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1.
<正>当我们在黄河首曲湿地深入一家家牧户,与牧民们直接交谈时,才知道这里人畜饮水正在出现危机!原本是对这片水源涵养地的考察,变成了一次水危机的发现。  相似文献   

2.
一边是水资源的严重短缺,一边是干旱导致的农业减产,无疑使世界粮食危机雪上加霜。水资源正成为世界多数国家制约农业发展的重要因素,培育“不怕渴”农作物品种成为摆在世界育种学家面前的共同难题,也是节水农业中最有效的技术手段。  相似文献   

3.
一边是水资源的严重短缺,一边是干旱导致的农业减产,无疑使世界粮食危机雪上加霜。水资源正成为世界多数国家制约农业发展的重要因素,培育“不怕渴”农作物品种成为摆在世界育种学家面前的共同难题,也是节水农业中最有效的技术手段。  相似文献   

4.
我国水资源生态足迹分析与预测   总被引:28,自引:0,他引:28  
谭秀娟  郑钦玉 《生态学报》2009,29(7):3559-3568
生态足迹模型的提出为水资源可持续利用的定量评价提供了新思路.通过构建水资源生态足迹和水资源生态承载力的计算模型,对我国1949~2007年水资源的可持续利用状况作出了客观的评价,并运用ARIMA模型对我国水资源生态足迹变动趋势作出深入的研究.结果表明,1949~2007年,我国人均水资源生态承载力总体上呈下降态势,而人均水资源生态足迹则逐年上升,从而造成人均水资源生态赤字逐渐增大,我国水资源处于一种不安全状态.运用ARIMA(2,1,3)模型的预测结果表明,2008~2012年,我国人均水资源生态足迹将继续呈上升态势,水危机形势将日益严峻.在此基础上,针对我国水资源的可持续利用问题提出了一组政策建议.  相似文献   

5.
从第二届世界水资源论坛看辽宁的水资源危机及对策   总被引:11,自引:2,他引:11  
辽宁是我国重要的工业省份 ,境内分布着我国三大城市群之一 ,农业也很发达 ,工农业生产、城市建设和居民生活对水资源的需求量都很大。本文根据第二届世界水资源大会有关会议资料[4 ] 及后续影响 ,从世界范围内水资源的分布、取用和污染现状与发展趋势[6,9] ,对辽宁省水资源危机进行分析 ,对其今后宜采取的有效措施进行建议与论证。1 第二届世界水资源论坛的简要回顾“第二届世界水资源论坛”是 2 0世纪末和 2 1世纪初水资源领域一次最重要的会议。在世界水资源委员会的组织下 ,在荷兰交通与公共事务及水资源管理部、荷兰住房与空间规划及…  相似文献   

6.
两度普利策奖得主、克拉夫特奖获得者——爱德华·威尔逊,总结他的成就,对于我们是一件“自不量力”的事——一切过往的争论都显露出他看待世界的独特视角及其不断革新理论的活力。2012年5月,83岁高龄的威尔逊出版的新书《社会性征服地球》又一次引起了激烈的争论,而这,相比威尔逊之前遭遇过的两次巨大危机。  相似文献   

7.
从第二届世界水资源论坛看辽宁的水资源危机及对策   总被引:11,自引:1,他引:10  
辽宁是我国重要的工业省份,境内分布着我国三大城市群之一,农业也很发达,工农业生产、城市建设和居民生活对水资源的需求量都很大.本文根据第二届世界水资源大会有关会议资料[4]及后续影响,从世界范围内水资源的分布、取用和污染现状与发展趋势[6,9],对辽宁省水资源危机进行分析,对其今后宜采取的有效措施进行建议与论证.  相似文献   

8.
在大多数人的眼中,吃饭是再自然不过的事情。如果有人告诉你,世界粮食危机正伴着全球经济衰退的浪潮悄然而至,你能够意识到这意味着什么吗?环顾我们身处的世界,粮食价格高居不下,饥饿人口有增无减,粮食供需持续处于紧平衡状态……发达国家拉响警钟,欠发达国家和地区已频频亮起粮食安全的红灯。2008年,在罗马召开的世界粮食峰会上,  相似文献   

9.
植物水分利用效率和半干旱地区农业用水   总被引:87,自引:1,他引:86  
干旱是一个全球性问题,人类面临的第一个生态问题就是水分不足。减少农业生产中水的需求量成为一个国际目标,我国的情况尤为严峻。我国水资源总量虽居世界第六位[1],但人均占有量仅为2400m3,相当于世界平均数的1/4,且时空分布不均。长江以北地区耕地面积占全国的64%.而水资源不足18%。我国的灌溉面积已达7.2亿亩,居世界首位,但灌溉水浪费严重,其利用系数只有0.5,致使整个农业用水量占到总用水量的85%,而一些发达国家仅占到50%左右。由于水资源短缺和生态环境恶化,1959年以来全国平均每年受旱面积呈增大趋势,在占国土面积…  相似文献   

10.
走进衡水湖,我们发现它的困境折射出整个华北地区水的危机,它的出路呼唤人对水的态度的根本转变。所庆幸的是国家政策正在由过去的“征服自然,充分开发利用水资源”,向“人类与自然和谐发展,合理共享水资源”转变。在此背景下我们请专家来和我们一起对衡水湖作了一次回顾和展望。[编者按]  相似文献   

11.
孟祥明  任东  刘明  梁军辉 《昆虫知识》2006,43(1):134-138
古昆虫学研究始于200年前。此后,该学科不断发展,不断提高。依据研究方法及综合水平的不同,可将其发展历程划分为6个部分:朴素的萌芽和学科的诞生、基础分类研究、归纳总结研究、系统发育学研究、古环境古生态及古地理的研究、化石昆虫与其他物种相互作用的研究。文章简要介绍了上述各部分,并作了简评。  相似文献   

12.
王玉  温福岳  陈利君  陈庭 《广西植物》2018,38(7):960-968
该文综述了指甲兰属种质资源的历史、地理分布概况和保护现状,以及该属植物在组织培养、药用价值及化学成分分析、香味成分研究与种系发生等领域的国内外研究成果,并对该属植物在未来的研究重点进行了探讨和分析。结果表明:指甲兰属植物是热带地区重要的花卉,具有极高的观赏价值和药用价值,通过有效地保护和利用好该属资源,并在多个学术领域内开展该属植物研究,不仅可以为相关研究提供技术参考和理论支持,而且能够充分挖掘其应用价值。然而,国内外在相关领域的各项研究进展还不够深入,未来指甲兰属植物应加强以下方面的研究:(1)开展资源引种与回归保育等方面的实践工作及研究;(2)利用稀缺资源和母本优势,开展组织培养与属间品种培育方面的研究;(3)充分发掘其药用价值,积极开展植物化学成分方面的研究;(4)开展指甲兰属香味成分分析与应用研究,进而开展该属传粉生物学的研究;(5)利用分子生物学领域的最新技术和方法,揭示出该属在相关类群中的地位和其界定范围。  相似文献   

13.
  1. In many countries, more resources are required for the conservation of threatened species than are made available. Australia, the home to many unique mammalian species, has been identified as one of the top seven countries worldwide with the highest biodiversity loss and lowest amount of funding dedicated to conservation. Conservation action is generally determined by what we perceive to be the most significant conservation problems; therefore, identifying potential biases in research effort is crucial for prioritising research actions for effective conservation outcomes.
  2. We reviewed the published literature on the koala Phascolarctos cinereus, a vulnerable arboreal marsupial. Our aim was to assess and quantify research efforts (number of publications) and research coverage (diversity of subject areas) of koala‐related research. We then focused on the research effort of threats to identify primary threats and fields requiring further research.
  3. Using a combination of key words, journal name, study title, and methods, we reviewed and categorised 714 publications to identify the focus of research efforts. We investigated subject area, geographic and temporal publication patterns, and the extent to which primary threats have been addressed.
  4. We found a trend of increasing number of publications with a diversification of threat‐based studies, and identified both geographic and subject bias in research effort. Geographic bias in the volume of research indicates that the level of koala research between regions may be a response to the species’ distribution, status and impact of threats. Research areas ‘anatomy and physiology’ and ‘threats’ received comparatively more research attention than other areas. We found a research bias between threats, with ‘disease’ representing a high percentage of all threat‐based publications. Areas that have been identified but are receiving little research attention include habitat selection and use, along with the effects of habitat loss, fragmentation, and degradation.
  相似文献   

14.
  1. Basic knowledge on the biology and ecology of a species is fundamental for the realistic assessment of its conservation status and for planning effective conservation strategies. The latest assessment of the 21 extant armadillo species (Xenarthra, Dasypodidae) by the International Union for Conservation of Nature (IUCN) for its Red List of Threatened Species shows that considerable gaps exist in our knowledge of these Neotropical mammals.
  2. Our goal was to analyse the existing literature on armadillos to define thematic and regional research priorities that will eventually benefit their conservation.
  3. We categorized 3117 publications on extant armadillos published between 1660 and 2011 according to their research topic, species studied, country and publication language.
  4. The number of publications per research topic and the number per species were very variable. The nine best‐studied species are classed as Least Concern by the IUCN, while three of the four least‐studied species are classed as Data Deficient. At least one field study was done in each range country, but over 80% of field research took place in the USA, Brazil, Argentina and Bolivia. Most research was done in the USA on leprosy in Dasypus novemcinctus. Most ecological research has been focused on four species, and data on the ecology of Data Deficient and Vulnerable taxa are virtually absent.
  5. Field research on armadillos should be intensified to broaden conservation‐relevant knowledge. Additional studies in the Guianas, Peru, Ecuador, Colombia, Venezuela and Paraguay are urgently needed to assess the conservation status of armadillos in these regions. Future research should focus on ecology, conservation, population genetics, reproduction and threats. Species priorities should include country endemics, such as Dasypus pilosus (Peru), Tolypeutes tricinctus (Brazil) and Dasypus yepesi and Chlamyphorus truncatus (Argentina), as well as other Data Deficient and Vulnerable species, especially Cabassous centralis and Calyptophractus retusus.
  相似文献   

15.
It is not yet clear what mental disorders are and what are the causal pathways that lead to them. That makes it difficult to decide what the targets and outcomes of psychotherapies should be. In this paper, the main types of targets and outcomes of psychotherapies are described, and a brief overview is provided of some of the main results of research on these types. These include symptom reduction, personal targets and outcomes from the patient's perspective, improvement of quality of life, intermediate outcomes depending on the theoretical framework of the therapist, negative outcomes to be avoided, and economic outcomes. In line with the dominance of the DSM and ICD systems for diagnoses, most research has been focused on symptom reduction. This considerable body of research, with hundreds of randomized trials, has shown that for most mental disorders effective psychotherapies are available. There is also research showing that psychotherapies can result in improvement of quality of life in most mental disorders. However, relatively little research is available on patient‐defined outcomes, intermediate outcomes, negative outcomes and economic outcomes. Patients, relatives, therapists, employers, health care providers and society at large each have their own perspectives on targets and outcomes of psychotherapies. The perspective of patients should have more priority in research, and a standardization of outcome measures across trials is much needed.  相似文献   

16.
中国园林生态学发展综述   总被引:2,自引:0,他引:2       下载免费PDF全文
于艺婧  马锦义  袁韵珏 《生态学报》2013,33(9):2665-2675
运用文献计量等方法对已有科研成果进行统计分析,结果表明:中国近50年园林生态学科领域科研发展经过了起步探索(1962-1981)、缓慢发展(1982-2001)、快速发展(2002-2011)3个时期,园林生态学作为生态学一个新的分支学科,于20世纪90年代末初见端倪,作为一门新兴独立的应用生态学分支学科于21世纪初已基本形成.中国园林生态学领域的研究包括园林生态系统中生物与环境相互作用关系问题、人与环境相互作用关系问题以及园林生态系统与其他生态系统之间相互作用关系问题.当代园林生态研究主要有生态效益研究、生物与环境研究、人的需求与行为研究、生态规划与生态管理研究4个方面,目前园林生态学研究主要侧重生物与环境研究和生态效益研究,两方面的研究成果占总体研究成果的76.3%.不同研究方面也有各自的侧重点,如生物与环境研究侧重对植物的研究,生态效益研究侧重净化环境、水土保持和防灾减灾,生态规划与生态管理研究则侧重生态规划与设计.对四个研究方面的论文主题词检索和高频主题关键词的分布进行统计,结果显示,研究的热点有多样性、群落、水土保持、防灾避险、净化环境、生态规划与设计等.对CNKI中4个研究方面成果中获基金资助项目论文进行统计(不排重),总体成果中基金项目论文所占比重为10.8%,国家和地方基金是园林生态学科研基金资助的主要来源,基金论文比例之和达到85.4%,且国家和地方基金资助论文较多的是“生态与环境研究”和“生态效益研究”,合计占基金论文79.1%.SCI-E中收录的文献基金论文率为47.1%,是CNKI数据库收录的文献基金论文率的4.3倍,且国际基金是基金论文的主要资助来源之一,说明中国园林生态学领域部分科研成果得到国际学界关注.基于CNKI相关主题词统计,“园林生态学”的研究成果只有“景观生态学”的1%,“城市生态学”的8.3%,“园林生态学”学科系统理论研究在相关生态学科研究中所占比重很低,其理论和方法研究还较薄弱.今后在进一步完善学科理论体系、持续开展生态效益和园林植物研究的同时,为更好地研究和解决人-自然复合生态系统问题,提供更多的科学理论支撑,还需拓展交叉生态心理学或环境心理学等其他相关理论,更多地关注人与环境互相作用关系以及生态规划与生态管理等方面的研究,既使环境更好地满足人的行为需求,也使人认识到改变一些行为能更好地保护环境.  相似文献   

17.
【背景】面对全球气候变暖,土壤微生物在陆地生态系统对全球变暖反馈中起到了至关重要的作用。【目的】了解土壤微生物对气候变暖响应研究的发展现状、研究热点及前沿动态,厘清当前该研究领域的知识结构关系。【方法】以1999-2021年Web of Science核心数据库中土壤微生物对气候变暖响应研究已发表的3 189篇论文为数据源,利用Vosviewer和CiteSpace软件对年发文量、文献被引频次、作者、机构、国家、学科和关键词等进行可视化分析。【结果】研究总体呈逐步增长趋势,经历缓慢增长、稳步增长和高速增长3个阶段;高被引论文均发表在国际顶级期刊上,研究成果具有较高的学术影响力。在学科融合与合作交流方面,环境科学、生态学和土壤学是该研究领域的主要学科,而多学科交叉学在该领域占有重要地位;作者骆亦其、Schuur和周集中是该领域核心学者,作者之间的合作关系主要以同一研究团队内部合作为主;主要的科研机构有中国科学院、加利福尼亚大学和美国能源部,各科研机构之间合作较为紧密;中国、美国和欧洲是土壤微生物对气候变暖响应研究领域的主要力量,国家之间相互合作程度高。该领域的主要研究热点是气候变暖改变了土壤微生物的群落结构组成、多样性和生理生化功能,进而对地球化学物质循环产生影响;土壤微生物在土壤碳库释放中的作用机理和调控机制是该领域研究前沿。【结论】目前,不同生态系统研究中土壤微生物对增温的响应与适应机制存在着差异,而且对微生物碳功能基因和多环境交互因子的研究较少。因此,建议后期应更加聚焦特定生态系统的细化研究,开展大范围、大尺度、长时期的定位研究,加强对微生物碳降解和碳固定功能基因的研究,多关注环境因子变化的交互作用对土壤微生物生态过程的影响。  相似文献   

18.
柯丽娜  阴曙升  刘万波 《生态学报》2018,38(15):5602-5610
以CNKI和CSSCI数据库中1980—2017年的1779篇文献为原始数据,基于文献计量分析方法和文献可视化工具,对海洋生态经济领域的研究成果进行信息挖掘。研究发现:(1)海洋生态经济的研究始于1982年,2009年论文发表数量激增成为学术界的研究热点。(2)狄乾斌、高强、殷克东等在海洋生态经济方面做出了大量研究,中国海洋大学、国家海洋局和辽宁师范大学为主要研究机构,研究机构之间合作联系主要以部门和地域联系为主,跨区域和跨部门的合作有待增强。(3)海洋生态经济的研究热点指向"蓝色经济"、"海洋生态系统协调"、"人海可持续发展"等方向。(4)海洋生态经济研究的综合性不断增强,《海洋开发与管理》是海洋生态经济研究刊文量最多的期刊。  相似文献   

19.
  1. Evidence‐based knowledge is critical for the delineation and success of conservation interventions. However, despite limited research resources, research efforts frequently fail to target conservation priorities. Island endemic bats (IEBs) are a poorly studied group inhabiting some of the world's most vulnerable habitats, and for which no review of research allocation has ever been conducted.
  2. We conducted a bibliometric review to evaluate the global research patterns for IEBs with respect to individual species, geographical distribution and the International Union for Conservation of Nature (IUCN) Red List categories. Additionally, we studied the relationship between the number of publications and changes in Red List category, and identified species‐based and area‐based priorities for future research.
  3. IEBs are significantly more threatened than bat species that are not island endemics. However, research focusing on IEBs is scarce, centred on species of lesser conservation concern, and spatially asymmetric, overlooking areas of high IEB biodiversity. Conservation‐oriented research seems to target species facing high extinction risk, but is extremely thinly and unevenly distributed. Although we found a positive association between research effort and improvement in Red List category, an increase in extinction risk did not trigger more scientific attention. A prioritisation analysis highlighted, as the top five islands for species richness in the least‐studied and highest conservation concern IEBs: Sulawesi, Timor, New Guinea, Java, and Borneo. The ten species of highest research priority include threatened and Data Deficient species from Southeast Asian and Pacific islands.
  4. Conservation‐oriented research seems to be too scarce to satisfy conservation needs. The observed mismatch between research allocation and conservation priorities may reflect the fact that highly endangered species are unattractive targets for fund‐raising, due to species crypticity, high research budget requirements, and high risk of project failure. However, our findings support the importance of research for the conservation of IEBs, and we therefore advocate that more attention is directed towards the least‐known species.
  相似文献   

20.

Background

Citation analysis has become an important tool for research performance assessment in the medical sciences. However, different areas of medical research may have considerably different citation practices, even within the same medical field. Because of this, it is unclear to what extent citation-based bibliometric indicators allow for valid comparisons between research units active in different areas of medical research.

Methodology

A visualization methodology is introduced that reveals differences in citation practices between medical research areas. The methodology extracts terms from the titles and abstracts of a large collection of publications and uses these terms to visualize the structure of a medical field and to indicate how research areas within this field differ from each other in their average citation impact.

Results

Visualizations are provided for 32 medical fields, defined based on journal subject categories in the Web of Science database. The analysis focuses on three fields: Cardiac & cardiovascular systems, Clinical neurology, and Surgery. In each of these fields, there turn out to be large differences in citation practices between research areas. Low-impact research areas tend to focus on clinical intervention research, while high-impact research areas are often more oriented on basic and diagnostic research.

Conclusions

Popular bibliometric indicators, such as the h-index and the impact factor, do not correct for differences in citation practices between medical fields. These indicators therefore cannot be used to make accurate between-field comparisons. More sophisticated bibliometric indicators do correct for field differences but still fail to take into account within-field heterogeneity in citation practices. As a consequence, the citation impact of clinical intervention research may be substantially underestimated in comparison with basic and diagnostic research.  相似文献   

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