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141.
This study addresses the exhaust emissions of CO2, NOx, SOx, CO, and PM2.5 originated from Baltic Sea shipping in 2006–2009. Numerical results have been computed using the Ship Traffic Emissions Assessment Model. This model is based on the messages of the automatic identification system (AIS), which enable the positioning of ships with a high spatial resolution. The NOx emissions in 2009 were approximately 7 % higher than in 2006, despite the economic recession. However, the SOx emissions in 2009 were approximately 14 % lower, when compared to those in 2006, mainly caused by the fuel requirements of the SOx emission control area (SECA) which became effective in May 2006, but affected also by changes in ship activity. Results are presented on the differential geographic distribution of shipping emissions before (Jan–April 2006) and after (Jan–April 2009) the SECA regulations. The predicted NOx emissions in 2009 substantially exceeded the emissions in 2006 along major ship routes and at numerous harbors, mostly due to the continuous increase in the number of small vessels that use AIS transmitters. Although the SOx emissions have been reduced in 2009 in most major ship routes, these have increased in the vicinity of some harbors and on some densely trafficked routes. A seasonal variation of emissions is also presented, as well as the distribution of emissions in terms of vessel flag state, type, and weight. 相似文献
142.
143.
Setting population targets for mammals using body mass as a predictor of population persistence 下载免费PDF全文
Jelle P. Hilbers Aafke M. Schipper Cecilia Pinto Carlo Rondinini Mark A.J. Huijbregts 《Conservation biology》2017,31(2):385-393
Conservation planning and biodiversity assessments need quantitative targets to optimize planning options and assess the adequacy of current species protection. However, targets aiming at persistence require population‐specific data, which limit their use in favor of fixed and nonspecific targets, likely leading to unequal distribution of conservation efforts among species. We devised a method to derive equitable population targets; that is, quantitative targets of population size that ensure equal probabilities of persistence across a set of species and that can be easily inferred from species‐specific traits. In our method, we used models of population dynamics across a range of life‐history traits related to species’ body mass to estimate minimum viable population targets. We applied our method to a range of body masses of mammals, from 2 g to 3825 kg. The minimum viable population targets decreased asymptotically with increasing body mass and were on the same order of magnitude as minimum viable population estimates from species‐ and context‐specific studies. Our approach provides a compromise between pragmatic, nonspecific population targets and detailed context‐specific estimates of population viability for which only limited data are available. It enables a first estimation of species‐specific population targets based on a readily available trait and thus allows setting equitable targets for population persistence in large‐scale and multispecies conservation assessments and planning. 相似文献
144.
Decomposition studies were carried out at sites throughout Sweden, including the four Integrated Monitoring sites. Scots pine
needle litterbag weight loss measurements over 3 or 5 years were determined at 26 sites and repeated up to 27 times, depending
on the site. Humus layer respiration rates were determined for 20 sites in 1987–1989 and repeated in 2007–2008. Partial Least
Squares (PLS) regression was used to elucidate the relative importance of climatic and soil factors. Annual needle weight
losses decreased only slowly (20–10%) over 3–5 years for all northern (>60°N) sites but decreased sharply from 30 to 10% in
the third year in southern (<60°N) sites. Respiration rates of southern sites were less (40% on average) than those of northern
sites. Humus layer N was positively correlated to needle weight loss during the first and the second years, but negatively
correlated in the third year and to respiration rates. The results indicated that litter formed in southern Sweden became
more recalcitrant in later stages of decomposition compared to litter produced in northern Sweden. 相似文献
145.
146.
Ian Henshaw Thord Fransson Sven Jakobsson Cecilia Kullberg 《Behavioral ecology and sociobiology》2010,64(8):1317-1323
Night-migrating song birds travel to and from their wintering and breeding areas often separated thousands of kilometers apart
and are clearly capable of finding intended goal areas from a distant location. Displacement experiments provide a useful
way to highlight orientation and navigational skills in migrants. To investigate which cues birds actually use to compensate
for displacement and the exact mechanism of each cue, experiments with manipulation of single cues are required. We conducted
a simulated displacement of lesser whitethroats Sylvia curruca on spring migration. Birds were displaced not geographically but in geomagnetic space only, north and south of their breeding
area to test whether they incorporate information from the geomagnetic field to find their breeding area. Lesser whitethroats
held in southeast Sweden but experiencing a simulated displacement north of their breeding area (Norway) failed to show a
consistent direction of orientation, whereas birds displaced south of their breeding area (Czech Republic) exhibited consistent
northerly orientation, close to the expected seasonally appropriate direction, after displacement toward the trapping location.
The absence of a clear compensatory direction in birds displaced north might be due to unfamiliar magnetic information or
lack of sufficient information such as a magnetic gradient when moving around. By isolating one orientation cue, the geomagnetic
field, we have been able to show that lesser whitethroats might incorporate geomagnetic field information to determine latitude
during spring migration. 相似文献
147.
This paper presents a study of recycling stations in the municipality of Borl?nge, Sweden. The main objectives were to measure volume weights of recyclables, to facilitate future planning of collection intervals and bin/container volume, and to investigate the general attitudes among the public towards waste management in general and recycling stations in particular. Volume weights measured in bins/containers were: paper/newsprint: 297 kg/m3, glass packaging: 297 kg/m3, metal packaging: 81.7 kg/m3, paper packaging: 27.8 kg/m3, plastic packaging: 28.1 kg/m3. The recycling stations have been in use since 1994. Most visitors (90%) arrived by car but said the visit to the recycling station was not the main purpose of the trip. The results from the interviews indicated that the people who use the recycling stations have found ways to incorporate waste sorting into their everyday lives, with the help of information, design of the collection system and environmental concerns. 相似文献
148.
Ninety-five white-collar workers employed by an insurance company using visual display units (VDU) connected by telecommunication to a central computer filled in a questionnaire concerning psychosocial stressors in connection with work at the VDU. Eleven persons with extensive and ten with no work at VDUs were also studied during regular work, during breakdown of machinery, and in their leisure time. Self-reports on mood and alertness were recorded along with blood pressure, heart rate, and excretion of adrenaline and noradrenaline. Results indicate that (1) stress and mental strain occurred in association with delayed response times in the computer system and unpredicted interruptions of system operation, (2) such a temporary interruption caused an increase of blood pressure and adrenaline excretion, (3) complaints of stress and strain were repotted mainly by data-entry staff, (4) data-entry groups displayed a higher level of physiological arousal during post-work hours than a control group, and (5) that a majority of those who worked continuously at a VOU reported physical discomfort within 1.5 hours. It is concluded that stress and strain in computerized work may be counteracted at the technological and the organizational level: by reducing the duration and frequency of breakdowns, by reducing response times in the system, and by eliminating pure data-entry tasks. 相似文献
149.
Daniel J. A. Johansson Paul L. Lucas Matthias Weitzel Erik O. Ahlgren A. B Bazaz Wenying Chen Michel G. J. den Elzen Joydeep Ghosh Maria Grahn Qiao-Mei Liang Sonja Peterson Basanta K. Pradhan Bas J. van Ruijven P. R. Shukla Detlef P. van Vuuren Yi-Ming Wei 《Mitigation and Adaptation Strategies for Global Change》2015,20(8):1335-1359
150.
Riparian zones are hotspots of plant species richness in temperate and boreal biomes. The phenomenon is believed to be caused primarily by river-related processes, and upland influences on riparian zones have received relatively little attention. We investigated the importance of discharge of groundwater derived from uplands on riparian patterns in vascular plant species composition. We found that groundwater discharge areas in riparian zones were 36-209% more species rich than non-discharge areas, depending on spatial scale (1-50 m wide transects from annual high-water levels to summer low-water levels) and river (one free-flowing and one regulated). Higher nitrogen availability and less drought stress during low river stages are suggested as the major causes for the higher species diversity in discharge areas. Riparian zones lacking groundwater discharge lost more species following water-level regulation than did discharge areas. This indicates that groundwater discharge areas are more resistant to regulation because both individual plants and plant populations may grow larger in discharge areas. These results demonstrate that riparian zones are controlled by water and nutrient input from upland parts of catchments in ways that have been overlooked despite more than three decades of research into linkages between stream ecosystems and their valleys. 相似文献