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131.
The impacts of strategically located contour prairie strips on sediment and nutrient runoff export from watersheds maintained under an annual row crop production system have been studied at a long-term research site in central Iowa. Data from 2007 to 2011 indicate that the contour prairie strips utilized within row crop-dominated landscapes have greater than proportionate and positive effects on the functioning of biophysical systems. Crop producers and land management agencies require comprehensive information about the Best Management Practices with regard to performance efficacy, operational/management parameters, and the full range of financial parameters. Here, a farm-level financial model assesses the establishment, management, and opportunity costs of contour prairie strips within cropped fields. Annualized, depending on variable opportunity costs the 15-year present value cost of utilizing contour prairie strips ranges from $590 to $865 ha?1 year?1 ($240–$350 ac?1 year?1). Expressed in the context of “treatment area” (e.g., in this study 1 ha of prairie treats 10 ha of crops), the costs of contour prairie strips can also be viewed as $59 to about $87 per treated hectare ($24–$35 ac?1). If prairie strips were under a 15-year CRP contract, total per acre cost to farmers would be reduced by over 85 %. Based on sediment, phosphorus, and nitrogen export data from the related field studies and across low, medium, and high land rent scenarios, a megagram (Mg) of soil retained within the watershed costs between $7.79 and $11.46 mg?1, phosphorus retained costs between $6.97 and $10.25 kg?1, and nitrogen retained costs between $1.59 and $2.34 kg?1. Based on overall project results, contour prairie strips may well become one of the key conservation practices used to sustain US Corn Belt agriculture in the decades to come.  相似文献   
132.
Crop and livestock losses to wildlife are a concern for people neighboring many protected areas (PAs) and can generate opposition to conservation. Examining patterns of conflict and associated tolerance is important to devise policies to reduce conflict impacts on people and wildlife. We surveyed 398 households from 178 villages within 10 km of Ranthambore, Kanha, and Nagarahole parks in India. We compared different attitudes toward wildlife, and presented hypothetical response scenarios, including killing the problem animal(s). Eighty percent of households reported crop losses to wildlife and 13 % livestock losses. Higher crop loss was associated with more cropping months per year, greater crop variety, and more harvest seasons per year but did not vary with proximity to the PA, suggesting that PAs are not necessarily “sources” for crop raiders. By contrast, complaints of “depredating carnivores” were associated with people-grazing animals and collecting resources from PAs. Many households (83 %) engaged in mitigation efforts. We found that only fencing and guard animals reduce crop losses, and no efforts to lower livestock losses. Contrary to our expectations, carnivores were not viewed with more hostility than crop-raiding wildlife. Households reported greater inclination to kill herbivores destroying crops or carnivores harming people, but not carnivores preying on livestock. Our model estimated crop loss was 82 % across surveyed households (highest in Kanha), while the livestock loss experienced was 27 % (highest in Ranthambore). Our comparative study provides insights into factors associated with conflict loss and tolerance, and aids in improving ongoing conservation and compensation efforts.  相似文献   
133.
In contrast to an open environment where a specific celestial cue is predominantly used, visual contrast of canopies against the sky through the gap, known as canopy cues, is known to play a major role for visually guided insect navigators in woodland habitats. In this paper, we investigated whether a subsocial shield bug, Parastrachia japonensis, could gauge direction using canopy cues on a moonless night. The results show that they could perform the round trip foraging behaviour even in an experimental arena with only an artificial round gap opened in the ceiling of the arena and adjust their homing direction for a new azimuth when the gap was rotated. Thus, P. japonensis can use slightly brighter canopy cues as a compass reference but not complex landmarks during nocturnal homing behaviour.  相似文献   
134.
Applying 3DCE to environmentally responsible manufacturing practices   总被引:1,自引:0,他引:1  
A review of recent literature in the fields of operations, supply chain, and management indicates there is on-going interest in improving new product development (NPD) performance. Three-dimensional concurrent engineering (3DCE), the simultaneous design of product, process and supply chain have been proposed as a way to improve traditional NPD outcomes, such as reduced time to market, lower costs, and improved customer acceptance. There appears to be a lesser concern associated with the environmental impacts of new products. Environmentally responsible manufacturing (ERM) on new product development focuses on reduced emissions, hazardous materials elimination, and lower product weight without sacrificing functionality. This paper explores the following issue: will employing 3DCE to integrate NPD and ERM yield better benefits than the separate and uncoordinated application of environmental goals and NPD initiatives?  相似文献   
135.
Because of the similarities in European and North American dietary exposure, it has been suggested that the order of magnitude higher body burdens in North Americans may be due to international variations in exposure via ingestion of indoor dust. Furthermore, ingestion of indoor dust has been suggested as a possible source of PBDEs in the blood serum of New Zealanders. Hence, polybrominated diphenyl ethers (PBDEs) were measured in domestic indoor dust from: Amarillo/Austin, Texas, US; Birmingham, UK; Toronto, Canada; and Wellington, New Zealand. Concentrations of BDE 209 in two UK samples were - at 520,000 and 100,000 ng g(-1) - the highest ever recorded in a domestic (or office) indoor dust sample. Median concentrations in ng g(-1) were: in Canada 620 and 560 for Sigmatri-hexa-BDEs and BDE 209 respectively; in New Zealand 96, BDE 209 not determined; in the UK 59 and 2,800; and in the US 1600 and 1300. With respect to BDE 209, concentrations were in the order: UK approximately US>Canada. For Sigmatri-hexa-BDEs, the order of concentrations was US approximately Canada>New Zealand approximately UK. Combined with principal component analysis of congener patterns, this suggests that, while North American dusts are contaminated by both Deca- and Penta-BDE commercial formulations, UK dusts are contaminated predominantly by Deca-BDE. The Octa-BDE formulation appears of minimal importance in accordance with available market demand figures. Despite the commercial formulations of PBDEs never having been manufactured in, nor imported into New Zealand, their presence in dusts from that country suggests international trade in PBDE-containing goods is an important pathway effecting their global distribution.  相似文献   
136.
Whether information and communication technology (ICT) constitutes a threat or a cure to environment??s deterioration is controversially discussed. Empirical evidence on the impacts of ICT is rare, so that generalizable lessons can hardly be drawn. This study provides empirical results on the role of ICT in research for environmental sustainability, but instead of ascertaining the impact of ICT on environmental protection, we conduct an analysis of the use of ICT in sustainability research. We assess the preferences of experts in different thematic sustainability fields for applying ICT tools, and we investigate ways to improve the application of these tools in order to augment their returns with respect to environmental protection research. This analysis is based on a set of surveys that were administered to international experts to evaluate the importance of ICT in environmental sustainability research and the research demands in key environmental sectors, such as climate change, natural resources, energy and biodiversity. The methodological framework is built on the analysis of users?? preferences for future developments in ICT tools using stated preferences techniques. Overall results suggest that ICT tools need to be developed in specific contexts, taking into account users?? needs and expectations. Our analysis shows that the use of ICT in environmental research is of great importance in the scientific community, but it can also play a crucial role in the policy context.  相似文献   
137.
Urban stormwater runoff is often of poor quality, impacting aquatic ecosystems and limiting the use of stormwater runoff for recreational purposes. Several stormwater treatment facilities (STFs) are in operation or at the pilot testing stage, but their efficiencies are neither well documented nor easily compared due to the complex contaminant profile of stormwater and the highly variable runoff hydrograph. On the basis of a review of available data sets on urban stormwater quality and environmental contaminant behavior, we suggest a few carefully selected contaminant parameters (the minimum data set) to be obligatory when assessing and comparing the efficiency of STFs. Consistent use of the minimum data set in all future monitoring schemes for STFs will ensure broad-spectrum testing at low costs and strengthen comparability among facilities. The proposed minimum data set includes: (i) fine fraction of suspended solids (<63 μm), (ii) total concentrations of zinc and copper, (iii) total concentrations of phenanthrene, fluoranthene, and benzo(b,k)fluoranthene, and (iv) total concentrations of phosphorus and nitrogen. Indicator pathogens and other specific contaminants (i.e., chromium, pesticides, phenols) may be added if recreational or certain catchment-scale objectives are to be met. Issues that need further investigation have been identified during the iterative process of developing the minimum data set.  相似文献   
138.
Assessing the impact of climate change on species and associated management objectives is a critical initial step for engaging in the adaptation planning process. Multiple approaches are available. While all possess limitations to their application associated with the uncertainties inherent in the data and models that inform their results, conducting and incorporating impact assessments into the adaptation planning process at least provides some basis for making resource management decisions that are becoming inevitable in the face of rapidly changing climate. Here we provide a non-exhaustive review of long-standing (e.g., species distribution models) and newly developed (e.g., vulnerability indices) methods used to anticipate the response to climate change of individual species as a guide for managers grappling with how to begin the climate change adaptation process. We address the limitations (e.g., uncertainties in climate change projections) associated with these methods, and other considerations for matching appropriate assessment approaches with the management questions and goals. Thorough consideration of the objectives, scope, scale, time frame and available resources for a climate impact assessment allows for informed method selection. With many data sets and tools available on-line, the capacity to undertake and/or benefit from existing species impact assessments is accessible to those engaged in resource management. With some understanding of potential impacts, even if limited, adaptation planning begins to move toward the development of management strategies and targeted actions that may help to sustain functioning ecosystems and their associated services into the future.  相似文献   
139.
Increasingly government agencies are seeking to quantify the outcomes of proposed policy options in terms of ecosystem service benefits, yet conflicting definitions and ad hoc approaches to measuring ecosystem services have created confusion regarding how to rigorously link ecological change to changes in human well-being. Here, we describe a step-by-step framework for producing ecological models and metrics that can effectively serve an economic-benefits assessment of a proposed change in policy or management. A focus of the framework is developing comparable units of ecosystem goods and services to support decision-making, even if outcomes cannot be monetized. Because the challenges to translating ecological changes to outcomes appropriate for economic analyses are many, we discuss examples that demonstrate practical methods and approaches to overcoming data limitations. The numerous difficult decisions that government agencies must make to fairly use and allocate natural resources provides ample opportunity for interdisciplinary teams of natural and social scientists to improve methods for quantifying changes in ecosystem services and their effects on human well-being. This framework is offered with the intent of promoting the success of such teams as they support managers in evaluating the equivalency of ecosystem service offsets and trades, establishing restoration and preservation priorities, and more generally, in developing environmental policy that effectively balances multiple perspectives.  相似文献   
140.
Carson HS  Cook GS  López-Duarte PC  Levin LA 《Ecology》2011,92(10):1972-1984
Recently researchers have gone to great lengths to measure marine metapopulation connectivity via tagging, genetic, and trace-elemental fingerprinting studies. These empirical estimates of larval dispersal are key to assessing the significance of metapopulation connectivity within a demographic context, but the life-history data required to do this are rarely available. To evaluate the demographic consequences of connectivity we constructed seasonal, size-structured metapopulation matrix models for two species of mytilid mussel in San Diego County, California, USA. The self-recruitment and larval exchange terms were produced from a time series of realized connectivities derived from trace-elemental fingerprinting of larval shells during spring and fall from 2003 to 2008. Both species exhibited a strong seasonal pattern of southward movement of recruits in spring and northward movement in fall. Growth and mortality terms were estimated using mark-recapture data from representative sites for each species and subpopulation, and literature estimates of juvenile mortality. Fecundity terms were estimated using county-wide settlement data from 2006-2008; these data reveal peak reproduction and recruitment in fall for Mytilus californianus, and spring for M. galloprovincialis. Elasticity and life-stage simulation analyses were employed to identify the season- and subpopulation-specific vital rates and connectivity terms to which the metapopulation growth rate (lambda) was most sensitive. For both species, metapopulation growth was most sensitive to proportional changes in adult fecundity, survival and growth of juvenile stages, and population connectivity, in order of importance, but relatively insensitive to adult growth or survival. The metapopulation concept was deemed appropriate for both Mytilus species as exchange between the subpopulations was necessary for subpopulation persistence. However, highest metapopulation growth occurred in years when a greater proportion of recruits was retained within the predominant source subpopulation. Despite differences in habitat and planktonic duration, both species exhibited similar overall metapopulation dynamics with respect to key life stages and processes. However, different peak reproductive periods in an environment of seasonal current reversals led to different regional (subpopulation) contributions to metapopulation maintenance; this result emphasizes the importance of connectivity analysis for spatial management of coastal resources.  相似文献   
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