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111.
The Welfare Quality® project has developed an operational definition of farm animal welfare, which consists of 12 criteria grouped into four principles (‘good feeding’, ‘good housing’, ‘good health’ and ‘appropriate behaviour’). As part of a larger survey, 204 farmers, 72 vegetarians, and a representative sample of 459 adult citizens in Flanders (Belgium) scored the importance of each of the 12 criteria on a 1–10 scale, and divided 100 points across the four principles according to the perceived relative weights for farm animal welfare. These data were analysed to verify quantitatively whether (1) the grouping of 12 criteria into the four principles, and (2) the relative weights used by Welfare Quality® for aggregating the 12 criteria into an overall welfare judgement correspond with the perception of these three stakeholder groups from a region and setting not previously covered by Welfare Quality® studies. Moreover, the effects of various socio-demographic variables on the importance allocated to the welfare criteria and principles were investigated. Vegetarians and females gave consistently higher importance scores to all 12 criteria as compared with farmers, citizens and males, respectively, particularly for the (criteria belonging to the) principle ‘appropriate behaviour’. Farmers allocated more weight to ‘good feeding’ than did vegetarians or citizens. These differences confirm that farmers view animal welfare more in terms of biological functioning (instead of affective states or natural living) as compared to other citizens, and vegetarians in particular. As the concept has a different meaning to different people, any operational definition of animal welfare is unlikely to match equally well with the perception of every single stakeholder group or person. The structure of the Welfare Quality® operational definition with the 12 criteria aggregated into four principles, corresponds well with the opinion of the stakeholders as they judged all 12 criteria as rather important to extremely important for farm animal welfare. Factor analysis restricted to contain four factors confirmed the grouping of the criteria into the correct principles. Exploratory factor analysis using Eigenvalues > 1 as extraction criterion indicated, however, that from the citizen perspective two principles (‘good feeding & health’ and ‘appropriate behaviour & housing’) rather than four would suffice. The main discrepancy with the Welfare Quality® approach concerns the aggregation procedure: the stakeholders did not consider all four principles as equally important, and the relative importance allocated to criteria corresponded poorly across principles. Some of these discrepancies were consistent across the three different stakeholder groups.  相似文献   
112.
Over the last three decades solid empirical evidence for the positive influence of greenery on human psychological and cognitive functioning has been steadily accruing. Based on this evidence, researchers and practitioners increasingly realize the importance of urban greening as a strategic activity to promote human wellbeing. Although commercial and retail activities constitute a significant and influential component of urban contexts, a concern is that the stakeholders involved (e.g. merchants) can sometimes be reluctant to integrate vegetation in commercial districts. This can be an important stumbling block for the process of urban greening. In this paper we introduce the concept of Biophilic Store Design (BSD) as the retail design strategy to consciously tap the beneficial effects of vegetation. The central aim of this paper is to demonstrate that the reluctance of certain retail stakeholders to integrate greening practices like BSD is unjustified. Two lines of evidence in support of this claim will be discussed. On the one hand, we sketch a conceptual framework which supports the view that BSD can have restorative effects for those implied in store environments. On the other hand, we review Wolf's multi-study research program on the effects of urban greening on consumer behavior, attitudes, and perceptions. These two lines of evidence show that commercial activities and urban greening are not to be considered as antagonistic but as mutually reinforcing practices.  相似文献   
113.
The real-time PCR methods recommended in the European Union for the quantitation of genetically modified (GM) maize events NK603, GA21, and MON 863 measure the number of copies of the GM event in relation to those of the maize-specific adh1 reference gene. The study reported here revealed that the targeted 70 base pair adh1 region exhibits a single nucleotide polymorphism (SNP839) that hampers the binding of the reverse primer used in the adh1 detection method. Partial fragments of the adh1-A and adh1-F allele were cloned. By allele-specific real-time PCR, it was shown that SNP839 corresponds to a common allelic polymorphism in maize. As a result, the quantitation of the GM maize events mentioned is positively or negatively biased, depending on the adh1 genotype of sample and calibrant. Therefore, it is proposed to revise the quantitative detection methods for NK603, GA21, and MON 863 maize.  相似文献   
114.
Organic farming may contribute substantially to future agricultural production worldwide by improving soil quality and pest control, thereby reducing environmental impacts of conventional farming. We investigated in a comprehensive way soil chemical, as well as below and aboveground biological parameters of two organic and two conventional wheat farming systems that primarily differed in fertilization and weed management strategies. Contrast analyses identified management related differences between “herbicide-free” bioorganic (BIOORG) and biodynamic (BIODYN) systems and conventional systems with (CONFYM) or without manure (CONMIN) and herbicide application within a long-term agricultural experiment (DOK trial, Switzerland). Soil carbon content was significantly higher in systems receiving farmyard manure and concomitantly microbial biomass (fungi and bacteria) was increased. Microbial activity parameters, such as microbial basal respiration and nitrogen mineralization, showed an opposite pattern, suggesting that soil carbon in the conventional system (CONFYM) was more easily accessible to microorganisms than in organic systems. Bacterivorous nematodes and earthworms were most abundant in systems that received farmyard manure, which is in line with the responses of their potential food sources (microbes and organic matter). Mineral fertilizer application detrimentally affected enchytraeids and Diptera larvae, whereas aphids benefited. Spider abundance was favoured by organic management, most likely a response to increased prey availability from the belowground subsystem or increased weed coverage. In contrast to most soil-based, bottom-up controlled interactions, the twofold higher abundance of this generalist predator group in organic systems likely contributed to the significantly lower abundance of aboveground herbivore pests (aphids) in these systems. Long-term organic farming and the application of farmyard manure promoted soil quality, microbial biomass and fostered natural enemies and ecosystem engineers, suggesting enhanced nutrient cycling and pest control. Mineral fertilizers and herbicide application, in contrast, affected the potential for top-down control of aboveground pests negatively and reduced the organic carbon levels. Our study indicates that the use of synthetic fertilizers and herbicide application changes interactions within and between below and aboveground components, ultimately promoting negative environmental impacts of agriculture by reducing internal biological cycles and pest control. On the contrary, organic farming fosters microbial and faunal decomposers and this propagates into the aboveground system via generalist predators thereby increasing conservation biological control. However, grain and straw yields were 23% higher in systems receiving mineral fertilizers and herbicides reflecting the trade-off between productivity and environmental responsibility.  相似文献   
115.

Background, aim, and scope

In water systems, water quality and geochemical properties of sediments determine the speciation of trace metals, metal transport, and sediment–water exchange, influencing metal availability and its potential effects on biota. Studies from temperate climates have shown that iron-ore mining and tailing wastewaters, besides being a source of trace metals, usually show high levels of dissolved ions and particulate suspended matter, thus having the potential of indirectly changing metal bioavailability. For the first time in the tropics, we identified the effects of iron-ore mining and processing on metal bioavailability in a coastal lagoon. With an extensive sampling scheme, we investigated the potential sources of metals; the links among metal levels in water, sediments, and invertebrates; and the contrasting effects on metal speciation and bioavailability.

Methodology

The metals Fe, Mn, Al, Cr, Zn, Cu, Ni, Pb, Cd, Hg, and As were measured in water, sediments (surface and profiles), and invertebrates from Mãe-Bá Lagoon and in the sites directly influenced by the mining operations (tailing dams and nearby rivers). In addition, samples from two other lagoons, considered pristine, were analyzed. The study area is located in the southeast of Brazil (Iron Quadrangle Region and a coastal area of Espírito Santo State). General water characteristics included pH, dissolved organic carbon, alkalinity, and anion composition. Water metal speciation was assessed by a speciation model (Chemical Equilibria in Aquatic Systems). Grain-size distribution, organic carbon, carbonate, and acid volatile sulfide (AVS) were determined in sediments. Statistical methods included comparison of means by Mann–Whitney test, ordination and correlation analyses, and analysis of regression for geochemical normalization of metals with grain size.

Results and discussion

The dissolved metal concentrations, the total metal levels in sediments, and the normalization based on the fine sediment fraction showed that the mining operations constitute potential sources of Fe, Mn, Cr, Cu, Ni, Pb, As, and Hg to Mãe-Bá Lagoon. However, trace metal availability was reduced because of increased pH, hardness, and sulfide content (356 μmol/g) in the sites influenced by the mining. The lagoon showed similar water chemistry as in the mining sites, with metal bioavailability further decreased by the presence of dissolved organic carbon and chloride. Although AVS levels in the lagoon were low (0.48–56 μmol/g), metal bioavailability was reduced because of the presence of organic matter. Metal levels in invertebrates confirmed the predicted low metal bioavailability in Mãe-Bá Lagoon. The lagoon was considered moderately contaminated only by Hg and As.

Conclusions

The iron-ore mining and processing studied here constitute potential sources of metal pollution into the tropical lagoon. Contrary to expectations, however, it also contributes to reducing the overall metal bioavailability in the lagoon.

Recommendations and perspectives

These findings are believed to be useful for evaluating metal exposure in a more integrated way, identifying not only the sources of pollution but also how they can affect the components involved in metal speciation and bioavailability in water systems, leading to new insights.  相似文献   
116.
Linking soils,sediments and catchment ecosystems   总被引:6,自引:6,他引:0  
  相似文献   
117.
118.
The root-feeding nematode community of wild plants may vary throughout their natural range. Little is known about how the variation of wild plants along their range affects their relationship with root-feeding nematodes. In the present study, we examined local and non-local combinations of host plants and root-feeding nematodes to test the hypothesis that nematode reproduction is favoured by local hosts. In two indoor experiments, we exposed populations of the wild dune grass Ammophila arenaria from northern and southern European coastal sand dunes to plant parasitic nematode species (Helicotylenchus spp.) from those same geographical origins. First, we used the southern nematode species to determine whether the effect of a local versus a non-local host may depend on nematode density. Then, in a cross-inoculation experiment we investigated how both nematode species performed with their local, as compared to the non-local hosts.

In both experiments, plant biomass and ontogenetic characteristics were not significantly different between the northern and southern populations. The applied nematode densities did not have a negative impact on plant performance. This allowed us to consider the response of the two different nematode species and their host plants without co-varying differences in plant responses. Reproduction of the nematode species differed according to host origin, but contrary to what we expected, nematode species did not perform better on their local hosts. Helicotylenchus n. sp., the southern species originating from Portugal, performed better on the non-local than on the local host. Male to female ratios were significantly different between the two nematode populations and were lowest in Helicotylenchus pseudorobustus from The Netherlands. Female and juveniles percentages were also quite distinct, with more females in the nematode species from The Netherlands and more juveniles in the nematode species from Portugal.

We concluded that ectoparasitic root-feeding nematodes Helicotylenchus spp. do not necessarily perform best on their local host population of the foredune grass A. arenaria. Our results imply that the natural distribution of Helicotylenchus spp. along the European coast is determined by other factors than host populations. These other factors that could be abiotic, e.g. water availability, or biotic, e.g. local natural enemies adapted to Helicotylenchus spp. Introducing plant genotypes from other parts of the natural range will, therefore, not necessarily lead to reduced abundance of semi-endo or ectoparasitic root-feeding nematodes.  相似文献   

119.
1. Traditionally, the living and nonliving natural resources of the coastal waters of The Netherlands have been exploited. Part of this exploitation took the form of embankment and reclamation to produce new agricultural land. 2. The first nature reserve within the coastal waters was established in 1916. After this year the number of coastal nature reserves gradually increased. However, until about 1970 the status of a nature reserve provided little protection when other interests claimed the same area. 3. In the period 1965–1980 the situation changed drastically. The Dutch government took far-reaching decisions with regard to the protection of the Wadden Sea and the Oosterschelde estuary. 4. At the start of this century about 10 000 km2 of coastal waters existed between the mainland coast and the three-miles territorial border of The Netherlands. Of these, 4500 km2 have been embanked and reclaimed or changed into freshwater lakes, 4000 km2 have protected status, and about 1500 km2 within the former three-miles zone and in the Westerschelde estuary (250 km2) are still unprotected. 5. The present situation with regard to the conservation of coastal waters in The Netherlands is largely due to private initiatives. Scientists played an active part in the conservation movement by providing information, especially in the early phases of this development. © 1997 John Wiley & Sons, Ltd.  相似文献   
120.
In a four year study data on the presence of red squirrel were collected in an agricultural landscape by counting dreys in 49 woods ranging from 0.5 to 14 ha, and differing in quality of habitat and isolation.Logit regression analysis showed that the area per woodlot covered with conifers is a good predictor of squirrel presence for each year and during the whole period, but the significance of the regression decreases with time. During the study the number of woods occupied by red squirrel increased, and smaller woods and those without conifers also became inhabited. This trend is in accordance with the positive effect of time in regression analyses on the presence of the species and on the colonization of woods, and it suggests an increase of squirrel numbers in the area. Addition of several isolation variables in the regression analyses showed significant effects in different years, and the effect of isolation was independent of time. In the first two years the area of habitat around a woodlot, the distance to the nearest woodlot larger than 30 ha, and the density of possible movement corridors have significant effects on the presence of red squirrel.In the last two years, with presumably a high number of squirrels, the (short) distance to the nearest woodlot and also the area of habitat around woods have significant effects. It is concluded that the spatial dynamics of the population can be understood as the outcome of individual spatial behaviour, rather than as the result of metapopulation processes.  相似文献   
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