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111.
MARTIN M. GOSSNER THIBAULT LACHAT JÖRG BRUNET GUNNAR ISACSSON CHRISTOPHE BOUGET HERVÉ BRUSTEL ROLAND BRANDL WOLFGANG W. WEISSER JÖRG MÜLLER 《Conservation biology》2013,27(3):605-614
With the aim of wood production with negligible negative effects on biodiversity and ecosystem processes, a silvicultural practice of selective logging with natural regeneration has been implemented in European beech forests (Fagus sylvatica) during the last decades. Despite this near‐to‐nature strategy, species richness of various taxa is lower in these forests than in unmanaged forests. To develop guidelines to minimize the fundamental weaknesses in the current practice, we linked functional traits of saproxylic beetle species to ecosystem characteristics. We used continental‐scale data from 8 European countries and regional‐scale data from a large forest in southern Germany and forest‐stand variables that represented a gradient of intensity of forest use to evaluate the effect of current near‐to‐nature management strategies on the functional diversity of saproxylic beetles. Forest‐stand variables did not have a statistically significant effect on overall functional diversity, but they did significantly affect community mean and diversity of single functional traits. As the amount of dead wood increased the composition of assemblages shifted toward dominance of larger species and species preferring dead wood of large diameter and in advanced stages of decay. The mean amount of dead wood across plots in which most species occurred was from 20 to 60 m3/ha. Species occurring in plots with mean dead wood >60 m3/ha were consistently those inhabiting dead wood of large diameter and in advanced stages of decay. On the basis of our results, to make current wood‐production practices in beech forests throughout Europe more conservation oriented (i.e., promoting biodiversity and ecosystem functioning), we recommend increasing the amount of dead wood to >20 m3/ha; not removing dead wood of large diameter (50 cm) and allowing more dead wood in advanced stages of decomposition to develop; and designating strict forest reserves, with their exceptionally high amounts of dead wood, that would serve as refuges for and sources of saproxylic habitat specialists. Efectos Actuales del Manejo Casi Natural de Bosques sobre la Composición de Atributos Funcionales de Escarabajos Saproxílicos en Bosques de Haya 相似文献
112.
GPS车辆行驶记录定位监控信息管理系统 总被引:3,自引:2,他引:1
王来忠 《中国安全科学学报》2008,18(6)
利用GPS,GIS和GSM等技术,试验开发"GPS车辆行驶记录定位监控信息管理系统"。该系统由GPS定位系统、GPRS/CDMA移动通讯网络、Internet、监控中心组成。对装有车载终端的车辆进行行驶状态的数据采集,通过处理存储到数据库中,为管理人员查阅分析车辆当前状态提供数据。应用信息管理系统后,管理人员能及时了解掌握车辆的方位和状况,提高了生产和安全管理的效率,杜绝了跑私车、绕路行车等现象,有着较好的经济效益。由于信息系统的全天候、全方位监控车辆功能,为应对车辆行驶的安全突发事件的救助和决策提供了有效的手段,具有较好的安全运行效率、社会效益以及广泛的推广应用前景。 相似文献
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115.
根据某类事件发生时的行星空间位置分布,可以从理论上建立该事件的时间预测模型.指出这一方法有可能通过计时历史资料的归算,提供未来灾害事件发生时刻的预测信息.以地震为例,给出了该方法的具体思路.处理了1900-1996年中国震级6.5及以上级的311次地震资料,据此:(1)统计得出了历史时期的地震时间与行星位置分布的相关性;(2)利用这种相关性并以7星组合作1997-2010年间6.5及以上级地震的模拟预测,给出了6个可能的危险日期;(3)采用1997年1月至2006年6月的35次M6.5级地震对模型作检验,表明总计14种单星和组合模型中日、月、水星、金星和天王星等五种模型稍好,而冥王星和海王星模型则不理想.(4)指出该模型不适用于较大区域,因其难以提供较精确的地点信息.此外,预测精度还与步长和确定的危险日期的数量有关. 相似文献
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117.
DAVID J. HOEINGHAUS‡ ANGELO A. AGOSTINHO† LUIZ C. GOMES† FERNANDO M. PELICICE†§ EDSON K. OKADA† JOÃO D. LATINI† ELAINE A. L. KASHIWAQUI† KIRK O. WINEMILLER 《Conservation biology》2009,23(5):1222-1231
Abstract: Applying the ecosystem services concept to conservation initiatives or in managing ecosystem services requires understanding how environmental impacts affect the ecology of key species or functional groups providing the services. We examined effects of river impoundments, one of the leading threats to freshwater biodiversity, on an important ecosystem service provided by large tropical rivers (i.e., artisanal fisheries). The societal and economic importance of this ecosystem service in developing countries may provide leverage to advance conservation agendas where future impoundments are being considered. We assessed impoundment effects on the energetic costs of fisheries production (embodied energy) and commercial market value of the artisanal fishery of the Paraná River, Brazil, before and after formation of Itaipu Reservoir. High-value migratory species that dominated the fishery before the impoundment was built constituted a minor component of the contemporary fishery that is based heavily on reservoir-adapted introduced species. Cascading effects of river impoundment resulted in a mismatch between embodied energy and market value: energetic costs of fisheries production increased, whereas market value decreased. This was partially attributable to changes in species functional composition but also strongly linked to species identities that affected market value as a result of consumer preferences even when species were functionally similar. Similar trends are expected in other large tropical rivers following impoundment. In addition to identifying consequences of a common anthropogenic impact on an important ecosystem service, our assessment provides insight into the sustainability of fisheries production in tropical rivers and priorities for regional biodiversity conservation . 相似文献
118.
通过对目前瓦斯治理方法的对比,结合煤层瓦斯赋存与流动理论、回采工作面矿山压力规律及采场覆岩移动规律、采空区“O”型圈等理论,提出利用地面L型钻孔抽采煤层顶板裂隙带瓦斯的方法,用于缓解低位采空区抽采巷抽采负担,消除安全隐患。实践表明:地面L型钻孔使低位采空区抽采巷平均浓度由4.43%降低到3.37%,降低了24%,治理效果明显,该方法能为大采高综放工作面瓦斯治理工作提供新的思路。 相似文献
119.
为了探讨开口的位置与尺寸对受限空间内的细水雾灭火有效性的影响,设计了一个尺寸为1.2 m×1.2 m×1.2 m的特殊受限空间模拟实验台,开展了一系列细水雾灭火对比实验,测量了烟气温度以及灭火时间等实验参数,通过改变实验燃料、火源功率、开口尺寸、开口位置等因素来研究开口对特殊受限空间内细水雾灭火有效性的影响规律。结果表明:在特殊受限空间内,相同条件下,开口位置由下至上,细水雾抑制火灾有效性由低至高;开口尺寸由大至小,细水雾抑制火灾有效性由高至低。当开口尺寸足够小以后,细水雾抑制火灾有效性反而会逐渐增强。 相似文献
120.
Genetic modification leads to several important moral issues. Up until now they have mainly been discussed from the viewpoint that only individual living beings, above all animals, are morally considerable. The standpoint that also collective entities such as species belong to the moral sphere have seldom been taken into account in a more thorough way, although it is advocated by several important environmental ethicists. The main purpose of this article is to analyze in more detail than often has been done what the practical consequences of this ethical position would be for the use of genetic engineering on animals and plants. The practical consequences of the holistic standpoint (focused on collective entities) of Holmes Rolston, III, is compared with the practical consequences of the individualistic standpoints (focused on individual living beings) of Bernard E. Rollin and Philipp Balzer, Klaus Peter Rippe, and Peter Schaber, respectively. The article also discusses whether the claim that species are morally considerable is tenable as a foundation for policy decisions on genetic engineering. 相似文献