首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
微评     
<正>深夜捉虫每年立秋过后,河南延津县数万村民捉虫忙。8月16日凌晨5点,僧固乡德士村蟋蟀交易市场开始热闹起来。捉了一晚上蟋蟀的村民们,骑着摩托车、电动车,头戴矿灯,三两一群提着特制的篮子,兴致勃勃地到各摊位前,向收蟋蟀的老板们展示他们一晚的战利品。蟋蟀没有明码标价,每只少则10元,多则百元千元甚至万元。只要卖到千元的,村民们都会放鞭炮庆贺。蟋蟀俨然成了当地的"致富虫"。  相似文献   

2.
人类、昆虫和杀虫剂   总被引:1,自引:0,他引:1  
人类和昆虫是一对欢喜冤家。昆虫对人类既有益.又有害。有些昆虫以虫为食,人类就利用它们防治有害的昆虫,例如用七星瓢虫防治蚜虫,用金小蜂防治棉铃虫;有些昆虫善鸣叫,人们就豢养它们作宠物,聆听它们悦耳动听的鸣叫声.如金蛉子、蟋蟀、叫蝈蝈、纺织娘等等;有些昆...  相似文献   

3.
一块城市草坪,要是放在过去,准有许多的蚯蚓、蟋蟀、蝼蛄、屎克郎、地鳖虫等等……土地的上面,生活着许多的蚱猛,蝗虫、纺织娘、沙螽和蟾蜍……空中,有蜻蜓、蝉、金龟子、蝴蝶以及一些蓝色的、黑色的、棕色的小鸟……当然,地面上更包括许许多多野生植物和数不清的微生物……如今可好,这么多小生命的生存空间,竟被一种或几种“高贵”的小草占据了!举个例子:我们这里一种非常珍贵的小灰蝶(同世界最小的巴西小蝴蝶相当)的生存,就离不开几种特殊的野革,并且,它们的幼虫必须钻进草芯里才能成活。可建人工草坪后,那些野草已经绝迹  相似文献   

4.
欣赏美丽的大自然   大自然是美丽的,有蓝蓝的天空,无边的海洋,千姿百态的虫鱼鸟兽,万紫千红的花草树木。大自然的一切对孩子们有着无穷的吸引力。   在《我们的学校》一课,老师带领孩子来到学校各个花坛,看看青青的绿叶,鲜艳的花朵,抚摸柔软的草被。《植树节》一课,让孩子来到田野里,欣赏早春景色,感受春的气息。在《瓢虫与蜻蜓》、《软体动物》、《昆虫》等课中,让孩子们到草丛中捉蝗虫、瓢虫;在乱石堆里挖蚯蚓、蟋蟀;空旷处用网罩蜻蜓。在高年级的分区地理课中,通过多媒体,让学生领略北京故宫、颐和园、北海的豪华壮…  相似文献   

5.
给我一片天空 一片幼年的乳白色天空 游逛的白云像成群的娜羊 倒映在辽阔的池塘和草原上 衣晚总有月亮温柔的窥探 还有星星眨眼讲着芍远的故事 我爱这一片天空 让我看见蜻蜓和松鼠的腾跃 让我听到蟋蟀和清蛙的歌唱 别给我太多的娇宠和搀扶 我要试着从跌倒中学会走路 给我一片天空 一片童年的蔚蓝色天空 永远有长尾巴的风筝在飘扬 听到热带鱼唉喋和林鸟的叫啾 嗅到泥土和花草的馨香 别老叫我把心拴在斗室里 别让屯子游戏机昏眩我的视力 我的天空有一道畅快的滑梯 呼啸着滑向友伴的玩闹和嬉戏 给我一片天空 一片青年的金黄色天空 泳远有蒸发不…  相似文献   

6.
资源条件对城市可持续发展的影响--以重庆市为例   总被引:4,自引:0,他引:4  
根据城市发展对资源的依赖程度,把资源分为必需型资源和特色型资源两种类型,分别讨论了这两类资源对城市可持续发展的影响,然后在评价城市资源优劣势的基础上,提出了重庆市基于资源条件的持续发展对策.  相似文献   

7.
植物种质资源是人类赖以生存的资源,是一个国家和地区重要的基础性战略物质,四川植物种质资源无论是种类还是数量在全国都居重要地位。在分析四川种质资源特点和利用现状的基础上,对积极开展四川种质资源保护利用进行了探索和研究,提出了大力开展植物种质资源及其保存和利用现状的全面调查,摸清家底,逐步建立植物种质资源保护利用数据库和网络信息平台,大力开展多种形式的示范工程建设,积极开展植物种质资源监测网络建设,加强植物种质资源的研究开发,加强植物种质资源管理运行机制建设,搭建种质资源共享平台,加强人才队伍建设等植物资源保护和可持续利用对策及其保障措施。  相似文献   

8.
本文针对河北省资源文明城市、社区建设的经济社会背景以及省辖主要城市的社会经济和资源状况,研究了资源文明城市、资源文明社区的建设和限制因素,概述了能源和矿产资源型、港址资源型、人文旅游资源型城市以及白洋淀水乡社区和西柏坡革命纪念地社区的总体规划方案,提出了资源文明城市和资源文明社区建设的基本对策。  相似文献   

9.
随着资源型城市的资源不断耗竭,我国"矿竭城衰"现象越来越严重,许多资源型城市都面临着可持续发展的困境。因此,应以科学发展观为出发点,从改革资源税费制度和理顺资源利益分配关系两方面来完善我国资源开发补偿法律制度,以促进我国资源型城市的可持续发展,最终实现国家的可持续发展。  相似文献   

10.
基于旅游价值的陵墓资源开发研究——以扬州为例   总被引:1,自引:0,他引:1  
陵墓资源是一个地区人文资源的重要组成部分,具备一定的旅游开发价值。对陵墓资源进行旅游功能开发,首先要分析陵墓资源自身价值对旅游开发的意义。在阐述这一问题的基础上,对扬州地区陵墓资源的旅游价值进行了系统分析和评价,指出陵墓资源开发对发展旅游业的启示,最后提出陵墓资源旅游价值开发的思路和措施。  相似文献   

11.
底泥的氮、磷释放及其微生物影响的研究   总被引:2,自引:0,他引:2  
张恒军  吴群河 《环境技术》2003,41(Z1):20-23
氮和磷在自然界的循环已经引起了人们的关注,一方面因为氮和磷是生态系统中必不可少的营养元素,另一方面过剩的氮和磷会导致水域的富营养化 ,从而使生态平衡遭受破坏.本文综述了水体沉积物中氮和磷受微生物作用进行释放的影响,以及国内外的研究历史和现状.总结了氮磷微生物代谢的特点,并阐述了与传统认识相区别的最新发现和思想.本文试图从理论上说明微生物的氮磷释放机理,通过生物化学和分子动力的角度解释了细菌对氮磷的吸收和释放,即质子动势理论和Pho调控理论.目前,这一领域研究的热点是为了特殊的使用用途对于高效微生物的分离鉴别和组合培养,和对氮磷代谢的影响因素.  相似文献   

12.
In this study, the Tsunami-caused deterioration of soil and groundwater quality in the agricultural fields of coastal Nagapattinam district of Tamilnadu state in India is presented by analyzing their salinity and sodicity parameters. To accomplish this, three sets of soil samples up to a depth of 30cm from the land surface were collected for the first six months of the year 2005 from 28 locations and the ground water samples were monitored from seven existing dug wells and hand pumps covering the study region at intervals of 3 months. The EC and pH values of both the soil and ground water samples were estimated and the spatial and temporal variability mappings of these parameters were performed using the geostatistical analysis module of ArcGIS((R)). It was observed that the spherical semivariogram fitted well with the data set of both EC and pH and the generated kriged maps explained the spatial and temporal variability under different ranges of EC and pH values. Further, the recorded EC and pH data of soil and ground water during pre-Tsunami periods were compared with the collected data and generated variability soil maps of EC and pH of the post-Tsunami period. It was revealed from this analysis that the soil quality six months after the Tsunami was nearing the pre-Tsunami scenario (EC< 1.5dSm(-1); pH<8), whereas the quality of ground water remained highly saline and unfit for irrigation and drinking. These observations were compared with the ground scenarios of the study region and possible causes for such changes and the remedial measures for taking up regular agricultural practices are also discussed.  相似文献   

13.
It is increasingly clear that a wide range of stakeholders should be included in the problem formulation phase of research aimed at solving environmental problems; indeed the inclusion of stakeholders at this stage has been formalized as an integral part of ecological risk assessment. In this paper, we advocate the additional inclusion of stakeholders in the refinement of research methods and protocols and in the execution of the research, rather than just at the final communication and reporting phase. We use a large study of potential radionuclide levels in marine biota around Amchitka Island as a case study. Amchitka Island, in the Aleutian Island Chain of Alaska, was the site of three underground nuclear tests (1965-1971). The overall objective of the biological component of the study was to collect a range of marine biota for radionuclide analysis that could provide data for assessing current food safety and provide a baseline for developing a plan to monitor human and ecosystem health in perpetuity. Stakeholders, including regulators (State of Alaska), resource trustees (US Fish and Wildlife Service, State of Alaska), representatives of the Aleut and Pribilof Island communities, the Department of Energy (DOE), and others, were essential for plan development. While these stakeholders were included in the initial problem formulation and approved science plan, we also included them in the refinement of protocols, selection of bioindicators, selection of a reference site, choice of methods of collection, and in the execution of the study itself. Meetings with stakeholders resulted in adding (or deleting) bioindicator species and tissues, prioritizing target species, refining sampling methods, and recruiting collection personnel. Some species were added because they were important subsistence foods for the Aleuts, and others were added because they were ecological equivalents to replace species deleted because of low population numbers. Two major refinements that changed the research thrust were (1) the inclusion of Aleut hunters and fishers on the biological expedition itself to ensure that subsistence foods and methods were represented, and (2) the addition of a fisheries biologist on a NOAA research trawler to allow sampling of commercial fishes. Although the original research design called for the collection of biota by Aleut subsistence fishermen, and by a commercial fishing boat, the research was modified with continued stakeholder input to actually include Aleuts and a fisheries biologist on the expeditions to ensure their representation. The inclusion of stakeholders during the development of protocols and the research itself improved the overall quality of the investigation, while making it more relevant to the interested and affected parties. Final responsibility for the design and execution of the research and radionuclide analysis rested with the researchers, but the process of stakeholder inclusion made the research more valuable as a source of credible information and for public policy decisions.  相似文献   

14.
This paper presents results from research that identified and analysed barriers to accessing British woodlands and forests. This paper aims to contribute to an understanding of access and accessibility and to inform the design of policy and management interventions to encourage increased access by under-represented social groups. A brief review of policy and academic literature places the issue of inclusive woodland and forest access in the context of contemporary debates surrounding public health, well-being, diversity and the perceived role of public green space. There follows an analysis of quantitative and qualitative research findings, informing the presentation of a working typology of barriers. The typology is structured around the access needs of various social groups, allowing an analysis of the social distribution of barriers. The findings indicate the deep-seated psychological, emotional and socio-cultural nature of some barriers and highlight the need for carefully designed interventions that may lie outside the conventional remit of woodland management. This paper will be of particular interest to decision-makers and practitioners and to those involved in the design and delivery of policies, programmes and projects aimed at encouraging inclusive use of woodlands, forests and other types of green space.  相似文献   

15.
以协商的方式确定水污染物间接排放标准的规定打破了人们对标准确定性、强制性的传统认识。协定标准的优势在于充分利用污水处理厂的污水处理能力,减轻企业的污水处理负担,使企业可以集中力量搞生产。协定标准具有灵活性和优越性,应充分利用。通过对协定标准概念和重要性的分析,指出协定标准存在效力不确定、缺少对协定范围的限制等问题,造成协定标准在实践中通常被忽视或者滥用。并从明确协定标准的范围、加强排污企业的管理和协定标准的监督等方面,进一步提出了限制和完善水污染物间接排放标准的建议。  相似文献   

16.
BioScene (scenarios for reconciling biodiversity conservation with declining agriculture use in mountain areas in Europe) was a three-year project (2002–2005) funded by the European Union’s Fifth Framework Programme, and aimed to investigate the implications of agricultural restructuring and decline for biodiversity conservation in the mountain areas of Europe. The research took a case study approach to the analysis of the biodiversity processes and outcomes of different scenarios of agri-environmental change in six countries (France, Greece, Norway, Slovakia, Switzerland, and the United Kingdom) covering the major biogeographical regions of Europe. The project was coordinated by Imperial College London, and each study area had a multidisciplinary team including ecologists and social and economic experts, which sought a comprehensive understanding of the drivers for change and their implications for sustainability. A key component was the sustainability assessment (SA) of the alternative scenarios. This article discusses the development and application of the SA methodology developed for BioScene. While the methodology was objectives-led, it was also strongly grounded in baseline ecological and socio-economic data. This article also describes the engagement of stakeholder panels in each study area and the use of causal chain analysis for understanding the likely implications for land use and biodiversity of strategic drivers of change under alternative scenarios for agriculture and rural policy and for biodiversity management. Finally, this article draws conclusions for the application of SA more widely, its use with scenarios, and the benefits of stakeholder engagement in the SA process.  相似文献   

17.
The functions of packaging are derived from product requirements, thus for insight into the environmental effects of packaging the actual combination of product and package has to be evaluated along the production and distribution system. This extension to all related environmental aspects adds realism to the environmental analysis and provides guidance for design while preventing a too detailed investigation of parts of the production system. This approach is contrary to current environmental studies where packaging is always treated as an independent object, neglecting the more important environmental effects of the product that are influenced by packaging. The general analysis and quantification stages for this approach are described, and the currently available methods for the assessment of environmental effects are reviewed. To limit the workload involved in an environmental assessment, a step-by-step analysis and the use of feedback is recommended. First the dominant environmental effects of a particular product and its production and distribution are estimated. Then, on the basis of these preliminary results, the appropriate system boundaries are chosen and the need for further or more detailed environmental analysis is determined. For typical food and drink applications, the effect of different system boundaries on the outcome of environmental assessments and the advantage of the step-by-step analysis of the food supply system is shown. It appears that, depending on the consumer group, different advice for reduction of environmental effects has to be given. Furthermore, because of interrelated environmental effects of the food supply system, the continuing quest for more detailed and accurate analysis of the package components is not necessary for improved management of the environmental effects of packaging.  相似文献   

18.
Caves can be difficult to navigate and often require physical modification to allow easy access for visitors. Single entrance caves double the access impact of each visitor. Visitors in tourist caves have direct physical effects such as the introduction of concrete and steel structures; transport of mud, dust, and nutrients; installation of lights and the exhalation of water vapour and carbon dioxide into the air. Indirect physical effects include alteration of the microclimate, both through physical modifications that change the ventilation regime and through the presence of visitors leading to changes in temperature, humidity and CO2 within the cave environment. Anthropomorphic changes to cave physical environments to aid access or to reduce backtracking can have adverse effects on the internal microclimate of cave systems with subsequent changes to the cave environment affecting the quality of decorations and cave art and the diversity of cave fauna. Although often stated that caves operate at or near a constant temperature, closer examination indicates that cave temperatures are neither static nor constant. The degree of variation depends largely on the structure and physical characteristics of the cave. Air temperature and humidity gradients between the inside and outside cave environment can result in air density differences, which create airflow, which will in turn affect the cave microclimate. As part of the development of a management framework for King Solomons Cave, Tasmania, a study of the microclimate was carried out on behalf of Tasmanian Parks and Wildlife Service. Analysis of the variables showed significant differences in air temperature within each site and between sites. These differences range from 4 degrees C variation at one site to 0 degrees C at another site. The data were used to model potential airflow between the cave and the external environment. Results indicate that part of the cave is dominated by airflow between the chimney and the cave entrance leading to microclimatic fluctuations, while stable climatic conditions occur at the end of the cave. Future management strategies that propose a passage from the chamber to the surface via the current end zone would create a potential for airflow induced microclimatic change, leading to a change in both the temperature and moisture regimes, necessitating the construction of an airtight double door system.  相似文献   

19.
20.
The Groundwater Protection Project at the US Department of Energy Hanford Site in Washington State is currently developing the means to assess the cumulative impact to human and ecological health and the regional economy and cultures from radioactive and chemical waste that will remain at the Hanford Site after the site closes. This integrated system is known as the System Assessment Capability (SAC). The SAC Risk/Impact Module discussed in the article uses media- and time-specific concentrations of contaminants estimated by the transport models of the integrated system to project potential impacts on the ecology of the Columbia River corridor, the health of persons who might live in or use the corridor or the upland Hanford environment, the local economy, and cultural resources. Preliminary Monte Carlo realizations from the SAC modeling system demonstrate the feasibility of large-scale uncertainty analysis of the complex relationships in the environmental transport of contaminants on the one hand and ecological, human, cultural, and economic risk on the other. Initial impact results show very small long-term risks for the 10 radionuclides and chemicals evaluated. The analysis also helps determine science priorities to reduce uncertainty and suggests what actions matter to reduce risks.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号