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621.
城市空间扩展对生态系统服务价值的影响——以南宁市区为例 总被引:1,自引:0,他引:1
以南宁市区1994~2004年土地利用统计数据为基础,参照中国陆地生态系统服务价值系数,分析了南宁市区土地利用变化特征及其对生态系统服务价值的影响。结果表明,10年来,南宁市区土地利用变化比较剧烈,建设用地增加明显,且占用耕地和林地现象较为突出,林地、草地和水田面积减少较多,园地、旱地面积增加明显;区域生态系统服务价值由1994年的8751.9×106元/a下降到2004年的8 636.5×106元/a,区域生态系统服务功能出现明显衰退。 相似文献
622.
利用RAPD分子标记技术分析了医化废水驯化过程中细菌的遗传多样性. 结果表明:9种引物在5种浓度的废水驯化细菌中共扩增出134条带,其中88条表现为多态性,多态性位点百分率为65.7%. 根据Jacaard相异系数转换的距离矩阵,富集细菌与10%医化废水驯化细菌及20%医化废水驯化细菌之间的遗传距离最大,为0.750 0;而20%医化废水驯化细菌与40%医化废水驯化细菌之间遗传距离最小,为0.545 5. UPGMA法聚类结果表明,富集细菌与5%医化废水驯化细菌聚在一起组成一组;20%医化废水驯化细菌与40%医化废水驯化细菌先聚在一起,再与10%医化废水驯化细菌聚在一起组成另一组. 相似文献
623.
David J. Baker Stephen T. Garnett James O'Connor Glenn Ehmke Rohan H. Clarke John C.Z. Woinarski Melodie A. McGeoch 《Conservation biology》2019,33(2):319-328
Human modification of the environment is driving declines in population size and distributional extent of much of the world's biota. These declines extend to many of the most abundant and widespread species, for which proportionally small declines can result in the loss of vast numbers of individuals, biomass, and interactions. These losses could have major localized effects on ecological and cultural processes and services without elevating a species’ global extinction risk. Although most conservation effort is directed at species threatened with extinction in the very near term, the value of retaining abundance regardless of global extinction risk is justifiable based on many biodiversity or ecosystem service metrics, including cultural services, at scales from local to global. The challenges of identifying conservation priorities for widespread and abundant species include quantifying the effects of species’ abundance on services and understanding how these effects are realized as populations decline. Negative effects of population declines may be disconnected from the threat processes driving declines because of species movements and environment flows (e.g., hydrology). Conservation prioritization for these species shares greater similarity with invasive species risk assessments than extinction risk assessments because of the importance of local context and per capita effects of abundance on other species. Because conservation priorities usually focus on preventing the extinction of threatened species, the rationale and objectives for incorporating declines of nonthreatened species must be clearly articulated, going beyond extinction risk to encompass the range of likely harmful effects (e.g., secondary extinctions, loss of ecosystem services) if declines persist or are not reversed. Research should focus on characterizing the effects of local declines in species that are not threatened globally across a range of ecosystem services and quantifying the spatial distribution of these effects through the distribution of abundance. The case for conserving abundance in nonthreatened species can be made most powerfully when the costs of losing this abundance are better understood. 相似文献
624.
IntroductionEmergency service vehicle crashes (ESVCs), including rollovers and collisions with other vehicles and fixed objects, are a leading cause of death among U.S. firefighters. Risk management (RM) is a proactive intervention to identifying and mitigating occupational risks and hazards. The goal of this study was to assess the effect of RM in reducing ESVCs. Methods: Three fire departments (A, B and C), representing urban and suburban geographies, and serving medium to large populations, participated in facilitated RM programs to reduce their ESVCs. Interventions were chosen by each department to address their department-specific circumstances and highest risks. Monthly crash rates per 10,000 calls were calculated for each department an average of 28 months before and 23 months after the start of the RM programs. Interrupted time series analysis was used to assess the effect of the RM programs on monthly crash rates. Poisson regression was used to estimate the number of crashes avoided. Economic data from Department A were analyzed to estimate cost savings. Results: Department A had a 15.4% (P = 0.30) reduction in the overall monthly crash rate immediately post-RM and a 1% (P = 0.18) decline per month thereafter. The estimated two-year average cost savings due to 167 crashes avoided was $253,100 (95%CI= $192,355 – $313,885). Department B had a 9.7% (P = 0.70) increase in the overall monthly crash rate immediately post-RM and showed no significant changes in their monthly crash rate. Department C had a 28.4% (P = 0.001) reduction in overall monthly crash rate immediately post-RM and a 1.2% (P = 0.09) increase per month thereafter, with an estimated 122 crashes avoided. Conclusions: RM programs have the potential to reduce ESVCs in the fire service and their associated costs; results may vary based on the interventions chosen and how they are implemented. Practical applications: Risk management may be an effective and broadly implemented intervention to reduce ESVCs in the US fire service. 相似文献
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628.
池塘养殖生态系统空气调节服务价值的实证研究 总被引:4,自引:1,他引:3
生态服务价值的评估对于研究人员、政策制定者和公众都有重大意义,而农业生态系统价值往往集中于食物的供给价值,而生态系统的调控服务价值、支持服务价值和文化服务价值往往被忽略。空气调控服务属于生态系统调控服务中的一种,通过按季度检测池塘养殖水体的叶绿素a含量,计算养殖池塘的初级生产力,再以工业制氧法、碳税法和造林成本法估算了常规鱼类池塘养殖生态系统空气调节服务价值。结果表明:常规鱼类池塘养殖生态系统空气调节服务总价值为63 42248 yuan/a〖DK1〗·hm2。考虑到系统内部耗氧和向系统外释放含碳气体导致的价值损失,常规鱼类池塘养殖生态系统空气调节服务总净价值为28 88674 yuan/a〖DK1〗·hm2,其中固碳净价值为 25 46328 yuan/a〖DK1〗·hm2,释放氧气的净价值为3 42346 yuan/a〖DK1〗·hm2。相较44 0221 yuan/a〖DK1〗·hm2的池塘养殖水产品的市场价值,空气调节服务价值超过养殖水产品市场价值的一半以上,表明池塘养殖的生态服务价值对人类社会的贡献不可忽视。研究认为,由于池塘藻类的高增长率,常规水产池塘养殖系统空气调节服务价值高于一些种植业生态系统的空气调节服务价值。 相似文献
629.
安全生产中介组织建设与发展 总被引:2,自引:0,他引:2
阴建康 《中国安全生产科学技术》2009,5(2):125-128
社会主义市场经济体制要求政府职能转变成适合市场经济体制要求的功能,随着产权多元化、企业自主经营为基本内容的经济体制改革促使企业和政府所分离出来的大量社会事务,需要大量的专业人力、物力资源,特殊的运行机制去配置,有大量的工作需要有执行特定社会职能的组织去从事;要实现这一领域里活动的有序进行,需要特定的体制和机制去协调。因此,如何根据社会中介组织的特征把握发展方向,如何对社会中介组织功能进行科学定位,本文进行了论述和研究探索。根据社会中介组织功能定位,发挥其在政府和生产经营单位之间的联结纽带和桥梁的作用。通过研究当前安全生产中介发展过程中存在的现实问题和薄弱环节入手,探寻安全中介技术服务工作的切入点以及有利于安全生产的工作方式和手段,积极推进我国安全生产形势的稳步好转。 相似文献
630.
基于西安交通大学医学院第一附属医院发生的严重感染事件,简要介绍颇受关注的"组织事故"理论,尝试探索医疗事故的组织因素。做到医院安全行医,不仅要建立完善的医疗管理体系,并把管理制度深刻融入到组织成员的意识、观念中,加强安全医疗意识,还要加强医院感染应急系统及预案,建立可行的医疗风险防范机制及加强对医务工作者的管理;最重要的是在组织运营中不断发现和纠正其中的错误,提高组织的安全管理系统水平,体现安全文化的管理哲学。做到以上几点,才有可能避免医疗事故,让患者安全就医。 相似文献