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201.
Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far‐reaching consequences within aquatic ecosystems.  相似文献   
202.
Samples have been collected from major horizons of 34 podzol profiles distributed throughout Scotland, all developed from granite or granitic tills and under Calluna moorland. the pH in water and calcium chloride pastes, exchangeable cations and cation exchange capacity, and extractable aluminium of the soils collected have been measured, and the results studied in relation to reported atmospheric deposition of H+, non-marine sulphur and nitrate. for all horizons, significant positive correlations were found between soil pH and rainfall mean pH, as might be expected when the critical load of H+ deposition is exceeded. Acidifying pollutant deposition also apparently increased soil extractable aluminium concentrations in the B and C horizons. However, exchangeable base cation concentrations tended to increase, rather than decrease, with increasing precipitation acidity. This effect was attributed to increases in biogeochemical cycling of base cations, increases in leaching inputs of base cations from overlying A/E horizon soils, and increases in the inputs of base cations leached from upslope. the results suggest that the simple steady state mass approach to the quantification of critical loads, as often applied, may be an oversimplification.  相似文献   
203.
An experiment has been conducted to contrast the effects of enhanced oxidised and reduced nitrogen deposition upon key chemical parameters in a Calluna moorland podzol. A 40 cm deep podzol profile, derived from granite, was reconstructed in one hundred 4.2 cm diameter cores. for 20 weeks, the cores were subjected twice weekly to simulated rainfall containing either twice ambient nitrogen deposition in Aberdeen, or further enhanced nitrogen (further 2- and 6-fold increases) as nitric acid or ammonium sulphate. to quantify the dynamics of soil change in each horizon, randomly selected cores were destructively analysed every two weeks and the soils analysed. Increased nitrogen inputs, regardless of form, substantially and immediately reduced surface soil pHwater via the mobile anion or salt effect. for the higher nitrogen treatments, the pH reduction was seen throughout the profile. Longer term soil acidification was also seen in the pHcalcium chloride results over the 20 weeks. at a given nitrogen deposition rate, the effects of ammonium sulphate and nitric acid on soil pHcalcium chloride were similar. the ammonium sulphate treatments were especially effective at reducing base saturation throughout much of the profile, the direct base cation leaching being associated with substantial ammonium accumulation. the results suggest that the direct base cation leaching caused by ammonium deposition needs to be considered when assessing atmospheric pollution “damage” to heathland soils.  相似文献   
204.
Fleet, work-related or occupational road safety has the potential to make a major contribution to reducing both human harm and asset damage. To date, however, there would appear to be a dearth of well researched and evaluated case studies in the public domain in this area.This paper provides an on-going, documented, real-world case study of work-related road safety within an Australian company that has sought to manage, monitor and improve its road safety performance over the last 5 years through a range of proactive, fleet manager, insurance and risk-led initiatives.Roche Australia has successfully implemented a Company Motor Vehicle Safety Program with support from its fleet insurers and risk management advisors. Four key initiatives are set out covering: (1) Driver risk assessment, monitoring and improvement. (2) Policy development and communications. (3) Process and outcomes evaluation. (4) Continuous review and refinement of policies, processes, programs and future developments.The program has led to a range of process and performance-based outcomes. Typical barriers to success in work-related road safety have been identified and overcome. Almost 100% risk assessment and improvement process compliance by drivers has been achieved. A predictive relationship between risk assessment outcomes and collision history has been identified. Reductions in insurance claims, collision costs and claims ratio have been sustained. A detailed project plan is in place to continue the program for the next 3 years.The paper concludes that with effective management, a well developed work-related road safety program can result in performance improvements within the initiating organisation. Several limitations in the case study methodology, as well as areas for further work and lessons for policy makers, researchers and practitioners are also identified.  相似文献   
205.
There is a critical need for a national agroecosystem model for conservation policy and environmental planning, driven by issues including harmful algal blooms, water scarcity, flooding, and other weather‐related extremes. In this study, we illustrate the feasibility of a national agroecosystem model that will downscale processes to individual fields and first‐order channels. We propose to conceptually divide the conterminous United States (U.S.) into process domains as a framework for simulating processes and management at relevant scales. Specifically, we are proposing five domains: field (1–50 ha), transition (0.2–2.0 km2), headwater (1–15 km2), tributaries (15–150 km2), and main river (>150 km2). The proposed conceptual framework hydrologically connects fields across the U.S. using the National Hydrography Dataset (NHDPlus version 2). Parameterizing the Soil and Water Assessment Tool for the national agroecosystem model resulted in 4,880,000 agricultural fields, 2,250,000 non‐agricultural hydrologic response units, and 7,130,000 transition, 1,610,000 headwater, 591,000 tributary, and 432,400 main channels. Application of this framework was shown for Hydrologic Unit Code 07120002 in central Illinois and Indiana to demonstrate the feasibility of the approach using data that is readily available across the U.S. The new connectivity framework has the potential to dramatically improve national conservation and environmental assessments performed by U.S. Department of Agriculture and U.S. Environmental Protection Agency.  相似文献   
206.
As a result of 210Po's previously identified association with sulphur-rich proteins, metallothioneins could have a significant effect on the behaviour and fate of 210Po in molluscs. Starved control and cadmium-exposed mussels, Mytilus edulis, were fed 210Po-labelled algae (Isochrysis galbana) for 5 d and then allowed to depurate in clean sea water. Cadmium-exposed M. edulis accumulated less 210Po in the digestive gland and the remainder of the tissue than control mussels, although this was due to a decrease in tissue weight. More than 40% of 210Po was identified as being associated with high molecular weight and heat-treated cytosol proteins in M. edulis. Mussels in a starved state are known to recycle as much as 90% of their amino acids. It is proposed that 210Po associated with these and other proteins is recycled, explaining why no significant loss of 210Po was observed from the remainder of the tissue in either control or Cd-exposed mussels. Cadmium-induced metallothioneins had no effect on the distribution of 210Po in M. edulis; <5% associated with the cytosolic fraction was considered to principally contain metallothioneins. It is suggested that 210Po's apparent relationship with metallothioneins is coincidental rather than connected with its role in the regulation of metals. Received: 30 March 1998 / Accepted: 3 August 1998  相似文献   
207.
Conservation biology is a mission-driven discipline that must navigate a new relationship between conservation and science. Because conservation is a social and political as well as an ecological project, conservation biologists must practice interdisciplinarity and collaboration. In a comparative study of 7 cases (Jaguars in the Chaco, Grevy's zebra in Kenya, Beekeeping in Tanzania, Andean cats in Argentina, Jaguars in Mexico, Lobster fishing, and Black bears in Mexico), we examined motivations for collaboration in conservation, who can collaborate in conservation, and how conservation professionals can work well together. In 5 case studies, successful conservation outcomes were prioritized over livelihood benefits. In the other 2 cases, livelihoods were prioritized. All case studies employed participatory approaches. There were multiple external actors, including local and Indigenous communities, nongovernmental organizations, agencies, regional and national governments, and international organizations, which enhanced conservation and wider sustainability outcomes. Key collaboration aspects considered across the case studies were time (mismatch between relationship building and project schedules), trust required for meaningful partnerships, tools employed, and transformative potential for people, nature, and the discipline of conservation biology. We developed guidelines for successful collaboration, including long-term commitment, knowledge integration, multiscalar and plural approaches, cultivation of trust, appropriate engagement, evaluation, supporting students, and efforts for transformation.  相似文献   
208.
The increased use of grain-based feed for livestock during the last two decades has contributed, along with other factors, to a rise in grain prices that has reduced human food security. This circumstance argues for feeding more forages to livestock, particularly in the tropics where many livestock are reared on small farms. Efforts to accomplish this end, referred to as the ‘LivestockPlus’ approach, intensify in sustainable ways the management of grasses, shrubs, trees, and animals. By decoupling the human food and livestock feed systems, these efforts would increase the resilience of the global food system. Effective LivestockPlus approaches take one of two forms: (1) simple improvements such as new forage varieties and animal management practices that spread from farmer to farmer by word of mouth, or (2) complex sets of new practices that integrate forage production more closely into farms’ other agricultural activities and agro-ecologies.  相似文献   
209.
The amount of information required to adapt to climate change is vast: downscaled climate projections, information on environmental impact, sectoral performance, external drivers, regional strategies, policies and practices. It can be argued that most of this information is accessible at the community/regional level, and thus, the important challenges to adaptation are not information gaps, but constraints created by fragmented planning decisions and a sector-by-sector basis for financial and human resource allocations. To strategically address this through adaptation planning, we developed and tested a place-based decision-making framework that creates an integrated platform for considering regional and global sectoral drivers in Eastern Ontario, Canada. Using available socioeconomic and biophysical information from regional authorities, alternative future scenarios were used to describe the range of socioeconomic futures and their vulnerabilities to climate change. We found that: (1) integration of diverse sets of available data (rather than narrowly focused sectoral assessments) helped identify shared common objectives (maximizing the long-term environmental, economic, social well-being within the region), (2) a high degree of congruence existed as the key drivers of change, irrespective of sector, (3) exploring the future scenarios highlighted shared regional priorities and helped identify adaptation priorities requiring more integrated regional planning.  相似文献   
210.
The amount of toxic metal accumulated by an organism is often taken as an indicator of potential toxicity. We investigated this relationship in the freshwater snail, Lymnaea stagnalis, exposed to 500 μg l−1 Al over 30 days, either alone or in the presence of phosphate (500 μg l−1 P) or a fulvic acid surrogate (FAS; 10 mg l−1 C). Behavioural activity was assessed and tissue accumulation of Al quantified. Lability of Al within the water column was a good predictor of toxicity. FAS increased both Al lability and behavioural dysfunction, whereas phosphate reduced Al lability, and completely abolished Al-induced behavioural toxicity. Tissue accumulation of Al was not linked to toxicity. Higher levels of Al were accumulated in snails exposed to Al + P, compared to those exposed to Al alone, whereas FAS reduced Al accumulation. These findings demonstrate that the degree of tissue accumulation of a metal can be independent of toxicity.  相似文献   
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