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41.
Males often face strong mating competition by neighboring males in their social environment. A recent study by Plath et al. (Anim Behav 75:21–29, 2008a) has demonstrated that the visual presence of a male competitor (i.e., an audience male) affects the expression of male mating preferences in a poeciliid fish (Poecilia mexicana) with a weaker expression of mating preferences when an audience male observed the focal male. This may be a tactic to reduce sperm competition, since surrounding males likely share intrinsic preferences for female traits or copy mate choice decisions. Here, we examined the hypothesis that a same-sex audience would affect female mate preferences less than male mating preferences. Our hypothesis was based on the assumptions that (1) competition for mates in a fashion that would be comparable in strength to sperm competition or overt male–male aggression is absent among Poecilia females, and (2) P. mexicana females typically form female-biased shoals, such that almost any female mate choice in nature occurs in front of a female audience. Poecilia females (P. mexicana, surface and cave form, and the closely related gynogenetic Poecilia formosa) were given a choice between a large and a small male, and the tests were repeated while a conspecific, a heterospecific, or no audience female (control) was presented. Females spent more time in the neutral zone and, thus, less time near the males during the second part of a trial when an audience was presented, but—consistent with predictions—females showed only slightly weaker expression of mate preferences during the second part of the tests. This decline was not specific to the treatment involving an audience and was significantly weaker than the effect seen in the male sex.  相似文献   
42.
Environment Systems and Decisions - Organizational and technical approaches have proven successful in increasing the performance and preventing risks at socio-technical systems at all scales....  相似文献   
43.
Cultural sustainability has become a much discussed topic in the forestry and bioenergy sectors. However, there are not many indicators available for measuring cultural sustainability. In order to identify indicators for the assessment of the cultural sustainability impacts of wood-based bioenergy in eastern Finland, two-phased expert interviews were conducted. The process was supported by a hybrid approach: A qualitative mapping technique was applied when the indicators were identified, and weights for the indicators were set using a quantitative rating technique. The experts identified 49 indicators of cultural sustainability. Most of the generated indicators were relevant for local uses and highlighted the perceptions of the general public. Furthermore, most of the indicators were relevant from the perspective of raw material acquisition. Applying methods of differing backgrounds enabled advanced problem structuring, which allowed the identification of indicators suitable for assessing cultural sustainability of wood-based bioenergy in Eastern Finland. The quantitative rating technique enabled the determination of the importance of the indicators generated. Nevertheless, it seems that the hybrid approaches have many challenges related to the quantitative measuring of the participants’ perceptions. Cultural sustainability indicators should be identified within a case study, since it seems that most of the cultural sustainability indicators are case specific. The process introduced here offers steps for identifying case-specific cultural sustainability indicators; however, the concept of cultural sustainability cannot be strictly defined.  相似文献   
44.
Summary Solitary and social nests of the facultatively social carpenter bee Xyclopa pubescens can be found simultaneously during the major part of the breeding season. Social nests contain a reproductively dominant forager and either her adult offspring or a formerly reproductive, guarding female. The costs and benefits to the dominant animal of allowing a defeated female to remain as a guard in the nest were analysed in terms of brood loss and brood gain. The costs included the probability that the guard would regain reproductively dominant status. The most important benefits were the protection that a guard provided against pollen robbery by conspecifics and the longer foraging time available to a forager when her nest was protected. The balance between costs and benefits depended on the severity of ecological constraints. During certain periods of intense competition for pollen or nests, the benefits clearly outweighed the costs.Correspondence to: K. Hogendoorn  相似文献   
45.
46.
Recent studies suggest that carbon (C) is stored in the topsoil of pastures established after deforestation. However, little is known about the long-term capacity of tropical pastures to sequester C in different soil layers after deforestation. Deep soil layers are generally not taken into consideration or are underestimated when C storage is calculated. Here we show that in French Guiana, the C stored in the deep soil layers contributes significantly to C stocks down to a depth of 100 cm and that C is sequestered in recalcitrant soil organic matter in the soil below a depth of 20 cm. The contribution of the 50–100 cm soil layer increased from 22 to 31 % with the age of the pasture. We show that long-term C sequestration in C4 tropical pastures is linked to the development of C3 species (legumes and shrubs), which increase both inputs of N into the ecosystem and the C:N ratio of soil organic matter. The deep soil under old pastures contained more C3 carbon than the native forest. If C sequestration in the deep soil is taken into account, our results suggest that the soil C stock in pastures in Amazonia would be higher with sustainable pasture management, in particular by promoting the development of legumes already in place and by introducing new species.  相似文献   
47.
The intake fraction (iF) has been defined as the integrated incremental intake of a pollutant released from a source category or region summed over all exposed individuals. In this study we evaluated the iFs in the population of Europe for emissions of anthropogenic primary fine particulate matter (PM2.5) from sources in Europe, with a more detailed analysis of the iF from Finnish sources. Parameters for calculating the iFs include the emission strengths, the predicted atmospheric concentrations, European population data, and the average breathing rate per person. Emissions for the whole of Europe and Finland were based on the inventories of the European Monitoring and Evaluation Programme (EMEP) and the Finnish Regional Emission Scenario (FRES) model, respectively. The atmospheric dispersion of primary PM2.5 was computed using the regional-scale dispersion model SILAM. The iFs from Finnish sources were also computed separately for six emission source categories. The iFs corresponding to the primary PM2.5 emissions from the European countries for the whole population of Europe were generally highest for the densely populated Western European countries, second highest for the Eastern and Southern European countries, and lowest for the Northern European and Baltic countries. For the entire European population, the iF values varied from the lowest value of 0.31 per million for emissions from Cyprus, to the highest value of 4.42 per million for emissions from Belgium. These results depend on the regional distribution of the population and the prevailing long-term meteorological conditions. Regarding Finnish primary PM2.5 emissions, the iF was highest for traffic emissions (0.68 per million) and lowest for major power plant emissions (0.50 per million). The results provide new information that can be used to find the most cost-efficient emission abatement strategies and policies.  相似文献   
48.
Environmental Science and Pollution Research - Naturally occurring layered double hydroxide mineral, brucite (BRU), was compared with hydromagnesite (HYD) and a commercial Mg-rich mineral adsorbent...  相似文献   
49.
It is not clear so far whether alteration of leaf micromorphology and surface wax chemistry due to the impact of environmental factors, such as UV-B radiation, affects retention and rainfastness of applied pesticide solutions. In this study; UV-B treated and untreated adaxial leaf surfaces of apple seedlings (Malus domestica Borkh.) were characterized in terms of chemical composition, micromorphological fine structure, hydrophobicity, and wettability. Furthermore, the retention and rainfastness of applied fungicide mancozeb were studied. The samples were examined 0, 24 and 48 h after ultraviolet (UV)-B radiation (0.022 kW m? 2 for 150 min) The total wax mass, recovered from the adaxial leaf surface, amounted from 0.38 μ g cm? 2 (control) up to 0.49 μ g cm? 2 (24 h). Chemical composition of surface wax altered, whereas the contact angle of applied water droplets on leaf surface of UV-B treated plants did not change significantly compared to the control. The alteration of surface wax quantity and quality significantly affected retention of a.i.; it increased at a sampling time of 24 h after UV-B irradiation, whereas rainfastness of the fungicide spray solution was not significantly influenced.  相似文献   
50.
Policy-makers are increasingly recognising that the promotion of more sustainable consumption patterns is an indispensable prerequisite for achieving sustainable development in the long term. Policy documents and action plans have been published, and a wide array of policy instruments has been implemented with the aim of reducing the environmental and social burdens of consuming goods and services. But what are the latest trends and innovative approaches in sustainable consumption (SC) policies? What could be learnt for future policy-making? Based on an overview of European policy instruments and several case studies, the paper discusses instructive examples of SC policy instruments, in particular the Danish information campaign "One Tonne Less", the Dutch tax incentive scheme "Green Funds", the British "Red/Green calculator", and the pan-European internet platform "TopTen". Important features of novel policies — such as adaptability and collective action — are identified, and recommendations for future policies are presented. The recommendations refer to the foundation of SC policies, to the specific approach taken, to the applied instruments, and to the proper documentation of the implemented policies.  相似文献   
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