土壤氮素矿化模型研究进展

土壤氮素矿化研究对从农田生态系统氮素平衡到全球变化和环境问题均具有重要意义。土壤氮素矿化模型的研究方面．目前主要还是以简单功能模型模拟和预测氮素矿化量为主,以双组分一阶动力学模型和一阶-零阶混和动力学模型拟合效果较好;对机理模型的研究还处于探索阶段。从目前的研究看,土壤氮素矿化模型研究应当集中在建立机理模型以阐明主要生态系统的氮素矿化过程。     

A review of WTO and environmental issues

Multiple negotiating rounds of the General Agreement on Tariffs and Trade (GATT) and World Trade Organization (WTO) since 1947 have conferred economic benefits through liberalized international trade. A growing body of evidence also points to linkages between liberalized trade and damage to the global environment, ecology, and natural resource base. Ironically, the increased economic well-being conferred by trade liberalization ultimately provides the basis for improved environmental protection. It is the interim environmental damage due to trade liberalization that is controversial and needing amelioration. The proposition here is to promote further trade liberalization, but only as long as environmental ethics and sustainability issues are satisfactorily addressed. Trade liberalization should not be permitted at the expense of adequate environmental protection and sustainability. Future WTO rounds need to address both development benefits and environmental ethics issues in a net social welfare maximization setting.     

GIS与大气质量模型结合的探讨

从GIS与大气环境质量模型结合的必要性入手 ,对GIS在大气环境质量模型中的应用、所起作用进行了回顾 ,同时就二者结合的基本方式、步骤、框架等作了一些探讨 ,并指出了其未来的发展趋势。 更多还原      

A Review of WTO and Environmental Issues

Multiple negotiating rounds of the GeneralAgreement on Tariffs and Trade (GATT) and World TradeOrganization (WTO) since 1947 have conferred economicbenefits through liberalized international trade. Agrowing body of evidence also points to linkagesbetween liberalized trade and damage to the globalenvironment, ecology, and natural resource base.Ironically, the increased economic well-beingconferred by trade liberalization ultimately providesthe basis for improved environmental protection. It isthe interim environmental damage due to tradeliberalization that is controversial and needingamelioration. The proposition here is to promotefurther trade liberalization, but only as long asenvironmental ethics and sustainability issues aresatisfactorily addressed. Trade liberalization shouldnot be permitted at the expense of adequateenvironmental protection and sustainability. FutureWTO rounds need to address both development benefitsand environmental ethics issues in a net socialwelfare maximization setting.     

21世纪初我国粮食供需的新空间格局

利用2000-2003年县级统计数据,揭示21世纪初我国粮食供需的空间格局。我国粮食供需平衡以东西分异规律为主,其次是南北分异。地势第二级阶梯以东,主要余粮区分布最广,北方明显多于南方;胡焕庸线以西,常年缺粮区为主;两线之间,潜在缺粮区居多。东北地区、华北平原生产全国近70%的余粮。长江中下游以南地区既是我国温饱水平缺粮总数最多的地区,也是第三大余粮生产区。地势第二级阶梯上的农牧交错带,温饱水平缺粮总量列第二位,是我国粮食安全最脆弱的地区。上述地区主要位于环境变化敏感地带,粮食安全自然风险最大。因此,加强环境变化对粮食供需平衡的影响研究,对深入认识我国粮食供需平衡的稳定性具有重要的现实意义和理论价值。     

论可持续发展的区际关系内涵与我国西部大开发

本文在揭示可持续发展的宏观、中观、微观区际关系内涵的基础上,对我国西部大开发和如何协调区际关系,实现可持续发展提出了建议。     

The earth system: regional–global linkages

Understanding the earth system requires that the two-way linkages between regions and the global system be well understood and predictable. Most studies of global change are undertaken thematically across limited disciplinary boundaries; few are attempted holistically across many disciplines within regions. The regional approach offers many advantages. Here a variety of linkages associated with the regions of Southern Africa, South Asia, East Asia and Southeast Asia are presented to illustrate the power of a regional approach to earth system science. Major findings include the extent to which long-range transport of aerosols and nutrients affect terrestrial and marine ecosystem functioning in and around southern Africa. Aerosol transport, and the development of a regional haze layer, over South Asia are shown to alter significantly the radiative forcing of change in the atmosphere over the region. Changes in land cover and use over East Asia over along period of time are shown to have affected the strength of the monsoon circulation significantly. Finally, rampant economic development and globalization in Southeast Asia are demonstrated to have been a significant driver of regional change. Electronic Publication     

Situational awareness and safety

This paper considers the applicability of situation awareness concepts to safety in the control of complex systems. Much of the research to date has been conducted in aviation, which has obvious safety implications. It is argued that the concepts could be extended to other safety critical domains. The paper presents three theories of situational awareness: the three-level model, the interactive sub-systems approach, and the perceptual cycle. The difference between these theories is the extent to which they emphasise process or product as indicative of situational awareness. Some data from other studies are discussed to consider the negative effects of losing situational awareness, as this has serious safety implications. Finally, the application of situational awareness to system design, and training are presented.     

Comparing environmental influences on coral bleaching across and within species using clustered binomial regression

Differential susceptibility among reef-building coral species can lead to community shifts and loss of diversity as a result of temperature-induced mass bleaching events. We evaluate environmental influences on coral colony bleaching over an 8-year period in the Florida Keys, USA. Clustered binomial regression is used to develop models incorporating taxon-specific responses to the environment in order to identify conditions and species for which bleaching is likely to be severe. By building three separate models incorporating environment, community composition, and taxon-specific responses to environment, we show observed prevalence of bleaching reflects an interaction between community composition and local environmental conditions. Environmental variables, including elevated sea temperature, solar radiation, and reef depth, explained 90% and 78% of variability in colony bleaching across space and time, respectively. The effects of environmental variables were only partially explained (33% of variability) by corresponding differences in community composition. Taxon-specific models indicated individual coral species responded differently to local environmental conditions and had different sensitivities to temperature-induced bleaching. For many coral species, but not all, bleaching was exacerbated by high solar radiation. A 25% reduction in the probability of bleaching in shallow locations for one species may reflect an ability to acclimatize to local conditions. Overall, model results indicate predictions of coral bleaching require knowledge of not just the environmental conditions or community composition, but the responses of individual species to the environment. Model development provides a useful tool for coral reef management by quantifying the influence of the local environment on individual species bleaching sensitivities, identifying susceptible species, and predicting the likelihood of mass bleaching events with changing environmental conditions.     

Prospective spatial prediction of infectious disease: experience of New York State (USA) with West Nile Virus and proposed directions for improved surveillance

Infectious disease surveillance has become an international top priority due to the perceived risk of bioterrorism. This is driving the improvement of real-time geo-spatial surveillance systems for monitoring disease indicators, which is expected to have many benefits beyond detecting a bioterror event. West Nile Virus surveillance in New York State (USA) is highlighted as a working system that uses dead American Crows (Corvus brachyrhynchos) to prospectively indicate viral activity prior to human onset. A cross-disciplinary review is then presented to argue that this system, and infectious disease surveillance in general, can be improved by complementing spatial cluster detection of an outcome variable with predictive “risk mapping” that incorporates spatiotemporal data on the environment, climate and human population through the flexible class of generalized linear mixed models.