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61.
In this paper, it is demonstrated that partnership arrangements between farmers might be a way to secure the economic viability of their farms as well as to increase profitability. The article discusses empirical analyses of three different forms of collaboration, with an emphasis on the environmental improvements associated with collaboration. Collaboration between a dairy farm and a crop farm is analyzed in the first case. The results show that potential gains from improved diversification and crop rotation are substantial, and even larger when the collaboration also involves machinery. The second analysis considers external integration between farrowing and finishing-pig operations. Gains from collaboration originate from biological and technical factors, such as improved growth rate of the pigs and better utilization of buildings. Finally, an evaluation of a group of collaborating crop farmers is performed. In this case, the benefits that arise are mainly due to reduced machinery costs and/or gains due to other factors, such as improved crop rotation and managerial/marketing strategies.  相似文献   
62.
In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm(-3) and 20,000 cm(-3), whereas the summer min is approximately 5000-6000 cm(-3). In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4-10. The winter maximum in both Rome and Barcelona is close to 100,000 cm(-3), whereas the summer minimum is > 10,000 cm(-3). During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.  相似文献   
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64.
Environmental-stress-mediated geographic variation in reproductive parameters has been little studied in natural vertebrate populations outside the context of climatic variation. Based on life-history theory, an increase in the degree of environmental stress experienced by a population should lead to (1) a shift in reproductive allocation from fecundity to offspring quality, (2) stronger trade-offs between reproductive parameters, and (3) changes in the relationship between female phenotype and maternal investment. To test these predictions, we investigated geographic variation in maternal investment of moor frogs (Rana arvalis) in relation to breeding site acidity (pH 4-8). We found that mean egg size increased and clutch size and total reproductive output (TRO) decreased with increasing acidity among 19 Swedish moor frog populations. Tests for variation and co-variation in maternal investment and female size and age in 233 females from a subset of four acid origin (AO) and four neutral origin (NO) populations revealed that clutch size and TRO increased with female size in both acid and neutral environments. However, in AO populations, egg size also increased with female size, and clutch size and TRO with female age, whereas in NO populations, egg size increased with female age. The strength of the egg-size-clutch-size tradeoff tended to be stronger in AO than in NO females as expected if the former experience stronger environmental constraints. All in all, these results suggest that environmental acidification selects for investment in larger eggs at a cost to fecundity, imposes negative effects on reproductive output, and alters the relationship between female phenotype and maternal investment.  相似文献   
65.
A post-combustion CO2 capture process intended for offshore operations has been designed and optimised for integration with a natural gas-fired power plant on board a floating structure developed by the Norway-based company Sevan Marine ASA—designated Sevan GTW (gas-to-wire). The concept is constrained by the structure of the floater carrying a SIEMENS modular power system rated at 450 MWe, with a capture rate of 90% and CO2 compression (1.47 Mtpa) for pipeline pressure at 12 MPa. A net efficiency of 45% (based on a lower heating value) is estimated for the system with CO2 capture, thus suggesting that the post-combustion CO2 capture system is accountable for a fuel penalty of nine percentage points.The rationale behind the technology selection is the urgency of replacing the dispersed aero-derivative gas turbines which power the offshore oil and gas production units in Norwegian waters with near-zero emission power.As (inherently) fresh water usually constitutes a limiting factor in sea operations, efforts are made to obtain a neutral water balance to obtain an optimal design. This is primarily achieved by controlling the cleaned flue gas temperature at the top of the absorber column.  相似文献   
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67.
The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today’s major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.  相似文献   
68.
In a 2.5-year-long environmental engineering experiment in the By Fjord, surface water was pumped into the deepwater where the frequency of deepwater renewals increased by a factor of 10. During the experiment, the deepwater became long-term oxic, and nitrate became the dominating dissolved inorganic nitrogen component. The amount of phosphate in the water column decreased by a factor of 5 due to the increase in flushing and reduction in the leakage of phosphate from the sediments when the sediment surface became oxidized. Oxygenation of the sediments did not increase the leakage of toxic metals and organic pollutants. The bacterial community was the first to show changes after the oxygenation, with aerobic bacteria also thriving in the deepwater. The earlier azoic deepwater bottom sediments were colonized by animals. No structural difference between the phytoplankton communities in the By Fjord and the adjacent Havsten Fjord, with oxygenated deepwater, could be detected during the experiment.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-014-0524-9) contains supplementary material, which is available to authorized users.  相似文献   
69.
Anthropomorphism has long been considered a cardinal error when describing animals. Ethicists have feared the consequences of misrepresenting animals in their reasoning. Recent research within human-animal studies, however, has sophisticated the notion of anthropomorphism. It is suggested that avoiding anthropomorphism merely creates other morphisms, such as mechanomorphism. Instead of avoiding anthropomorphism, it is argued that it is a communicative strategy that should be used critically. Instances of anthropomorphism in animal ethics are analyzed in this paper. Some analogies made between people and non-human animals in present theories of animal ethics are clear instances of psychological anthropomorphism. Other analogies are implicit cases of cultural anthropomorphism. It is argued that animal ethics needs to take the wider discourse of critical anthropomorphism into account in order to sophisticate the understanding and use of anthropomorphic projections. Anthropomorphism is an efficient tool of communication, and it may be made an adequate one as well.  相似文献   
70.
Reconnecting to the Biosphere   总被引:3,自引:0,他引:3  
Humanity has emerged as a major force in the operation of the biosphere, with a significant imprint on the Earth System, challenging social-ecological resilience. This new situation calls for a fundamental shift in perspectives, world views, and institutions. Human development and progress must be reconnected to the capacity of the biosphere and essential ecosystem services to be sustained. Governance challenges include a highly interconnected and faster world, cascading social-ecological interactions and planetary boundaries that create vulnerabilities but also opportunities for social-ecological change and transformation. Tipping points and thresholds highlight the importance of understanding and managing resilience. New modes of flexible governance are emerging. A central challenge is to reconnect these efforts to the changing preconditions for societal development as active stewards of the Earth System. We suggest that the Millennium Development Goals need to be reframed in such a planetary stewardship context combined with a call for a new social contract on global sustainability. The ongoing mind shift in human relations with Earth and its boundaries provides exciting opportunities for societal development in collaboration with the biosphere--a global sustainability agenda for humanity.  相似文献   
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