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71.
Maximilian Berthold Ulf Karsten Mario von Weber Alexander Bachor Rhena Schumann 《Ambio》2018,47(1):146-158
The EU-water framework directive aims at nutrient reductions, since anthropogenically induced eutrophication is a major threat for coastal waters. However, phytoplankton biomass in southern Baltic Sea coastal water bodies (CWB) remains high and the underlying mechanisms are not well understood. Therefore, a CWB data set was analysed regarding changes in phytoplankton biomass and nutrient concentration of nitrogen (N) and phosphorus (P) from 2000 to 2014. It was expected to find imbalances between produced phytoplankton biomass and total nutrient concentrations. Inner CWB were cyanobacteria-dominated and showed up to five times higher chlorophyll a-concentrations compared to outer CWB with similar total phosphorus-concentrations. Phytoplankton tended to be P-limited during spring and N-limited during summer. Phytoplankton biomass and nutrient concentrations were even higher during very humid years, which indicated a close coupling of the CWB with their catchment areas. This study suggests that re-mesotrophication efforts need to consider the importance of changed phytoplankton composition and nutrient availabilities. 相似文献
72.
Henne Paul D. Bigalke Moritz Büntgen Ulf Colombaroli Daniele Conedera Marco Feller Urs Frank David Fuhrer Jürg Grosjean Martin Heiri Oliver Luterbacher Jürg Mestrot Adrien Rigling Andreas Rössler Ole Rohr Christian Rutishauser This Schwikowski Margit Stampfli Andreas Szidat Sönke Theurillat Jean-Paul Weingartner Rolf Wilcke Wolfgang Tinner Willy 《Regional Environmental Change》2018,18(1):205-221
Regional Environmental Change - Planning for the future requires a detailed understanding of how climate change affects a wide range of systems at spatial scales that are relevant to humans.... 相似文献
73.
Ongoing marine monitoring programs are seldom designed to detect changes in the environment between different years, mainly due to the high number of samples required for a sufficient statistical precision. We here show that pooling over time (time integration) of seasonal measurements provides an efficient method of reducing variability, thereby improving the precision and power in detecting inter-annual differences. Such data from weekly environmental sensor profiles at 21 stations in the northern Bothnian Sea was used in a cost-precision spatio-temporal allocation model. Time-integrated averages for six different variables over 6 months from a rather heterogeneous area showed low variability between stations (coefficient of variation, CV, range of 0.6–12.4%) compared to variability between stations in a single day (CV range 2.4–88.6%), or variability over time for a single station (CV range 0.4–110.7%). Reduced sampling frequency from weekly to approximately monthly sampling did not change the results markedly, whereas lower frequency differed more from results with weekly sampling. With monthly sampling, high precision and power of estimates could therefore be achieved with a low number of stations. With input of cost factors like ship time, labor, and analyses, the model can predict the cost for a given required precision in the time-integrated average of each variable by optimizing sampling allocation. A following power analysis can provide information on minimum sample size to detect differences between years with a required power. Alternatively, the model can predict the precision of annual means for the included variables when the program has a pre-defined budget. Use of time-integrated results from sampling stations with different areal coverage and environmental heterogeneity can thus be an efficient strategy to detect environmental differences between single years, as well as a long-term temporal trend. Use of the presented allocation model will then help to minimize the cost and effort of a monitoring program. 相似文献
74.
Aart Kroon Jakob Abermann Mette Bendixen Magnus Lund Charlotte Sigsgaard Kirstine Skov Birger Ulf Hansen 《Ambio》2017,46(1):132-145
A wide range of delta morphologies occurs along the fringes of the Young Sound in Northeast Greenland due to spatial heterogeneity of delta regimes. In general, the delta regime is related to catchment and basin characteristics (geology, topography, drainage pattern, sediment availability, and bathymetry), fluvial discharges and associated sediment load, and processes by waves and currents. Main factors steering the Arctic fluvial discharges into the Young Sound are the snow and ice melt and precipitation in the catchment, and extreme events like glacier lake outburst floods (GLOFs). Waves are subordinate and only rework fringes of the delta plain forming sandy bars if the exposure and fetch are optimal. Spatial gradients and variability in driving forces (snow and precipitation) and catchment characteristics (amount of glacier coverage, sediment characteristics) as well as the strong and local influence of GLOFs in a specific catchment impede a simple upscaling of sediment fluxes from individual catchments toward a total sediment flux into the Young Sound. 相似文献
75.
This study describes the relations between different dimensions of leadership commitment, safety climate and attitudes toward change, and how these affect employee perceptions of safety during organizational change in a high risk environment. We collected data from a European national air navigation services provider during a volatile 3-year corporatization process that ended in the sudden collapse of a deliberate change implementation project. Surprisingly, despite visible signs of internal and external stress caused by the volatile and disruptive change process, we did not observe any change in the traditional safety metrics of incident and accident reporting during the study. The study is based on a large survey (n = 422) of individual attitudes and perceptions of safety climate, perception of leadership commitment to safety, attitudes to organizational change, and perception of safety. The data support the claim that perception of safety at least, in part, depends on individual perceptions of the leadership’s commitment to safety, and the safety climate in place at a given point in time. The model shows how employee perceptions of the leadership’s commitment to safety and safety climate are related to both attitudes toward change, and to perceived safety. 相似文献
76.
Clay minerals show a variety of reactive properties, which make them used in industrial processes but are mostly neglected in soil science. In this overview these various properties of clay minerals are listed. Thereby it shall be pointed out, that these capabilities can also be of some importance in soils. 相似文献
77.
Daniel Hellstr?m Andras Baky Ulf Jeppsson H?kan J?nsson Erik K?rrman 《Water environment research》2008,80(8):708-718
An analysis of the environmental effects and resource consumption by four systems for management of wastewater and organic household waste in a new city area have been performed, as follows: (1) conventional system complemented with advanced sludge treatment for phosphorus recovery, (2) blackwater system with urine diversion and food waste disposers, (3) blackwater system with food waste disposers and reverse osmosis, and (4) local wastewater treatment plant with nutrient recovery by using reverse osmosis. Substance-flow analysis and energy/exergy calculations were performed by using the software tool URWARE/ORWARE. Emissions were calculated and classified based on the impact categories global warming potential, acidification, and eutrophication, according to ISO 14042 (2000). The analysis also included nutrient recovery (i.e., the potential to use nutrients as a fertilizer). Depending on which aspects are prioritized, different systems can be considered to be the most advantageous. 相似文献
78.
Ulf Roar Aakenes 《Chemistry and Ecology》1995,10(1):61-69
The principles and operation of a gamma radiation sensor mounted on oceanographic buoys are described. the sensor has proved rugged in severe weather conditions and has satisfactory detection limits and accuracy. Continuous monitoring of artificially produced γ-emitters such as 137Cs, 134Cs, 131I, 133I, 132Te, naturally occuring emitters such as 40k and 214Bi in open sea conditions can provide important information in critical situations. 相似文献
79.
80.
To study future, sustainable production systems, a step-wise method was used to create three future scenarios for pig production based on different sustainability goals. The first scenario focused on animal welfare and the natural behavior of the animals. The second targeted low impacts on the environment and the efficient use of natural resources. The third scenario aimed at product quality and safety. Each scenario fulfilled different aspects of sustainability, but there were goal conflicts because no scenario fulfilled all sustainability goals. The scenarios were then parameterized. The environmental impact was calculated using the life-cycle assessment (LCA) methodology, and the economic cost was calculated from the same data set. The cost per kilo of pork was highest for the animal welfare scenario and similar for the other two scenarios. The environmental scenario had the lowest environmental impact, and the product-quality scenario the highest. The results are discussed based on different future priorities. 相似文献