Comparing Burned and Mowed Treatments in Mountain Big Sagebrush Steppe

Fires in mountain big sagebrush [Artemisia tridentata spp. vaseyana (Rydb.) Beetle] plant communities historically shifted dominance from woody to herbaceous vegetation. However, fire return intervals have lengthened with European settlement, and sagebrush dominance has increased at the expense of herbaceous vegetation in some plant communities. Management actions may be needed to decrease sagebrush in dense sagebrush stands to increase herbaceous vegetation. Prescribed fire is often used to remove sagebrush; however, mechanical treatments, such as mowing, are increasingly used because they are more controllable and do not pose an inherent risk of escape compared with fire. However, information on the effects of burned and mowed treatments on herbaceous vegetation and whether fire and mowed applications elicit similar vegetation responses are limited. We evaluated the effects of prescribed burning and mowing for 3?years after treatment in mountain big sagebrush plant communities. The burned and mowed treatments generally increased herbaceous cover, density, and production compared with untreated controls (P??0.05). In contrast, annual forb (predominately natives) cover, density, and biomass increased with mowing and burning (P?相似文献   

A land management history for central Queensland,Australia as determined from land-holder questionnaire and aerial photography

Features of the land management history over a 125,755 km(2) area of central Queensland, Australia were determined from a variety of sources. A random sample of 205 site locations provided the basis for determining trends in land use. Trends in vegetation clearing were determined using sequential aerial photography for the sample sites, revealing a steady rate averaging nearly 1% of the region per annum over 41 years. This measure of sustained clearing over a large region is higher than recently published clearing rates from South America. Land types have been selectively cleared with over 90% of the Acacia on clay land type having been cleared. A land-holder questionnaire pertaining to the random sites yielded a response rate of 71% and provided information on vegetation clearing, ploughing, tree killing (ring-barking or tree poisoning), and fire frequency, season and intensity. The land-holder responses were compared with independent data sources where possible and revealed no mis-information. However, land-holders may have been marginally less likely to respond if the sample area had been cleared, although this effect was not statistically significant. Ploughing and tree killing are variable depending on land type, but the former has affected about 40% of the Acacia on clay land type, effectively eliminating options for natural regrowth. The proportion of decade-site combinations that were reported as having no fires increased from 22% in the 1950s to an average of 42% for subsequent decades, although the reporting of more than one fire per decade has been relatively constant through the study period. The reporting of at least one fire per decade varies from 46% for the Acacia on sand land type to 77% for the Eucalypt on sand land type for decade-site combinations. Fires are more intense when associated with clearing than in uncleared vegetation, but the proportion of cool and hot fires is relatively constant between land types in uncleared vegetation. Nearly all fires reported were either in spring or summer and this seasonally restricted regime is probably at variance with Aboriginal fire regimes. This study describes the rapid transformation of central Queensland. This has yielded substantially increased agricultural production but may also result in a range of negative impacts and these are discussed.     

油田采出水处理技术探讨

对油田采出水进行处理以净化水质,达到各种目的所要求的水质标准,可采用污水回注的处理工艺,污水作为热采锅炉给水处理工艺,污水外排处理工艺。由于不同的水质要求,具体选择最佳的水处理工艺,达到净化水质保护环境的目的。     

Urban environmental justice through the camera: understanding the politics of space and the right to the city

Using the lens of Lefebvre's spatial trialectics, we assess the utility of photo-elicited interviewing for environmental justice, recognising that a view to social spatial analysis is essential to engaging with the historical processes of exclusion and discrimination that are crucial to explaining why unequal distributions of environmental injustice are systemic and not random. Drawing on insights from our own photo-elicited interviewing-based work in the neighbourhood called Parkdale in Toronto, we make two main recommendations for future environmental justice work using photo-elicited interviewing. First, researchers must be open to a broader epistemology, one that draws on a more spatially nuanced and temporally evolving knowledge of the full range of environmental influences on communities. Second, in order to arrive at a more robust critical analysis of social space, researchers should complement photo-elicited interviewing with historical research about the relevant communities and include participants from other comparative communities.     

From the enclave to the city: the economic benefits of immigrant flexibility

While much attention has been paid to the entrepreneurial “base” of the ethnic economy, the enclave is primarily composed of thousands of hourly employees working in small co-ethnic or multi-ethnic immigrant firms. The US economy benefits from over 10?billion dollars in taxed income and wages from immigrants whose social security numbers do not match up with their employee tax identification numbers. Multiple mismatches and misinformation about immigrants (from an economic, cultural, and political standpoint) demonstrate the need to understand the unique potential of immigrant communities in facilitating urban growth. Koreatown in Los Angeles, an ethnic enclave economy that is also a central business district for many immigrant workers, is one emergent example of new types of flexibility around citizenship status and semi-formal jobs as they are negotiated on a daily basis in the neighbourhood. Previous studies of the ethnic enclave have maintained that there is a singular importance to the co-ethnic network (Korean to Korean, or Cuban to Cuban, for example), and yet this traditional characterisation of the ethnic enclave does not hold true in most urban ethnic enclaves, which include multiple ethnic groups working side by side. Interviews with Korean and Latino workers demonstrate the ways in which people (including undocumented individuals) contribute to the local economy, and informally communicate in neighbourhoods and cities to build a broader social and economic network outside of enclave boundaries.     

Culture and the environment in the United States

The beliefs of Americans about the proper relationship between humans and their environment were profoundly affected by waves of immigration from Europe. Immigrants valued ownership of land, individuality, freedom, domination of nature, and technological development. These themes remain strong today as centerpieces of the American dominant social paradigm (DSP).That DSP has been reexamined and found wanting by an increasing proportion of Americans. This departure from the old DSP has progressed further among the public than among the elite who have a greater stake in preserving the status quo. Environmentalists constitute a vanguard trying to lead the people to a new, more environmentally oriented social paradigm. The beliefs of the old DSP and the new environmental paradigm (NEP) are contrasted in Table 2. Briefly, the NEP advocates stress love of nature rather than domination of it; compassion for other peoples, future generations, and other species; planning to avoid risk; limits to growth; fundamental social change; and a new structuring of politics.These two worldviews are likely to be in vigorous conflict for several decades in the USA. Social learning, spurred by deterioration of the old ways, is likely to lead Americans to a new perspective on their relationship to nature.With the advice and assistance of Barbara V. Fisher.     

美术教育发展趋势的把握与美术课程构建的对策

对美术教育的一些带有倾向性的动势的认识和把握,从而为我们在一些更为具体的方面采取相应对策来适应和推动这种发展。     

试论环保产业在西部开发中的战略地位

在我国西部地区新一轮的开发中,人口、资源、环境与经济社会的协调发展、西部地区战略群体作用发挥和环保产业内在要求的实现,都需要将环保产业放在一个重要的战略位置上加以认真对待。本文对此进行了深入思考。     

Estimation of the effect of the degree of sewage treatment on the status of pollution along the coastline of the Mediterranean Sea using broad scale modelling

A preliminary investigation was performed to estimate the effect of the degree of treatment in Sewage Treatment Plants (STPs) on the status of pollution along the coastlines of the Mediterranean Sea. Data from questionnaires and the literature were collected and processed (a) to identify 18 approximate 1D surface coastal currents, (b) to estimate their prevailing direction and average flow velocity and (c) to estimate the water pollution loads and identify their locations of discharge. Then, a simplified 1D water quality model was formulated and applied for the existing conditions and two hypothetical scenarios: (1) all coastal cities have STPs with secondary treatment and (2) all coastal cities have STPs with tertiary treatment to determine BOD(5), TN and TP concentrations in the 18 surface coastal currents. Calculated concentrations were compared and discussed. A main conclusion is that, to reduce pollution in the Mediterranean Sea measures should be adopted for upgrading the water quality of the rivers discharging into the Mediterranean Sea, along with the construction of STPs for all the coastal cities.     

On averting the tragedy of the commons

One of the enduring facts of the human condition is that the earth's resources are finite and its environment fragile. It is also evident that human behavior is rarely based on an appreciation of these facts. While the outlook may be bleak, so are some of the proposed solutions. Reasonable people have suggested that, to survive, an environmentally enlightened authoritarian government must be adopted. This article suggests that such a solution is unworkable, in part because it fails to consider critical aspects of human nature. A framework is proposed for developing solutions compatible with human capabilities.     

番禺基本实现现代化环保目标和环境问题对策研究

本文根据番禺区到2005年率先基本实现现代化的总体发展目标,从经济、社会、环境协调持续发展的角度,在分析研究番禺区环境问题的基础上,制定环境保护目标和指标,提出实现环境保护目标的对策与措施.     

On the transmission of the effects of monetary policy to the regions

In the paper the theoretical framework is that of credit rationing theory, the regional differences being examined in terms of both financial markets and the real economy. Empirically the focus is upon regional trends in market conditions and the timelags experienced in the effects of monetary policies in two different regions. The period of time examined is from 1970 to 1978, the changes in the marginal interest on central bank credit issued to the commercial banks being taken as the indicator of monetary policy and data on employment opportunities vacant in the regions as representing market conditions and the delay‐effects of monetary policy. The methods used are those of cross‐correlation analysis.     

单推三校正系数在光离子化检测器应用中的测量研究

在利用光离子化检测器监测单推三推进剂贮存环境时,必须首先要知道单推三相对于光离子化检测器校准气体的校正系数。通过简要介绍了校正系数的测量计算原理,并进行实验测量计算,求得单推三的校正系数。     

Soil compaction--indicators for the assessment of harmful changes to the soil in the context of the German Federal Soil Protection Act

Soil compaction in agriculture induced by large-scale equipment is of growing concern. Heavy wheel loads used in arable cropping have the potential to cause irreversible damage to the subsoil structure and may lead to harmful soil compaction. In order to sustain or improve soil health or fitness on a sustainable basis, indicators are needed to assess the changes in the soil structure and the respective soil functions. This requires an adequate verification of methods for distinguishing between the impairment of soil structure and the disruption of soil functions, and for the respective subject of protection. In this article the link between existing models of soil physical prognosis, practical guidelines, and criteria for the identification of affected soil structure is demonstrated, and a viable concept to distinguish harmful changes to the soil is presented. The concept consists of methods for soil physical analysis such as "pre-compression stress" and "loading ratio", practical recommendations for best management practice, and an indicator-based model for the identification of harmful subsoil compaction derived from a research project for the German Federal Environmental Agency, making it possible to determine for a respective location the required level of action far beyond the common practice of precautions against harmful soil compaction.     

Environmental performance policy indicators for the public sector: the case of the defence sector

The development of environmental performance policy indicators for public services, and in particular for the defence sector, is an emerging issue. Despite a number of recent initiatives there has been little work done in this area, since the other sectors usually focused on are agriculture, transport, industry, tourism and energy. This type of tool can be an important component for environmental performance evaluation at policy level, when integrated in the general performance assessment system of public missions and activities. The main objective of this research was to develop environmental performance policy indicators for the public sector, specifically applied to the defence sector. Previous research included an assessment of the environmental profile, through the evaluation of how environmental management practices have been adopted in this sector and an assessment of environmental aspects and impacts. This paper builds upon that previous research, developing an indicator framework--SEPI--supported by the selection and construction of environmental performance indicators. Another aim is to discuss how the current environmental indicator framework can be integrated into overall performance management. The Portuguese defence sector is presented and the usefulness of this methodology demonstrated. Feasibility and relevancy criteria are applied to evaluate the set of indicators proposed, allowing indicators to be scored and indicators for the policy level to be obtained.     

关于地方推进现代环境治理体系实践进展的述评

为跟踪各地落实《关于构建现代环境治理体系的指导意见》的实践进展，本文通过比较各地发布的相关实施意见文本，结合实地调研座谈，总结典型案例，分析发现：①由于各地对现代环境治理体系内涵的理解存在差异，关注的重点领域有所不同，部分地方突破了“七大体系”。②实践中，在推动企业落实主体责任、优化政府监管服务、规范市场化建设、协同推进区域共建共保、激活基层治理效能、增强科学精准治理能力等方面形成了一些富有特色的实践经验。③《关于构建现代环境治理体系的指导意见》中的“七大体系”推进程度不均衡，政府、企业、社会组织和公众三大主体的力量结构失衡状态改善不明显，主要体现为“三多三少”，即政府责任体系和监管体系建设多，企业环境责任体系和社会治理体系建设少；关注规范第三方环境服务、落实“放管服”多，运用市场调节机制的案例少；社会治理以宣传活动和网格员机制多，践行绿色生活的全民行动体系成果少。为此，本文提出，加快建立环境治理体系现代化的评价体系，针对环境治理薄弱环节，协调推进“七大体系”建设等建议。     

关于改进“绿色化税制”测量方法的探讨

“绿色化税制”通常使用两项指标来进行测量：环境相关税收入占GDP的百分比和环境相关税收入占国家税收总收入的百分比。但是,这两个指标也存在着一个很大的缺点：当污染税增加时,税收收入也增加。因此,本文通过探讨测量绿色税制的指标,建立一个简单的分析框架,通过有效性、数据的可用性、全时段的比较、国际相似性、易聚合性、免税和减税、有限的复杂性七个指标来进行评价。最后,基于四种类型的指标的优缺点来做总结,对绿色税制的优化给出建议。     

Education at the Commission on Sustainable Development: the perception of the international community

This paper explores the role of education as it might assist in achieving a sustainable world. It examines the perceptions of the international community present at the seventh session of the Commission on Sustainable Development (CSD). A survey was conducted of 146 delegates and UN staff over the two weeks of the Commission's session in April 1999. The survey identified the primary importance placed on education as a cross-cutting theme of sustainability and the need for efforts to be co-ordinated to achieve education for sustainable development at all levels. To make further progress for implementing Agenda 21, the task management by UNESCO must improve through instigation of a supportive reporting system at the CSD. The education community must receive appropriate support and funding to make effective progress at local and national levels to implement the work programme for education, public awareness and training.     

破解绿色瓶颈——推进绿色生态城建设

"绿色经济与可持续发展"是当今人类社会的主题,而任何一种可持续发展的主体都离不开城市。因此,推动城市发展模式向绿色生态城的转变已成为必然趋势。本文以建设绿色生态城为例,主要阐述推进绿色生态城建设的重要意义。同时,重点分析目前国内绿色生态城建设过程中存在的主要问题。最后,对破解绿色瓶颈,推进绿色生态城的建设提出几点建议。     

Culture and the environment in the Soviet Union

The Soviet Union is one of the most physically and culturally diverse nations on earth. Its natural environment embraces a rich variety of resources and ecosystems, many of which, such as Lake Baikal, are of world significance. Culturally, it is comprised of over a hundred ethnic groups, belonging to eight major language groups and six major religions. However, two cultures are dominant: the Slavic group (which takes in 75% of the USSR population and 80% of its land area) and the Turkic-Islamic peoples who account for the large majority of the remainder. Owing to the highly centralized nature of the country's political-administrative system, however, the effect of culture or ethnic traditions in the resolution of national environmental issues is quite small. Major decisions regarding either specific conservation issues or basic environmental policies are made at the centralized level by ministerial, planning, and Communist Party officials, and are based on pragmatically refined ideological considerations, rather than on regional cultural attitudes. This pragmatic refining of ideological considerations will involve the weighing of specific economic and environmental imperatives, and deciding on appropriate trade-offs. To find cultural expression in environmental management, one would need to look closely at local projects and approaches in the various ethnic regions, particularly the non-Slavic ones.