Climate change and forage-intake are important components of livestock population systems,but our knowledge about the effects of changes in these properties on livestock is limited,particularly on the Northern Tibetan...Climate change and forage-intake are important components of livestock population systems,but our knowledge about the effects of changes in these properties on livestock is limited,particularly on the Northern Tibetan Plateau.Based on corresponding independent models（CASA and TEM）,a human-induced NPP（NPPH） value and forage-intake threshold were obtained to determine their influences on livestock population fluctuation and regrowth on the plateau.The intake threshold value provided compatible results with livestock population performance.If the forage-intake was greater than the critical value of 1.9（kg DM d^（-1） sheep^（-1））,the livestock population increased;otherwise,the livestock population decreased.It takes four years to transfer a disturbance in primary productivity to the next trophic level.The relationships between livestock population and NPP_H value determined population dynamics via the forage-intake value threshold.Improved knowledge on lag effects will advance our understanding of drivers of climatic changes on livestock population dynamics.展开更多
To investigate the long-term operating efficiencies of container ports, we extend the work of previous researches to present a new systemic and improved method of data envelopment analysis （DEA）-based Malmquist prod...To investigate the long-term operating efficiencies of container ports, we extend the work of previous researches to present a new systemic and improved method of data envelopment analysis （DEA）-based Malmquist productivity index （MPI） in this paper. An approach based on both panel data and multi-inputs/outputs is considered comprehensively, and aims at measuring the operating efficiencies of 10 leading container ports in China from 2001 to 2006 by applying this new systematic influence factor of total factor productivity change is the calculation method. The results illustrate that the main technology change, and the container transportation of these 10 ports is on the healthy development status and will recover and grow reposefully in the following years展开更多
基金Chinese Academy of Sciences project(XDB03030400)National Basic Research Program of China(2010CB951704)National Sciences Foundation of China(41171044)
文摘Climate change and forage-intake are important components of livestock population systems,but our knowledge about the effects of changes in these properties on livestock is limited,particularly on the Northern Tibetan Plateau.Based on corresponding independent models（CASA and TEM）,a human-induced NPP（NPPH） value and forage-intake threshold were obtained to determine their influences on livestock population fluctuation and regrowth on the plateau.The intake threshold value provided compatible results with livestock population performance.If the forage-intake was greater than the critical value of 1.9（kg DM d^（-1） sheep^（-1））,the livestock population increased;otherwise,the livestock population decreased.It takes four years to transfer a disturbance in primary productivity to the next trophic level.The relationships between livestock population and NPP_H value determined population dynamics via the forage-intake value threshold.Improved knowledge on lag effects will advance our understanding of drivers of climatic changes on livestock population dynamics.
基金the National Natural Science Foundation of China (No. 50578030)
文摘To investigate the long-term operating efficiencies of container ports, we extend the work of previous researches to present a new systemic and improved method of data envelopment analysis （DEA）-based Malmquist productivity index （MPI） in this paper. An approach based on both panel data and multi-inputs/outputs is considered comprehensively, and aims at measuring the operating efficiencies of 10 leading container ports in China from 2001 to 2006 by applying this new systematic influence factor of total factor productivity change is the calculation method. The results illustrate that the main technology change, and the container transportation of these 10 ports is on the healthy development status and will recover and grow reposefully in the following years
