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71.
Z. WangR.F. Grant M.A. ArainB.N. Chen N. CoopsR. Hember W.A. KurzD.T. Price G. StinsonJ.A. Trofymow J. Yeluripati Z. Chen 《Ecological modelling》2011,222(17):3236-3249
Forest productivity is strongly affected by seasonal weather patterns and by natural or anthropogenic disturbances. However weather effects on forest productivity are not currently represented in inventory-based models such as CBM-CFS3 used in national forest C accounting programs. To evaluate different approaches to modelling these effects, a model intercomparison was conducted among CBM-CFS3 and four process models (ecosys, CN-CLASS, Can-IBIS and 3PG) over a 2500 ha landscape in the Oyster River (OR) area of British Columbia, Canada. The process models used local weather data to simulate net primary productivity (NPP), net ecosystem productivity (NEP) and net biome productivity (NBP) from 1920 to 2005. Other inputs used by the process and inventory models were generated from soil, land cover and disturbance records. During a period of intense disturbance from 1928 to 1943, simulated NBP diverged considerably among the models. This divergence was attributed to differences among models in the sizes of detrital and humus C stocks in different soil layers to which a uniform set of soil C transformation coefficients was applied during disturbances. After the disturbance period, divergence in modelled NBP among models was much smaller, and attributed mainly to differences in simulated NPP caused by different approaches to modelling weather effects on productivity. In spite of these differences, age-detrended variation in annual NPP and NEP of closed canopy forest stands was negatively correlated with mean daily maximum air temperature during July-September (Tamax) in all process models (R2 = 0.4-0.6), indicating that these correlations were robust. The negative correlation between Tamax and NEP was attributed to different processes in different models, which were tested by comparing CO2 fluxes from these models with those measured by eddy covariance (EC) under contrasting air temperatures (Ta). The general agreement in sensitivity of annual NPP to Tamax among the process models led to the development of a generalized algorithm for weather effects on NPP of coastal temperate coniferous forests for use in inventory-based models such as CBM-CFS3: NPP′ = NPP − 57.1 (Tamax − 18.6), where NPP and NPP′ are the current and temperature-adjusted annual NPP estimates from the inventory-based model, 18.6 is the long-term mean daily maximum air temperature during July-September, and Tamax is the mean value for the current year. Our analysis indicated that the sensitivity of NPP to Tamax was nonlinear, so that this algorithm should not be extrapolated beyond the conditions of this study. However the process-based methodology to estimate weather effects on NPP and NEP developed in this study is widely applicable to other forest types and may be adopted for other inventory based forest carbon cycle models. 相似文献
72.
Large-scale environmental research efforts are conducted under frameworks that provide a common basis for evaluating research
in many diverse fields. Such frameworks should be subjected to critical review to determine if they meet crucial expectations.
In the case of the US Global Change Research Program, we perceive that most research follows a framework that we define as
the predictive model framework. We believe this framework is insufficient for resolving the unprecedented predicaments posed
by global change. We recommend a complementary framework, the system response framework, which directs research toward useful
indicators of change rather than precise predictions. We further argue that, even if research is complementary and effective
under the two frameworks, conclusive results prior to decisions should not be expected. The burden of proof must itself be
a continuing topic of open discourse and inquiry. 相似文献
73.
Reyer Gerlagh Snorre Kverndokk Knut Einar Rosendahl 《Journal of Environmental Economics and Management》2014
We study the optimal time path for clean energy innovation policy. In a model with emission reduction through clean energy deployment, and with R&D increasing the overall productivity of clean energy, we describe optimal R&D policies jointly with emission pricing policies. We find that while emission prices can be set at the Pigouvian level independently of innovation policy, the optimal level of R&D subsidies and patent lifetime change with the stages of the climate problem. In the early stages of clean energy development, innovators find it more difficult to capture the social value of their innovations. Thus, for a given finite patent lifetime, optimal clean energy R&D subsidies are initially high, but then fall over time. Alternatively, if research subsidies are kept constant, the optimal patent lifetime should initially be long and fall over time. 相似文献
74.
以大量的调查研究结果以及有关数据,论述了海南岛生物多样性的保护研究战略意义,并揭示了在开发利用中存在的问题,有针对性地提出了海南岛生物多样性保护研究的主要任务。 相似文献
75.
Due to the urgency and seriousness of the loss of biological diversity, scientists from across a range of disciplines are urged to increase the salience and use of their research by policy-makers. Increased policy nuance is needed to address the science–policy gap and overcome divergent views of separate research and policy worlds, a view still relatively common among conservation scientists. Research impact considerations should recognize that policy uptake is dependent on contextual variables operating in the policy sphere. We provide a novel adaptation of existing policy approaches to evidence impact that accounts for non-evidentiary “societal” influences on decision-making. We highlight recent analytical tools from political science that account for the use of evidence by policy-makers. Using the United Kingdom’s recent embrace of the ecosystem approach to environmental management, we advocate analyzing evidence research impact through a narrative lens that accounts for the credibility, legitimacy, and relevance of science for policy. 相似文献
76.
77.
新时期城市构造呈现多样性,加上城市化、工业化发展迅猛,城市的演变日新月异,如何对城市土壤环境监测点位布设的方法进行取舍是十分关键的,本文详细介绍了城市土壤环境监测点位布设的方法以及其应用的研究分析,希望能为我国城市土壤环境监测的相关研究提供参考。 相似文献
78.
British directors perspectives on the impact of health and safety on corporate performance 总被引:1,自引:0,他引:1
Occupational health and safety is established as a factor in international competitiveness, but we question the relevance of this economic argument at the organisational level. On this basis we assess the place of health and safety in the senior management agenda, based on findings from recent market research. Out of this we take a brief perspective on the literature on performance assessment and corporate reputation, and their relationship with health and safety in the workplace. We then report original in-depth research on directors' attitudes to and practice in workplace health and safety. We conclude with a summary of the key issues and a discussion of directions for further work. 相似文献
79.
80.
Matt Gillen Author Vitae 《Journal of Safety Research》2010,41(3):289-299
The U.S. National Institute for Occupational Safety and Health (NIOSH) conducts research to improve and protect the health and safety of workers. This paper describes the experience of the NIOSH Construction Program with two recent program planning initiatives intended to improve the program: (a) an independent external review of work over the past decade and (b) the development of strategic goals organized into a “National Construction Agenda” to guide a decade of future work. These goals, developed with input from construction industry stakeholders and researchers, are a part of the NIOSH National Occupational Research Agenda (NORA) initiative. The NORA goals are intended to provide an ambitious set of goals for all construction stakeholders to work together on. Both efforts relate to insuring the relevance and impact of research, reflecting an emerging policy perspective that research programs should be judged not just by the quality and quantity of science produced, but by the industry impact and tangible benefit resulting from the research. This paper describes how views on research planning have evolved to incorporate lessons learned about how research leads to improved safety and health for workers. It also describes the process used to develop the goals and the resulting strategic and intermediate goals that comprise the National Construction Agenda. 相似文献