Oligocene trace fossils from temporary fluvial plain ponds: An example from the Freshwater Molasse of Switzerland     

Alfred Uchman  Milena Pika-Biolzi  Peter A. Hochuli 《Eclogae Geologicae Helvetiae》2004,97(1):133-148

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黄河流域坡高地系统最小生态需水研究   总被引：2，自引：0，他引：2  

张远  杨志峰 《山地学报》2004,22(2):154-160

以保护和恢复流域坡高地生态系统为目的，对坡高地最小生态需水问题进行研究，提出了坡高地生态需水和生态缺水的计算方法。以黄河流域为实例，在GIS和遥感技术支持下对坡高地最小生态需水量和缺水量进行了计算，并从时空两个尺度揭示了黄河流域坡高地生态系统最小生态需水的变化规律，研究成果可为流域生态环境建设和水资源合理配置提供依据。  相似文献   

宁夏香山荒漠草原区植物群落多样性时空特征   总被引：10，自引：0，他引：10  

尚占环  妙爱兴  龙瑞军  辛明  郭旭生  马文志 《山地学报》2004,22(6):661-668

采用多个多样性指数对宁夏香山荒漠草原区植物群落多样性时间、空间动态进行分析。结果表明，该地区群落时、空动态特征不明显。长期过度放牧导致环境恶化，生境碎化，这些作用的长期性、循环性是造成物种、群落格局与原有时、空动态规律相悖的主要因素，这些因素消除了物种或群落在时间梯度上应有的变化规律。干旱山地物种在长期进化过程中成功的发展了对环境的适应机制，环境的波动性强烈导致了群落多样性在原来消长动态基础上的复杂化，也使多样性动态机制复杂化。应用多种指数数学模型对研究对象进行综合评价，能够真实地反映群落多样性动态。  相似文献   

Impact of habitat heterogeneity on plant community pattern in Gurbantunggut Desert   总被引：5，自引：1，他引：5  

QIAN Yibing  WU Zhaoning  ZHANG Liyun  SHI Qingdong  JIANG Jin  TANG Lisong 《地理学报(英文版)》2004,14(4):447-455

1IntroductionStudy on the interrelationship between vegetation patterns and their habitat heterogeneity is important to recover and rehabilitate the desert vegetation, stabilize the desert ecosystem and prevent desert expansion. Domestic and foreign researchers have carried out many studies on this topic (Archer etal., 2002; Bolling etal., 2000; Chen etal., 2003; Dasti etal., 1994; Gu etal., 2002, Li etal., 2001; Li etal., 2001; Liang etal., 2003), which have used and refined statistic tech…  相似文献   

东吴小筑园林植物应用评价   总被引：1，自引：0，他引：1  

彭丽彬 《云南地理环境研究》2004,16(4):75-78

园林植物配置是园林植物应用的重要内容，对充分发挥园林功能和观赏特性具有重要作用。通过对东吴小筑入口、前庭小院、主景区、山林区、园路、出口等6个功能区园林植物水平配置的现状调查，分析了本景区园林植物的物种多样性、水平结构、垂直结构、色彩变化等特征。结果表明：东吴小筑园林景观营造中．植物配置显示出较高水准。在树种选择、树丛组合、层次搭配、空间组织、色彩表现、季相变化等方面的设计布局十分精细，对今后园林设计及园林绿化水平的提高具有较好的指导作用。  相似文献   

The role of leaf inclination,leaf orientation and plant canopy architecture in soil particle detachment by raindrops     

Kirsten Foot  R. P. C. Morgan 《地球表面变化过程与地形》2005,30(12):1509-1520

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‘Committing to Place’ at the Local Scale: the potential of youth education programs for promoting community participation in regional natural resource management     

Ruth Lane  Damian Lucas  Frank Vanclay  Sophie Henry  Ian Coates 《The Australian geographer》2005,36(3):351-367

Emerging approaches to environmental governance require a greater level of community participation than did previous approaches in which these responsibilities largely rested with government agencies. There is consequently a need for increased engagement with NRM among a broad community sector. This paper examines initiatives by two prominent government agencies, the Murray–Darling Basin Commission (MDBC) and the National Museum of Australia (NMA), to engage school children from regional communities using education programs that focus on place and environmental health. We focus on the MDBC's International Riverhealth Conference held in Mildura in 2003 and the associated Murray–Darling Basin TalkBack Classroom sponsored by the NMA and the Parliamentary Education Office (PEO). We explore how key themes of local scale, place-based identities, youth voice and critical engagement are developed in these programs and consider how they relate to the environmental agency of children. We then reflect on the potential for the kinds of environmental agency promoted through these programs to help build the capacity of local communities to progress larger goals of environmental restoration and sustainability in the Murray–Darling Basin. The evaluation research reported here forms part of the Committing to Place research project, an Australian Research Council Linkage grant involving the University of Tasmania, the National Museum of Australia and the Murray–Darling Basin Commission.  相似文献   

洛阳热电厂汽机主厂房2、3号机房爆破拆除技术          下载免费PDF全文

袁长征  张锦灵 《探矿工程》2005,32(7):58-60

绍了采用控制爆破拆除大跨度工业厂房的施工方法，主要论述了在要求振动较小情况下，怎样控制爆破参数。  相似文献   

数字社区数据标准研究   总被引：4，自引：1，他引：4  

邬伦  徐宜勤  王晓明  刘岳峰  汪大明 《地理与地理信息科学》2005,21(4):20-23

当前数字社区建设缺乏统一的智能化综合管理平台以及相应的各项数据标准，使得数字社区难以真正实现统一的数字化管理。该文参考国内外相应数据标准，研究数字社区的标准体系结构。针对现有标准体系缺乏相关数据标准的现状，提出数字社区系列数据标准，包括数据接口层标准、数据分类编码标准、数据模型、数据字典和元数据标准。阐述系列标准中各标准间的相互关系以及各标准所包含的具体内容。  相似文献   

Effects of Enclosure on Plant and Soil Nutrients in Different Types of Alpine Grassland     

WANG Fang  HE Yongtao  FU Gang  NIU Ben  ZHANG Haorui  LI Meng  WANG Zhipeng  WANG Xiangtao  ZHANG Xianzhou 《资源与生态学报(英文版)》2020,11(3):290-297

Enclosure is one of the most widely used management tools for degraded alpine grassland on the northern Tibetan Plateau, but the responses of different types of grassland to enclosure may vary, and research on these responses can provide a scientific basis for improving ecological conservation. This study took one site for each of three grassland types (alpine meadow, alpine steppe and alpine desert) on the northern Tibetan Plateau as examples, and explored the effects of enclosure on plant and soil nutrients by comparing differences in plant community biomass, leaf-soil nutrient content and their stoichiometry between samples from inside and outside the fence. The results showed that enclosure can significantly increase all aboveground biomass in these three grassland types, but it only increased the 10-20 cm underground biomass in the alpine desert. Enclosure also significantly increased the leaf nutrient content of the dominant plants and contents of total nitrogen (N), total potassium (K), and organic carbon (C) in 10-20 cm soil in alpine desert, thus changing the stoichiometry between C, N and P (phosphorus). However, enclosure significantly increased only the N content of dominant plant leaves in alpine steppe, while other nutrients and stoichiometries of both plant leaves and soil did not show significant differences in alpine meadow and alpine steppe. These results suggested that enclosure has differential effects on these three types of alpine grasslands on the northern Tibetan Plateau, and the alpine desert showed the most active ecological conservation in the responses of its soil and plant nutrients.  相似文献