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281.
The lack of a particular use associated with abandoned farmland provides real opportunities with respect to the various land-use pressures occurring in productive territories. These environments remain generally poorly known and, because of this, require in-depth studies on the feasibility of management options, on biological as well as social grounds. This study, based on research on the biophysical potential and the perceptions by the owners of abandoned farmlands, analyzes the feasibility of silvicultural management options to improve forestry potential. Using a questionnaire, we surveyed abandoned farmland owners on different aspects of the status of their abandoned farmland in order to determine their willingness toward the management of these private lands. The land owners were also asked to express their interests and their constraints toward various types of interventions, with an emphasis on silvicultural work. The data were analyzed using multivariate methods to establish relationships between the questionnaire data and the characteristics of the land owners (socioeconomic profile and value system toward the environment). The results show that, in general, abandoned farmland is an unwanted space, is generally little used, is poorly known, and has little importance in the plans of its owners. We have found three types of owner profiles; the owners with a farmer’s profile are those who are the most interested in managing their abandoned farmland, whether for agriculture or silviculture. The desire to improve abandoned farmland seems less important to owners with an ecocentric profile (high awareness of the environment) and to older owners. Finally, by associating the type of abandoned farmland owned and the characteristics of the owners, it is possible to propose different management options that reconcile the wishes of the owners as well as the biophysical potential of their abandoned farmland.  相似文献   
282.
Some researches studied the removal of steroid estrogens by enzymatic treatment, however none verified the residual estrogenicity after the enzymatic treatment at environmental conditions. In this study, the residual estrogenic activities of the key natural and synthetic steroid estrogens were investigated following enzymatic treatment with horseradish peroxidase (HRP) and laccase from Trametes versicolor. Synthetic water and municipal wastewater containing environmental concentrations of estrone, 17beta-estradiol, estriol, and 17alpha-ethinylestradiol were treated. Liquid chromatography-mass spectrometry analysis demonstrated that the studied steroid estrogens were completely oxidized in the wastewater reaction mixture after a 1-h treatment with either HRP (8-10 U ml(-1)) or laccase (20 U ml(-1)). Using the recombinant yeast assay, it was also confirmed that both enzymatic treatments were very efficient in removing the estrogenic activity of the studied steroid estrogens. The laccase-catalyzed process seemed to present great advantages over the HRP-catalyzed system for up-scale applications for the treatment of municipal wastewater.  相似文献   
283.
The aim of this investigation was to evaluate the environmental impact associated to PCDDs/Fs and dioxin-like PCBs in the Ebro River basin. Sediments and fish from several species were sampled at three sites with different historical pollution records, including the Barbastro area with different industrial activities, and the Flix and Monzón sites, associated to heavy organochlorine compound pollution. Seventeen toxic PCDDs/Fs and 12 dioxin-like PCBs were analyzed by GC-MS. The results obtained indicated significant accumulation of dioxin-like PCBs, but not PCDDs/Fs, in sediments and fish at the Flix site compared to the other sites. Concomitantly, cytochrome p450 1A (CYP1A) expression, a known indicator for pollution by dioxins and dioxin-like PCBs, was significantly elevated in barbel (Barbus graellsii) from the Flix site, compared to the population from the Barbastro site. CYP1A expression correlated with the concentration of dioxin-like PCBs in the fish fat, whereas no significant correlation was found with PCDDs/Fs concentrations. Our data suggest a significant biological impact at the Flix site, closely related to the presence of dioxin-like PCBs, whereas the PCDDs/Fs contribution to this impact appears to be non-significant, at least in the studied sites.  相似文献   
284.
Hydrocarbon biodegradation is an important process for remediating petroleum hydrocarbons and managing large sites. However, this biodegradation results in what are essentially unavoidable CO2 emissions to the atmosphere. A feasibility assessment was conducted to quantitatively consider reuse options for petroleum brownfields that would offset contaminant respiration emissions rates in the 2 to 10 micromoles CO2 per meters squared per second (μmol CO2 m?2 s?1) typically observed. Under a wide range of solar resource scenarios, placement of solar panels over only a fraction (no more than 35%) of the site footprint is estimated as necessary to achieve an emissions offset. Similarly, placement of one 30‐meter tall wind turbine of moderate rating (approximately 30 to 50 kW) is sufficient to provide an offset for a nominal 1,000 square meters site. For spreading of spent calcium‐rich construction materials, under even a high emissions scenario, the required footprint for the offset is less than the site footprint. While these approaches appear feasible, revegetation as forestland is estimated as sufficient only at contaminant respiration rates up to 2 μmol CO2 m?2 s?1. Revegetation as rangeland and cropland, which sequesters CO2 mainly in soil organic carbon, is estimated as requiring more than the site footprint under many contaminant respiration rates. Revegetation as a wetland fares slightly better from a carbon storage perspective, but it also has the potential for N2O and CH4 emissions that may largely undo the benefit from sequestration in soil organic matter. Overall, the results indicate several methods that are viable for achieving emissions offsets and a quantitation method that can be honed with site‐specific input parameters as appropriate.  相似文献   
285.
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.  相似文献   
286.
Grassland birds are declining faster than any other bird guild across North America. Shrinking ranges and population declines are attributed to widespread habitat loss and increasingly fragmented landscapes of agriculture and other land uses that are misaligned with grassland bird conservation. Concurrent with habitat loss and degradation, temperate grasslands have been disproportionally affected by climate change relative to most other terrestrial biomes. Distributions of grassland birds often correlate with gradients in climate, but few researchers have explored the consequences of weather on the demography of grassland birds inhabiting a range of grassland fragments. To do so, we modeled the effects of temperature and precipitation on nesting success rates of 12 grassland bird species inhabiting a range of grassland patches across North America (21,000 nests from 81 individual studies). Higher amounts of precipitation in the preceding year were associated with higher nesting success, but wetter conditions during the active breeding season reduced nesting success. Extremely cold or hot conditions during the early breeding season were associated with lower rates of nesting success. The direct and indirect influence of temperature and precipitation on nesting success was moderated by grassland patch size. The positive effects of precipitation in the preceding year on nesting success were strongest in relatively small grassland patches and had little effect in large patches. Conversely, warm temperatures reduced nesting success in small grassland patches but increased nesting success in large patches. Mechanisms underlying these differences may be patch‐size‐induced variation in microclimates and predator activity. Although the exact cause is unclear, large grassland patches, the most common metric of grassland conservation, appears to moderate the effects of weather on grassland‐bird demography and could be an effective component of climate‐change adaptation.  相似文献   
287.
Based on a review of the history of the employee engagement construct and its measurement, we define workforce engagement as the aggregate of the work engagement experiences of individual employees in an organization. In contrast to most research on employee engagement, we study companies rather than individuals and the companies represent a diverse set of industries. We hypothesize and demonstrate on a sample of (up to) 102 publicly traded companies that workforce engagement significantly predicts organizational financial (adjusting for industry: Return on Assets, Net Margin but not Tobin's q) and customer metrics (the American Customer Satisfaction Index and the Harris Reputation Quotient) 1 and 2 years after the workforce engagement data were collected. In addition, using a split‐sample approach to avoid method bias, we hypothesize and show that (a) company organizational practices (the strongest correlate), supervisory support, and work attributes are significant correlates of workforce engagement and (b) that workforce engagement mediates the relationship between these correlates of engagement and the organizational performance metrics. Implications of the findings for research and practice are discussed.  相似文献   
288.
水产养殖环境中抗生素的大量使用促进了抗生素耐药细菌(antibiotic resistant bacteria,ARB)和抗生素抗性基因(antibiotic resistance genes,ARGs)的出现及传播.利用荧光定量PCR分析了浙江省某水产养殖尾水集中处理系统中8种ARGs的分布特征.结果表明,出水中ARGs的绝对丰度降低了0.91个数量级.磺胺类抗性基因(sul1、sul2)在所检测的抗性基因中占主导地位,且绝对丰度在出水中依然维持较高水平(4.94×109、1.79×109copies·L-1).16S r RNA基因高通量测序结果显示变形菌门、蓝藻门、拟杆菌门、厚壁菌门和放线菌门是优势菌门,变形菌门和绿弯菌门与sul1、sul2和sul3呈显著相关.筛选出一株对磺胺类抗生素具有耐药性的弗氏柠檬酸杆菌,该菌株为条件致病菌,全基因组测序结果显示该菌株共携带了17个ARGs,其中sul1、sul2、tet A、blaTEM-1等ARGs均位于1个Inc FIB质粒上,质粒图谱揭示了磺胺...  相似文献   
289.
Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow‐nesting seabirds, and to a lesser extent adults, are attracted to and then grounded (i.e., forced to land) by lights when they fly at night. We reviewed the current state of knowledge of seabird attraction to light to identify information gaps and propose measures to address the problem. Although species in families such as Alcidae and Anatidae can be grounded by artificial light, the most affected seabirds are petrels and shearwaters (Procellariiformes). At least 56 species of Procellariiformes, more than one‐third of them (24) threatened, are subject to grounding by lights. Seabirds grounded by lights have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and employed mitigation to reduce the rate of light‐induced mortality and save thousands of birds every year. These programs also provide useful information for seabird management. However, these data are typically fragmentary, biased, and uncertain and can lead to inaccurate impact estimates and poor understanding of the phenomenon of seabird attraction to lights. We believe the most urgently needed actions to mitigate and understand light‐induced mortality of seabirds are estimation of mortality and effects on populations; determination of threshold light levels and safe distances from light sources; documentation of the fate of rescued birds; improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and research on seabird‐friendly lights to reduce attraction.  相似文献   
290.
River restoration efforts require interdisciplinary approaches involving fluvial geomorphology, hydraulic engineering, ecology, sedimentology, chemistry, social geography, and sociology. We investigated the functioning of artificial structures called “Casiers Girardon” (groyne fields) in the Rhône River. We assessed potential benefits and risks linked to removing the Rhône groyne fields in a restoration context, with particular focus on the potential for increased bank erosion. Hydraulic, morphological, chemical, ecological, and social issues resulting from dismantlement were studied for terrestrialized and aquatic Casiers Girardon. Only 10% of Casiers Girardon have maintained their aquatic features, whereas most of the Casiers are terrestrialized. Our results help to confirm the effectiveness of restoration actions; however, they also indicate uncertainties and additional knowledge needs, especially in regard to potential incompatibilities between Casier restoration and conservation. Then, an interdisciplinary conceptual model was developed to identify interventions to be considered in Casiers Girardon, according to their terrestrialization rate and physiochemical characteristics (connectivity, amount of gravel vs. fine sediment, contamination level). This model synthetizes scientific results and expert judgment and provides management recommendations based on ecological and sociological expectations about the restoration of Casiers Girardon. The model highlights high heterogeneity in functioning and ecological potential between terrestrialized and aquatic Casiers. Dismantling of terrestrialized Casiers has strong potential to provide multiple benefits, whereas aquatic Casiers could be maintained as valuable backwaters. The managing guidelines for the Casiers Girardon of the Rhône River should be adapted according to local conditions, as well as expected benefits and needs, and conducted in co-ordination with all actors involved in and affected by the restoration.  相似文献   
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