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271.
Sven Kullander 《Ambio》2010,39(3):249-256
Humankind is currently faced with the huge challenge of securing a sustainable energy supply and biofuels constitute one of
the major options. However, the commercially traded edible crops are barely sufficient to meet food demand of the present
world population. Certain regions, for example EU-27, do not even have a sufficient indigenous crop production. Of this follows
that motor biofuels based on edible crops should be avoided. To replace more than some percent of the fossil motor fuels,
non-edible biomass—rest products and wastes—should instead be considered for conversion to biofuels. In this way, about 10%
of the current fossil fuels can be replaced. Feeding a world population expected to grow by some 50% during the next 50 years
will be a major challenge. For environmental reasons it seems that agricultural land cannot be expanded very much, maybe not
at all. The solution to the increasing food demand seems therefore to be using the present crop production more efficiently
and increasing output from present agricultural land, maintaining biodiversity and climate stability within reasonable limits.
In the future, agriculture will need more energy and more water irrigation. Food production is, however, already very energy
demanding, requiring several times more externally provided energy than the energy content of the food itself. A sufficient
energy supply will be a key issue for the future farming! 相似文献
272.
Ove C. Mφrck Jens O. Hansen 《生态毒理学报》2001,23(3):16-17
MEDUCA(教育性建筑模式)项目包括7个国家的8个示范项目.这些项目分布在挪威的格龙(65°);瑞典的哥德堡(58°N);瑞典的Falkenberg(57°N);丹麦的巴勒鲁普(56°N);德国的新明斯特(54°N);西班牙的阿尔梅里亚(36°50'N);意大利的Bagheria(38°N);和希腊的Legraina(38°N). 相似文献
273.
Ziková A Trubiroha A Wiegand C Wuertz S Rennert B Pflugmacher S Kopp R Mareš J Spurný P Kloas W 《Journal of environmental monitoring : JEM》2010,12(12):2276-2281
Nile tilapia (Oreochromis niloticus) were fed by diets supplemented with cyanobacteria containing in part the cyanotoxin microcystin-LR (MC-LR) to determine the potential impacts on detoxification. Four different diets were prepared based on a commercial diet: (1) control, (2) MC-5% (containing 5% dried Microcystis sp. biomass with 4.92 μg MC-LR g(-1) diet), (3) MC-20% (containing 20% dried Microcystis sp. biomass with 19.54 μg MC-LR g(-1) diet), and (4) Arthr-20% (containing 20% dried Arthrospira sp. biomass without MC-LR). Blood and liver samples were taken after one, 7, and 28 days and protein has been determined in plasma and liver. In the liver, impacts on detoxification were measured by glutathione-S-transferase (GST) activities and gene expression of multi drug resistance protein (MDRP). Plasma protein did not change between all four diets at any sampling time whereas liver protein was significantly elevated already after one day in Arthr-20% and after 28 days in both, MC-20% and Arthr-20%. Biochemical measurements of GST activities revealed no significant impact at any sampling time. In order to characterize the potential effect of MC-LR on MDRP, RT-qPCR method was established. However, as for GST activities no significant changes in MDRP gene expression have been observed. Thus, in summary, oral exposure of MC-LR containing cyanobacteria to Nile tilapia via feed ingestion did not impact significantly detoxification in liver concerning GST activities and MDRP expression despite biochemical composition concerning liver protein was significantly elevated by the diets containing 20% cyanobacteria biomass, regardless whether they contained MC-LR or not. 相似文献
274.
Implications of climate and land-use change for landscape processes,biodiversity, ecosystem services,and governance 总被引:1,自引:0,他引:1
This introduction to the Special Issue summarizes the results of 14 scientific articles from the interdisciplinary research program Ekoklim at Stockholm University, Sweden. In this program, we investigate effects of changing climate and land use on landscape processes, biodiversity, and ecosystem services, and analyze issues related to adaptive governance in the face of climate and land-use change. We not only have a research focus on the 22 650 km2 Norrström catchment surrounding lake Mälaren in south-central Sweden, but we also conduct research in other Swedish regions. The articles presented here show complex interactions between multiple drivers of change, as well as feedback processes at different spatiotemporal scales. Thus, the Ekoklim program highlights and deals with issues relevant for the future challenges society will face when land-use change interacts with climate change. 相似文献
275.
Anders Stigebrandt Bengt Liljebladh Loreto de Brabandere Michael Forth ?ke Granmo Per Hall Jonatan Hammar Daniel Hansson Mikhail Kononets Marina Magnusson Fredrik Norén Lars Rahm Alexander H. Treusch Lena Viktorsson 《Ambio》2015,44(1):42-54
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276.
Jean-Sébastien Moquet Jean-Loup Guyot Alain Crave Jérôme Viers Naziano Filizola Jean-Michel Martinez Tereza Cristina Oliveira Liz Stefanny Hidalgo Sánchez Christelle Lagane Waldo Sven Lavado Casimiro Luis Noriega Rodrigo Pombosa 《Environmental science and pollution research international》2016,23(12):11405-11429
The aim of the present study is to estimate the export fluxes of major dissolved species at the scale of the Amazon basin, to identify the main parameters controlling their spatial distribution and to identify the role of discharge variability in the variability of the total dissolved solid (TDS) flux through the hydrological cycle. Data are compiled from the monthly hydrochemistry and daily discharge database of the “Programa Climatologico y Hidrologico de la Cuenca Amazonica de Bolivia” (PHICAB) and the HYBAM observatories from 34 stations distributed over the Amazon basin (for the 1983–1992 and 2000–2012 periods, respectively). This paper consists of a first global observation of the fluxes and temporal dynamics of each geomorphological domain of the Amazon basin. Based on mean interannual monthly flux calculations, we estimated that the Amazon basin delivered approximately 272?×?106 t year?1 (263–278) of TDS during the 2003–2012 period, which represents approximately 7 % of the continental inputs to the oceans. This flux is mainly made up by HCO3, Ca and SiO2, reflecting the preferential contributions of carbonate and silicate chemical weathering to the Amazon River Basin. The main tributaries contributing to the TDS flux are the Marañon and Ucayali Rivers (approximately 50 % of the TDS production over 14 % of the Amazon basin area) due to the weathering of carbonates and evaporites drained by their Andean tributaries. An Andes–sedimentary area–shield TDS flux (and specific flux) gradient is observed throughout the basin and is first explained by the TDS concentration contrast between these domains, rather than variability in runoff. This observation highlights that, under tropical context, the weathering flux repartition is primarily controlled by the geomorphological/geological setting and confirms that sedimentary areas are currently active in terms of the production of dissolved load. The log relationships of concentration vs discharge have been characterized over all the studied stations and for all elements. The analysis of the slope of the relationship within the selected contexts reveals that the variability in TDS flux is mainly controlled by the discharge variability throughout the hydrological year. At the outlet of the basin, a clockwise hysteresis is observed for TDS concentration and is mainly controlled by Ca and HCO3 hysteresis, highlighting the need for a sampling strategy with a monthly frequency to accurately determine the TDS fluxes of the basin. The evaporite dissolution flux tends to be constant, whereas dissolved load fluxes released from other sources (silicate weathering, carbonate weathering, biological and/or atmospheric inputs) are mainly driven by variability in discharge. These results suggest that past and further climate variability had or will have a direct impact on the variability of dissolved fluxes in the Amazon. Further studies need to be performed to better understand the processes controlling the dynamics of weathering fluxes and their applicability to present-day concentration–discharge relationships at longer timescales. 相似文献
277.
278.
Andersson KG Nielsen SP Thørring H Hansen HS Joensen HP Isaksson M Kostiainen E Suolanen V Pálsson SE 《Journal of environmental radioactivity》2011,102(11):1024-1031
The ECOSYS model is the ingestion dose model integrated in the ARGOS and RODOS decision support systems for nuclear emergency management. The parameters used in this model have however not been updated in recent years, where the level of knowledge on various environmental processes has increased considerably. A Nordic work group has carried out a series of evaluations of the general validity of current ECOSYS default parameters. This paper specifically discusses the parameter revisions required with respect to the modelling of deposition and natural weathering of contaminants on agricultural crops, to enable the trustworthy prognostic modelling that is essential to ensure justification and optimisation of countermeasure strategies. New modelling approaches are outlined, since it was found that current ECOSYS approaches for deposition and natural weathering could lead to large prognostic errors. 相似文献
279.
Regulating BFRs--from science to policy 总被引:1,自引:0,他引:1
Hansson SO 《Chemosphere》2008,73(2):144-147
An adequate distribution of responsibilities between scientists and policy-makers requires that a distinction be made between theoretical rationality (what to believe) and practical rationality (what to do). In chemical risk management, it is often necessary to base decisions on indications of risk that do not amount to full scientific proof. Guidelines are offered for how this can be done without infringing upon the integrity of science. Furthermore, it is shown that the application of standard decision theory to chemical risks yields conclusions very much in agreement with the precautionary principle. 相似文献
280.
Bustnes JO Erikstad KE Lorentsen SH Herzke D 《Environmental pollution (Barking, Essex : 1987)》2008,156(2):417-424
Despite global occurrence of several perfluorinated compounds (PFCs) the potential ecological effects of such substances on natural populations are not known. In endangered lesser black-backed gulls (Larus fuscus fuscus) on the Norwegian Coast, the blood concentrations of PFCs were as high as legacy organochlorines (OCs), and here we examined whether PFCs show associations similar to those of OCs to factors potentially affecting population growth, by evaluating relationships between contaminant concentrations and demographic parameters (reproductive performance and the probability of adults returning between breeding seasons). PFCs were not adversely associated with demographic parameters, while the most persistent OCs; notably PCB and p,p′-DDE, were adversely associated with early chick survival, and adult return rate. This study thus suggests that when the concentrations of PFCs and OCs are of similar magnitude in a gull population, OCs are more likely to cause adverse ecological effects. 相似文献