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141.
先秦灾害神话记录了自然灾害,表现了远古先民的原始宗教信仰,是灾害研究的材料来源。与此同时,灾害神话神秘又夸张的书写笔法,对后世文学题材、结构等方面所产生的深刻影响,更使其成为灾害文学的重要主题之一。因此,从文学角度入手,概括研究先秦灾害神话的文本内容,深入分析《山海经》《楚辞》等经典著作对灾害神话的描写。进而梳理灾害神话的文学特征、神灵形象描写,才能得出灾害神话乃中国灾害文学之源流的结论,最终达到灾害神话的基础性研究之目的。  相似文献   
142.
在天山北麓9个州(市、地区)2002-2011年工业能源消费量、人口等数据基础上,利用LMDI法对该地区工业碳排放影响因素进行实证分析,结果表明,经济发展水平、工业化水平、人口规模是天山北坡经济带工业碳排放增加的拉动因素。工业能源强度和工业能源消费结构的变化是天山北坡经济带工业碳排放增加的抑制因素。总体来说,该地区抑制因素的抑制作用远小于拉动因素的拉动作用,工业碳排放量呈现增加趋势。  相似文献   
143.
分析区域社会经济发展与环境的生态效率关系,描述区域发展对生态环境资源消耗和占用状况,揭示导致生态变化的重要因素,有助于为区域可持续发展政策提出奠定基础.通过对陕西秦岭南麓区域发展与生态足迹影响因素的差异性分析以及区域内2005—2014年城市发展指数CDI和生态足迹EF的测算,分析陕南三市CDI、EF和生态效率的年际变化趋势及相互影响关系.研究表明:陕南三市CDI和人均EF均呈现不断增长态势,2005—2014年,汉中市、安康市、商洛市CDI分别增长34.99%、42.91%、33.39%;人均EF分别增长66.59%、73.59%、67.04%.结果显示,陕南三市生态效率呈现先升后降的趋势,环境效率年际变化波动较大.资源效率是导致陕南三市生态效率波动变化的主要因素,与生态效率的变化趋势基本一致.化石能源消耗和建设用地占用不断增长是导致资源效率降低的主要原因.陕西秦岭南麓区域社会经济发展能力逐步增强,但资源的高消耗和占用使生态环境压力持续增大,发展循环经济、开发生态旅游等成为政策着力点.  相似文献   
144.
关帝山森林土壤真菌群落结构与遗传多样性特征   总被引:7,自引:6,他引:1  
乔沙沙  周永娜  柴宝峰  贾彤  李毳 《环境科学》2017,38(6):2502-2512
土壤微生物群落驱动土壤碳、氮、磷、硫生物地球化学循环,在维持土壤碳汇和生态系统功能等方面发挥重要的作用.分析环境与空间因素在寒温性针叶林土壤微生物群落构建中的作用,可以为区域森林生态系统管理措施的制定提供理论依据.本文利用Illumina高通量测序技术分析了关帝山庞泉沟自然保护区华北落叶松(Larix principis-rupprechtii)林、青杄(Picea wilsonii)林、油松(Pinus tabulaeformis)林以及桦树(Betula spp.)林这4种林型的5个土壤真菌群落(Lp MC1、Lp MC2、Pw MC、Pt MC和BMC)的结构.同时测定林下土壤环境因子及林下植被多样性,分析真菌群落的结构与植被和土壤环境因子的相关性.结果表明:(1)5个样地中共有7个真菌门和33个优势真菌属;(2)冗余分析结果表明:土壤pH、温度、含水率、全氮含量、NH+4含量、全碳含量、蔗糖酶活性、脲酶活性、林下植被优势度和均匀度与土壤真菌群落结构显著相关;(3)聚类分析和PCA分析结果表明,森林植被类型、土壤环境因子和林下植被对土壤真菌群落结构影响显著.(4)空间变量(PCNM)分析结果表明,在局域尺度(local scale)上扩散限制对研究区域真菌群落构建的影响不显著.本研究区森林土壤真菌群落结构主要受到环境选择(土壤pH、温度、含水率、全氮含量、NH+4含量、全碳含量、蔗糖酶活性、脲酶活性、林下植被优势度和均匀度、森林类型)的显著影响.  相似文献   
145.
长江上游玉龙雪山植物物种多样性形成的探讨   总被引:5,自引:0,他引:5  
玉龙雪山位于云南省西北部的丽江市,是界于澜沧江和金沙江之间云岭山脉的主峰。南临丽江坝,东、西、北三面均为金沙江环绕,处于中国三大植物多样性中心之一的横断山区的核心地带,具有很高的植物物种多样性。该区有藻类植物31科72属196种,地衣植物17科20余种,在苔藓植物中有苔类45种、藓类130种,蕨类植物约有220 多种,种子植物有171科804属2 646种(不含栽培种及种下等级),其中中国特有种1 631种,占本区种子植物总数的61.46%。对玉龙雪山植物物种多样性的形成进行了探讨,认为玉龙雪山丰富的植物物种多样性主要来源于3个第三纪古植物区系成分即古北大陆、古地中海以及古南大陆成分,其中以古北大陆成分为主。之后的新构造运动及第四纪冰期冰川的反复作用,形成了玉龙雪山复杂多样的生态环境。来源于以上3个古植物区系成分的植物物种在以后的进化过程中经过不断分化、发展以及与临近区域的交流,形成了现在丰富的植物物种多样性格局。  相似文献   
146.
The aim of this article is to propose a new analytical framework for comparing and explaining the emergence and diffusion of European regional mountain initiatives (ERMIs), envisaged as ‘functional regulatory spaces’ (FRS). The article examines three exploratory hypotheses. The first hypothesis considers that the different ERMIs (Alps, Pyrenees, Jura, Carpathian, Balkan Mountains, Dinaric Arc, Caucasus) can be compared, distinguished, and classified using the FRS approach. The second hypothesis addresses the relationship between the degree to which ERMIs correspond to an ideal-type FRS and their role and position within policy diffusion processes. We suggest that the more an ERMI corresponds to an ideal-type FRS, the more important is its role in diffusion processes. The third hypothesis focuses on the relationship between the degree of formalization and institutionalization of ERMIs and their role in policy diffusion processes. We argue that the more and the earlier an ERMI is “formalized” and “institutionalized” in a clear and robust way as a “mature” FRS, the more important its role, and the more central its position, in diffusion processes. This article is a very first attempt to link FRS and policy diffusion concepts. As such it seeks to assess the link's feasibility and relevance, rather than a definitive empirical (in)validation of the three hypotheses.  相似文献   
147.
Good quality data apt for an assessment of temporal trends of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) in soils are difficult to obtain since there is a general lack of information on their residues in soils. Variability of soil profiles, non-homogeneity of samples, and often also inconsistency of applied sampling procedures further complicate this problem. To assess spatial and temporal trends of contamination, three soil sampling campaigns have been performed over the period of 12 years at the mountain forest sites in the Czech Republic. Relation between the air, needle and soil contaminations was addressed in addition to time-related variability of soil. It has been confirmed that soil is a good matrix for evaluation of spatial distribution of persistent organic pollutants (POPs) but difficult for establishment of temporal trends. A slow rate of the soil-forming processes and their site-specificity was generally the major source of uncertainties.  相似文献   
148.
Abstract: In conservation biology, understanding the causes of endangerment is a key step to devising effective conservation strategies. We used molecular evidence (coalescent simulations of population changes from microsatellite data) and historical information (habitat and human population changes) to investigate how the most‐isolated populations of giant pandas (Ailuropoda melanoleuca) in the Xiaoxiangling Mountains became highly endangered. These populations experienced a strong, recent demographic reduction (60‐fold), starting approximately 250 years BP. Explosion of the human population and use of non‐native crop species at the peak of the Qing Empire resulted in land‐use changes, deforestation, and habitat fragmentation, which are likely to have led to the drastic reduction of the most‐isolated populations of giant pandas. We predict that demographic, genetic, and environmental factors will lead to extinction of giant pandas in the Xiaoxiangling Mountains in the future if the population remains isolated. Therefore, a targeted conservation action—translocation—has been proposed and is being implemented by the Chinese goverment.  相似文献   
149.
Moore, Johnnie N., Alicia S. Arrigoni, and Andrew C. Wilcox, 2012. Impacts of Dams on Flow Regimes in Three Headwater Subbasins of the Columbia River Basin, United States. Journal of the American Water Resources Association (JAWRA) 48(5): 925‐938. DOI: 10.1111/j.1752‐1688.2012.00660.x Abstract: We compared long‐term changes in flow regimes resulting from climate change with those resulting from dams in three matched pairs of natural and modified headwater subbasins of the Columbia River. Based on the analysis of 12 flow‐regime metrics, we found that damming had minimal effect on most quantity of flow metrics, but major effect on timing of flow metrics, especially those representing “spring runoff.” In all modified subbasins, “spring runoff” metrics occurred much earlier than natural flow (up to ~44 days earlier for April‐July flows). Storage capacity modulated the magnitude of timing of flow‐metric changes, with the largest storage capacity leading to the most change. However, even in subbasins with low storage capacity, we found significant change in most timing of flow metrics. We also found that damming, especially in subbasins with higher storage capacity, overwhelmed climate variability in all basins for most flow metrics. This shows that reservoir operations need to be modified to more closely match the natural timing of flow regimes to promote positive ecologic response in modified rivers, even in basins where quantity of flow metrics have not changed substantially as a result of damming.  相似文献   
150.
Inadequacy and poor quality of water supply for domestic purposes is increasingly becoming a concern in rural catchments of the Middle Mountains of Nepal. Water quantity is an issue in pocket areas of these catchments, while water quality is subject to concern in most of the water sources. Microbiological contamination in particular poses a risk to human health. In addition, sediment pollution during the monsoon season is perceived as an issue by the local residents. Elevated phosphate and nitrate levels in many water sources indicate intensive interaction with surface water hailing from agricultural areas and human settlements. These water quantity and quality concerns in two watersheds of Nepal, the Jhikhu Khola and the Yarsha Khola watersheds, are not isolated cases. Similar problems are reported from other watersheds monitored under the People and Resource Dynamics in Mountain Watersheds of the Hindu Kush-Himalayas (PARDYP) project in China, India, and Pakistan and the literature of this region.  相似文献   
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