The Sanjiang Plain is the largest and most concentrated wetland region in China, the total area is about 1.088×107ha with rich marsh resources and biodiversity. Before 1949, the Sanjiang Plain was a large untrave...The Sanjiang Plain is the largest and most concentrated wetland region in China, the total area is about 1.088×107ha with rich marsh resources and biodiversity. Before 1949, the Sanjiang Plain was a large untravelled wild plant and waterfowl habitat, and there were some rare swans, red-crowned cranes and thousands of hydrophytes. From 1950, the local government began to reclaim the marsh in the Sanjiang Plain, built the commodity grain base of Northeast China, and developed the industry of grain processing, animal husbandry, etc. Up to now, there are 54 farms which control 3.5087×106ha agriculture field. The marsh areas are reduced by 1/2; many rare animals and plants are near extinction. The human activities and agriculture reclamation made a great change on the environment, especially made water balance change and regional climate change. So to study and protect the wetland ecosystem and marsh resource are extremely urgent. This paper focus on the hydrology change and climate change before and after marsh reclamation, including evapotranspiration, run off, soil character, micro-climate on both marsh and agriculture field, and the reason that cause seasonal drought, waterlogging and degeneration of marsh.展开更多
Nitric oxide(NO)emissions from alpine ecosystems conventionally being long-term cultivated with feed crops are not well quantified.The authors attempted to address this knowledge gap by performing a year-round experim...Nitric oxide(NO)emissions from alpine ecosystems conventionally being long-term cultivated with feed crops are not well quantified.The authors attempted to address this knowledge gap by performing a year-round experimental campaign in the northeastern Tibetan Plateau.Fertilized(F)and unfertilized(UF)treatments were established within a flat calcareous-soil site for the long-term cultivation of feed oats.NO fluxes and five soil variables were simultaneously measured.A single plow tillage accounted for approximately 54%–73%of the NO releases during the cropping period(CP);and the non-cropping period(NCP)contributed to 51%–58%of the annual emissions.The direct NO emissions factor(EFd)was 0.021%±0.021%.Significantly lower Q10 values(p<0.01)occurred in the F treatment during the CP(approximately 3.6)compared to those during the other period or in the other treatment(approximately 4.9?5.1),indicating a fertilizer-induced reduction in the temperature sensitivity.The selected soil variables jointly accounted for up to 72%(p<0.01)of the variance for all the fluxes across both treatments.This finding suggests that temporally and/or spatially distributed fluxes from alpine calcareous-soil ecosystems for feed crop production may be easily predicted if data on these soil variables are available.Further studies are needed to test the hypothesis that the EFd is larger in alpine feed-oat fields than those in this study if the soil moisture content is higher during the period following the basal application of ammoniumor urea-based fertilizer.展开更多
Soil environment in Sanjiang Plain has changed greatly because of the reclamation on a large scale.The physical and chemical properties of soil have changed, and soil erosion, soil saline-alkalization and soil polluti...Soil environment in Sanjiang Plain has changed greatly because of the reclamation on a large scale.The physical and chemical properties of soil have changed, and soil erosion, soil saline-alkalization and soil pollution occurred in some areas. These problems have obstructed the sustainable development of agriculture. For the sustainable use of soils in Sanjiang Plain, in this paper we raise some suggestions and countermeasures which might be references for experts and departments concerned.展开更多
In the paper, three farms of Jiansanjiang Farming Bureau and five villages in of Dayushu Town in Fujin county randomly were taken as data sources for the investigation of household behavior of reclamation and agricult...In the paper, three farms of Jiansanjiang Farming Bureau and five villages in of Dayushu Town in Fujin county randomly were taken as data sources for the investigation of household behavior of reclamation and agricultural area under different land systems, and it can be concluded that the main content included production scale, arable land use structure, household behavior and economic benefits. By comparison and analysis, the advantages and disadvantages of reclamation and agricultural area can be found, which could provide references for agricultural land reform for achieving a more suitable socio-economic of efficient use and sustained and healthy development of agriculture.展开更多
Northeast China is an important agricultural region in China. The NortheastPlain is the largest plain in the country and one of the three famous black soil zones in the world.Despite of fertility of the soil, however,...Northeast China is an important agricultural region in China. The NortheastPlain is the largest plain in the country and one of the three famous black soil zones in the world.Despite of fertility of the soil, however, large-scale agricultural development mainly took placesince 1900. The land exploitation and utilization has been fast and intensive in this region sincethen and change in the land-cover process has been remarkable. Both national and internationalresearchers on land use and land cover are paying more attention to these processes in this regionand their implication for local ecological environment. This article discusses the land reclamationprocesses and their main driving forces in Northeast China since 1900. According to the research,the 20th century was the most important period for land reclamation in Northeast China. In theseyears the rate, intensity and quantity of land reclamation have been staggering, and more than 100000km^2 of land was converted into farmland. This magnitude of land reclamation inland is unique inthe world. Research on the land reclamation of Northeast China can provide some data on the effectof human activity on environment. As in many other places in the world, the primary driving force ofreclamation in Northeast China was the increasing pressure of population. In the 20th century thepopulation increased from 10 x 10~6 to 110 x 10~6 in Northeast China and from 400 x 10~6 to 1. 3 x10^9 in China. Population pressure is thus the most important driving force for land reclamation.展开更多
The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological res...The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological restoration, is important to ensure food security and environmental improvement in the agro-pastoral ecotone. We selected Horqin Left Back Banner(HLBB) as the subject of our case study. The landscape ecological security pattern of this area was determined using the minimum cumulative resistance model. Over-cultivation, quantity of reserved land resource for cultivation, and changes in landscape indexes before and after land use adjustment were then analyzed. Over-cultivation is a serious problem in the agro-pastoral ecotone. Reserved land resource for cultivation is less than that considered previously, and the area of reserved land resource for cultivation in HLBB only accounts for 11.50% of total uncultivated land. With regard to changes in landscape indexes, the adjusted land use pattern is effective for anti-desertification. The compensation standard for abandoned cultivated land should be improved and the comprehensive results of ‘Grain for Green' should be evaluated to further implement ecological restoration in the agro-pastoral ecotone.展开更多
This research was carried out to evaluate the effect of the reclamation procedure with respect to soil fertility and nutrient distribution pattern in the reprecipitated reclaimed soil. Although there was an obvious i...This research was carried out to evaluate the effect of the reclamation procedure with respect to soil fertility and nutrient distribution pattern in the reprecipitated reclaimed soil. Although there was an obvious indication of low levels of essential nutrients in the reclaimed farmlands (organic matter=0.32 g kg -1 ,total N=380.8 mg kg -1 , available P=4.7 mg kg -1 ), compared to the undisturbed farmlands (organic matter=2.5 g kg -1 , total N=1 220 g kg -1 , available P=20.8 mg kg -1 ), the uneven pattern of nutrient distribution was also shown to have been the major limitation to successful reclamation. Further improvement can be achieved through the integration of intensive eco farming systems using proper fertilizer field correction (PFFC) and organic manure for successful reestablishment and management of newly reclaimed farmlands overlying the Xuzhou coal mine subsidence.展开更多
基金Supported by the National Natural Science Foundation of China (No. 49771002) and the Foundation of the Labo-ratory of Wetland Pr
文摘The Sanjiang Plain is the largest and most concentrated wetland region in China, the total area is about 1.088×107ha with rich marsh resources and biodiversity. Before 1949, the Sanjiang Plain was a large untravelled wild plant and waterfowl habitat, and there were some rare swans, red-crowned cranes and thousands of hydrophytes. From 1950, the local government began to reclaim the marsh in the Sanjiang Plain, built the commodity grain base of Northeast China, and developed the industry of grain processing, animal husbandry, etc. Up to now, there are 54 farms which control 3.5087×106ha agriculture field. The marsh areas are reduced by 1/2; many rare animals and plants are near extinction. The human activities and agriculture reclamation made a great change on the environment, especially made water balance change and regional climate change. So to study and protect the wetland ecosystem and marsh resource are extremely urgent. This paper focus on the hydrology change and climate change before and after marsh reclamation, including evapotranspiration, run off, soil character, micro-climate on both marsh and agriculture field, and the reason that cause seasonal drought, waterlogging and degeneration of marsh.
基金jointly financed by the Ministry of Science and Technology of China(Grant No.2016YFA0602303)the National Natural Science Foundation of China(Grant Nos.41775141,41375152,and 41603075)
文摘Nitric oxide(NO)emissions from alpine ecosystems conventionally being long-term cultivated with feed crops are not well quantified.The authors attempted to address this knowledge gap by performing a year-round experimental campaign in the northeastern Tibetan Plateau.Fertilized(F)and unfertilized(UF)treatments were established within a flat calcareous-soil site for the long-term cultivation of feed oats.NO fluxes and five soil variables were simultaneously measured.A single plow tillage accounted for approximately 54%–73%of the NO releases during the cropping period(CP);and the non-cropping period(NCP)contributed to 51%–58%of the annual emissions.The direct NO emissions factor(EFd)was 0.021%±0.021%.Significantly lower Q10 values(p<0.01)occurred in the F treatment during the CP(approximately 3.6)compared to those during the other period or in the other treatment(approximately 4.9?5.1),indicating a fertilizer-induced reduction in the temperature sensitivity.The selected soil variables jointly accounted for up to 72%(p<0.01)of the variance for all the fluxes across both treatments.This finding suggests that temporally and/or spatially distributed fluxes from alpine calcareous-soil ecosystems for feed crop production may be easily predicted if data on these soil variables are available.Further studies are needed to test the hypothesis that the EFd is larger in alpine feed-oat fields than those in this study if the soil moisture content is higher during the period following the basal application of ammoniumor urea-based fertilizer.
文摘Soil environment in Sanjiang Plain has changed greatly because of the reclamation on a large scale.The physical and chemical properties of soil have changed, and soil erosion, soil saline-alkalization and soil pollution occurred in some areas. These problems have obstructed the sustainable development of agriculture. For the sustainable use of soils in Sanjiang Plain, in this paper we raise some suggestions and countermeasures which might be references for experts and departments concerned.
基金Supported by the National Natural Science Foundation of China(41571167)
文摘In the paper, three farms of Jiansanjiang Farming Bureau and five villages in of Dayushu Town in Fujin county randomly were taken as data sources for the investigation of household behavior of reclamation and agricultural area under different land systems, and it can be concluded that the main content included production scale, arable land use structure, household behavior and economic benefits. By comparison and analysis, the advantages and disadvantages of reclamation and agricultural area can be found, which could provide references for agricultural land reform for achieving a more suitable socio-economic of efficient use and sustained and healthy development of agriculture.
文摘Northeast China is an important agricultural region in China. The NortheastPlain is the largest plain in the country and one of the three famous black soil zones in the world.Despite of fertility of the soil, however, large-scale agricultural development mainly took placesince 1900. The land exploitation and utilization has been fast and intensive in this region sincethen and change in the land-cover process has been remarkable. Both national and internationalresearchers on land use and land cover are paying more attention to these processes in this regionand their implication for local ecological environment. This article discusses the land reclamationprocesses and their main driving forces in Northeast China since 1900. According to the research,the 20th century was the most important period for land reclamation in Northeast China. In theseyears the rate, intensity and quantity of land reclamation have been staggering, and more than 100000km^2 of land was converted into farmland. This magnitude of land reclamation inland is unique inthe world. Research on the land reclamation of Northeast China can provide some data on the effectof human activity on environment. As in many other places in the world, the primary driving force ofreclamation in Northeast China was the increasing pressure of population. In the 20th century thepopulation increased from 10 x 10~6 to 110 x 10~6 in Northeast China and from 400 x 10~6 to 1. 3 x10^9 in China. Population pressure is thus the most important driving force for land reclamation.
基金Foundation item:Under the auspices of the Special Scientific Research of the Ministry of Land and Resources of China(No.201411009)
文摘The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological restoration, is important to ensure food security and environmental improvement in the agro-pastoral ecotone. We selected Horqin Left Back Banner(HLBB) as the subject of our case study. The landscape ecological security pattern of this area was determined using the minimum cumulative resistance model. Over-cultivation, quantity of reserved land resource for cultivation, and changes in landscape indexes before and after land use adjustment were then analyzed. Over-cultivation is a serious problem in the agro-pastoral ecotone. Reserved land resource for cultivation is less than that considered previously, and the area of reserved land resource for cultivation in HLBB only accounts for 11.50% of total uncultivated land. With regard to changes in landscape indexes, the adjusted land use pattern is effective for anti-desertification. The compensation standard for abandoned cultivated land should be improved and the comprehensive results of ‘Grain for Green' should be evaluated to further implement ecological restoration in the agro-pastoral ecotone.
文摘This research was carried out to evaluate the effect of the reclamation procedure with respect to soil fertility and nutrient distribution pattern in the reprecipitated reclaimed soil. Although there was an obvious indication of low levels of essential nutrients in the reclaimed farmlands (organic matter=0.32 g kg -1 ,total N=380.8 mg kg -1 , available P=4.7 mg kg -1 ), compared to the undisturbed farmlands (organic matter=2.5 g kg -1 , total N=1 220 g kg -1 , available P=20.8 mg kg -1 ), the uneven pattern of nutrient distribution was also shown to have been the major limitation to successful reclamation. Further improvement can be achieved through the integration of intensive eco farming systems using proper fertilizer field correction (PFFC) and organic manure for successful reestablishment and management of newly reclaimed farmlands overlying the Xuzhou coal mine subsidence.
