Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and...Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and distributions of soil water and salt in Songnen Plain,Northeast China,five levels of groundwater sodium adsorption ration of water(SARw)and total salt content(TSC mmol/L)were conducted in an oil column lysimeters.The five treated groundwater labeled as ST0:0,ST0:10,ST5:40,ST10:70 and ST20:100,were prepared with NaCl and CaCl2 in proportion,respectively.The results showed the groundwater evaporation(GWE)and soil evaporation(SE)increased firstly and then decreased with the increase of groundwater salinity.The values of GWE and SE in ST10:70 treatment were the highest,which were 2.09 and 1.84 times the values in the ST0:0 treatment with the lowest GWE and SE.There was a positive linear correlation between GWE and the Ca^(2+)content in groundwater,with R^(2)=0.998.The soil water content(SWC)of ST0:0 treatment was significantly(P<0.05)less than those of other treatments during the test.The SWC of the ST0:0 and ST0:10 treatments increased with the increase of soil depth,while the other treatments showed the opposite trend.Statistical analysis indicated the SWC in the 0–60 cm soil layer was positively correlated with the groundwater TSC and its ion contents during the test.Salt accumulation occurred in the topsoil and the salt accumulation in the 0–20 cm soil layer was significantly(P<0.05)greater than that in the subsoil.This study revealed the effects of the salinity level of groundwater,especially the Ca^(2+)content and TSC of groundwater,on the GWE and distributions of soil water and salt,which provided important support for the prevention and reclamation of soil salinization and sodificaton in shallow groundwater regions.展开更多
The Songnen Plain is a crucial agricultural area in China,and in the past 20 years,a large number of dry fields have been developed into paddy fields in order to improve land output efficiency.As a result,the effectiv...The Songnen Plain is a crucial agricultural area in China,and in the past 20 years,a large number of dry fields have been developed into paddy fields in order to improve land output efficiency.As a result,the effective irrigation area of agriculture has increased annually,and the conversion mode and quantity between surface water and groundwater have changed considerably.It is essential to identify the changes in groundwater resources and their influencing factors for the sustainable development of economy and society.This study evaluates groundwater resources in the Songnen Plain using the water balance method based on meteorological,hydrological and groundwater monitoring data from 2000 to 2020.The results 3 show that the groundwater resources in the region amount to 15.945 billion m with precipitation infiltration being the most important component,accounting for 73.09%,which is followed surface water irrigation infiltration and river and ditch infiltration,constituting 14.55%and 10.32%,respectively.Different factors influence groundwater resources in different periods.Compared to 1985,the increase of surface water irrigation infiltration is the primary factor responsible for the increase of groundwater resources,while other recharge sources have decreased during the same period.Compared to 2005,all groundwater resources have increased,with the increase of surface water irrigation infiltration and river channel infiltration being the primary factors.展开更多
Understanding the effects of land use/cover change(LUCC) on regional climate is critical for achieving land use system sustainability and global climate change mitigation. However, the quantitative analysis of the con...Understanding the effects of land use/cover change(LUCC) on regional climate is critical for achieving land use system sustainability and global climate change mitigation. However, the quantitative analysis of the contribution of LUCC to the changes of climatic factors, such as precipitation & temperature(P&T), is lacking. In this study, we combined statistical methods and the gravity center model simulation to quantify the effects of long-term LUCC on P&T in the Songnen Plain(SNP) of Northeast China from 1980–2018. The results showed the spatiotemporal variability of LUCC. For example, paddy field had the largest increase(15 166.43 km2) in the SNP, followed by dry land, while wetland had the largest decrease(19 977.13 km;) due to the excessive agricultural utilization and development. Annual average precipitation decreased at a rate of –9.89 mm per decade, and the warming trends were statistically significant with an increasing rate of 0.256°C per decade in this region since 1980. The model simulation revealed that paddy field, forestland, and wetland had positive effects on precipitation, which caused their gravity centers to migrate towards the same direction accompanied by the center of precipitation gravity, while different responses were seen for building land, dry land and unused land. These results indicated that forestland had the largest influence on the increase of precipitation compared with the other land use types.The responses in promoting the temperature increase differed significantly, being the highest in building land, and the lowest in forestland. In general, the analysis of regional-scale LUCC showed a significant reduction of wetland, and the increases in building land and cropland contributed to a continuous drying and rapid warming in the SNP.展开更多
To understand the relationship between planktonic diatoms and environmental variables in the lakes on the Songnen Plain,northeast(NE)China,we investigated water quality and planktonic diatoms from 71 sampling points i...To understand the relationship between planktonic diatoms and environmental variables in the lakes on the Songnen Plain,northeast(NE)China,we investigated water quality and planktonic diatoms from 71 sampling points in 27 lakes,based on which Canonical Correspondence Analysis(CCA)was conducted.The result show that planktonic diatoms displayed certain responses to environment gradients,and the total phosphorus(TP)explained the maximum variation of planktonic diatom species among the 15 environmental variables,suggesting that TP was the most important and significant environmental parameter affecting the distribution of diatom species.In addition,we established a diatom-total phosphorus transfer(DTPT)function,of which component 5 of the weighted averaging partial least squares regression(WAPLS)was chosen to and compared with a series of weighted average regression(WA)models and WA-PLS models.According to the jackknifing statistical test,the component 5 of WA-PLS models provided a lower root-mean-square error prediction(RMSEP=0.202)and a higher correlation coefficient between observation and prediction(R^2_Jack=0.759).After deletion of three outliers,the root-mean-square error prediction of the DTPT function was reduced(RMSEP=0.169)while the correlation coefficient between observation and prediction was increased(R^2_Jack=0.823).Therefore,this DTPT function performed better than other regional TP models in the world.However,it remains demanding for expanding the background dataset to improve the prediction ability of the model.展开更多
Biochar amendment is considered as an efficient practice for improving carbon storage in soils.However,to what extent that biochar application promotes organic carbon in saline-sodic soils remains poorly understood.By...Biochar amendment is considered as an efficient practice for improving carbon storage in soils.However,to what extent that biochar application promotes organic carbon in saline-sodic soils remains poorly understood.By comparing soil organic carbon(SOC)contents change before and after biochar addition,we deciphered the driving factors or processes that control SOC change in response to biochar application.A limited increase in SOC was observed,about by 1.16%-12.80%,even when biochar was applied at the rate of 10%of bulk soil weight.Biochar application enhanced soil dissolved organic carbon(DOC)significantly by up to 67%.It was estimated that about 50%SOC was allocated to small macroaggregates(250-2000μm,CPOC),and SOC in silt and clay-sized particles(<53μm)decreased obviously after biochar addition.Microbial biomass increased with biochar amendment,of which actinomycetes(ACT),fungus(FUN),protozoon(PRO),and bacteria with straight-chain saturated fatty acids(OB)increased remarkably.Multiple linear regression models implied that DOC was governed by ACT and soil N∶P ratio,while SOC mostly depended on CPOC.The principal component analysis and the partial least square path model(PLS-PM)indicated that biochar addition aggravated nitrogen limitation in saline-sodic soils,and effects of microorganisms on regulating SOC greatly depended on nitrogen bioavailability.Biochar application had vastly changed interactions between environmental factors and SOC in saline-sodic soils.Effects of nutrients on SOC shifted to great inhibition from strong stimulation after biochar addition,meanwhile,aggregation was the only factor presenting positive effects on SOC.How to eliminate nutrient limitation and better soil aggregation process should be considered in priority when biochar was used to improve SOC in saline-sodic soils.展开更多
The lake groups in the Songnen Plain are low plain lake groups, which are located in the temperate semihumid area in China. They are characterized by small area, shallow basin, thick density and various types. In the ...The lake groups in the Songnen Plain are low plain lake groups, which are located in the temperate semihumid area in China. They are characterized by small area, shallow basin, thick density and various types. In the try for classifying comprehensively the lake groups, a classification system is developed based on three main factors, i.e. forming cause, water quantity and water quality. The most internal character can be concisely grasped through three principal indexes and three auxiliary indexes of three main factors. A sample of complicated changeable path is put forward for further analyzing and outlining these basic types, in the meantime, it’s linking up easily with the classification system of the single factor. According to the regional environment, the regional differences of the type composition and the principal types, the lake groups in the Songnen Plain can be divided into 6 sub-regions.展开更多
As the important reserve land resources for food production,saline-alkali land should play a significant role to ensure the national food security in the context of global food crisis. The western Songnen Plain is one...As the important reserve land resources for food production,saline-alkali land should play a significant role to ensure the national food security in the context of global food crisis. The western Songnen Plain is one of main distribution regions of saline-alkali land in China,with great potential in agricultural development. In this study,the extent,transformation,spatial distribution and temporal change of saline-alkali land in the western Songnen Plain during 1954–2005 were investigated by using remote sensing and GIS spatial analysis methods. Saline-alkali land change was detected from a temporal series of topographic maps in 1954,satellite images of Landsat MSS in 1976,Landsat TM/ETM in 1988,2000 and 2005 through artificial visual interpretation. The results indicated a significant expansion in saline-alkali land area and aggravation in salinization. The area of saline-alkali land had increased from 401.48×103 ha in 1954 to 1 097.45×103 ha in 2005. While the ratio of light,moderate and serious salinized land areas changed from 6.72︰2.92︰1.00 to 1.25︰1.06︰1.00 in the study period. Grassland,cropland,swampland and water body were the major land use and land cover types from which saline-alkali land transformed. And the secondary salinization occured mainly in Da′an City,Tongyu County,Changling County,Daqing City,Dorbod Mongolian Autonomous County and Zhaoyuan County. Finally,seven large ecoregions and 14 corresponding sub-ecoregions were delineated out based on spatio-temopral dynamic characteristics of saline-alkali land and geo-relational environmental attributes. According to the results,measures of amelioration and ways of development of saline-alkali land in the western Songnen Plain were put forward.展开更多
There is great potential for agriculture in saline-alkali soil area in Songnen Plain, Northeast China. But the sustainable crop production in this area has been restricted by a few of main factors, such as less precip...There is great potential for agriculture in saline-alkali soil area in Songnen Plain, Northeast China. But the sustainable crop production in this area has been restricted by a few of main factors, such as less precipitation, h igher evaporation and frequent drought, high salinity and alkalinity, high excha ngeable sodium content and poor infiltration of the soil, and insufficiency and low availability in nutrition. It is also considered that there are a few of fav orable conditions for agricultural development in this region, such as sufficien t light and heat resources, rich ground water resources, plenty of manure produc ed by livestock, and so on. At the same time, scientific management and measurem ents have been employed; rational irrigation and drainage system has been establ ished; reclamation, amendment and fertilization of soil, and suitable strategies of cropping practices have been made for the sustainable development of agricul ture. Great progress has been made during 1996-2000.展开更多
The Songnen Plain in Northeast China,one of the key national bases of agricultural production,went through remarkable land use/cover changes in recent years.This study aimed to explore the long-term land use/cover cha...The Songnen Plain in Northeast China,one of the key national bases of agricultural production,went through remarkable land use/cover changes in recent years.This study aimed to explore the long-term land use/cover changes and the effects of these changes on the environment.The Landsat-based analysis showed that,during 1986-2000,cropland,built-up land and barren land had increased,among which cropland had the largest increase of 9,198km2 with an increase rate of 7.5%.Woodland,grassland,water body and swampland had decreased correspondingly,among which grassland had the most dramatic decrease of 6,127km2 with a decrease rate of 25.6%.The transition matrix results revealed that grassland,woodland and swampland were the three main land use types converted to cropland.Climate warming created the potential environment for the conversion of grassland and swampland into cropland.Land resources policy made by central and provincial governments of China affected the pattern and intensity of land use.Land use/cover changes accompanied by climatic variation brought out a series of environmental consequences,such as sand desertification of land,land salinization and alkalinization,grassland degradation,and more frequent floods.Under this circumstance,optimized land use structure and restoration measures are needed.展开更多
Ecosystem services are premises for human beings to exist and develop in the world, and it is of importance to study effects of land use change on ecosystem functions. Songnen plain, located in Northeast China, is one...Ecosystem services are premises for human beings to exist and develop in the world, and it is of importance to study effects of land use change on ecosystem functions. Songnen plain, located in Northeast China, is one of the national key bases for agricultural production. Because there were remarkable variations in land use in recent years, it can supply specific foundation for protection and restoration of regional eco-environment to explore changes in its values of ecosystem services. This study aims to qualify long-term changes in land use of Songnen plain from 1980 to 2000, and to explore the impact of land use change on ecosystem services. With 2-period land use data using RS and GIS, this paper analyzed changes in land use and in ecosystem service values using the ecosystem service value coefficients (VC) put forward by Costanza et al. Results showed that from 1980 to 2000, area of rangeland, water area and wetlands and area of cropland decreased, but urban area and unused land increased. Due to cropland's comparatively low VC and comparatively high VC of wetlands and water area, increment in cultivated land could not offset the total decrement in regional ecosystem service values because of the decrease in area of wetlands and water area. Meanwhile, city sprawl has also led to loss of ecological values. Total ecosystem service values of the study area reduced dramatically, from 34,926.10×10^6＄ to 31,744.54×10^6＄ in the period 1980-2000. This represents a 9.11% net decline in annual value of ecosystem services in the study area.展开更多
Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rat...Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rates and trends ofdesertification during the past 100 years in the Songnen Plain. According to the macroscopic analysis, we find that the eco-environment in the plain has reached to the threshold of catastrophic change since the 1950s. The Thom Needle Catastrophic Model was used to determine and validate this conclusion. Human activities, including large-scale construction projects, such as huge dams and dikes, and excessive grazing were the primary factors contributing to regional eco-environmental catastrophe. And irrational reclamation of the wilderness also affected the eco-environmental change. The results reveal the complex human-land interactions.展开更多
Groundwater is a key component for water resources in Sanjiang and Songnen Plain,an important agriculture basement in China.The quality and the renewability of irrigation groundwater are essential for the stock raisin...Groundwater is a key component for water resources in Sanjiang and Songnen Plain,an important agriculture basement in China.The quality and the renewability of irrigation groundwater are essential for the stock raising and agricultural production.Shallow groundwater was sampled and analyzed for various variables.The salinity sodium concentration and bicarbonate hazard,were examined with regard to the United States Department of Agriculture(USDA) irrigation water standards.The concentration of chlorofluorocarbons(CFCs) was determined to analyze the age of groundwater.Most groundwater samples labeled as excellent to good for irrigation with low salinity hazard or medium salinity hazard.Four groundwater samples were good and suspected for irrigation with high salinity hazard.Generally groundwater in Sanjiang Plain was younger than the groundwater in Songnen Plain.Meanwhile,groundwater nearby river is younger than the groundwater further away inside the watershed.The mean age of groundwater in Sanjiang Plain is in average of 44.1,47.9 and 32.8 years by CFC-11(CCI_3F),CFC-12(CCI_2F_2) and CFC-113(C_2CI_3F_3),respectively.The mean ages of groundwater in Songnen Plain is in average of 46.1,53.4,and 40.7 years by CFC-11,CFC-12 and CFC-113,respectively.Thus,groundwater nearby rivers could be directly exploited as irrigation water.Partial groundwater has to be processed to lowerthe salt concentration rather than directly utilized as irrigation water in Songnen Plain.Both water quality and renewability should be put in mind for sustainable agricultural development and water resources management.展开更多
Under the influence of global climate changes and human activities, the Songnen Plain's groundwater environment is deteriorating, which becomes an important factor restricting the social economic development and e...Under the influence of global climate changes and human activities, the Songnen Plain's groundwater environment is deteriorating, which becomes an important factor restricting the social economic development and ecological balance. As a relatively independent water system in the Songnen Plain, the groundwater system of the Songhua River provides the main water sources for industry, agriculture, life and other aspects. According to the hydrogeological investigation, groundwater sample collection and testing in the eastern Songnen Plain, descriptive statistics analysis, piper diagram, Gibbs diagram and reverse hydrogeochemical simulation were used to analyze the hydrochemical characteristics and evolution laws of regional groundwater. The results of this study show that HCO_3^- and Ca^(2+) are the main anion and cation in the groundwater; the formation of groundwater chemical components are controlled by topographic and geomorphic factors and groundwater occurrence conditions; groundwater subarea of the Lalin-Ashi River is mainly controlled by weathering-dissolution process, and evaporation and ion-exchange reactions are more obvious in groundwater subarea of the Hulan-Tongken River, whose chemical composition also affects the valley plain groundwater subarea in the discharge area; in addition, local high intensity withdrawal causes abnormal hydrochemical evolution processes. The research results can offer scientific basis for rational utilization and protection of groundwater.展开更多
In western Songnen Plain of China, the saline-alkaline degree of water bodies is high in salt marsh wetlands. Generally, pH is above 8.0, and the hydrochemical types belong to HCO32--Na+. Through analysis on the basic...In western Songnen Plain of China, the saline-alkaline degree of water bodies is high in salt marsh wetlands. Generally, pH is above 8.0, and the hydrochemical types belong to HCO32--Na+. Through analysis on the basic saline variables such as CO32-, HCO32-, Cl-, Ca2+, Mg2+, SO42-, Na+, and the derivative variables such as SAR, SDR, RSC, SSP, the relationships between different variables are found, and the discriminant equations are established to identify different saline-alkaline water bodies by using principal component analysis.展开更多
The fragile eco-environment is a special type of ecosystem,its response to the change of environmental condi -tions is very susceptive.So it is rather prone to be disturbed under unfav orable conditions.Human activity...The fragile eco-environment is a special type of ecosystem,its response to the change of environmental condi -tions is very susceptive.So it is rather prone to be disturbed under unfav orable conditions.Human activity h as greatly changed the geo-chemical process in the ecosystem,thus caused a series o f positive and negative effects.In t he ecosys-tem,especially in the fragile eco-e nvironment,different systems and r egimes are interconnected and interdetermined.For the suntainable development of ecosystem and the protection and rational utilization of resources,it is of great impor-tance to study these internal relati onships and seek rational regulatio n and control measure.This paper tak es the fragile eco-environment in the west of the Songnen Plain as an example.Based on th e study of the topograph,physiognom y,soil,vegetation and their geographic distribution in the landscape,th e paper explains the structure of the ecologic land-scape and quantifies the ecologic ge o-chemical processes under differe nt landscape conditions.In additio n,the paper al-so tries making coupling analyses of the ecologic succession and the landscape geochemical environment.And in the pa-per,some research results are given.展开更多
The salt-resistant nitrogen-fixing cyanobacteria 888 was experimentally applied to the reclamation of saline and alkali soil in Songnen Plain in China. The pH, electrical conductivity (EC) and sodium adsorption ratio ...The salt-resistant nitrogen-fixing cyanobacteria 888 was experimentally applied to the reclamation of saline and alkali soil in Songnen Plain in China. The pH, electrical conductivity (EC) and sodium adsorption ratio (SAR) of different saline soils were studied and compared. Results show that different saline soils exhibit various physico-chemical properties. Saline-sodic soils in Songnen Plain are ameliorated by using nitrogen-fixing blue-green algae 888 in the experiment. It is indicated that cyanobacteria 888 can grow in saline and alkaline soils, and the conditions favorable for its growth are soil moisture of 50% and dry algae inoculation at 0.03 mg/cm2. The main actions of nitrogen-fixing cyanobacteria are keeping the adsorbability of rubber sheath for sodium, increasing the organic matter content of the soils and decreasing the pH and the degree of salinity in the soils. But the arid climate and soil depth are the main factors that limit the restoration of saline and alkaline soils.展开更多
Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Str...Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain.展开更多
Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a signific...Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a significant eco-environmental problem. Based on the characteristics of eco-environment and the situation ofdesertification in western Songnen plain, this paper reports the analyzes of its formation in background and cause. An early warning system on the salt-alkalization desertification is established and the GIS technology is used to abstract the information of desertification evaluation index. Supported by the integrated technology of the GIS and ANN, the orientation and quantitative result of desertification are gained, which is helpful to the eco-environment protection and resource development in western Songnen Plain.展开更多
The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and aerosols.Accurate ...The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and aerosols.Accurate estimation of cropland burned area is both crucial and challenging,especially for the small and fragmented burned scars in China.Here we developed an automated burned area mapping algorithm that was implemented using Sentinel-2 Multi Spectral Instrument(MSI)data and its effectiveness was tested taking Songnen Plain,Northeast China as a case using satellite image of 2020.We employed a logistic regression method for integrating multiple spectral data into a synthetic indicator,and compared the results with manually interpreted burned area reference maps and the Moderate-Resolution Imaging Spectroradiometer(MODIS)MCD64A1 burned area product.The overall accuracy of the single variable logistic regression was 77.38%to 86.90%and 73.47%to 97.14%for the 52TCQ and 51TYM cases,respectively.In comparison,the accuracy of the burned area map was improved to 87.14%and 98.33%for the 52TCQ and 51TYM cases,respectively by multiple variable logistic regression of Sentind-2 images.The balance of omission error and commission error was also improved.The integration of multiple spectral data combined with a logistic regression method proves to be effective for burned area detection,offering a highly automated process with an automatic threshold determination mechanism.This method exhibits excellent extensibility and flexibility taking the image tile as the operating unit.It is suitable for burned area detection at a regional scale and can also be implemented with other satellite data.展开更多
The characteristics of phytoliths in Leymus chinensis leaves from five different pH-value habitats from Songnen Plain in China were analyzed to reveal their environmental implications and possible use for quantitative...The characteristics of phytoliths in Leymus chinensis leaves from five different pH-value habitats from Songnen Plain in China were analyzed to reveal their environmental implications and possible use for quantitative reconstruction of the paleoenvironment. The phytoliths in leaves of L. chinensis from the five habitats showed a non-linear correlation with soil pH. The main types of phytoliths from the different habitats were exactly the same, including silicified stomata, hat-shaped, lanceolate, elongated, multilateral-plate, and tooth-shaped. However, there were significant differences in the contents of each shape of phytoliths among the five habitats. The amount and the volume of weakly tooth-shaped, lanceolate phytoliths and silicified stomata increased with increased pH, while the total amount of phytoliths was reduced. In addition, there were different types of phytoliths in the L. chinensis leaves from the five habitats of different pH, suggesting that the types of phytoliths were controlled, at least in part, by soil pH. The changes of size and percentage of phytoliths were most remarkable at pH 10.15–10.18, indicating that this is the highest pH value that L. chinensis can tolerate.展开更多
基金Under the auspices of National Key Research and Development Program of China(No.2022YFD1500501)National Natural Science Foundation of China(No.41971066)+1 种基金Key Laboratory Foundation of Mollisols Agroecology(No.2020ZKHT-03)High Tech Fund Project of S&T Cooperation Between Jilin Province and Chinese Academy of Sciences(No.2022SYHZ0018)。
文摘Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and distributions of soil water and salt in Songnen Plain,Northeast China,five levels of groundwater sodium adsorption ration of water(SARw)and total salt content(TSC mmol/L)were conducted in an oil column lysimeters.The five treated groundwater labeled as ST0:0,ST0:10,ST5:40,ST10:70 and ST20:100,were prepared with NaCl and CaCl2 in proportion,respectively.The results showed the groundwater evaporation(GWE)and soil evaporation(SE)increased firstly and then decreased with the increase of groundwater salinity.The values of GWE and SE in ST10:70 treatment were the highest,which were 2.09 and 1.84 times the values in the ST0:0 treatment with the lowest GWE and SE.There was a positive linear correlation between GWE and the Ca^(2+)content in groundwater,with R^(2)=0.998.The soil water content(SWC)of ST0:0 treatment was significantly(P<0.05)less than those of other treatments during the test.The SWC of the ST0:0 and ST0:10 treatments increased with the increase of soil depth,while the other treatments showed the opposite trend.Statistical analysis indicated the SWC in the 0–60 cm soil layer was positively correlated with the groundwater TSC and its ion contents during the test.Salt accumulation occurred in the topsoil and the salt accumulation in the 0–20 cm soil layer was significantly(P<0.05)greater than that in the subsoil.This study revealed the effects of the salinity level of groundwater,especially the Ca^(2+)content and TSC of groundwater,on the GWE and distributions of soil water and salt,which provided important support for the prevention and reclamation of soil salinization and sodificaton in shallow groundwater regions.
基金supported by Hydrogeological Survey of Songnen Plain(DD20190340)Investigation and Monitoring of Hydrogeology and Water Resources in Songliao Basin(DD20221753).
文摘The Songnen Plain is a crucial agricultural area in China,and in the past 20 years,a large number of dry fields have been developed into paddy fields in order to improve land output efficiency.As a result,the effective irrigation area of agriculture has increased annually,and the conversion mode and quantity between surface water and groundwater have changed considerably.It is essential to identify the changes in groundwater resources and their influencing factors for the sustainable development of economy and society.This study evaluates groundwater resources in the Songnen Plain using the water balance method based on meteorological,hydrological and groundwater monitoring data from 2000 to 2020.The results 3 show that the groundwater resources in the region amount to 15.945 billion m with precipitation infiltration being the most important component,accounting for 73.09%,which is followed surface water irrigation infiltration and river and ditch infiltration,constituting 14.55%and 10.32%,respectively.Different factors influence groundwater resources in different periods.Compared to 1985,the increase of surface water irrigation infiltration is the primary factor responsible for the increase of groundwater resources,while other recharge sources have decreased during the same period.Compared to 2005,all groundwater resources have increased,with the increase of surface water irrigation infiltration and river channel infiltration being the primary factors.
基金supported by the National Natural Science Foundation of China(41671520)the Harbin Youth Reserve Talent Program,China(2016RAQXJ058)。
文摘Understanding the effects of land use/cover change(LUCC) on regional climate is critical for achieving land use system sustainability and global climate change mitigation. However, the quantitative analysis of the contribution of LUCC to the changes of climatic factors, such as precipitation & temperature(P&T), is lacking. In this study, we combined statistical methods and the gravity center model simulation to quantify the effects of long-term LUCC on P&T in the Songnen Plain(SNP) of Northeast China from 1980–2018. The results showed the spatiotemporal variability of LUCC. For example, paddy field had the largest increase(15 166.43 km2) in the SNP, followed by dry land, while wetland had the largest decrease(19 977.13 km;) due to the excessive agricultural utilization and development. Annual average precipitation decreased at a rate of –9.89 mm per decade, and the warming trends were statistically significant with an increasing rate of 0.256°C per decade in this region since 1980. The model simulation revealed that paddy field, forestland, and wetland had positive effects on precipitation, which caused their gravity centers to migrate towards the same direction accompanied by the center of precipitation gravity, while different responses were seen for building land, dry land and unused land. These results indicated that forestland had the largest influence on the increase of precipitation compared with the other land use types.The responses in promoting the temperature increase differed significantly, being the highest in building land, and the lowest in forestland. In general, the analysis of regional-scale LUCC showed a significant reduction of wetland, and the increases in building land and cropland contributed to a continuous drying and rapid warming in the SNP.
基金Supported by the National Natural Science Foundation of China(Nos.41571199,41030743,31870187)。
文摘To understand the relationship between planktonic diatoms and environmental variables in the lakes on the Songnen Plain,northeast(NE)China,we investigated water quality and planktonic diatoms from 71 sampling points in 27 lakes,based on which Canonical Correspondence Analysis(CCA)was conducted.The result show that planktonic diatoms displayed certain responses to environment gradients,and the total phosphorus(TP)explained the maximum variation of planktonic diatom species among the 15 environmental variables,suggesting that TP was the most important and significant environmental parameter affecting the distribution of diatom species.In addition,we established a diatom-total phosphorus transfer(DTPT)function,of which component 5 of the weighted averaging partial least squares regression(WAPLS)was chosen to and compared with a series of weighted average regression(WA)models and WA-PLS models.According to the jackknifing statistical test,the component 5 of WA-PLS models provided a lower root-mean-square error prediction(RMSEP=0.202)and a higher correlation coefficient between observation and prediction(R^2_Jack=0.759).After deletion of three outliers,the root-mean-square error prediction of the DTPT function was reduced(RMSEP=0.169)while the correlation coefficient between observation and prediction was increased(R^2_Jack=0.823).Therefore,this DTPT function performed better than other regional TP models in the world.However,it remains demanding for expanding the background dataset to improve the prediction ability of the model.
基金Under the auspices of the National Key Research and Development Program of China(No.2016YFC0500404-5)。
文摘Biochar amendment is considered as an efficient practice for improving carbon storage in soils.However,to what extent that biochar application promotes organic carbon in saline-sodic soils remains poorly understood.By comparing soil organic carbon(SOC)contents change before and after biochar addition,we deciphered the driving factors or processes that control SOC change in response to biochar application.A limited increase in SOC was observed,about by 1.16%-12.80%,even when biochar was applied at the rate of 10%of bulk soil weight.Biochar application enhanced soil dissolved organic carbon(DOC)significantly by up to 67%.It was estimated that about 50%SOC was allocated to small macroaggregates(250-2000μm,CPOC),and SOC in silt and clay-sized particles(<53μm)decreased obviously after biochar addition.Microbial biomass increased with biochar amendment,of which actinomycetes(ACT),fungus(FUN),protozoon(PRO),and bacteria with straight-chain saturated fatty acids(OB)increased remarkably.Multiple linear regression models implied that DOC was governed by ACT and soil N∶P ratio,while SOC mostly depended on CPOC.The principal component analysis and the partial least square path model(PLS-PM)indicated that biochar addition aggravated nitrogen limitation in saline-sodic soils,and effects of microorganisms on regulating SOC greatly depended on nitrogen bioavailability.Biochar application had vastly changed interactions between environmental factors and SOC in saline-sodic soils.Effects of nutrients on SOC shifted to great inhibition from strong stimulation after biochar addition,meanwhile,aggregation was the only factor presenting positive effects on SOC.How to eliminate nutrient limitation and better soil aggregation process should be considered in priority when biochar was used to improve SOC in saline-sodic soils.
基金Under the auspices of the National Natural Science Foundation of China(49671077).
文摘The lake groups in the Songnen Plain are low plain lake groups, which are located in the temperate semihumid area in China. They are characterized by small area, shallow basin, thick density and various types. In the try for classifying comprehensively the lake groups, a classification system is developed based on three main factors, i.e. forming cause, water quantity and water quality. The most internal character can be concisely grasped through three principal indexes and three auxiliary indexes of three main factors. A sample of complicated changeable path is put forward for further analyzing and outlining these basic types, in the meantime, it’s linking up easily with the classification system of the single factor. According to the regional environment, the regional differences of the type composition and the principal types, the lake groups in the Songnen Plain can be divided into 6 sub-regions.
基金Under the auspices of National Natural Science Foundation of China (No. 40771162)Key Item of Knowledge Innova-tion Programs of Chinese Academy of Sciences (No.KZCX2-SW-320-1)
文摘As the important reserve land resources for food production,saline-alkali land should play a significant role to ensure the national food security in the context of global food crisis. The western Songnen Plain is one of main distribution regions of saline-alkali land in China,with great potential in agricultural development. In this study,the extent,transformation,spatial distribution and temporal change of saline-alkali land in the western Songnen Plain during 1954–2005 were investigated by using remote sensing and GIS spatial analysis methods. Saline-alkali land change was detected from a temporal series of topographic maps in 1954,satellite images of Landsat MSS in 1976,Landsat TM/ETM in 1988,2000 and 2005 through artificial visual interpretation. The results indicated a significant expansion in saline-alkali land area and aggravation in salinization. The area of saline-alkali land had increased from 401.48×103 ha in 1954 to 1 097.45×103 ha in 2005. While the ratio of light,moderate and serious salinized land areas changed from 6.72︰2.92︰1.00 to 1.25︰1.06︰1.00 in the study period. Grassland,cropland,swampland and water body were the major land use and land cover types from which saline-alkali land transformed. And the secondary salinization occured mainly in Da′an City,Tongyu County,Changling County,Daqing City,Dorbod Mongolian Autonomous County and Zhaoyuan County. Finally,seven large ecoregions and 14 corresponding sub-ecoregions were delineated out based on spatio-temopral dynamic characteristics of saline-alkali land and geo-relational environmental attributes. According to the results,measures of amelioration and ways of development of saline-alkali land in the western Songnen Plain were put forward.
文摘There is great potential for agriculture in saline-alkali soil area in Songnen Plain, Northeast China. But the sustainable crop production in this area has been restricted by a few of main factors, such as less precipitation, h igher evaporation and frequent drought, high salinity and alkalinity, high excha ngeable sodium content and poor infiltration of the soil, and insufficiency and low availability in nutrition. It is also considered that there are a few of fav orable conditions for agricultural development in this region, such as sufficien t light and heat resources, rich ground water resources, plenty of manure produc ed by livestock, and so on. At the same time, scientific management and measurem ents have been employed; rational irrigation and drainage system has been establ ished; reclamation, amendment and fertilization of soil, and suitable strategies of cropping practices have been made for the sustainable development of agricul ture. Great progress has been made during 1996-2000.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No KZCX2-YW-341)National Natural Science Foundation of China (No 40871187)
文摘The Songnen Plain in Northeast China,one of the key national bases of agricultural production,went through remarkable land use/cover changes in recent years.This study aimed to explore the long-term land use/cover changes and the effects of these changes on the environment.The Landsat-based analysis showed that,during 1986-2000,cropland,built-up land and barren land had increased,among which cropland had the largest increase of 9,198km2 with an increase rate of 7.5%.Woodland,grassland,water body and swampland had decreased correspondingly,among which grassland had the most dramatic decrease of 6,127km2 with a decrease rate of 25.6%.The transition matrix results revealed that grassland,woodland and swampland were the three main land use types converted to cropland.Climate warming created the potential environment for the conversion of grassland and swampland into cropland.Land resources policy made by central and provincial governments of China affected the pattern and intensity of land use.Land use/cover changes accompanied by climatic variation brought out a series of environmental consequences,such as sand desertification of land,land salinization and alkalinization,grassland degradation,and more frequent floods.Under this circumstance,optimized land use structure and restoration measures are needed.
基金National Natural Science Foundation of China No.40401003+3 种基金 Knowledge Innovation Project of Chinese Academy of Sciences No.KZCX1-SW-19 Foundation Item of Key Laboratory of Ecological Restoration and Ecosystem Management of Jilin Province No.DS2004-0
文摘Ecosystem services are premises for human beings to exist and develop in the world, and it is of importance to study effects of land use change on ecosystem functions. Songnen plain, located in Northeast China, is one of the national key bases for agricultural production. Because there were remarkable variations in land use in recent years, it can supply specific foundation for protection and restoration of regional eco-environment to explore changes in its values of ecosystem services. This study aims to qualify long-term changes in land use of Songnen plain from 1980 to 2000, and to explore the impact of land use change on ecosystem services. With 2-period land use data using RS and GIS, this paper analyzed changes in land use and in ecosystem service values using the ecosystem service value coefficients (VC) put forward by Costanza et al. Results showed that from 1980 to 2000, area of rangeland, water area and wetlands and area of cropland decreased, but urban area and unused land increased. Due to cropland's comparatively low VC and comparatively high VC of wetlands and water area, increment in cultivated land could not offset the total decrement in regional ecosystem service values because of the decrease in area of wetlands and water area. Meanwhile, city sprawl has also led to loss of ecological values. Total ecosystem service values of the study area reduced dramatically, from 34,926.10×10^6＄ to 31,744.54×10^6＄ in the period 1980-2000. This represents a 9.11% net decline in annual value of ecosystem services in the study area.
基金Under the auspices of the Key Project of Chinese Academy of Sciences (No. KZCX2)
文摘Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rates and trends ofdesertification during the past 100 years in the Songnen Plain. According to the macroscopic analysis, we find that the eco-environment in the plain has reached to the threshold of catastrophic change since the 1950s. The Thom Needle Catastrophic Model was used to determine and validate this conclusion. Human activities, including large-scale construction projects, such as huge dams and dikes, and excessive grazing were the primary factors contributing to regional eco-environmental catastrophe. And irrational reclamation of the wilderness also affected the eco-environmental change. The results reveal the complex human-land interactions.
基金supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(KZCX2-YW-Q06-1)the Key Program of National Natural Science Foundation of China(40830636)+1 种基金the Joint Program of Tianjin Science Foundation,China(15JCQNJC44200)the Doctoral Found of Tianjin Normal University,China(52XB1401)
文摘Groundwater is a key component for water resources in Sanjiang and Songnen Plain,an important agriculture basement in China.The quality and the renewability of irrigation groundwater are essential for the stock raising and agricultural production.Shallow groundwater was sampled and analyzed for various variables.The salinity sodium concentration and bicarbonate hazard,were examined with regard to the United States Department of Agriculture(USDA) irrigation water standards.The concentration of chlorofluorocarbons(CFCs) was determined to analyze the age of groundwater.Most groundwater samples labeled as excellent to good for irrigation with low salinity hazard or medium salinity hazard.Four groundwater samples were good and suspected for irrigation with high salinity hazard.Generally groundwater in Sanjiang Plain was younger than the groundwater in Songnen Plain.Meanwhile,groundwater nearby river is younger than the groundwater further away inside the watershed.The mean age of groundwater in Sanjiang Plain is in average of 44.1,47.9 and 32.8 years by CFC-11(CCI_3F),CFC-12(CCI_2F_2) and CFC-113(C_2CI_3F_3),respectively.The mean ages of groundwater in Songnen Plain is in average of 46.1,53.4,and 40.7 years by CFC-11,CFC-12 and CFC-113,respectively.Thus,groundwater nearby rivers could be directly exploited as irrigation water.Partial groundwater has to be processed to lowerthe salt concentration rather than directly utilized as irrigation water in Songnen Plain.Both water quality and renewability should be put in mind for sustainable agricultural development and water resources management.
基金supported by the fund from China Geological Survey Project(DD20160238)Scientific Research Starting Foundation of Hebei GEO University(BQ201610)Water Conservancy Scientific Research and Promotion Plan Project of Hebei Province(2017-58)
文摘Under the influence of global climate changes and human activities, the Songnen Plain's groundwater environment is deteriorating, which becomes an important factor restricting the social economic development and ecological balance. As a relatively independent water system in the Songnen Plain, the groundwater system of the Songhua River provides the main water sources for industry, agriculture, life and other aspects. According to the hydrogeological investigation, groundwater sample collection and testing in the eastern Songnen Plain, descriptive statistics analysis, piper diagram, Gibbs diagram and reverse hydrogeochemical simulation were used to analyze the hydrochemical characteristics and evolution laws of regional groundwater. The results of this study show that HCO_3^- and Ca^(2+) are the main anion and cation in the groundwater; the formation of groundwater chemical components are controlled by topographic and geomorphic factors and groundwater occurrence conditions; groundwater subarea of the Lalin-Ashi River is mainly controlled by weathering-dissolution process, and evaporation and ion-exchange reactions are more obvious in groundwater subarea of the Hulan-Tongken River, whose chemical composition also affects the valley plain groundwater subarea in the discharge area; in addition, local high intensity withdrawal causes abnormal hydrochemical evolution processes. The research results can offer scientific basis for rational utilization and protection of groundwater.
基金Project of the Limnic Foundation of the Chinese Academy of Sciences, ZKHZ-2-3
文摘In western Songnen Plain of China, the saline-alkaline degree of water bodies is high in salt marsh wetlands. Generally, pH is above 8.0, and the hydrochemical types belong to HCO32--Na+. Through analysis on the basic saline variables such as CO32-, HCO32-, Cl-, Ca2+, Mg2+, SO42-, Na+, and the derivative variables such as SAR, SDR, RSC, SSP, the relationships between different variables are found, and the discriminant equations are established to identify different saline-alkaline water bodies by using principal component analysis.
文摘The fragile eco-environment is a special type of ecosystem,its response to the change of environmental condi -tions is very susceptive.So it is rather prone to be disturbed under unfav orable conditions.Human activity h as greatly changed the geo-chemical process in the ecosystem,thus caused a series o f positive and negative effects.In t he ecosys-tem,especially in the fragile eco-e nvironment,different systems and r egimes are interconnected and interdetermined.For the suntainable development of ecosystem and the protection and rational utilization of resources,it is of great impor-tance to study these internal relati onships and seek rational regulatio n and control measure.This paper tak es the fragile eco-environment in the west of the Songnen Plain as an example.Based on th e study of the topograph,physiognom y,soil,vegetation and their geographic distribution in the landscape,th e paper explains the structure of the ecologic land-scape and quantifies the ecologic ge o-chemical processes under differe nt landscape conditions.In additio n,the paper al-so tries making coupling analyses of the ecologic succession and the landscape geochemical environment.And in the pa-per,some research results are given.
基金Sponsored by the Major State Scientific and Technological Projects of Water Pollution Control and Treatment(Grant No.2008ZX07208-005)
文摘The salt-resistant nitrogen-fixing cyanobacteria 888 was experimentally applied to the reclamation of saline and alkali soil in Songnen Plain in China. The pH, electrical conductivity (EC) and sodium adsorption ratio (SAR) of different saline soils were studied and compared. Results show that different saline soils exhibit various physico-chemical properties. Saline-sodic soils in Songnen Plain are ameliorated by using nitrogen-fixing blue-green algae 888 in the experiment. It is indicated that cyanobacteria 888 can grow in saline and alkaline soils, and the conditions favorable for its growth are soil moisture of 50% and dry algae inoculation at 0.03 mg/cm2. The main actions of nitrogen-fixing cyanobacteria are keeping the adsorbability of rubber sheath for sodium, increasing the organic matter content of the soils and decreasing the pH and the degree of salinity in the soils. But the arid climate and soil depth are the main factors that limit the restoration of saline and alkaline soils.
文摘Population demography, seed production, biomass allocation, net photosynthesis and transpiration of two Leymus chinensis divergent populations and between two years in Songnen plain, northeast China were compared. Strong differences between the dry 1997 and moist 1998 occurred in vegetative shoot and sexual shoot densities, sexual differentiation and tiller densities, as well as in the lengths of inflorescence, seed numbers per inflorescence, seed weights and biomass allocation in each population respectively ( P < 0.01). While strong differences between the two populations occurred in vegetative shoot densities, sexual shoot densities, sexual differentiation and seed weights in each year ( P < 0.01). The differences between the two populations in tiller densities and in biomass allocation to sexual shoots were significant ( P <0.05). But there were no significant differences between the two populations in the lengths of inflorescence, seed numbers per inflorescence and biomass allocation to rhizomes and vegetative shoots ( P >0.05). Excepting the transpiration rate in the early June, the differences between the two populations in net photosynthesis and transpiration rate of vegetative shoots and sexual shoots were strongly significant in the early June and July respectively ( P <0.01). Relative stable variations in population demography and physiological traits between the two populations indicated that they are divergently in the Songnen Plain.
基金the National Natural Science Foundation of China
文摘Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a significant eco-environmental problem. Based on the characteristics of eco-environment and the situation ofdesertification in western Songnen plain, this paper reports the analyzes of its formation in background and cause. An early warning system on the salt-alkalization desertification is established and the GIS technology is used to abstract the information of desertification evaluation index. Supported by the integrated technology of the GIS and ANN, the orientation and quantitative result of desertification are gained, which is helpful to the eco-environment protection and resource development in western Songnen Plain.
基金Under the auspices of National Natural Science Foundation of China(No.42101414)Natural Science Found for Outstanding Young Scholars in Jilin Province(No.20230508106RC)。
文摘The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and aerosols.Accurate estimation of cropland burned area is both crucial and challenging,especially for the small and fragmented burned scars in China.Here we developed an automated burned area mapping algorithm that was implemented using Sentinel-2 Multi Spectral Instrument(MSI)data and its effectiveness was tested taking Songnen Plain,Northeast China as a case using satellite image of 2020.We employed a logistic regression method for integrating multiple spectral data into a synthetic indicator,and compared the results with manually interpreted burned area reference maps and the Moderate-Resolution Imaging Spectroradiometer(MODIS)MCD64A1 burned area product.The overall accuracy of the single variable logistic regression was 77.38%to 86.90%and 73.47%to 97.14%for the 52TCQ and 51TYM cases,respectively.In comparison,the accuracy of the burned area map was improved to 87.14%and 98.33%for the 52TCQ and 51TYM cases,respectively by multiple variable logistic regression of Sentind-2 images.The balance of omission error and commission error was also improved.The integration of multiple spectral data combined with a logistic regression method proves to be effective for burned area detection,offering a highly automated process with an automatic threshold determination mechanism.This method exhibits excellent extensibility and flexibility taking the image tile as the operating unit.It is suitable for burned area detection at a regional scale and can also be implemented with other satellite data.
基金supported by National Natural Science Foundation of China (Grant Nos. 40201052, 30870238, 40971116)
文摘The characteristics of phytoliths in Leymus chinensis leaves from five different pH-value habitats from Songnen Plain in China were analyzed to reveal their environmental implications and possible use for quantitative reconstruction of the paleoenvironment. The phytoliths in leaves of L. chinensis from the five habitats showed a non-linear correlation with soil pH. The main types of phytoliths from the different habitats were exactly the same, including silicified stomata, hat-shaped, lanceolate, elongated, multilateral-plate, and tooth-shaped. However, there were significant differences in the contents of each shape of phytoliths among the five habitats. The amount and the volume of weakly tooth-shaped, lanceolate phytoliths and silicified stomata increased with increased pH, while the total amount of phytoliths was reduced. In addition, there were different types of phytoliths in the L. chinensis leaves from the five habitats of different pH, suggesting that the types of phytoliths were controlled, at least in part, by soil pH. The changes of size and percentage of phytoliths were most remarkable at pH 10.15–10.18, indicating that this is the highest pH value that L. chinensis can tolerate.
