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11.
Protected areas are recognized as an essential tool to safeguard habitat integrity and biodiversity in the Anthropocene. Substantial efforts have been made to clarify the conditions under which they deliver conservation outcomes effectively. Location, spatial design, management strategy and threats, have commonly been identified as key factors. The impacts of these factors have, however, often been evaluated independently, and there is limited information on how their combined and interactive effects can improve or hinder protected area effectiveness. Here we develop a framework for understanding the combined effects of these factors. This has important implications for how protected areas are established and maintained.  相似文献   
12.
杭州西溪国家湿地公园1993年以来景观演变及其驱动力分析   总被引:22,自引:2,他引:22  
程乾  吴秀菊 《应用生态学报》2006,17(9):1677-1682
在遥感和GIS技术支持下,以杭州西溪国家湿地公园的TM影像为主要数据源,研究了西溪湿地近10年的景观空间格局特征和演变情况,探讨了景观演变的驱动因素.结果表明,景观多样性指数由1993年的1.7854上升到2001年的1.8438和2003年的2.2096, 景观多样性指数在1993年以后持续上升.景观的破碎化指数从1993年的0.0036增加到2001年的0.0042和2003年的0.0047,表明西溪整个景观的破碎化程度随时间而加深,各类景观受人类活动的干扰在增强.人为活动成为西溪湿地格局演变的主要驱动因素.房地产开发是地处城市边缘的西溪湿地景观演变的主要内在动力,景观整体多样性的演变受到景区社会经济发展水平和各种政策的强烈影响.  相似文献   
13.
The subgroup ‘Driving Forces for Data Exchange’ as part of the SETAC LCA Workgroup on Data Availability and Quality is finishing its final report with recommendations and guidelines to stimulate availability and exchange of LCI data. Activities in the past three years involved a literature review, interviews with LCI data publishers and stakeholder discussions. The final report will be part of a SETAC ‘Code of Life Cycle Inventory Practice’, dealing with LCI data availability and quality aspects in a broader sense.  相似文献   
14.
典型草原区不同生境反硝化菌群的空间特征   总被引:2,自引:0,他引:2  
【背景】锡林河-河滨湿地-阶地草原是蒙古高原典型草原区代表性的水生-湿生-陆生生境,但不同生境中反硝化菌群的空间分布特征尚不明晰。【目的】阐明典型草原区不同生境反硝化菌群的组成、丰度、空间分布特征及异质性成因。【方法】利用16S rRNA基因测序研究锡林河流域水生、湿生、陆生生境6个样带沉积物/土壤细菌群落组成及相对丰度。基于2014年及以前文献报道的反硝化细菌及16S rRNA基因信息构建参比菌库,筛选生境关联的反硝化菌属。通过典范对应分析等探究反硝化菌群空间异质性成因。【结果】参比菌库包含80种反硝化细菌(65个属),6个样带测序获得的469个细菌属中36个为反硝化细菌属。3种生境共存的反硝化细菌有14个属,其中黄杆菌属(1.65%-14.17%)和噬氢菌属(1.56%-1.69%)是水生和湿生生境共有的优势菌,假单胞菌属(1.85%)是低河漫滩样带的优势菌。空间分布特征显示反硝化菌群沿水生-湿生-陆生生境呈现先升后降的分布趋势,在低河漫滩湿地达到最高值。典范对应分析表明:黄杆菌属、噬氢菌属、气单胞菌属、鞘氨醇单胞菌属等与pH值、水分及沙粒含量呈正相关关系,而芽孢杆菌属、链霉菌属、马杜拉放线菌属等与粘粒、粉粒、有机质、总氮含量等呈正相关关系。【结论】典型草原区反硝化菌群组成及丰度具有明显的生境异质性,低河漫滩湿地是反硝化细菌生长繁殖的最佳生境,由颗粒组成、水分含量和pH等环境因子共同驱动。  相似文献   
15.
To determine the alterations in optical characteristics and cerebral blood oxygenation (CBO) during activation and deactivation, we evaluated the changes in mean optical pathlength (MOP) and CBO induced by a verbal fluency task (VFT) and driving simulation in the right and left prefrontal cortex (PFC), employing a newly developed time-resolved near infrared spectroscopy, which allows quantitative measurements of the evoked-CBO changes by determining the MOP with a sampling time of 1 s. The results demonstrated differences in MOP in the foreheads with the subjects and wavelength; however, there was no significant difference between the right and left foreheads (p > 0.05). Also, both the VFT and driving simulation task did not affect the MOP significantly as compared to that before the tasks (p > 0.05). In the bilateral PFCs, the VFT caused increases of oxyhemoglobin and total hemoglobin associated with a decrease of deoxyhemoglobin, while the driving simulation task caused decreases of oxyhemoglobin and total hemoglobin associated with an increase of deoxyhemoglobin; there were no significant differences in evoked-CBO changes between the right and left PFC. The present results will be useful for quantitative measurement of hemodynamic changes during activation and deactivation in the adults by near infrared spectroscopy.  相似文献   
16.
17.
Research on ecosystems patterns and dynamics is critical for understanding the regional problems of resources and environment. In this study, based on the technology of RS and GIS, the composition, patterns and dynamics of the ecosystems in Haihe river basin during 1990–2005 were analyzed using landscape indices including the area of average patches, aggregation index and Shannon–Weaver diversity index. According to the development situation of economy and society in Haihe river basin, some driving factors for dynamics of ecosystems patterns were concluded based on correlation analysis. Results showed that the ecosystems patterns in Haihe river basin changed greatly from 1990 to 2005. The area of urban and grassland increased, but farmland, forest and wetland decreased. As for landscape indices, the area of average patches, value of aggregation index, clump index and diversity index all increased, indicating the trend of evenness for the whole ecosystems. Growth of population, economy growth together with urbanization and policy were the main driving factors for dynamics of ecosystem pattern in this basin.  相似文献   
18.
Fatigue is an increasingly noted factor in road accidents. The ability to predict and be aware of impairment in terms of driving capability is important for potential legal liability and road safety. However, to date, there have been few studies that have investigated the accuracy of individuals in predicting how safely they could drive during conditions of sleep loss. Research has demonstrated that individuals rate themselves as better than the population average in a number of domains, including driving‐related skills. Therefore, this study also aimed to investigate self‐ratings of predicted driving ability during extended wakefulness and compare them to ratings made of a hypothetical other person under the same conditions. Thirty‐two participants remained awake for a period of 40 h. Every 2 h, they completed the Psychomotor Vigilance Task (PVT) and rated on a seven‐point scale how well they thought they could drive safely, react quickly in an emergency, and stay in their own lane. They were also asked to assess how they thought someone else in their own position could drive. The participants rated their driving ability as becoming significantly poorer at the same time that their PVT performance became significantly slower. Self‐ratings indicating a qualitative assessment of poorer than neutral driving occurred at 03:00 h for both the “drive safely” and “react quickly” questions, after 19 h of continuous wakefulness (starting at 08:00 h). This occurred at 05:00 h for the “keep in my lane” question. Previous studies with a similar protocol demonstrated that under these conditions, individuals exhibit a performance decrements equivalent to someone with a blood alcohol concentration of 0.05% (the legal driving limit in Australia). Participants consistently rated the ability of others to drive as poorer than their own. The main implication from this study for road safety and legal liability is that it is reasonable to focus on a person's perception of the situation, as it does align with objective reality to a certain extent. A concern in terms of road safety is potential overconfidence, indicated by rating others consistently poorer than themselves.  相似文献   
19.
 本文根据乱流扩散法原理,利用实验集水区连续6年实测数据,对杉木人工林蒸散规律进行了探讨。结果表明:杉木人工林年平均蒸散量875.45mm,占年降雨量的82.2%。其中,林冠蒸散量781.77mm,林地93.68mm,分别为总蒸散量的89.3%和10.7%。与水量平衡法的结果比较,为水量平衡法的101.2%。在研究蒸散规律的同时,对乱流扩散法的应用及参数的估算也进行了较详细的分析。  相似文献   
20.
甘肃民勤绿洲的景观格局变化及驱动力分析   总被引:55,自引:12,他引:55  
应用GIS、RS技术与景观格局分析软件FRAGSTATS研究了甘肃省民勤绿洲近14年间的景规格局变化.结果表明,该绿洲的各类景观拼块体在此期间发生了十分复杂的时空转换,荒漠化过程与开荒过程同时存在,绿洲毁林、毁草开荒过程主要发生在1994-1998年期间,并集中分布在绿洲南部水资源条件较好的地带,土地弃耕化过程主要发生在1998-2001年期间,集中分布在绿洲北部水资源条件较差地带;Shannon多样性指数、Shannon均匀度指数的下降与蔓延度指数的上升表明了人类对绿洲景观改造程度的不断加强,绿洲仍然维持着以耕地与居民地为主的强烈人为干扰的人工绿洲景观.人类不合理的土地利用方式改变了绿洲景观的空间格局,水资源条件的变化进一步促进了景观结构的演变.  相似文献   
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