Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a...Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m 3 and 0.93-1.09 mg/m 3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 3l.743 mg/m 3, and averaged l.143 mg/m 3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m 3, the average was 1.168 mg/m 3. The primary productivity reached 1418.76 mgC/(m 2·d) in summer and 1360.69 mgC/(m 2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m 2·d) in summer and 159.04 mgC/(m 2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.展开更多
This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implement...This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implementation of selected energy saving measures in practice. The source data collected from the six european union （EU） countries represent five agricultural regions of continental Europe and three climates： continental, temperate and Mediterranean. The life cycle assessment （LCA） methodology was applied to analyze the data excluding of pre-farm gate activities. The total primary energy consumption was decomposed into main energy input streams and it was regressed to yield. In order to compare energy efficiency of wheat production across the geographical areas, the data envelopment analysis （DEA） was applied. It was shown that the highest wheat yield （6.7 t/ha to 8.7 t/ha） at the lowest specific energy input （2.08 GJ/t to 2.56 G J/t） is unique for temperate climate conditions. The yield in continental and Mediterranean climatic conditions is on average lower by 1.3 t/ha and 2.7 t/ha and energy efficiency lower by 14% and 38%, respectively. The case studies have shown that the energy saving activities in wheat production may be universal for the climatic zones or specific for a given geographical location. It was stated that trade-offs between energy, economic, and environmental effects, which are associated with implementation of a given energy saving measure or a set of measures to a great extent depend on the current energy efficiency status of the farm and opportunity for investment, which varies substantially across Europe.展开更多
文摘Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m 3 and 0.93-1.09 mg/m 3 in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 3l.743 mg/m 3, and averaged l.143 mg/m 3 below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m 3, the average was 1.168 mg/m 3. The primary productivity reached 1418.76 mgC/(m 2·d) in summer and 1360.69 mgC/(m 2·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m 2·d) in summer and 159.04 mgC/(m 2·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper.
文摘This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implementation of selected energy saving measures in practice. The source data collected from the six european union （EU） countries represent five agricultural regions of continental Europe and three climates： continental, temperate and Mediterranean. The life cycle assessment （LCA） methodology was applied to analyze the data excluding of pre-farm gate activities. The total primary energy consumption was decomposed into main energy input streams and it was regressed to yield. In order to compare energy efficiency of wheat production across the geographical areas, the data envelopment analysis （DEA） was applied. It was shown that the highest wheat yield （6.7 t/ha to 8.7 t/ha） at the lowest specific energy input （2.08 GJ/t to 2.56 G J/t） is unique for temperate climate conditions. The yield in continental and Mediterranean climatic conditions is on average lower by 1.3 t/ha and 2.7 t/ha and energy efficiency lower by 14% and 38%, respectively. The case studies have shown that the energy saving activities in wheat production may be universal for the climatic zones or specific for a given geographical location. It was stated that trade-offs between energy, economic, and environmental effects, which are associated with implementation of a given energy saving measure or a set of measures to a great extent depend on the current energy efficiency status of the farm and opportunity for investment, which varies substantially across Europe.
