Application of divided convective-dispersive transport model to simulate variability of conservative transport processes inside a planted horizontal subsurface flow constructed wetland

Environmental Science and Pollution Research - This paper offers a novel application of our model worked out in Maple environment to help understand the very complex transport processes in...     

Community composition and consumer identity determine the effect of resource species diversity on rates of consumption

The effect of species diversity on ecosystem function is commonly studied within a single trophic level, but less is known about how resource diversity affects species interactions between trophic levels. We conducted a grazing experiment to determine how resource species diversity affects rates of consumption by three species of freshwater zooplankton consumers. We measured the effect of resource diversity on rates of consumption for several resource community compositions. These compositions varied in terms of palatability for the consumers. The effect of resource diversity on consumption rates depended on the diet breadth of the consumer species (from specialist to generalist) and the community composition of resources. Overall, high resource diversity commonly caused a decline in consumption rates of consumers. The most selective grazer showed reduced consumption for nearly all community compositions, whereas the most generalist grazer showed accelerated consumption when all resource species were palatable. Our results demonstrate that resource species diversity can modulate rates of consumption through the action of multiple different mechanisms.     

Physiological,biochemical and growth responses of Azolla pinnata to chlorpyrifos and cypermethrin pesticides exposure: a comparative study

Cypermethrin and chlorpyrifos pesticide- (5, 15 and 30 ppm) induced effects on growth, metabolic and antioxidative behaviour of Azolla pinnata were analysed after 96 h of treatment. Growth of A. pinnata was increased by 72–76% over the initial mass under control condition. Further, the growth was decreased by 26 and 30% following treatment with 5 ppm of cypermethrin and chlorpyrifos, respectively, compared to control. Whereas, 30 ppm of pesticide treatment caused substantial decrease in biomass accumulation, even less than the initial mass. The Chlorophyll a content was declined at higher concentrations of chlorpyrifos, while carotenoids content increased significantly in the presence of both the pesticides. Photosynthetic rate showed declining trend with rising concentration of pesticides, while an increasing trend was noticed in the case of respiratory O₂ consumption. The oxidative biomarkers malondialdehyde, superoxide radicals and hydrogen peroxide increased with increasing concentration of both the pesticides. The activity of enzymatic antioxidants enzyme superoxide dismutase, glutathione-S-transferase and ascorbate peroxidase (APX) was enhanced with increasing concentrations of both the pesticides; however, a declining trend was noticed in the case of APX at 30 ppm chlorpyrifos treatment. The study concludes that chlorpyrifos appeared to be more toxic than cypermethrin; however, both the pesticides significantly reduced the growth performance.     

Primary NO2 emissions and their impact on air quality in traffic environments in Germany

Background

The decreasing NO_X concentrations at urban measurement stations in Germany are in agreement with the reduction of NO_X emissions from vehicular traffic. However, the measured NO₂ concentrations are stagnating nationwide. In 2010, at more than the half of the urban measurement stations in Germany, annual mean values for NO₂ exceeded the new Europe-wide limit value of 40 μg/m³ (20 ppbv) NO₂. Similar findings are reported from many other member states of the European Union.

Results

The observed trend of the airborne NO₂ concentrations has different reasons. Firstly, the NO₂/NO_x emission ratio has increased significantly during the last two decades. Furthermore, secondary NO₂, caused by the titration reactions of NO with ozone (O₃) and peroxy radicals (RO₂), is responsible for the major fraction (approximately 70%) of the measured NO₂. However, secondary NO₂ shows a highly nonlinear dependency on NO_x and thus, is decreasing much more slowly than expected from the decreasing NO_x levels. Based on the results from the present study, the increased NO₂/NO_X emission ratio can only explain a minor fraction of the observed high airborne NO₂ concentration in the city center.

Conclusions

A further reduction of primary NO₂ emissions, due to improved exhaust gas treatment, will not have a strong influence on urban NO₂ levels, and a further significant reduction of the NO_X emissions, in particular from vehicular traffic, is necessary in order to meet the annual mean limit value for NO₂ of about 20 ppb in the future.     

Motivations for the use and consumption of wildlife products

The dominant approach to combating the illegal wildlife trade has traditionally been to restrict the supply of wildlife products. Yet conservationists increasingly recognize the importance of implementing demand-side interventions that target the end consumers in the trade chain. Their aim is to curb the consumption of wildlife or shift consumption to more sustainable alternatives. However, there are still considerable knowledge gaps in understanding of the diversity of consumer motivations in the context of illegal wildlife trade, which includes hundreds of thousands of species, different uses, and diverse contexts. Based on consultation with multiple experts from a diversity of backgrounds, nationalities, and focal taxa, we developed a typology of common motivations held by wildlife consumers that can be used to inform conservation interventions. We identified 5 main motivational categories for wildlife use: experiential, social, functional, financial, and spiritual, each containing subcategories. This framework is intended to facilitate the segmentation of consumers based on psychographics and allow the tailoring of interventions—whether behavior change campaigns, enforcement efforts, or incentive programs—to the specific context in which they will be used. Underlining the importance of consumer research and collaborating with local actors is an important step toward promoting a more systematic approach to the design of demand reduction interventions.     

A national and local media perspective on responsibility for and solutions to storm-related power outages in the northeastern United States

Major storms in the northeastern United States in 2011 and 2012 caused widespread power outages, bringing attention to the vulnerability of utility infrastructure as a result of extreme weather and environmental change. Media coverage of such focusing events provides context for and can affect government and public response. Our objective was to analyze gatekeeping, agenda setting, and framing in the New York Times (NYT) and local newspapers covering power outages related to large storm events in 2011 and 2012 (Tropical Storm Irene, October snowstorm, Hurricane Sandy). Government and utility officials focused on structural solutions to mitigate future storm impacts, whereas residents and businesses targeted individual actions. NYT interviews included residents more frequently than local newspapers, influencing coverage of impacts and solutions. Geographic differences between NYT and local newspapers’ foci may relate to coverage of solutions to and responsibility for outages. Our findings demonstrate the importance of collective action toward shared solutions.     

Selected landslide types in the Central Himalaya: their relation to geological structure and anthropogenic activities

In a region that is highly sensitive to tectonic instability, the fragile nature of the Himalayas becomes further adversely affected by anthropogenic intervention. In the present study observations indicate that the landsliding process occurs along various tectonic zones where it is assisted by human activities. Bedding and joint plane dip slopes, high joint and joint set frequencies, low vegetation cover, high monsoonal rainfall, thin soil cover and anthropogenic activities were found to be the main causative factors of the landslides. Anthropogenic activities include local path, canal and road construction, mining and quarrying, overgrazing, deforestation and unscientific agricultural practices, such as tilling steeper slopes (>30) without contour benches and without provision of drainage ditches, and overcropping without giving rest to the overtaxed soils. Where slope conditions are critical human activities should be controlled so as to minimise the slope failure processes. Various recommendations are proposed.     

Modelling economic impacts and adaptation to extreme events: Insights from European case studies

Adaptation to climate change in Europe has only recently become a true policy concern with the management of extreme events one priority item. Irrespective of future climatic changes increasing the need for systematic evaluation and management of extremes, weather-related disasters already today pose substantial burdens for households, businesses and governments. Research in the ADAM project identified substantial direct risks in terms of potential crop and asset losses due to combined drought and heatwave, as well as flood hazards in Southern and Eastern Europe, respectively. This paper focuses on the indirect, medium to longer term economic risks triggered by the direct risks and mediated by policy responses. We present a selection of three economic impact and adaptation assessments and modelling studies undertaken on extreme event adaptation in Europe. Responding to a need for more economically based adaptation assessments, we address some relatively unresearched issues such as the understanding of past adaptation, the role of market response to impacts as well as government’s ability to plan for and share out extreme event risks. The first analysis undertakes an empirical exploration of observed impacts and adaptation in the agricultural sector in the UK comparing the impact of consecutive extreme events over time in order to determine whether adaptation has occurred in the past and whether this can be used to inform future estimates of adaptation rates. We find that farmers and the agricultural sector clearly have adapted to extreme events over time, but whether this rate can be maintained into the future is unclear, as some autonomous adaptation enacted seemed rather easy to be taken. Markets may mediate or amplify impacts and in the second analysis, we use an economic general equilibrium model to assess the economic effects of a reduction in agricultural production due to drought and heatwave risk in exposed regions in Spain. The analysis suggests that modelled losses to the local economy are more serious in a large-scale scenario when neighbouring provinces are also affected by drought and heatwave events. This is due to the supply-side induced price increase leading to some passing on of disaster costs to consumers. The simulation highlights the importance of paying particular attention to the spatial and distributional effects weather extremes and possibly changes therein induced by climate change may incur. Finally, we discuss how national governments may better plan their disaster liabilities resulting from a need to manage relief and reconstruction activities post event. We do so using a risk based economic planning model assessing the fiscal consequences associated with the coping with natural extremes. We identify large weather-related disaster contingent liabilities, particularly in the key flood hot spot countries Austria, Romania, and Hungary. Such substantial disaster liabilities (“hidden disaster deficits”) when interacting with weak fiscal conditions may lead to substantial additional stress on government budgets and reduced fiscal space for funding other relevant public investment projects. Overall, our paper suggests the importance of respecting the specific spatial and temporal characteristics of extreme event risk when generating information on adaptation decisions. As our adaptation decisions considered, such as using sovereign risk financing instruments are associated with a rather short time horizon, the analysis largely focuses on the management of today’s extreme events and does not discuss in detail projections of risks into a future with climate change. Such projections raise important issues of uncertainty, which in some instances may actually render future projections non-robust, a constraint to be kept in mind when addressing longer term decisions, which at the same time should account for both climate and also socioeconomic change.     

Policy design,spatial planning and climate change adaptation: a case study from Australia

There are gaps in the existing climate change adaptation literature concerning the design of spatial planning instruments and the relationship between policy instruments and the sociopolitical barriers to adaptation reform. To help address this gap, this article presents a typology of spatial planning instruments for adaptation and analyses the pattern of instrument choice in Australian planning processes in order to shed light on contextual factors that can impede adaptation. The analysis highlights how policy design can amplify the barriers to adaptation by arranging policy actors in ways inimical to reform and stripping decision makers of the instruments necessary to make and sustain desired policy changes.