Increasing cases of lake eutrophication globally have raised concerns among stakeholders,and particularly in China.Evaluating the causes of eutrophication in waterways is essential for effective pollution prevention a...Increasing cases of lake eutrophication globally have raised concerns among stakeholders,and particularly in China.Evaluating the causes of eutrophication in waterways is essential for effective pollution prevention and control.Xiao Xingkai Lake is part of and connected to Xingkai(Khanka)Lake,a boundary lake between China and Russia.In this study,we investigated the spatio-temporal variabilities in water quality(i.e.,dissolved oxygen(DO),total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(CODMn)and ammonium-nitrogen(NH4+-N))in Xiao Xingkai Lake,from 2012 to 2014,after which a Trophic Level Index was used to evaluate trophic status,in addition to the factors influencing water quality variation in the lake.The DO,TN,TP,CODMn and NH4+-N concentrations were 0.44-15.57,0.16-5.11,0.01-0.45,0.16-48.31,and 0.19-0.78 mg/L,respectively.Compared to the Environmental Quality Standards for surface water(GB 3838-2002)in China,the lake transitioned to an oligotrophic status in 2013 and 2014 from a mesotrophic status in 2012,TN and TP concentrations were the key factors influencing water quality of Xiao Xingkai Lake.Non-para-metric test results showed that sampling time and sites had significant effects on water quality.Water quality was worse in summer and in tourism and aquaculture areas,followed by agricultural drainage areas.Furthermore,lake water trophic status fluctuated between medium eutrophic and light eutrophic status from September 2012 to September 2014,and was negatively correlated with water level.Water quality in tourism and aquaculture sites were medium eutrophic,while in agricultural areas were light eutrophic.According to the results,high water-level fluctuations and anthropogenic activities were the key factor driving variability in physicochemical parameters associated with water quality in Xiao Xingkai Lake.展开更多
Taking the water ecosystem of Small Xingkai Lake as research object,through the survey and analysis of aquatic organism indicators,this paper established an ecosystem integrity evaluation system with the biological in...Taking the water ecosystem of Small Xingkai Lake as research object,through the survey and analysis of aquatic organism indicators,this paper established an ecosystem integrity evaluation system with the biological integrity as the criterion layer. Using the index of biological integrity and comprehensive health index,it evaluated the health status of water ecosystem of Small Xingkai Lake.展开更多
The xingkai Lake pine(Pinus lakahasii Nakai) gall rust caused by Cronartiumquereuum(Berk.)Miyabe:Shirai is a serious stem rust in the northeast region of China.The alternatehost is oak (Quercus mongolica Fisch).Germin...The xingkai Lake pine(Pinus lakahasii Nakai) gall rust caused by Cronartiumquereuum(Berk.)Miyabe:Shirai is a serious stem rust in the northeast region of China.The alternatehost is oak (Quercus mongolica Fisch).Germination of both acciospores and urediospores wasoptimal at 12℃ and occurred over a range of temperatures,from 4℃ to 32℃.Teliosperes germinatedoptimally at 16--18℃ and over a range of 8--28℃.All spores germinated best under natural light anddark conditions.Direct light inhibited germination eren when followed by darkness.The incubauonperiods of urediospores and teliospores in inoculation experiments were 6--16 days and 3--33daysrespectively. Anatomical studies of Cribartium quercuum galls showed that rust hyphae freely ramify throughthe intereellular spaces within parenchymatous lissues of the cortex,phloem,cambium,and xylemHyphac are perennial;largc haustoria are cylindrical with rounded or blunt ends. Among the 12 fungieides tested for control the rust,pine-tar,pine-tar;diesel oil(1:1。展开更多
In the study of scientific and technical key problems of the Sangjiang Plain some new information on the historical chang eof the strandline of the Xingkai Lak(?) were obtained, and the location of three ancient river...In the study of scientific and technical key problems of the Sangjiang Plain some new information on the historical chang eof the strandline of the Xingkai Lak(?) were obtained, and the location of three ancient riverheads of the Song’acba Rive was discovered.展开更多
Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period...Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine trans gression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions (during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka) and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concur- rent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctuations in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while shortterm fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.展开更多
华南板块新元古代的兴凯地裂运动始于晋宁运动后(800 Ma B.P.),强烈活动于新元古代中期的苏雄—开建桥组火山岩喷发期(700 Ma B.P.),结束于中奥陶世的郁南运动(458 Ma B.P.)。演化历程大体相当于Rodinia(罗迪尼亚)超大陆解体时,应为Rodi...华南板块新元古代的兴凯地裂运动始于晋宁运动后(800 Ma B.P.),强烈活动于新元古代中期的苏雄—开建桥组火山岩喷发期(700 Ma B.P.),结束于中奥陶世的郁南运动(458 Ma B.P.)。演化历程大体相当于Rodinia(罗迪尼亚)超大陆解体时,应为Rodinia超大陆裂解期的组成部分。兴凯地裂运动在新元古代形成扬子板块的基底,对中上扬子区后期构造变形有重要的影响,为后兴凯期(加里东运动)形成大型古隆起和大形拗陷提供了基础;产生的基底断裂对四川盆地后期构造活动有控制作用;形成的稳定大陆边缘为下组合烃源岩发育提供了条件等。展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41771120,41771550)the National Basic Research Program of China(No.2012CB956100)。
文摘Increasing cases of lake eutrophication globally have raised concerns among stakeholders,and particularly in China.Evaluating the causes of eutrophication in waterways is essential for effective pollution prevention and control.Xiao Xingkai Lake is part of and connected to Xingkai(Khanka)Lake,a boundary lake between China and Russia.In this study,we investigated the spatio-temporal variabilities in water quality(i.e.,dissolved oxygen(DO),total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(CODMn)and ammonium-nitrogen(NH4+-N))in Xiao Xingkai Lake,from 2012 to 2014,after which a Trophic Level Index was used to evaluate trophic status,in addition to the factors influencing water quality variation in the lake.The DO,TN,TP,CODMn and NH4+-N concentrations were 0.44-15.57,0.16-5.11,0.01-0.45,0.16-48.31,and 0.19-0.78 mg/L,respectively.Compared to the Environmental Quality Standards for surface water(GB 3838-2002)in China,the lake transitioned to an oligotrophic status in 2013 and 2014 from a mesotrophic status in 2012,TN and TP concentrations were the key factors influencing water quality of Xiao Xingkai Lake.Non-para-metric test results showed that sampling time and sites had significant effects on water quality.Water quality was worse in summer and in tourism and aquaculture areas,followed by agricultural drainage areas.Furthermore,lake water trophic status fluctuated between medium eutrophic and light eutrophic status from September 2012 to September 2014,and was negatively correlated with water level.Water quality in tourism and aquaculture sites were medium eutrophic,while in agricultural areas were light eutrophic.According to the results,high water-level fluctuations and anthropogenic activities were the key factor driving variability in physicochemical parameters associated with water quality in Xiao Xingkai Lake.
文摘Taking the water ecosystem of Small Xingkai Lake as research object,through the survey and analysis of aquatic organism indicators,this paper established an ecosystem integrity evaluation system with the biological integrity as the criterion layer. Using the index of biological integrity and comprehensive health index,it evaluated the health status of water ecosystem of Small Xingkai Lake.
文摘The xingkai Lake pine(Pinus lakahasii Nakai) gall rust caused by Cronartiumquereuum(Berk.)Miyabe:Shirai is a serious stem rust in the northeast region of China.The alternatehost is oak (Quercus mongolica Fisch).Germination of both acciospores and urediospores wasoptimal at 12℃ and occurred over a range of temperatures,from 4℃ to 32℃.Teliosperes germinatedoptimally at 16--18℃ and over a range of 8--28℃.All spores germinated best under natural light anddark conditions.Direct light inhibited germination eren when followed by darkness.The incubauonperiods of urediospores and teliospores in inoculation experiments were 6--16 days and 3--33daysrespectively. Anatomical studies of Cribartium quercuum galls showed that rust hyphae freely ramify throughthe intereellular spaces within parenchymatous lissues of the cortex,phloem,cambium,and xylemHyphac are perennial;largc haustoria are cylindrical with rounded or blunt ends. Among the 12 fungieides tested for control the rust,pine-tar,pine-tar;diesel oil(1:1。
文摘In the study of scientific and technical key problems of the Sangjiang Plain some new information on the historical chang eof the strandline of the Xingkai Lak(?) were obtained, and the location of three ancient riverheads of the Song’acba Rive was discovered.
基金supported by the National Natural Science Founda-tion of China (40872117)
文摘Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine trans gression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions (during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka) and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concur- rent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctuations in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while shortterm fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.
文摘华南板块新元古代的兴凯地裂运动始于晋宁运动后(800 Ma B.P.),强烈活动于新元古代中期的苏雄—开建桥组火山岩喷发期(700 Ma B.P.),结束于中奥陶世的郁南运动(458 Ma B.P.)。演化历程大体相当于Rodinia(罗迪尼亚)超大陆解体时,应为Rodinia超大陆裂解期的组成部分。兴凯地裂运动在新元古代形成扬子板块的基底,对中上扬子区后期构造变形有重要的影响,为后兴凯期(加里东运动)形成大型古隆起和大形拗陷提供了基础;产生的基底断裂对四川盆地后期构造活动有控制作用;形成的稳定大陆边缘为下组合烃源岩发育提供了条件等。
