加拿大矿产资源与开发

加拿大矿产资源在世界上占有重要地位,许多矿产的储量居世界前列,其中居世界第1位的有铟、钾盐、硫;第2位的有石油、铌、钨、石棉;第3位的有铀、镉、硒;第4位的有镍、铅、铂族金属、钼、钽;第6位的有金刚石、锌、金;第7位的有银、钛;第10位的有煤;第12位的有铜;第13位的有铁矿石。加拿大的采矿业十分发达,是世界最大的矿业国之一。2003年加拿大的铀和钾盐的产量居世界第一,钴产量居世界第二位,钛精矿、镍、铝、石膏和铂族金属产量居世界第三位。产量位居世界前五位的其他矿产品还有石棉、锌、35镉、钼、盐。加拿大是世界最大的矿产品出口国,…     

加强湿地保护管理工作确保湿地健康持续发展

<正>我国是个湿地大国,湿地资源约占世界总量的10%.居世界第4位,亚洲第1位。随着人们对湿地生态系统重要性认识的不断提高,加强湿地保护管理工作显得越来越迫切。党中央、国务院对湿地保护工作高度重视.2002年.江泽民同志曾经指出,加强湿地保护刻     

留一片绿洲 此处肾好

<正>2015年4月14日中国湿地保护协会成立,湿地再一次进入了人们的视野。我国湿地面积6 600万hm2,占世界湿地面积的10%,位居亚洲第1位,世界第4位。自我国改革开放以来,大量湿地被改造成农田,加上过度的资源开发和污染,湿地面积大幅度缩小,湿地生境受到严重破坏。近10年来我国湿地面积减少了339.63万hm2,其中自然湿地面积减少了337.62万hm2,减少率为9.33%,这相当于300万个足球场。此外,     

科技支撑在我国野生动植物保护及自然保护区建设工程中的作用

<正> 我国是世界上生物多样性最为丰富的国家之一,约有脊椎动物6266种,约占世界脊椎动物种类的10％。我国约有30000多种植物,仅次于世界植物最丰富的马来西亚和巴西,居世界第三位。大熊猫、朱鹮、华南虎、藏羚羊和水杉、珙桐等均是我国特有的珍稀濒危野生动物和植物。我国天然湿地面积2600多万公顷,其中内陆和海岸湿地堪称亚洲之     

近几年我国林学科技论文呈现平稳发展态势

<正> 科技论文是衡量一国科技竞争力的重要标志,是提高原始创新能力的基础。我国科技论文数在世界上所处的位次,1996年第11位,1997、1998年均为第9位,1999、2000年为第8位,2001年上升到第6位,增长保持强劲势头,标志着我国科学技术产出达到了一个较高水平,科技创新能力和国际竞争力跃上了一个新台阶。     

钨矿简史

从1783年西班牙首次用炭从黑钨矿中提取了金属钨至今已有200余年的钨矿开发、冶炼、加工历史. 中国对世界钨业发展做出了举世瞩目的贡献.我国钨矿于1907年发现于江西省大余县西华山,钨矿开采始于1915～ 1916年(据《中国矿床发现史·江西卷》,1996年).此后在南岭地区相继发现不少钨矿区,生产不断扩大,至第一次世界大战末期,钨精矿产量达到万吨,跃居世界钨精矿产量首位,至今仍居世界第1位.     

我国清末中小学地理教科书内容结构研究

清末地理教科书的内容结构反映当时西方近代地理学对我国地理教科书编写的影响以及我国地理教科书从古代向近代的转变;在系统地理方面,大致为数理地理、地文学和政治地理的结构;在世界和中国区域地理方面,以乡土地理——中国地理——世界地理的结构为主;既遵循清政府的学堂章程,借鉴国外经验,又融入编者个人观点;有发展初期的无序和庞杂之嫌,也有多样化和善于吸收他人先进经验的特点。     

关于实现我国水资源持续利用的思考

<正> 水是人类赖以生存和发展不可替代的资源,是经济和社会可持续发展的基础。当前,水资源匮乏已成为全球共同关注的热点问题之一。我国是一个水资源短缺,而且在时间和地区分布上极不均匀的国家。我国淡水资源总量为2.8万亿立方米,列世界第6位,     

资料集锦

中国占世界人口比重降至19%国家人口和计划生育委员会主任李斌11日在"7?11世界人口日"纪念大会上表示,中国占世界人口的比重从改革开放初期的22%下降至2010年的19%。李斌在会上说,中国的婴儿死亡率、孕产妇死亡率等指标均处于发展中国家最好水平。与改革开放初期相比,人口平均预期寿命从68岁提高到73.5岁,达到中等发达国家水平;人类发展指数从0.53上升到0.66,是     

中国国家竞争力升至第17位

中国社会科学院城市与竞争力研究中心昨天在京发布《国家竞争力蓝皮书》。蓝皮书指出,过去20年间,中国的国家竞争力发生了显著变化。在全球100个国家中,中国的排名从1990年的第73位跃升至目前的第17位。     

为对抗世界沙漠化培养人才的继续教育

沙漠化已是世界性的严重生态环境问题。沙漠化土地的整治是一门复杂的生态环境工程学科。中国沙漠化治理的成就和经验受到国际社会的重视, 中国科学院兰州沙漠研究所受国际组织委托为发展中国家举办了七期国际沙漠化治理讲习班, 取得了很好效果。当前发展中国家更需要对抗沙漠化的人才, 因此为对抗世界沙漠化培养人才的继续教育工程是当前一项迫切的任务, 期望得到国际社会的重视和支持。     

Using Digital Earth to Expose Students to GIScience

Students in U.S. geography programs face particular challenges that may discourage them from taking advanced GIScience courses and considering geospatial careers. This article provides a preliminary discussion of the development, delivery, and evaluation of a University of Colorado Colorado Springs sophomore-level, required geography course designed to address this concern. The course, Digital Earth (DE), introduces students to the principles, concepts, and applications of major geographic information technologies (GITs) early in their academic careers. The success of DE is evaluated by examining the extent to which the course excited students about GIScience and motivated them to take higher level elective geospatial courses. Results suggest that DE generates considerable student interest in GIScience, prepares students reasonably well for elective courses, and greatly inspires them to seek a geospatial career.     

Converting Brazil's pastures to cropland: An alternative way to meet sugarcane demand and to spare forestlands

Brazil seeks to rapidly increase its agricultural production to meet future demands, especially for sugarcane, which is an agricultural commodity and a biofuel source. In this paper, we explore how to achieve this increase without compromising existing forestlands. We propose that it is possible to substantially expand sugarcane production in Brazil while avoiding further environmental losses and the indirect land use changes often associated with them, such as deforestation. This task could be accomplished by converting existing pasturelands with agricultural potential into cropland. A great deal of pastureland exists in Brazil. Thus, we addressed the following questions in this study: (1) where are the most suitable pasturelands for sugarcane located geographically and (2) what potential do these pasturelands have for sugarcane production regarding their physical suitability and other significant factors, such as infrastructure availability and socioeconomic factors. We conducted a land suitability analysis using a spatial location model based on multicriteria decision-making and geographic information systems (GIS) to identify the cultivated pasturelands most suitable for conversion to sugarcane production in Brazil. “What if” scenarios were built to determine how changes in the subjectively derived weights of the priority criteria would modify the spatial distribution of the suitability classes relative to the MCDA model and demonstrate the robustness of the crop suitability assessment. The most suitable pastureland areas for conversion to sugarcane production were predominantly located in Minas Gerais, São Paulo, Paraná, Goiás, Mato Grosso do Sul, Mato Grosso and Pará. These zones have large contiguous areas of pasture with moderate and high agricultural potentials for sugarcane production. The total estimated area of cultivated pasturelands with moderate or high suitability for sugarcane production was 50 million hectares, which is much larger than the area currently used for sugarcane production in Brazil.     

A path that buys time to decide where to go

This paper considers the problem of planning a path in a circumstance where its origin is given, but its destination is not specified and is to be selected from among a set of candidate destinations during a trip. A situation like this may be experienced by a group of people who have different preferred destinations, as well as by an individual who is simply indecisive about where to go. To resolve such an uncertainty, one may stay at the origin until he decides on a destination, or choose to proceed on some path that does not overly deviate from a shortest path, whichever destination is eventually chosen, and make a decision on the way. The latter action is sensible when the risk of traveling longer is outweighed by the benefit of buying more time for a better destination decision. The problem of finding such a time-buying path is formulated and a simple algorithm is developed for its solution. Some extensions and applications are also discussed.     

Instructions to Authors

正1 About JoRE1.1 Aims and scope?Journal of Resources and Ecology(JoRE)is an international journal for the publication of recent work across the fields of natural resources science and ecology.JoRE was established in 2010 and is published quarterly.It will be published bimonthly from 2015 on.?The journal is indexed by BioOne,Chinese Science Citation Database(CSCD),China Academic Journal Network Publishing Database,Chinese Academic Journal Comprehensive Evaluation Database and Wanfang Data Digital Periodicals.     

Guidelines to Authors

1. Aims and scope
Sciences in Cold and Arid Regions （SCAR） is a bimonthly journal that publishes in English the latest research achievements in processes and the pattems of the Earth surface system in cold and arid regions. Researches in cold regions emphasize particularly on the cold-region-characterized physical,