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1.
The ungulate and rodent fossil records are often used independently to understand mammalian evolutionary history. Few studies have directly compared both records over long time periods and large geographic areas. Here, we compiled two datasets of European fossil localities containing rodents and/or ungulates over 20 My (Early Miocene–Early Pliocene) and processed the data with the same methodology. We counted the raw diversity and calculated a measure of evenness (Pielou’s index). After controlling for potential biases on diversity estimators, we identify the evenness index as a more reliable estimator bringing interesting insights into the way both mammal groups are structured by biotic or abiotic factors. In this study, we consider that an uneven distribution of the species richness among families, when only some families successfully diversify within the “continental-scale community”, represents a lower adaptability of this community to the environmental context. Pielou’s index is used to estimate this adaptability through time. The responses of ungulates and rodents to environmental changes are very divergent, especially facing the climatic changes known since the Middle Miocene. The general patterns suggest that rodent broad-scale assemblages are affected by all kinds of perturbations, even short biotic and abiotic events, but show a better adaptability when facing long-term abiotic changes. Unlike rodents, the ungulate assemblages show more stability in periods of relative environmental stability but show less adaptability to long-term climatic changes. Life-history traits of mammals can help explain patterns of diversity and biogeography at different spatial scales and may probably partly explain the opposite patterns evidenced here.  相似文献   

2.
We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.  相似文献   

3.
One of the climate change scenarios that have been developed for the Netherlands predicts hotter and drier summers and a substantial drop in river discharge. This might lead to water scarcity with detrimental economic and environmental effects. Among the possible adaptation responses to climate change-induced water scarcity, the re-allocation of water resources among competing uses should also be considered. In this paper, we extend and apply a computable general equilibrium (CGE) model to assess the potential of water markets (water allocation according to its shadow price) to guide the allocation of scarce water across agriculture, manufacturing, and public water supply. We develop four scenarios in which the scope of water markets is increased from industry-specific to economy-wide. The results show that the agricultural sector bears nearly all of the losses from a new water-scarce climate, while the manufacturing sectors are able to mitigate their losses to a large extent by technical measures. Extending the scope of water markets unambiguously increases economic output and results in a re-allocation of water to the manufacturing sector from the agricultural sector and from public water services. If, perhaps for political reasons, public water services are excluded from water trading, water is re-allocated from agriculture to manufacturing. Depending on which sectors are included, the construction of a water market can have negative or positive effects on a sector’s output, and although the implementation of water markets may be positive for overall economic output and can hence assist adaptation, the effect on vulnerable or societally sensitive economic sectors, such as public water, should be taken into account when implementing such a market.  相似文献   

4.
为研究南水北调东线工程调水对南四湖硅藻藻密度、种群结构变化的影响,于2010年5月—2013年4月在南四湖进行逐月采样,应用NMDS(non-metric multi-dimensional scaling,非度量性多元标度)分析硅藻种群组成的相似性,并通过冗余分析和Pearson相关性分析研究了硅藻种群结构和环境因子间的相关性. 结果表明:①共检出硅藻23属69种,硅藻藻密度在14.3×104~663.2×104 L-1之间,呈明显的季节性变化,表现为冬春季大于夏秋季;②硅藻种群演替呈明显的季节性变化,冬春季主要以冷水种尖针杆藻(冬春季所占比例分别为15.3%、24.0%)为主,夏秋季则以暖水种扭曲小环藻(夏秋季所占比例分别为17.8%、19.1%)为主;③氮磷营养盐水平、pH和表层水温是影响南四湖硅藻种群变化的主要环境因子. 南四湖硅藻种群对于环境因子变化的反应较为灵敏,可作为南四湖水质的潜在指示工具进行长期研究.   相似文献   

5.
Some Lessons Learned from Public Health on the Process of Adaptation   总被引:1,自引:1,他引:0  
Lessons learned from more than 150 years of public health research and intervention can provide insights to guide public health professionals and institutions as they design and implement specific strategies, policies, and measures to increase resilience to climate variability and change. This paper identifies both some modifications to public health systems that may enhance adaptive capacity, and lessons drawn from the history of managing environmental and other threats in the public health sector that may have relevance for other sectors as they design approaches to increase their adaptive capacity to more effectively cope with climate variability and change. The views expressed are the author’s own and do not represent official US EPA policy.  相似文献   

6.
The environmental structural change strategy claims that by shifting our expenditures to economic sectors with lower environmental intensity, absolute resource consumption and environmental impact can be lowered. Environmental Input-Output methodologies for computing these intensities attribute no resource consumption to labour or households because these are not classified as sectors. The suggestion that service sectors entail less environmental impact, however, loses force if a unit of labour contains embodied energy, and attributing these inputs to labour drastically reduces intensity variation between sectors. Relative growth of service sectors has furthermore not been accompanied by decreased resource consumption; thus models whose intensity computations cover not only inter-firm payments but also labour earnings and household expenditures may have superior predictive power. If moreover natural-resource and labour inputs to product are incommensurable, intensity ratios themselves have perhaps only monetary, rather than real, significance.  相似文献   

7.
向梦宇  王深  吕连宏  张楠  白梓函 《环境科学》2023,44(7):3637-3648
当前我国同时面临改善生态环境质量和实现碳达峰碳中和两大战略任务,协同推进减污降碳已成为我国经济社会发展全面绿色转型的必然选择,电力部门在转型过程中将发挥重要作用.面向不同的电力需求情景,构建低成本实现碳达峰、碳中和的多目标模型,求解得出减污降碳协同增效最优路径方案.结果表明,在如期实现碳达峰、碳中和目标的前提下,减污和降碳协同性较好,两者协同控制可高效助力低碳转型的实现;优化电力部门发电结构是实现减污降碳协同增效的关键措施,研究期火电占比不断下降,清洁电力占比超过92.5%;不同电力需求下二氧化碳和主要大气污染物排放量有明显差异,其中二氧化碳排放量受电力需求影响最大,低电力需求、中等电力需求和高电力需求情景下峰值二氧化碳排放量分别为94.16亿、 104.09亿和107.46亿t,主要污染物二氧化硫、氮氧化物和颗粒物的排放同样表现出在低电力需求、中等电力需求和高电力需求情景下依次递增的趋势.电力需求的提高仅增加了电力部门内部发电结构调整的压力,未影响到其他部门的产量和活动水平,即电力需求导致的电力部门减排压力未表现出部门间传递的趋势.  相似文献   

8.
利用CAMx(区域空气质量模型)中的PSAT(颗粒物源示踪技术),分析了重污染天气下分区域、分行业的污染物排放对京津冀地区PM2.5的贡献,设计了分行业排放的环境影响效率系数(EESCR)计算方法,并对“电能替代”(以电力行业产能替代民用能源消耗)情景方案下的排放进行模拟分析. 结果表明:在重污染天气背景下,电力行业排放对京津冀地区ρ(PM2.5)的贡献率较低,各地均低于10%,并且区域排放的贡献次序为京津冀以外地区>京津冀其他城市>当地,这与电力行业高架源排放的特征有关,而工业和民用行业对区域排放的贡献次序相反. PM2.5主要组分和前体物的分行业EESCR计算结果表明,电力行业ESSCR值均在y=1/2x趋势线之下,远低于其他行业,因此优先控制其他行业排放才是改善京津冀地区空气质量的关键.电能替代的情景模拟结果表明,电能替代是有效降低京津冀地区ρ(PM2.5)的可行方式. 研究显示,充分利用电力行业高架源排放的特点和便于集中处理的行业优势,尽力降低因产能增长带来的排放增量,实施电能替代可成为改善区域空气质量的有效途径之一.   相似文献   

9.
This paper investigates the current status and trends over time in the environmental performance of European ports. The research is based on the provision of data from 79 European ports on issues related to their environmental management, environmental priorities and current environmental monitoring practices. This study updates previous environmental reviews, so that the trends over time are drawn. For instance, 90% of respondent ports stated that they have an environmental policy and 94% of ports have designated environmental personnel. The percentage of ports that have an Environmental Management System has increased by +33% in the last 9 years. Air quality, port waste and energy consumption emerged as the three major environmental priorities of the European port sector in 2013. The research also reveals the diversity amongst European ports in terms of size and physical surroundings. Some examples are presented on specific initiatives carried out by sector organisations about the Top-10 port priority issues. The future expectations of European ports on data collection and reporting are described.  相似文献   

10.
11.
近年来我国环境污染事件浅析   总被引:1,自引:0,他引:1  
本文基于我国近年来环境污染事件,从污染事件的发生时间、发生原因、发生地、所属行业等几个方面进行了统计分析。分析结果表明:近年来我国环境污染事件呈上升趋势,且东部地区多于西部地区,化工行业、运输行业污染事件发生的次数多于其他行业,污染物以液态为主,事件表现方式主要为爆炸和泄漏。针对我国环境污染事件现状,本文最后对环境污染事件的预防与应对提出了几点建议。  相似文献   

12.
Characterizing the paleoenvironmental context of the first hominids is a key issue for understanding their behavioral and morphological evolution. The present study aims at reconstructing the paleoenvironment of the TM266 vertebrate assemblage (Toros-Menalla, Northern Chad) that yielded the earliest known hominid Sahelanthropus tchadensis (7 Ma). For the first time, a quantitative analysis is carried out on the fossil mammal assemblage associated with that hominid. Two complementary approaches were applied: (1) the analysis of the relative abundances of taxa and their habitat preferences; and (2) the study of the distribution of taxa within three meaningful ecovariables: locomotion, feeding preferences, and body mass. The resulting taxonomic and paleoecological structures are used to reconstruct the diversity and the relative extent of the habitats in that part of northern Chad seven million years ago. The paleoenvironment was composed of open areas with dry and humid grasslands, prevailing over wooded habitats. Water was also widely available as freshwater bodies and certainly swamps. It appears that the high habitat diversity of the landscape is a common feature among paleoenvironments associated with early hominids.  相似文献   

13.
中国工业行业的生态效率   总被引:5,自引:2,他引:3  
毛建素  曾润  杜艳春  姜畔 《环境科学》2010,31(11):2788-2794
中国工业是资源消费和污染物排放的主要源头,解析工业各行业的生态效率可为中国产业结构调整和整体环境质量改善提供必要信息.在分析工业构成并构建工业系统与外部环境之间关系的基础上,选择能源消费和废水、固体废物、SO2、工业烟尘、粉尘等污染物的排放量作为研究的环境影响类别,界定了与这些环境影响相关的生态效率,估算了中国2007年的工业生态效率现状,结果为:能源效率615.5万元·ktce-1;废水和固废方面的生态效率分别为54.3万元·kt-1和1.9万元·t-1;工业SO2、烟尘和粉尘方面的生态效率分别为59.6、169.2和184.6万元·t-1.深入分析了39个工业部门的生态效率,结果表明,以上几种生态效率具有明显的行业不均衡性,表现为不同行业在不同类型生态效率中的工业排序明显不同;与此同时,对于同一种生态效率,不同工业行业的数值可相差几百倍到几万倍,表明通过优化工业结构将具有较大的提高工业生态效率的可能性.  相似文献   

14.
This paper introduces a new methodology for measuring and modeling manufacturers’ environmental performance and the managerial and technological practices that affect it. Facility level licensing data are used to develop indicators based on sector-specific criteria but capable of being analyzed across sectors, at various levels of aggregation. This addresses the problem that environmental performance and determinants tend to be highly context-specific, while modeling and policy interests are often more general. Using Integrated Pollution Control (IPC) information generated EU-wide, this approach should be capable of cross-country extension. The methodology is tested on a sample of Irish facilities in three sectors during 1996–2004. Preliminary results show its usefulness in exploring the determinants of environmental performance at the sector and cross sector levels. Word count = 10,049.  相似文献   

15.
我国行业水资源消耗的关联度分析   总被引:1,自引:0,他引:1       下载免费PDF全文
选取2007年相关数据进行整理分析,应用基于假设抽取法的水资源消耗产业关联度计量模型,比较各行业水资源的直接消耗和纵向集成消耗,定量测算出我国行业间水资源的流动转移情况.通过分析得到:不同行业的水资源直接消耗量与满足自身需求所需的水资源量有所差异,但是对于经济系统而言,所有行业水资源的直接消耗总量等于为满足最终需求所需的水资源总量,即水资源在经济系统的不同行业之间发生了转移;在经济系统中,农业、基础工业作为产业链上游行业将大量的水资源通过中间投入的方式转移到其下游行业中,轻工业、高科技工业等产业链下游行业的直接消耗的水资源无法满足自身需求,必须从其上游行业转移水资源;水资源从产业链的上游逐级向下游转移,维持着经济系统产品的生产与交换;如果行业的最终需求不变,单纯调整产业结构仅是将水资源消耗量大的行业进行区位或行业上的转移,而经济系统水资源消耗的总量并没有改变.本文通过定量化的方式来研究行业水资源消耗关联,初步揭示了水资源在行业间的消耗规律,能够为产业调整提供新视角,为产业结构调整政策提供更为科学的依据.  相似文献   

16.
黄河兰州段水污染物规划环境容量和排污总量控制研究   总被引:1,自引:0,他引:1  
曹磊 《环境科学》1993,14(1):54-58
黄河甘肃河段,按水域功能划分为水源保护区、准水源保护区和综合功能区三个串联的功能河段。本研究提出各河段水环境规划容量新概念和排污总量控制方案。河段环境容量的计算,是以有机污染指标COD为例,在美国“PDM-PC模型”的基础上,简化边界条件后,重新推导建立了近似解析求解数学表达式。所得环境容量和规划环境容量都是在不同目标和不同达标概率的随机条件下连续的风险环境容量系列值,为总量控制和环境决策提供了更多的选择余地。  相似文献   

17.
红碱淖是中国最大、最年轻的沙漠淡水湖,水域面积67平方公里。通过数据收集统计及打分计算的方式对红碱淖水环境质量、生态环境质量、水生态健康进行定量分析,结果表明,红碱淖水环境质量从1981年至2010年有逐渐恶化的趋势;2010年红碱淖生态系统健康综合指数为59.86,属于中等水平,已经受到了一定影响;生态质量综合评价值为81.6分,具有较高的保护价值。并对造成红碱淖水质和生态系统逐步恶化的原因进行解析,同时提出相应的对策。  相似文献   

18.
税负水平是税收调节作用的重要因素,各地区需要科学地制定符合本地区发展水平的环境保护税税率来平衡环境保护与经济发展.基于2016年东北某省14个市的钢铁、电力、化工、水泥行业的排污及治理成本数据,建立污染削减费用函数模型,计算该省大气、水中主要污染物的边际治理成本,并设置不同环境保护税税率的情景方案,以探究环境保护税税率对该省经济发展的影响.结果表明:①SO2、NOx、COD、NH3-N的边际治理成本分别为3.44、5.03、3.81、8.15元/污染当量. ②重点行业主要污染物的边际治理成本不同,钢铁行业主要污染物的边际治理成本较高,其COD、NH3-N的边际治理成本均高于总体边际治理成本;化工行业的COD边际治理成本高于总体边际治理成本;电力行业的大气主要污染物边际治理成本高于总体边际治理成本;水泥行业的大气主要污染物边际治理成本则相对较低. ③适当提高环境保护税税率对经济发展总体影响不大.研究显示:该省的边际治理成本远高于目前的环境保护税征收标准,若以边际治理成本作为环境保护税税率,不但会增加企业负担,而且会导致不同行业的边际治理成本相差较大,因此,建议提高该省的环境保护税税率标准,即大气污染物征收标准为2.4元/污染当量,水污染物征收标准为2.8元/污染当量,并设置环境保护税税率的行业差异化,将有利于政策功能的发挥.   相似文献   

19.
The objective of this paper is to discuss the mapping methodology implemented in the selection of BAT candidates and to present the results of the mapping of B&H food and beverage sector, prepared as a baseline for the development of national reference documents on Best Available Techniques. The subsectors subject to analysis were: dairy, fish farming, fish processing, fruit and vegetable processing, meat processing, breweries, and slaughterhouses.The sector was mapped from several aspects, including socio-economic, legal, and environmental point of view. The socio-economic aspect focused on understanding the sector’s structure and financial capabilities, pricing for water, energy, and solid waste consumption, as well as employee profiles, in order to better assess the sustainability of decisions taken. Legal mapping focused on relevant regulations, including policies from the following sectors: environment, water use and protection, food safety, agriculture, and veterinary, in order to determine legal requirements from an environmental protection aspect set in the various sector policies. Environmental performance indicators were calculated in order to assess present resource efficiencies and relevant environmental impacts. In addition, the mapping process also addressed the existing level of BAT implementation in the subsectors under consideration.The paper presents a rationale for methodology selection, offers a review of the mapping methodology used, discusses mapping results and provides conclusions in regards to that methodology used and discusses issues that need to be considered in the selection of BAT candidates.  相似文献   

20.
We reviewed existing and planned adaptation activities of federal, tribal, state, and local governments and the private sector in the United States (U.S.) to understand what types of adaptation activities are underway across different sectors and scales throughout the country. Primary sources of review included material officially submitted for consideration in the upcoming 2013 U.S. National Climate Assessment and supplemental peer-reviewed and grey literature. Although substantial adaptation planning is occurring in various sectors, levels of government, and the private sector, few measures have been implemented and even fewer have been evaluated. Most adaptation actions to date appear to be incremental changes, not the transformational changes that may be needed in certain cases to adapt to significant changes in climate. While there appear to be no one-size-fits-all adaptations, there are similarities in approaches across scales and sectors, including mainstreaming climate considerations into existing policies and plans, and pursuing no- and low-regrets strategies. Despite the positive momentum in recent years, barriers to implementation still impede action in all sectors and across scales. The most significant barriers include lack of funding, policy and institutional constraints, and difficulty in anticipating climate change given the current state of information on change. However, the practice of adaptation can advance through learning by doing, stakeholder engagements (including “listening sessions”), and sharing of best practices. Efforts to advance adaptation across the U.S. and globally will necessitate the reduction or elimination of barriers, the enhancement of information and best practice sharing mechanisms, and the creation of comprehensive adaptation evaluation metrics.  相似文献   

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