Distribution patterns of soil lichens across the principal biomes of southern Africa     

L. Zedda  A. GröngröftM. Schultz  A. PetersenA. Mills  G. Rambold 《Journal of Arid Environments》2011,75(2):215-220

The present study was undertaken to assess baseline distribution patterns for soil lichens occurring in the principal biomes of southern Africa, and to analyse their relationship to selected environmental parameters. Among the lichen species found across our survey sites, four distinct groups could be delineated, each as distinct consortium of lichen species sharing particular morphological characters (e.g. growth-form, pigmentation and type of photobiont kind). These groups are largely correlated with specific environmental parameters. These findings suggest that lichens may serve as valuable bioindicators for evaluating climate and soil change in this region of Africa.  相似文献   

Characteristics of Australian droughts under enhanced greenhouse conditions: Results from 14 global climate models   总被引：3，自引：0，他引：3  

D.G.C. Kirono  D.M. KentK.J. Hennessy  F. Mpelasoka 《Journal of Arid Environments》2011,75(6):566-575

This paper presents characteristics of droughts simulated by global climate models (GCMs) under enhanced greenhouse gases conditions. We used a drought index called the Reconnaissance Drought Index (RDI) which takes both rainfall and potential evapotranspiration into account to investigate variations of droughts among 12 regions in Australia. The RDI was applied to simulated climate variables from 14 GCMs performed for the IPCC 4th Assessment Report.The results show a general increase in drought areal extent and/or frequency for most regions. However, the increases are not significant over the North West, North Queensland, Queensland East Coast and Central Queensland. For most regions, the change beyond 2030 is larger than that prior to 2030, but the uncertainty in the projections also increases with time. By 2030, there is a likely (>66% probability) risk of twice or more drought affected area and/or twice as often drought frequency over South West Western Australia. By 2050, this will include the Murray-Darling Basin, South Australia and Victoria, and by 2070 this will extend to New South Wales and Tasmania. For North Queensland such a risk is unlikely (<33% probability) for the next 100 years. This information can be considered indicative in long-term planning focussing on sustainability.  相似文献   

Recent trends of temperature change under hot and cold desert climates: Comparing the Sahara (Libya) and Central Asia (Xinjiang, China)     

B. Mamtimin  A.M.M. Et-TantawiD. Schaefer  F.X. Meixner  M. Domroes 《Journal of Arid Environments》2011,75(11):1105-1113

According to trend computations at three stations each in Sahara desert (Libya), characterized by a “hot” desert type (“BWh”, according to the Koeppen climate classification), and in Central Asia (Xinjiang, China) identified as a “cold” desert type (“BWk”, after Koeppen), increasing annual temperatures were detected over the period 1955-2005 corresponding with global temperature warming. From 1955-1978, negative (decreasing) temperature trends were, however, observed at all three hot desert stations and at two of the three cold desert stations. From 1979-2005, strikingly positive temperature trends were seen at all six stations. In seasonal respects, winter (December to February) and summer (June to August) show different temperature trends over the period 1955-2005: the hot desert experienced an increasing temperature trend at a greater extent in summer than in winter; vice-versa, in the cold desert positive trends were computed for winter and negative for summer. It can also be observed that mostly hot desert warming occurred in summer, opposite to cold desert warming in winter.  相似文献   

内蒙古草原的畜牧业气候   总被引：1，自引：1，他引：0  

孙金铸 《地理研究》1988,7(1):36-45

畜牧业的发展是我国农业发展的一个重要方面,天然牧草是畜牧业的主要物质基础,本文试图对影响牧草和牲畜的地理分布及生物生产力作一初步分析。  相似文献   

2×CO₂ Eastern Asia regional responses in the RSM/CCM3 modeling system     

S. -C. Chen  M. -C. Wu  S. Marshall  H. -M. H. Juang  J. O. Roads 《Global and Planetary Change》2003,37(3-4):277

A global to regional modeling system has been developed to evaluate precipitation under doubled CO₂. The National Centers for Environmental Prediction (NCEP) regional spectral model (RSM) is initialized and forced by current and doubled CO₂ simulations from the NCAR community climate model (CCM3). Three RSM simulations, RSM0, RSM1, and RSM2, with resolution of 280, 50 and 15 km, are examined. The RSM0 setup resolution matches the T42 CCM3 simulations. The RSM2 simulation is centered over Taiwan. Due to incompatibility of the model physics, noticeable differences between RSM0 and CCM3 are found, especially in wintertime, which suggests that simulation from RSM0, rather than CCM3, should be used to contrast high-resolution regional variations produced by RSM1 or RSM2 simulations.While the spatial distributions of RSM1 and RSM2 simulations over Taiwan are greatly improved over the CCM3 simulation, the intensity of the unique wintertime drizzle is overestimated, especially in RSM2. There is also a spurious northward extension of the precipitation pattern from the subtropical warm-pool region. Thus the regional response to doubled CO₂, which consists of more summerlike wintertime precipitation characteristics over the northeastern and eastern sides of Taiwan, with increased intensity mostly in the extreme events, is still in doubt and must be examined with improved global and regional models.  相似文献   

作为随机振动的海冰变化模型     

蒋维东 《成都信息工程学院学报》1990,(Z1)

本文从B.Saltzman的海温—海冰模式出发,得到了一个描述海冰范围变化的随机气候模型,接着对模型的性质进行了一些分析和讨论,并把从模型得到的模拟谱与计算的南极海冰扩展范围的观测谱做了比较。  相似文献   

中国七大地区“气候变化—作物产量—经济影响”综合评价     

刘远  王芳  张正涛  黄承芳  陈曦  李宁 《气候变化研究进展》2021,17(4):455-465

农业作为响应气候变化最敏感的领域之一,未来作物产量可能受到深刻影响。量化气候变化冲击作物产量导致的最终经济影响,需要综合“气候变化—作物产量—经济影响”开展链式研究。文中采用系统回顾和Meta回归分析方法整合了55篇文献的667项研究结果,推导出我国七大地区主要作物（水稻、玉米、小麦）产量与地区内未来温度和降水变化的定量关系,并将其作为农业部门的损失量代入改进的多区域投入产出模型,量化七大地区内与地区间遭受的经济波及影响（ERE)。结果显示：(1)气候变化对我国作物产量的影响主要体现在温度升高上,每升温1℃减产2.6%~12.7%,东北和西北地区作物受升温影响最显著;(2) 气候变化导致的作物减产将对经济产生更严重的波及影响,GDP因作物减产每下降1%将额外产生17.8%的波及影响;(3) 21世纪末,若不考虑CO₂肥效作用,作物减产导致的ERE将占GDP的-0.1%~13.6%（负值表示收益),最悲观情况下ERE与当前我国农业总产值相当（2012年为基准年);(4)不同地区受ERE影响程度的差异较大,因各区之间产业结构、贸易联系及经济发展程度存在差异,西南地区遭受本区及来自其他地区的ERE比华东地区高2.8~8.5倍。  相似文献   

应对气候变化南南合作优先合作国家选择方法探讨     

王谋  康文梅  张莹 《气候变化研究进展》2021,17(6):744-752

应对气候变化南南合作是中国领导人在巴黎气候大会上的庄严承诺,也是体现“十九大”会议精神“成为全球生态文明建设的重要参与者、贡献者、引领者”的具体实践。作为我国重要的对外援助方案,相关研究还比较缺乏。实践中对外援助国的选择通常是根据领导人出访地和一些重要国际会议举办地等确定,缺乏系统性、连续性,这也符合对外援助初级阶段的特征。为了更加高效、系统地推进气候变化南南合作持续开展,产生更好的环境和社会效益,文中基于定量评估的方法学对南南合作优先合作国家的选择开展了讨论。通过专家集体打分与层次分析法确定评价指标及权重,采用阶段阈值法将不同国家在评估指标上的表现转化为定量分值,并进行国家综合得分计算和排名。计算结果显示,南非、巴基斯坦、孟加拉国、柬埔寨、印度尼西亚等国位于潜在受援国前五位,文中还列出了建议优先合作的20个国家及位序。总体来看,排名前20的受援国均属于联合国机制下77+中国集团,90%为“一带一路”倡议参与国,70%是亚投行成员国,评估结论与中国发起的重大合作倡议具有高度的相关性,不仅可以支持应对气候变化南南合作开展,也能呼应和推动中国主导的其他国际议程发展。本文尝试在传统的定性描述和评估为主的领域,引入定量评估研究方法,在研究方法学应用上进行拓展。论文研究结论可以为相关部门选择应对气候变化南南合作优先合作国家提供参考。  相似文献   

IPCC AR6报告解读：气候系统对二氧化碳移除响应     

曹龙 《气候变化研究进展》2021,17(6):664-670

IPCC AR6报告中控温1.5℃和2℃的低排放情景需要在21世纪中叶以后实现净负CO₂排放,这需要在很大程度上依赖CO₂移除措施。AR6对CO₂移除的主要评估结论如下：CO₂移除有潜力从大气中去除CO₂（高信度);如果CO₂移除量超过CO₂排放量,将实现净负CO₂排放,降低大气CO₂浓度,减缓海洋酸化（高信度);通过CO₂移除方法从大气中去除的CO₂会部分被海洋和陆地释放的CO₂抵消（非常高信度);如果净负CO₂排放可以实现并且持续,CO₂引起的全球升温趋势将会逐渐扭转,但是气候系统的其他变化（例如海平面升高）仍会在未来的几十年到千年尺度上持续（高信度);不同CO₂移除方法会对生物化学循环和气候产生广泛的影响,这些影响会加强或减弱CO₂移除的降温潜力,并且影响水资源、食物生产和生物多样性（高信度）。  相似文献   

影响中国沿海地区青少年气候变化减缓意愿及行为的因子分析     

王雪琦  陈进 《气候变化研究进展》2021,17(2):212-222

对青少年开展气候变化教育是应对气候变化挑战的重要举措之一。了解哪些因素会影响青少年的气候变化减缓意愿及行为则是开展有效气候变化教育的前提。文中基于影响青少年气候变化行为因素的理论框架,针对厦门、深圳、宁波9所中学1539名学生,开展问卷调查。结果表明,我国沿海地区12~14岁青少年整体上对气候变化关注程度和气候变化减缓行动表现一般,且其气候变化科学知识水平相对较低;回归分析显示影响他们减缓行为意愿的主要因素是过去参与过的气候变化减缓行为、自我效能和气候变化卷入度,而影响他们减缓行为的主要因素为气候变化卷入度和自我效能;气候变化主观认知较高和高责任心型人格的青少年表现出较高的减缓行为。最后提出建议：我国青少年气候变化教育应该重点关注提高青少年气候变化卷入度、增加气候科学认知水平和增进自我效能,以期提高青少年的气候变化减缓行为意愿和减缓行为。  相似文献