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Juggins S.,Northumbria University | Kelly M.,Bowburn Consultancy | Allott T.,University of Manchester | Kelly-Quinn M.,University College Dublin | Monteith D.,Center for Ecology and Hydrology
Science of the Total Environment | Year: 2016

Freshwater acidification continues to be a major problem affecting large areas of Europe, and while there is evidence for chemical recovery, similar evidence for biological recovery of freshwaters is sparse. The need for a methodology to identify waterbodies impacted acidification and to assess the extent of biological recovery is relevant to the EU Water Framework Directive, which requires methods to quantify differences in biology between impacted and unimpacted or reference sites. This study presents a new WFD-compliant metric based on diatoms (Diatom Acidification Metric: DAM) for assessing the acidification status of rivers. A database of 558 benthic diatom samples and associated water chemistry data was assembled. Diatom taxa were assigned to one of 5 indicator classes on the basis of their pH optimum, assessed using Gaussian logistic regression, and these indicator values used to calculate a DAM score for each site using weighted averaging. Reference sites were selected on the basis of their acid neutralising capacity (ANC) and calcium concentration, and a regression model developed to predict expected DAM for each site using pH and total organic carbon (TOC) concentration. Site-specific DAM scores were used to calculate ecological quality ratios ranging from ≥. 1, where the diatom assemblage showed no impact, to (theoretically) 0, when the diatom assemblage was indicative of major anthropogenic activities. The boundary between 'high' and 'good' status was defined as the 25th percentile of Ecological Quality Ratios (EQRs) of all reference sites. The boundary between 'good' and 'moderate' status was set at the point at which nutrient-sensitive and nutrient-tolerant taxa were present in equal relative abundance. The methodology was evaluated using long-term data from 11 sites from the UK Uplands Waters Monitoring Network and is shown to perform well in discriminating naturally acid from acidified sites. © 2016 Elsevier B.V. Source

Bertoldo R.,Institute Symlog | Bertoldo R.,Instituto Universitario Of Lisbon Iscte Iul | Mays C.,Institute Symlog | Poumadere M.,Institute Symlog | And 2 more authors.
Journal of Risk Research | Year: 2015

Nanotechnologies are becoming a larger presence in everyday life and are viewed by governments and economic actors as a key area for development. The theory of social representations suggests that specialist views eventually disseminate to shape representations among the public. Yet nanotechnologies remain relatively little known to the general public. The media emphasize potential benefits, while potential risks get less attention. The literature has not yet addressed whether representations by a well-informed population (scientists) are indeed structured in terms of the risk–benefit polarity that dominates research framing to date. We attempted a systematic assessment of how background knowledge about nanotechnology may influence experts’ perception. Study 1 delivered the first demonstration derived from a qualitative analysis confirming the existence of a polarized representation of nanotechnologies, contrasting opportunity (medical, economic, and technological) and risk. Interestingly, risk was distinguished at two levels: that associated with nanomaterial characteristics (toxicity, reactivity) and at the larger scale of impact (health, environment, legislation). Does this polarity indicate a ‘yes, but’ logic (nanotechnology carries opportunity but also risk), or two clusters of specialists (sensitive, respectively, to opportunity or to risk)? Study 2 surveyed a larger sample of experts who self-described their scientific background and role viz. nanotechnology. Role had no influence. Specialists consensually viewed that nanotechnology represents opportunity, but depending on scientific background they did not agree to the same extent that nanotechnology also constitutes a risk. Participants with a physics and chemistry background tended to represent nanotechnologies predominantly in terms of opportunities and not in terms of inherent risks or impacts. In contrast, toxicologists, life and social scientists appeared to explicitly incorporate both benefits and risks in their representation of this new technology. Environmental scientists were a more diverse group, divided between the two patterns of representation. © 2015 Taylor & Francis Source

News Article | August 17, 2016
Site: http://www.techtimes.com/rss/sections/earth.xml

There is a worrying reduction in the population of bees worldwide. Because bees are considered as major pollinator of crops, decline in their number threatens global food production and supply. Now, a new research provides another evidence that the long-term and large-scale decline in bee population could be blamed in part to the use of neonicotinoid insecticides. In a new study spanning 18 years, researchers looked at wild bees that forage from oilseed rape crops, which are widely treated with neonicotinoids. They found that these insects are three times more likely to experience long-term population decline compared with bees that forage from other sources. "Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape," the researchers wrote in their study, which was published in the journal Nature Communications on Aug. 16. Neonicotinoids are widely used worldwide in a variety of crops to keep away insects that eat through harvests, but they also harm insects that benefit plants. Lab-based studies have shown that this pesticide is also harmful to certain species of bee, particularly commercial honeybees and bumblebees. The result of the new study offers some of the first evidences that exposure to neonicotinoid can scale up and lead to major damages to bees. "Prior to this, people had an idea that something might be happening, but no-one had an idea of the scale," said study author Ben Woodcock, from the Natural Environmental Research Council Center for Ecology and Hydrology. "(Our results show that) it's long-term, it's large scale, and it's many more species than we knew about before." Until now, most of the studies that looked at the effects of the chemical was limited to short-term and small-scale research. Many of these studies were also performed in laboratory settings and focused on just a few species. The result of the new study is different and more reliable in that it used 18 years' worth of data and involved more than 60 bee species in England. The research also relied on field data. "It's nice to see the use of long-term data to look at trends in pesticide impacts over longer time scales," said Dara Stanley, from the National University of Ireland Galway, who was involved in earlier research on the impact of neonicotinoids on bees. "That is something that has been missing in the debate on bees and pesticides so far, and there have been many calls to look at effects over time." © 2016 Tech Times, All rights reserved. Do not reproduce without permission.

Fowler D.,Center for Ecology and Hydrology
Philosophical transactions of the Royal Society of London. Series B, Biological sciences | Year: 2013

Global nitrogen fixation contributes 413 Tg of reactive nitrogen (Nr) to terrestrial and marine ecosystems annually of which anthropogenic activities are responsible for half, 210 Tg N. The majority of the transformations of anthropogenic Nr are on land (240 Tg N yr(-1)) within soils and vegetation where reduced Nr contributes most of the input through the use of fertilizer nitrogen in agriculture. Leakages from the use of fertilizer Nr contribute to nitrate (NO3(-)) in drainage waters from agricultural land and emissions of trace Nr compounds to the atmosphere. Emissions, mainly of ammonia (NH3) from land together with combustion related emissions of nitrogen oxides (NOx), contribute 100 Tg N yr(-1) to the atmosphere, which are transported between countries and processed within the atmosphere, generating secondary pollutants, including ozone and other photochemical oxidants and aerosols, especially ammonium nitrate (NH4NO3) and ammonium sulfate (NH4)2SO4. Leaching and riverine transport of NO3 contribute 40-70 Tg N yr(-1) to coastal waters and the open ocean, which together with the 30 Tg input to oceans from atmospheric deposition combine with marine biological nitrogen fixation (140 Tg N yr(-1)) to double the ocean processing of Nr. Some of the marine Nr is buried in sediments, the remainder being denitrified back to the atmosphere as N2 or N2O. The marine processing is of a similar magnitude to that in terrestrial soils and vegetation, but has a larger fraction of natural origin. The lifetime of Nr in the atmosphere, with the exception of N2O, is only a few weeks, while in terrestrial ecosystems, with the exception of peatlands (where it can be 10(2)-10(3) years), the lifetime is a few decades. In the ocean, the lifetime of Nr is less well known but seems to be longer than in terrestrial ecosystems and may represent an important long-term source of N2O that will respond very slowly to control measures on the sources of Nr from which it is produced. Source

Oliver T.H.,University of Reading | Heard M.S.,Center for Ecology and Hydrology | Isaac N.J.,Center for Ecology and Hydrology | Roy D.B.,Center for Ecology and Hydrology | And 13 more authors.
Trends in ecology & evolution | Year: 2015

Accelerating rates of environmental change and the continued loss of global biodiversity threaten functions and services delivered by ecosystems. Much ecosystem monitoring and management is focused on the provision of ecosystem functions and services under current environmental conditions, yet this could lead to inappropriate management guidance and undervaluation of the importance of biodiversity. The maintenance of ecosystem functions and services under substantial predicted future environmental change (i.e., their 'resilience') is crucial. Here we identify a range of mechanisms underpinning the resilience of ecosystem functions across three ecological scales. Although potentially less important in the short term, biodiversity, encompassing variation from within species to across landscapes, may be crucial for the longer-term resilience of ecosystem functions and the services that they underpin. Copyright © 2015 Elsevier Ltd. All rights reserved. Source

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