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331.
Understanding how climate change, exploitation and eutrophication will affect populations and ecosystems of the Baltic Sea can be facilitated with models which realistically combine these forcings into common frameworks. Here, we evaluate sensitivity of fish recruitment and population dynamics to past and future environmental forcings provided by three ocean-biogeochemical models of the Baltic Sea. Modeled temperature explained nearly as much variability in reproductive success of sprat (Sprattus sprattus; Clupeidae) as measured temperatures during 1973-2005, and both the spawner biomass and the temperature have influenced recruitment for at least 50 years. The three Baltic Sea models estimate relatively similar developments (increases) in biomass and fishery yield during twenty-first century climate change (ca. 28 % range among models). However, this uncertainty is exceeded by the one associated with the fish population model, and by the source of global climate data used by regional models. Knowledge of processes and biases could reduce these uncertainties.  相似文献   
332.
Before climate change is considered in long-term coastal management, it is necessary to investigate how institutional stakeholders in coastal management conceptualize climate change, as their awareness will ultimately affect their actions. Using questionnaires in eight Baltic Sea riparian countries, this study examines environmental managers' awareness of climate change. Our results indicate that problems related to global warming are deemed secondary to short-term social and economic issues. Respondents agree that problems caused by global warming will become increasingly important, but pay little attention to adaptation and mitigation strategies. Current environmental problems are expected to continue to be urgent in the future. We conclude that an apparent gap exists between decision making, public concerns, and scientific consensus, resulting in a situation in which the latest evidence rarely influences commonly held opinions.  相似文献   
333.
The climate in Timor Leste (East Timor) is predicted to become about 1.5 °C warmer and about 10 % wetter on average by 2050. By the same year, the population is expected to triple from 1 to 2.5–3 million. This article maps the predicted changes in temperature and rainfall and reviews the implications of climate change and population growth on agricultural systems. Improved cultivars of maize, rice, cassava, sweet potato and peanuts with high yield performance have been introduced, but these will need to be augmented in the future with better adapted cultivars and new crops, such as food and fodder legumes and new management practices. The requirements for fertilizers to boost yields and terracing and/or contour hedgerows to prevent soil erosion of steeply sloping terrain are discussed. Contour hedges can also be used for fodder for improved animal production to provide protein to reduce malnutrition.  相似文献   
334.
Abstract

Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8–10?years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA?+?AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P?=?0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA?+?AA) genotypes and smoking has a significant effect on telomere length (β = ?0.258, P?=?0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA?+?AA) of p21 rs1801270, and interactions of (CA?+?AA) genotypes and smoking factor.  相似文献   
335.
极端气候事件的灾后适应能力研究——以水稻为例   总被引:1,自引:0,他引:1  
本研究以水稻种植业为例,基于1985-2008年中国水稻主产区的面板数据,实证分析了中国极端气候事件灾后适应能力的机制及绩效。结论表明:西南、华中、华东地区在极端气候事件灾后,并没有将农业产业结构向养殖业调整,相反,种植业在政府扶持与创新激励下反而恢复生产甚至进一步扩张。特别对于西南等经济相对欠发达地区而言,较强的灾后适应能力,往往是农业生产机会成本较低的作用结果,同样由于此原因,华东地区在水灾之后却出现了劳动力转移现象。现阶段,灾后适应能力较多的表现为微观层面的农户响应行为,此种民间调控机制必然有其局限性,政府部门应加大投入力度,通过水利工程建设、气象灾害预警体系构建、标准化农田建设、良种补贴等方式引领粮食主产区应对气象灾害。  相似文献   
336.
This paper aims to estimate the effects of changing life style and consumption demands driven by income growth and urbanization on increase of energy requirements in China, and es-timate the impacts of improvement in household consumption on mitigating energy requirements towards 2020, based on input-out-put analysis and scenarios simulation approach. The result shows that energy requirement per capita has increased by 159% for urban residents and 147% for rural residents from 1995 to 2004. Growth in household consumption driven by income growth and urbanization may induce a successive increase in energy require-ments in future. Per capita energy requirements of urban residents will increase by 240% during 2002-2015 and 330% during 2002-2020. Urbanization might lead to 0.75 billion ton of increment of energy requirements in 2020. About 45%-48% of total energy requirements in China might be a consequence of residents’ life styles and the economic activities to support consumption demands in 2020. Under low-carbon life style scenario, per capita energy requirements of urban residents may decline to 97% in 2015 and 92% in 2020 in contrast with baseline scenario. That implies that China needs to pay a great attention to developing green low-carbon life style in order to realize mitigation target towards 2020.  相似文献   
337.
This experimental research addresses the effectiveness of communication about complex environmental issues, depending on whether the same information is provided by multiple collaborating or by individual organizations (i.e., stakeholders). The information provided pertains to carbon dioxide capture and storage (CCS) technology, as an example of a complex environmental issue. In Studies 1 (N = 75) and 2 (N = 66) we found that participants perceived factual information from collaborating stakeholders to be of higher quality than when the same information was provided by individual stakeholders. As predicted, the expectation of diverse perspectives being represented in the collaborative information mediated this effect. In addition, in Study 3 (N = 79) the perceived dissimilarity of collaborating stakeholders was shown to be an important precondition for the collaboration effect observed in Studies 1 and 2. Finally, these studies indicate that occasional collaboration between different stakeholders does not necessarily harm the perceived credibility of each individual stakeholder.  相似文献   
338.
Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO2]) and elevated ozone concentration ([O3]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO2] and [O3] predicted for ∼2050. The responses of two clones were compared during the first month of spring leaf out when CO2 fumigation had begun, but O3 fumigation had not. Trees in elevated [CO2] plots showed a stimulation of leaf area index (36%), while trees in elevated [O3] plots had lower leaf area index (−20%). While individual leaf area was not significantly affected by elevated [CO2], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO2]; however, the two clones responded differently to long-term growth at elevated [O3]. The O3-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O3] (−32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O3] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O3], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions.  相似文献   
339.
Since lichens lack roots and take up water, solutes and gases over the entire thallus surface, these organisms respond more sensitively to changes in atmospheric purity than vascular plants. After centuries where effects of sulphur dioxide and acidity were in the focus of research on atmospheric chemistry and lichens, recently the globally increased levels of ammonia and nitrate increasingly affect lichen vegetation and gave rise to intense research on the tolerance of lichens to nitrogen pollution. The present paper discusses the main findings on the uptake of ammonia and nitrate in the lichen symbiosis and to the tolerance of lichens to eutrophication. Ammonia and nitrate are both efficiently taken up under ambient conditions. The tolerance to high nitrogen levels depends, among others, on the capability of the photobiont to provide sufficient amounts of carbon skeletons for ammonia assimilation. Lowly productive lichens are apparently predisposed to be sensitive to excess nitrogen.  相似文献   
340.
野骆驼是世界上骆驼科真驼属唯存的野生种,目前全世界只分布在我国新疆和蒙古国的中蒙边境地区,在世界上仅存730~880头左右,是比大熊猫更为珍稀的野生动物,濒临灭绝。野骆驼的生存环境非常恶劣,气候十分干旱,荒漠化十分严重,蒸发量远远大于降雨量,空气非常干燥,日夜温差极大。分布区的植物也非常稀少,没有淡水,只有零星散布的又苦又咸的盐泉,大部分地区寸草不生,只有在盐泉附近长着稀稀拉拉的盐生草、沙拐枣、骆驼刺等。野骆驼能在严酷的荒漠半荒漠地区生活,对恶劣气候环境有很强的适应性,具有耐饥渴抗风暴等抵抗恶劣环境的能力,是动物界中任何一种动物无可比拟的。  相似文献   
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