of sensitivity or specificity of this relationship for any particular ecosystem. A widely-held opinion is that ecosystem functioning is relatively stable to environmental impact, whereas biodiversity is more sensitive. We tested this in streams of the Atlantic forest using leaf decomposition as an aspect of ecosystem functioning and measuring the diversity of the associated fauna. In lightly impacted streams of the urban park Parque Estadual da Pedra Branca, RJ, leaf processing rate of a hard-leaf species, Myrcia rostrata (Myrtaceae) was more than 50% slower than in "intact" streams at the biological reserve of Ilha Grande, RJ. Taxon diversity of fauna of the leaves was not significantly lower in the impacted than the intact streams. We construe this as preliminary evidence contrary to the notion that ecosystem functioning is less sensitive than biodiversity to impacts in this system.

In the Al Madinah Al Munawarah city, urbanization has accelerated rapidly over the last few decades which has caused both decline of groundwater level and deterioration of groundwater. The city is located in the center of sedimentary basin that consists of alluvial deposits originated from the erosion of surrounding igneous rocks. It has been grown very rapidly both in population and land use. The hydrogeological and hydrogeochemical characteristics of Al Madinah Al Munawarah city have been studied. The only recharge source of the groundwater of the study area is rainwater. Concentrations of total dissolved solids, major constituents, and trace elements in groundwater increased significantly after construction of industrial area to the south of the city near Wadi Al Aqiq and after increasing the urbanization, indicating an important pollutant process over the study area. The EC and TDS values ranged widely from 1,179.83 to 9,843.03 μmohs/cm and from 755.09 to 6,299.54 mg/l, respectively. Such a wide range of EC and TDS values indicate that the hydrochemistry of groundwater is controlled by various hydrochemical processes such as agricultural and farm activities, industrial development, landfills leachate, septic tanks, and wastewater of municipal and domestic consumption. Hydrochemical facies of groundwaters change broadly from a Ca-SO type in southwestern part near Wadi Al Aqiq to a Na-Cl type in both southeastern part at Harrat Rahat and northern part of the study area. Values of Na/Cl ratio indicate that silicate weathering and halite dissolution are the main processes resulting in release of Na into groundwater. Nitrate originates from fertilizers application and leakage of sewage with the highest value of 261 mg/l. Groundwater samples from southeastern part have high levels of heavy metals which render them unsafe for drinking purposes as compared with WHO guidelines. Where the maximum concentration values reach 0.850 mg/l for Fe, 0.120 mg/l for As, 0.985 mg/l for Ba, 1.030 mg/l for V, and 0.890 mg/l for Al. These high concentrations are mainly derived from leakage from the unlined industrial wastewater disposal site located to the southwest of the city. Disposal of industrial wastewater in such insecure landfill should be prohibited and the landfill should be properly designed to prevent further groundwater pollution. [ABSTRACT FROM AUTHOR]

In order to assess the role of urea in the Gulf of Trieste, oceanographic data collected from 2002 to 2011 were analyzed together with ancillary ambient information and compared to past studies. The recent levels of urea found in these coastal waters (median = 1.1 µM N, maximum value = 19.7 µM N) are often high and similar to those reported in the early 1980s. A preliminary estimate of the external inputs indicated that this enrichment in urea is mainly due to emissions from urban sewage systems, whereas the contributions of rivers and atmospheric deposition are scarce. As a consequence, urea appears to be a reliable tracer of the diffusion of wastewaters in the coastal marine environment, more specific and sensitive than other nutrients, with a behavior that also reflects the technology of the treatment plants. The stability of urea levels over the last three decades suggests that the upgrade of wastewater treatment technologies was probably balanced by the concomitant increase of the anthropogenic pressure in the area (477,000 to 1,300,000 inhabitant equivalent). Budget estimates on the gulf-wide scale indicate that urea (177-530 t N) is not negligible compared to dissolved inorganic nitrogen (409-919 t N) and that it can constitute up to 56% of the nitrogen available for plankton growth. A large accumulation of urea can occur during summer periods characterized by stable weather conditions and weak circulation, whereas a biologically mediated degradation to ammonium is observed in autumn in concomitance to a strong shift of the marine ecosystem toward heterotrophic conditions. These processes, together with a potential competition between phytoplankton and bacteria for the utilization of this nitrogen form, suggest that the biogeochemical role of urea should be better investigated in mid-latitude coastal zones subjected to highly variable ambient conditions and to overloads of this compound. [ABSTRACT FROM AUTHOR]

The pressure exerted by a large city determines non-agricultural forms of land use in areas situated in its neighbourhood. Among the most alarming consequences of urban sprawl onto the surrounding areas are a steady and irreversible shrinkage of farmland and conflicts resulting from a mix of functions performed by the areas. This article describes the dynamics, scale and spatial differences of the process of taking agricultural land out of production in the Poznań agglomeration in the 21st century in terms of changes in the land-use pattern. In characterising the converted land, it also presents chief directions of its transformation, the regulations in force, and the resultant lack of full information about factual, and not only partial, conversions. [ABSTRACT FROM AUTHOR]

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In northeast Mexico is Linares City, which has an extensive agricultural area and many industrial activities. Near this city is the Cerro-Prieto Dam (~12 km NE direction); this drinking water reservoir captures the water of the Pablillo River catchment area and constitutes an important source of potable water for the metropolitan area of Monterrey, the largest urban center of this region. Groundwater sources in this area provide drinking water to Linares inhabitants. A hydrogeological and hydrochemical study was conducted on the shallow aquifers surrounding the urban centers (Linares and Hualahuises) to determine the evolution of the water quality between 1981 and 2009. The hydrochemistry was assessed upgradient and downgradient from the potential contamination sources in Linares city. Groundwater showed a chemical evolution from calcium-bicarbonate type to calcium-sodium-sulfate type. The water qualities in the downstream area after Linares are inferior compared to the upstream area before the city. Nitrate concentrations in groundwater increased significantly after 28 years indicating an important pollutant process in this period of time over the study area. The possible pollution sources could be the agricultural and farm activities, industrial development, landfills leachate, septic tanks and wastewater of municipal and domestic consumption. If the present scenario continues, an aquifer vulnerability assessment would be important for the sustainable water management. [ABSTRACT FROM AUTHOR]

The distribution of the endangered species Boros schneideri was studied by checking the presence of larvae and adults under the bark of dead Pinus sylvestris trees in 13 pine forests in Lithuania. B. schneideri was found in 10 biggest pine forests, the area of which exceeded 20,000 ha. However, it was not detected in smaller isolated forests. In Kazlų Rūda, Šimonys, Pabradė and Rūdiškės forests this species was recorded for the first time. The part of localities in which B. schneideri was found and the percentage of trees with B. schneideri were significantly higher in the main parts of the biggest forests than in satellite or smaller forests. Both these parameters were significantly lower in forests located in the close vicinity of urban territories than in forests further from them. Consequently, the forest size and the distance of the forest from urban territories were found to be of critical importance for the survival and density of the B. schneideri population. These distribution regularities are important for the establishment of protected areas for this species conservation. [ABSTRACT FROM AUTHOR]

PM10 levels of the mineral components Si, Al, Fe, Ca, Mg and some trace metals were measured at three different sites in the urban area of Vienna (Austria). Observed trace metal concentrations varied between less than 0.1ngm−3 (Cd) and approximately 200ngm−3 (Zn), mineral components showed enhanced concentrations ranging from 0.01μgm−3 (Ca) to 16.3μgm−3 (Si). The contribution of the respective mineral oxides to PM10 mass concentrations accounted on average for 26.4±16% (n=1090) of the PM10 mass, with enhanced rates in spring and autumn (monthly averages of up to 40%) and decreased contributions in the cold season (monthly averages below 10%). The atmospheric occurrence of Al, Ti and Sr could be assigned to crustal sources, whereas for the elements Ba, Ca, Fe, Mg, Mn and V an increased contribution of non-crustal origin was observed. PM10 levels of As, Cd, Co, Cr, Cu, Ni, Pb, Sb, Sn and Zn were predominantly derived from man-made emissions. Intersite comparison indicated that urban PM10 mass concentrations and PM10 levels of As, Pb and Zn were predominantly influenced from the transport of aerosols from outside into the city, whereas for the elements Ba, Mg, Ca, Cu and Fe a distinctly increased impact of local emissions was observed. The contribution of these urban emissions to total PM10 concentrations was estimated by calculating the so-called “urban impact”, which was found to be 32.7±18% (n=392) in the case of PM10 mass concentrations. The investigated elements accounted on average for 31.3±19% (n=392) of the observed PM10 mass increase. The mean values for the “urban impacts” of individual elements varied between 25.5% (As) and 77.0% (Ba). [Copyright &y& Elsevier]

This study examined the relationship between land cover and three solute (chloride, total organic carbon (TOC), and lead) concentrations during winter rainstorms in 10 subbasins of Spring Creek, Pennsylvania, USA at two spatial scales. Despite similar percent land cover at both scales, correlations between water quality and land cover were stronger at the subbasin scale than at the riparian scale. As basin percent urban land cover increased, mean chloride and lead concentrations increased. Chloride and lead were likely to be a result of roadside sediments and residential housing, as demonstrated by a strong positive relationship between road density and chloride concentration at both spatial scales ( r = 0.83, 0.71). Basin percent forested cover at the subbasin scale was weakly positively related to TOC concentrations, suggesting leaf litter as a source. Changes in flow rate related to changes in concentrations of solutes for representative urban and rural subbasins. TOC and lead showed weak positive relationships (flushing effect), while chloride exhibited a strong negative relationship (dilution effect). These different responses to changes in flow rate implied different sources of solutes – soils for TOC and lead and groundwater for chloride. This study underscores some negative effects of increased basin urbanization on stream water quality and potential aquatic ecosystems in small streams during storm events. [ABSTRACT FROM AUTHOR]