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491.
Climate change represents one of the most pressing societal and scientific challenges of our time. While much of the current research on climate change focuses on future prediction, some of the strongest signals of warming can already be seen in Arctic and alpine areas, where temperatures are rising faster than the global average, and in the oceans, where the combination of rising temperatures and acidification due to increased CO2 concentrations has had catastrophic consequences for sensitive marine organisms inhabiting coral reefs. The scientific papers highlighted as part of this anniversary issue represent some of the most impactful advances in our understanding of the consequences of anthropogenic climate change. Here, we reflect on the legacy of these papers from the biotic perspective.  相似文献   
492.
493.
Anthropogenic environmental impacts can disrupt the sensory environment of animals and affect important processes from mate choice to predator avoidance. Currently, these effects are best understood for auditory and chemosensory modalities, and recent reviews highlight their importance for conservation. We examined how anthropogenic changes to the visual environment (ambient light, transmission, and backgrounds) affect visual communication and camouflage and considered the implications of these effects for conservation. Human changes to the visual environment can increase predation risk by affecting camouflage effectiveness, lead to maladaptive patterns of mate choice, and disrupt mutualistic interactions between pollinators and plants. Implications for conservation are particularly evident for disrupted camouflage due to its tight links with survival. The conservation importance of impaired visual communication is less documented. The effects of anthropogenic changes on visual communication and camouflage may be severe when they affect critical processes such as pollination or species recognition. However, when impaired mate choice does not lead to hybridization, the conservation consequences are less clear. We suggest that the demographic effects of human impacts on visual communication and camouflage will be particularly strong when human‐induced modifications to the visual environment are evolutionarily novel (i.e., very different from natural variation); affected species and populations have low levels of intraspecific (genotypic and phenotypic) variation and behavioral, sensory, or physiological plasticity; and the processes affected are directly related to survival (camouflage), species recognition, or number of offspring produced, rather than offspring quality or attractiveness. Our findings suggest that anthropogenic effects on the visual environment may be of similar importance relative to conservation as anthropogenic effects on other sensory modalities.  相似文献   
494.
Regional Environmental Change - Globally increasing temperature and modifications in precipitation patterns induce major environmental alterations in aquatic ecosystems. Particularly profound...  相似文献   
495.
徐君儒  邱榕  熊才溢  蒋勇  黄玥 《火灾科学》2017,26(3):147-156
高层建筑竖井火灾中影响因素众多,并且各因素对高层楼梯井火灾中重要现象、关键数值等的影响大小不一,使得此类火灾中的实验或理论研究成本较高。通过建立全局敏感性分析平台,定量考察了高层楼梯井结构所涉及因素的影响大小,并能够方便地筛选掉对所考察量影响较小的因素,以降低实验或计算成本。使用数值模拟方法,通过CFD软件对包含阶梯几何框架的高层楼梯井结构火灾进行了共计60次工况计算。并且根据计算结果,使用全局参数敏感性分析方法,得出建筑尺寸、热释放速率、环境参数对高层楼梯井内烟气湍流特性及输运特性的敏感性排序。结果表明,火源热释放速率对各输出参数的影响均占38%以上。  相似文献   
496.
The concentrations of trace metals (Cd, Pb, Cu, Cr, Fe, Ni, Zn and Co) were studied in soil profiles of eight municipal waste dump sites in Warri metropolis. The results indicate that concentrations of trace metals varied widely among the different dumpsites and decreased with depths in a studied soil profile. The accumulation pattern for the heavy metals in the soil profiles follows the order: Fe > Pb > Mn > Co > Cr > Zn > Ni > Cu > Cd. The concentrations of metals found in these sites was below the Canadian remediation criteria for land for agricultural, residential and commercial/industrial purposes except for the cadmium levels in some sites that exceeded criterion values for agricultural and residential. In such sites, remedial actions are required before any form of chosen development can take place. The levels of heavy metals found in these dump sites were higher than that of the control site. The examined metals showed no significant correlation with soil physicochemical properties at the surface horizon, which is suggestive evidence that these metals arise from anthropogenic input.  相似文献   
497.
The critical review of norms and standards and corresponding tests to determine the compostability of biodegradable plastics, possibly applicable also to biodegradable agricultural plastics, shows that many norms concerning testing and labelling of compostable plastics have been established at the international level. Some of them are about plastic materials, some others are about products like packaging. The media and conditions of testing cover mainly the conditions designed for industrial composting facilities, and only a few concern home composting conditions. Considering that the end of life management of biodegradable agricultural plastic products will be done at the farm to reduce the management of the waste and also its cost, only a few of these norms are considered to be suitable for adaptation to cover also biodegradable agricultural plastic products. The biodegradability validation criteria under composting conditions, such as the threshold percentage of biodegradation and disintegration, the time and temperature, and the ecotoxicity, are presented for the main norms and standard testing methods. Based on these different norms and their content, a list of specs and technical requirements that could be adapted to meet farm composting conditions for agricultural compostable plastics is proposed. These requirements may be used as criteria for the establishment of a new integrative norm for agricultural compostable plastics.  相似文献   
498.
Phytoremediation, the use of plants for in situ contaminant cleanup, is gaining new appreciation as an aesthetically pleasing, sustainable method that naturally makes use of solar power. Hybrid poplars are widely used because they grow rapidly and have high transpiration rates, making them advantageous for hydraulic control of groundwater. However, the tendency for trees and other vegetation to uptake metals may be a disadvantage in some settings due to potential redistribution of metals from groundwater to the ground surface. Therefore, a pilot test in the upper midwestern United States was implemented to evaluate the applicability of poplars to groundwater withdrawal and metals transport. © 2009 Wiley Periodicals, Inc.  相似文献   
499.
1IntroductionAs a many-volcano-distributed country,China is covered with many volcanoes and lava rocks.A-mong the one-thousand-or-so volcanoes,Changbai Mountain Volcano,Wudalianchi Volcano,Tengchong Volcano and Ashikule Volcano of West Kunlun are the mostlatentcatastrophic erup-tive active volcanoes.In recent years,the activity of the earth' s crust in some volcanic areas isobviously becoming increasing violent.Butfew scholars have monitored and evaluated volcano inChina.So building VDI…  相似文献   
500.
为研究昌黎生态监控区夏季浮游植物群落结构特征及其与环境因子关系,采用2005~2013年夏季(8月)昌黎生态监控区海域浮游植物及环境因子的监测资料,基于Arc GIS 10.0和Canoco软件平台,运用典范对应分析方法,对浮游植物群落结构进行分析.结果表明,近9 a共鉴定出浮游植物3门23科39属105种,其中,硅藻门16科32属90种,占浮游植物总数的85.7%;甲藻门共6科6属14种,占总种类数的13.3%;金藻门1种.各年的优势种存在很大差异,按照优势度Y值的大小包括辐射圆筛藻(Coscinodiscus radiatus)、柔弱角毛藻(Coscinodiscus debilis)、笔尖根管藻(Rhizosolenia styliformis)、柏氏角管藻(Cerataulina bergoni)、威氏圆筛藻(Coscinodiscus wailesii)、海链藻(Thalassiosira sp.)、三角角藻(Ceratium tripos)、洛氏角毛藻(Coscinodiscus wailesii)、中肋骨条藻(Ceratium tripos)等.夏季细胞丰度年际变化较大,呈现逐渐降低的趋势.浮游植物的多样性指数H'值介于0.015~3.889,均匀度指数J值介于0.009~1,年际变化幅度较小;各站位间物种分布不均匀,优势种较少且优势度较大.对浮游植物群落与环境因子进行典范对应分析(CCA),结果表明影响夏季浮游植物群落结构变化的环境因子包括水温、营养盐(磷酸盐、硝酸氮、氨氮)、盐度等,且是各个环境因子相互作用的结果.  相似文献   
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