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531.
Population variation in ecophysiological traits of four co-occurring montane conifers was measured on a large latitudinal gradient to quantitatively assess their potential for response to environmental change. White fir (Abies concolor) had the highest variability, gross photosynthetic rate (Pg), and foliar carbon (C) and nitrogen (N) content. Despite low water use efficiency (WUE), stomatal conductance (gs) of fir was the most responsive to unfavorable environmental conditions. Pinus lambertiana exhibited the least variability in Pg and WUE, and is likely to be the most vulnerable to environmental changes. Pinus ponderosa had an intermediate level of variability, and high needle growth at its higher elevational limits. Pinus Jeffreyi also had intermediate variability, but high needle growth at its southern latitudinal and lower elevational limits. The attributes used to assess tree vigor were effective in predicting population vulnerability to abiotic (drought) and biotic (herbivore) stresses.  相似文献   
532.
从以大区域进行规划的经济发展思路出发,提出公路建设区划的概念和公路建设区划理论基础,并建立西部公路网合理规模评价指标体系,利用主成分分析方法将指标进行降维,避免了多指标间存在的相关性及信息重叠性的不足,并对西部地区的公路发展水平进行评价。再利用降维后新的互不相关的综合主成分指标体系替代原先存在较多的信息重叠及相关关系的评价指标,对西部各省区的公路发展进行聚类分析。聚类分析结果可用于西部地区公路网合理规模的确定。该方法不但能够使原来复杂的问题简单化,而且所得结论具有客观、可信、较有说服力,使西部地区公路网合理规模的确定具有针对性和可操作性。  相似文献   
533.
Pinning down vulnerability: from narratives to numbers   总被引:2,自引:0,他引:2  
Social vulnerability analyses have typically relied upon narratives to capture the nuances of the concept. While narratives have enhanced our understanding of the multiple drivers of vulnerability, they have had limited influence on hazards and climate adaptation policy. This is partially a function of the different needs and goals of the policy and research communities. The former prioritises generalised quantitative information, while the latter is more concerned with capturing complexity. A theoretically driven and empirically tested quantitative vulnerability and capacities index (VCI) for use at the local scale is presented to help connect vulnerability research and policy. There are four versions of the index for use in rural and urban contexts at the household and community levels. There can be an infinite number of drivers of vulnerability, but the VCI draws upon 12 indicators to represent material, institutional and attitudinal aspects of differential vulnerability and capacities.  相似文献   
534.
Extinction‐risk assessments aim to identify biological diversity features threatened with extinction. Although largely developed at the species level, these assessments have recently been applied at the ecosystem level. In South Africa, national legislation provides for the listing and protection of threatened ecosystems. We assessed how land‐cover mapping and the detail of ecosystem classification affected the results of risk assessments that were based on extent of habitat loss. We tested 3 ecosystem classifications and 4 land‐cover data sets of the Little Karoo region, South Africa. Degraded land (in particular, overgrazed areas) was successfully mapped in just one of the land‐cover data sets. From <3% to 25% of the Little Karoo was classified as threatened, depending on the land‐cover data set and ecosystem classification applied. The full suite of threatened ecosystems on a fine‐scale map was never completely represented within the spatial boundaries of a coarse‐scale map of threatened ecosystems. Our assessments highlight the importance of land‐degradation mapping for the listing of threatened ecosystems. On the basis of our results, we recommend that when budgets are constrained priority be given to generating more‐detailed land‐cover data sets rather than more‐detailed ecosystem classifications for the assessment of threatened ecosystems. El Efecto de la Cobertura Terrestre y el Mapeo de Ecosistemas en la Valoración de Riesgos en los Ecosistemas en Little Karoo, Sudáfrica  相似文献   
535.
We observe a paradigm shift toward collaborative, multi‐level (from local to global) water management and suggestions for scale‐related design principles in the literature. Decision‐support tools are needed that can help achieve scale design principles. Mediated modeling (MM) refers to model building with people, rather than for people. This tool belongs to a family of participatory, systems oriented tools. This article explores their suitability for addressing challenges and principles that arise at multiple‐scales. MM can promote the understanding of cross‐level and cross‐scale links, creating salient, credible, and legitimate knowledge and encouraging boundary functions. Prerequisites for successful MM processes include an openness and willingness to collaborative learning. As new “meso‐level” institutions emerge to address complex challenges in water management collaboratively, tools like MM may play an important role in structuring dialogues, developing adaptive management capacity and advance an ecosystem services approach.  相似文献   
536.
有色冶炼重金属废水回用研究   总被引:6,自引:0,他引:6  
通过对株洲冶炼厂重金属废水回用结垢问题的研究,针对其垢样主要属碳酸钙垢型的特点,提出以投加高效低剂量的阻垢剂作为防止结垢的主要方法,运行证明,该防止结垢方法具有明显的经济效益和环境效益,应用前景广阔。  相似文献   
537.
选取2000~2010年为时间断面,以江西省为研究对象,利用第五、第六次人口普查数据和统计年鉴,结合Arcgis、Geoda、SPSS软件和主成分分析、回归分析等方法,测算文化素质指数,分析人口文化素质概况并研究其空间格局演变,从赣北、赣中、赣南三大区域和地级市两大角度分析人口文化 城市匹配程度。研究发现:(1)人口文化素质指数在空间上以低低聚集为主,高素质人口仍聚集在赣北地区;(2)文化 城市偏移状况得到改善,由区域差异较大向均衡发展;(3)赣北、赣中、赣南三大区域均属于文化主导,其中赣北地区文化 城市逐渐匹配,赣中、赣南地区偏离度增加,文化主导加剧;地级市匹配状态总体较好,3种类型均有分布  相似文献   
538.
旅游风险感知就是旅游者在其旅游行为前及过程中对可能发生的负面结果的感知,风险感知目前已成为旅游安全研究中的重要内容。通过构建旅游者风险感知量表,以九寨沟为案例地进行实证研究得出:(1)旅游者感知风险主要分为3个维度:功能障碍型、危机事件型及文化冲突型;(2)旅游者的总体风险感知较小,其中功能障碍型风险较大,其次为危机事件和文化冲突,并且地震等危机事件并未成为旅游者担心的主要风险;(3)不同旅游者的差异主要体现在“花费冤枉钱”、“迷路或与同伴走失”、“语言障碍”等方面,性别、地域、是否经历过灾害、是否买保险、是否带药品等因素对各类风险感知差异没有显著影响。旅游者风险感知研究为完善旅游安全理论提供了参考,并且对旅游地的风险管理提供了依据,具有指导和借鉴意义  相似文献   
539.
ABSTRACT

The exploration and potential extraction of shale gas – better known as fracking – has emerged as one of the most contentious dimensions to local environmental politics in the UK. Local residents and environmental activists have raised concerns about health, noise, ground water contamination, seismicity, environmental amenity, and other impacts of the industry on communities. Despite the complexities of shale gas extraction, an emphasis on the local has shaped key dimensions of the debate around the appropriate location for well pads to the relative exclusion of other issues. This paper draws on fieldwork in Lancashire, UK, to reflect on the political construction of scale in order to explore how an emphasis on “the local” can restrict political debate over shale gas to narrow concerns with land-use planning thereby obviating a fuller engagement with wider questions concerning risk, energy policy, and climate change. It is concluded that a more nuanced conception of scale is necessary for understanding how concerns with shale gas are diminished rather than strengthened through the current planning policy and regulatory regime operating in the UK.  相似文献   
540.
Debates surrounding the decarbonisation of energy systems in developed societies have been overlaid with controversy about the merits of decentralised or “community” energy. These are ambiguous concepts, implicating energy generation or demand reduction activities carried out in buildings or across neighbourhood or urban areas, as well as social and political aspects such as trust and communitarian relations amongst participating actors. This research was based on the criticism that most existing advocacy for, and research into decentralised energy (DE) has neglected the spatiality of such initiatives. In particular, the concept of “local” has been largely presumed to be self-evident and unproblematic. Drawing on the analysis of primary and secondary data from nine UK case studies, this study reveals the different degrees to which DE initiatives are locally embedded, dependent upon the sector of the instigating actors. Findings also reveal the multi-dimensionality of discourses of DE, going beyond purely physical or technical aspects to encompass social, spatial and political issues that are intertwined in complex patterns. In particular, it reveals how aspirations to “roll out” successful DE initiatives, consistent with broader policy goals for carbon reduction, are challenged by discourses of local uniqueness and “bottom-up” engagement. Future research is required to investigate the generalisability of the patterns observed.  相似文献   
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