[Objective] Jishu 21 with strong drought tolerance and Jizishu 1 with weak drought tolerance were chosen to reveal antioxidant characteristics in seedling roots of sweetpotato with different drought tolerance. [Method...[Objective] Jishu 21 with strong drought tolerance and Jizishu 1 with weak drought tolerance were chosen to reveal antioxidant characteristics in seedling roots of sweetpotato with different drought tolerance. [Method] Active oxygen, antioxidant substances and antioxidant enzymes in seedling roots of sweetpotato with different drought tolerance were analyzed by hydroponics with PEG-6000 for simulating drought stress in the experiment. [Result] The results showed that under drought stress, H202 content and formation rate of 02_ in seedling roots of Jizishul were higher than Jishu 21 by 1.9% and 102.6%, respectively, the contents of Vc in seed- ing roots of Jizishu 1 and Jizishu 1 increased by 25.3% and 81.1%, respectively, and the contents of polyphenols increased by 24.8% and 37.6% in the two vari- eties, respectively. The increase amplitudes of Jizishu 1 were higher than Jishu 21 in the above indexes. Antioxidant enzyme activities were higher in seedling roots of Jisl^u 21 and Jizishul under drought stress than normal treatments; and among them, POD activity was the highest, while PPO activity was the lowest in all an- tioxidant enzymes. The increases of SOD, POD, APX and PPO activities in Jishu 21 were twice of those in Jizishul. The bands of SOD3, POD2, CAT1, APX2 and PPO2 changed obviously between the drought treatments of the two varieties. [Con- clusion] In conclusion, stronger drought tolerance in sweetpotato results in lower in- crease amplitudes of H202 content, formation rate of 02- and contents of Vc and polyphenols under drought stress, and the activities of antioxidant enzymes are stronger in seeding roots under drought stress; and the differences in antioxidant enzymes are mainly related to the changes of isoenzymes including SOD3, POD2, CAT1. APX2 and PPO2.展开更多
Lop Nur potash mine greening projects is located in the heart of the Lop Nur, known as the "green zone ban". The project overcomes the extreme drought, high temperature, gale and dust salt and salt, and many other a...Lop Nur potash mine greening projects is located in the heart of the Lop Nur, known as the "green zone ban". The project overcomes the extreme drought, high temperature, gale and dust salt and salt, and many other adverse environmen- tal factors. Adopted the suitable salt improvement measures and management tech- nology, the artificial green has emerged in the sea of death. At the same time the greening project improved the office environment of mining area, and shaped ex- treme environment greening projects successful cases.展开更多
[Objective] This study aimed to reveal responses of Magnolia multiflora to soil drought stress. [Method] Pot experiment was employed to simulate drought stress, and photosynthetic and physiological indices of M. multi...[Objective] This study aimed to reveal responses of Magnolia multiflora to soil drought stress. [Method] Pot experiment was employed to simulate drought stress, and photosynthetic and physiological indices of M. multiflora were determined. [Result] The net photosynthetic rate (Pn) of M. multiflora did not change significantly under mild drought stress, and reduced significantly under moderate and severe drought stress. Drought stress reduced stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO2 concentration (Ci), and compared with those in the control group, the Pn, Gs, Tr and Ci under severe drought stress declined by 61.04%, 86.27%, 87.77% and 42.63%, respectively. The malondialdehyde (MDA) content in M. multiflora leaves did not increase significantly under mild drought stress, and increased significantly under moderate and severe drought stress. The MDA content in M. multiflora leaves under severe drought stress was 1.63 times as high as that in the control group. The proline (Pro) and soluble sugar contents of M. multiflora increased significantly with the aggravation of drought stress, and those under severe drought stress were 8.06 times and 3.16 times respectively higher than those in the control group. [Conclusion] M. multiflora has a strong drought tolerance, and is suitable for growing in relatively arid environment. It can be used as candidate for vegetation restoration in hydropower engineering slope.展开更多
This paper summarizes research related to the 2012 record the NEWS (NASA (National Aeronautics and Space Administration) drought in the central United States conducted by members of Energy and Water cycle Study) W...This paper summarizes research related to the 2012 record the NEWS (NASA (National Aeronautics and Space Administration) drought in the central United States conducted by members of Energy and Water cycle Study) Working Group. Past drought patterns were analyzed for signal coherency with latest drought and the contribution of long-term trends in the Great Plains low-level jet, an important regional circulation feature of the spring rainy season in the Great Plains. Long-term changes in the seasonal transition from rainy spring into dry summer were also examined. Potential external forcing from radiative processes, soil-air interactions, and ocean teleconnections were assessed as contributors to the intensity of the drought. The atmospheric Rossby wave activity was found to be a potential source of predictability for the onset of drought. A probabilistic model was introduced and evaluated for its performance in predicting drought recovery in the Great Plains.展开更多
Some unsaturated soils may undergo volumetric changes when submitted to an increase in its water content or are inundated under applied loads. This behavior is related to the volumetric instability when the water cont...Some unsaturated soils may undergo volumetric changes when submitted to an increase in its water content or are inundated under applied loads. This behavior is related to the volumetric instability when the water content is changed. Natural collapsible soils in Brazil are generally found in alluvial, colluvial and residual soils. There are known occurrences of natural collapsible soils in many states of Brasil. In the last two decades, many public projects have been developed in areas where the occurrence of collapsible soils has been associated to geotechnical problems. The present paper devoted to study the collapsible soils in the state of Pernambuco which has been associated with large engineering projects such as housing and irrigation canals. The geotechnical investigation program included test with a field apparatus, called Expanso-colapsometer, which allows the measurement of the field settlements of a small 0.10 m of diameter plate inserted at any depth inside an auger boring hole. Reconnaissance borings with SPT (standard penetration test), investigation pits with undisturbed block sampling and disturbed samples for laboratory tests were also made in order to assess the type and characteristics of the soil. Field tests used the Expanso-colapsometer to measure the settlement of the soil in selected depths under controlled flooding. Laboratory work included double and standard oedometer tests with a controlled rate of water inflow of 1.0 mL/s. It was found that the volume change of the soils when flooded depends on their natural stress state (vertical stress, suction head and structure of soil).展开更多
Climate change will lead to a significant alteration in the temporal and spatial pattern variation in the regional hydrological cycle, and the subsequent lack of water, environmental deterioration, floods and droughts...Climate change will lead to a significant alteration in the temporal and spatial pattern variation in the regional hydrological cycle, and the subsequent lack of water, environmental deterioration, floods and droughts etc. And it is especially remarkable in semi-humid and semi-arid region. In this paper, the impacts of climate change on the hydrological cycle were analyzed for the Hai River Basin, a semi-humid and semi-arid basin and also the water receiving area of the middle route of South-to-North Water Diversion project. Meanwhile it is the most vulnerable to climate change. Firstly, the linear regression and Mann-Kendall non-parametric test methods were used to analyze the change characteristics of the hydrological and meteorological elements for the period from 1960 to 2009. The results show a significant increase in temperature, while precipitation decreases slightly, and runoff decreases drastically over the past 50 years. Secondly, the applicability of SWAT (Soil and Water Assessment Tool) model based on the DEM (Digital Elevation Model), land use and soil type was verified in the basin. Results show the model performs well in this basin. Furthermore, the water balance model, Fu's theory and Koichiro's theory were used to calculate the actual evaporation, comparing to the simulated actual evaporation by SWAT model to validate the result for the lack of large-scale observed evaporation datasets. Possible reasons were also analyzed to explore the reasonable factor for the decline of the runoff. Finally the precipitation, temperature, runoff and evaporation response processes based on the IPCC AR4 multi-mode climate models and the verified SWAT model under different GHG emission scenarios (SRES-A2, AIB and B1) in the 21st century were discussed in three time periods: 2020s (2011-2040), 20S0s (2041-2070), 2080s (2071-2099). Results show that there are systematic positive trends for precipitation and temperature while the trends for runoff and evaporation will differ among sub-areas. The results will offer some references for adaptive water management in a changing environment, also including adaptation of a cross-basin water transfer project.展开更多
基金Supported by the Earmarked Fund for China Agriculture Research System(CARS-11-B-11)~~
文摘[Objective] Jishu 21 with strong drought tolerance and Jizishu 1 with weak drought tolerance were chosen to reveal antioxidant characteristics in seedling roots of sweetpotato with different drought tolerance. [Method] Active oxygen, antioxidant substances and antioxidant enzymes in seedling roots of sweetpotato with different drought tolerance were analyzed by hydroponics with PEG-6000 for simulating drought stress in the experiment. [Result] The results showed that under drought stress, H202 content and formation rate of 02_ in seedling roots of Jizishul were higher than Jishu 21 by 1.9% and 102.6%, respectively, the contents of Vc in seed- ing roots of Jizishu 1 and Jizishu 1 increased by 25.3% and 81.1%, respectively, and the contents of polyphenols increased by 24.8% and 37.6% in the two vari- eties, respectively. The increase amplitudes of Jizishu 1 were higher than Jishu 21 in the above indexes. Antioxidant enzyme activities were higher in seedling roots of Jisl^u 21 and Jizishul under drought stress than normal treatments; and among them, POD activity was the highest, while PPO activity was the lowest in all an- tioxidant enzymes. The increases of SOD, POD, APX and PPO activities in Jishu 21 were twice of those in Jizishul. The bands of SOD3, POD2, CAT1, APX2 and PPO2 changed obviously between the drought treatments of the two varieties. [Con- clusion] In conclusion, stronger drought tolerance in sweetpotato results in lower in- crease amplitudes of H202 content, formation rate of 02- and contents of Vc and polyphenols under drought stress, and the activities of antioxidant enzymes are stronger in seeding roots under drought stress; and the differences in antioxidant enzymes are mainly related to the changes of isoenzymes including SOD3, POD2, CAT1. APX2 and PPO2.
基金Supported by National Natural Science Foundation of China(31300449)Science and Technology Support Program of Xinjiang Uyghur Autonomous Region(201433101)+1 种基金Doctoral Fund in the West of China of the Chinese Academy of Sciences(XBBS201205)Major Science and Technology Program of Xinjiang Uyghur Autonomous Region(201130106-3)
文摘Lop Nur potash mine greening projects is located in the heart of the Lop Nur, known as the "green zone ban". The project overcomes the extreme drought, high temperature, gale and dust salt and salt, and many other adverse environmen- tal factors. Adopted the suitable salt improvement measures and management tech- nology, the artificial green has emerged in the sea of death. At the same time the greening project improved the office environment of mining area, and shaped ex- treme environment greening projects successful cases.
基金Supported by National Natural Science Foundation of China(No.51179094)~~
文摘[Objective] This study aimed to reveal responses of Magnolia multiflora to soil drought stress. [Method] Pot experiment was employed to simulate drought stress, and photosynthetic and physiological indices of M. multiflora were determined. [Result] The net photosynthetic rate (Pn) of M. multiflora did not change significantly under mild drought stress, and reduced significantly under moderate and severe drought stress. Drought stress reduced stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO2 concentration (Ci), and compared with those in the control group, the Pn, Gs, Tr and Ci under severe drought stress declined by 61.04%, 86.27%, 87.77% and 42.63%, respectively. The malondialdehyde (MDA) content in M. multiflora leaves did not increase significantly under mild drought stress, and increased significantly under moderate and severe drought stress. The MDA content in M. multiflora leaves under severe drought stress was 1.63 times as high as that in the control group. The proline (Pro) and soluble sugar contents of M. multiflora increased significantly with the aggravation of drought stress, and those under severe drought stress were 8.06 times and 3.16 times respectively higher than those in the control group. [Conclusion] M. multiflora has a strong drought tolerance, and is suitable for growing in relatively arid environment. It can be used as candidate for vegetation restoration in hydropower engineering slope.
文摘This paper summarizes research related to the 2012 record the NEWS (NASA (National Aeronautics and Space Administration) drought in the central United States conducted by members of Energy and Water cycle Study) Working Group. Past drought patterns were analyzed for signal coherency with latest drought and the contribution of long-term trends in the Great Plains low-level jet, an important regional circulation feature of the spring rainy season in the Great Plains. Long-term changes in the seasonal transition from rainy spring into dry summer were also examined. Potential external forcing from radiative processes, soil-air interactions, and ocean teleconnections were assessed as contributors to the intensity of the drought. The atmospheric Rossby wave activity was found to be a potential source of predictability for the onset of drought. A probabilistic model was introduced and evaluated for its performance in predicting drought recovery in the Great Plains.
文摘Some unsaturated soils may undergo volumetric changes when submitted to an increase in its water content or are inundated under applied loads. This behavior is related to the volumetric instability when the water content is changed. Natural collapsible soils in Brazil are generally found in alluvial, colluvial and residual soils. There are known occurrences of natural collapsible soils in many states of Brasil. In the last two decades, many public projects have been developed in areas where the occurrence of collapsible soils has been associated to geotechnical problems. The present paper devoted to study the collapsible soils in the state of Pernambuco which has been associated with large engineering projects such as housing and irrigation canals. The geotechnical investigation program included test with a field apparatus, called Expanso-colapsometer, which allows the measurement of the field settlements of a small 0.10 m of diameter plate inserted at any depth inside an auger boring hole. Reconnaissance borings with SPT (standard penetration test), investigation pits with undisturbed block sampling and disturbed samples for laboratory tests were also made in order to assess the type and characteristics of the soil. Field tests used the Expanso-colapsometer to measure the settlement of the soil in selected depths under controlled flooding. Laboratory work included double and standard oedometer tests with a controlled rate of water inflow of 1.0 mL/s. It was found that the volume change of the soils when flooded depends on their natural stress state (vertical stress, suction head and structure of soil).
基金supported by National Basic Research Program of China(2010CB428406)the National Natural Science Foundation of China (No. 41071025/40730632)MWR Commonweal Project (200801001)
文摘Climate change will lead to a significant alteration in the temporal and spatial pattern variation in the regional hydrological cycle, and the subsequent lack of water, environmental deterioration, floods and droughts etc. And it is especially remarkable in semi-humid and semi-arid region. In this paper, the impacts of climate change on the hydrological cycle were analyzed for the Hai River Basin, a semi-humid and semi-arid basin and also the water receiving area of the middle route of South-to-North Water Diversion project. Meanwhile it is the most vulnerable to climate change. Firstly, the linear regression and Mann-Kendall non-parametric test methods were used to analyze the change characteristics of the hydrological and meteorological elements for the period from 1960 to 2009. The results show a significant increase in temperature, while precipitation decreases slightly, and runoff decreases drastically over the past 50 years. Secondly, the applicability of SWAT (Soil and Water Assessment Tool) model based on the DEM (Digital Elevation Model), land use and soil type was verified in the basin. Results show the model performs well in this basin. Furthermore, the water balance model, Fu's theory and Koichiro's theory were used to calculate the actual evaporation, comparing to the simulated actual evaporation by SWAT model to validate the result for the lack of large-scale observed evaporation datasets. Possible reasons were also analyzed to explore the reasonable factor for the decline of the runoff. Finally the precipitation, temperature, runoff and evaporation response processes based on the IPCC AR4 multi-mode climate models and the verified SWAT model under different GHG emission scenarios (SRES-A2, AIB and B1) in the 21st century were discussed in three time periods: 2020s (2011-2040), 20S0s (2041-2070), 2080s (2071-2099). Results show that there are systematic positive trends for precipitation and temperature while the trends for runoff and evaporation will differ among sub-areas. The results will offer some references for adaptive water management in a changing environment, also including adaptation of a cross-basin water transfer project.