In this paper,Eddy Correlation (EC) method was employed to measure the latent heat and CO 2 flux density and to calculate Water Use Efficiency (WUE) of winter wheat community in Yucheng district,Shandong Province in 1...In this paper,Eddy Correlation (EC) method was employed to measure the latent heat and CO 2 flux density and to calculate Water Use Efficiency (WUE) of winter wheat community in Yucheng district,Shandong Province in 1997.The results showed that the CO 2 flux density had an obvious diurnal change,with a maximum about1.5 mg·s -1 ·m -2 ,which appeared at about 9:00～10:00 am in general.The WUE of wheat community presented a fall trend from morning to afternoon,and the CO 2 flux density and WUE also had an obvious seasonal change,being lower in the early and late growth stages,and higher in the middle growth stage.The ranges of daily mean CO 2 flux density and WUE were 0.2～0.9 mg·s -1 ·m -2 and 5～20 gCO 2·kg -1 H 2O,respectively.展开更多
The dynamic changes of land system in Huang-Huai-Hai Plain between 1988 and 2000 were researched in this paper.Spatial dominance econometric model was estabilished on 1 km cell to quantificationally analyze the drivin...The dynamic changes of land system in Huang-Huai-Hai Plain between 1988 and 2000 were researched in this paper.Spatial dominance econometric model was estabilished on 1 km cell to quantificationally analyze the driving-force for the dynamic change mechanism of land system,such as natural,social and economic factors.The future dynamic changes of land system in Huang-Huai-Hai Plain on each 1 km cell during 2000 to 2020 were stimulated by combining the dynamic changes of land system on each 1 km cell with different situations.The research indicated that the dynamic changes of land system structure changed mainly from the cultivated areas to building areas and industrial areas,and forest areas increased during this period.Although the revolutions of land system structure were different during 2000 to 2020 with the different referrence standard,ecological protection and economic development,the primary dynamic changes of land system structure were that the increase of building land areas with the decline cultivated land areas and the increase of woodlands.展开更多
文摘In this paper,Eddy Correlation (EC) method was employed to measure the latent heat and CO 2 flux density and to calculate Water Use Efficiency (WUE) of winter wheat community in Yucheng district,Shandong Province in 1997.The results showed that the CO 2 flux density had an obvious diurnal change,with a maximum about1.5 mg·s -1 ·m -2 ,which appeared at about 9:00～10:00 am in general.The WUE of wheat community presented a fall trend from morning to afternoon,and the CO 2 flux density and WUE also had an obvious seasonal change,being lower in the early and late growth stages,and higher in the middle growth stage.The ranges of daily mean CO 2 flux density and WUE were 0.2～0.9 mg·s -1 ·m -2 and 5～20 gCO 2·kg -1 H 2O,respectively.
基金Supported by the National Natural Science Foundation of China(70503025)the Knowledge Innovation Project of Chinese Academy of Sci-ences(KZCX2-YW-305-2+3 种基金KSCX2-YW-N-039)the National Project of Scientific and Technical Supporting Programs(2006BAC08B032006BAC08B06)international cooperation program of science and technolo-gy ministry(2006DFB919201).~~
文摘The dynamic changes of land system in Huang-Huai-Hai Plain between 1988 and 2000 were researched in this paper.Spatial dominance econometric model was estabilished on 1 km cell to quantificationally analyze the driving-force for the dynamic change mechanism of land system,such as natural,social and economic factors.The future dynamic changes of land system in Huang-Huai-Hai Plain on each 1 km cell during 2000 to 2020 were stimulated by combining the dynamic changes of land system on each 1 km cell with different situations.The research indicated that the dynamic changes of land system structure changed mainly from the cultivated areas to building areas and industrial areas,and forest areas increased during this period.Although the revolutions of land system structure were different during 2000 to 2020 with the different referrence standard,ecological protection and economic development,the primary dynamic changes of land system structure were that the increase of building land areas with the decline cultivated land areas and the increase of woodlands.
