Based on the observed data in monitored drainage areas and GIS spatial analysis tools,watershed basic database of Shitoukoumen Reservoir Basin was built.The multivariate analysis and redundancy analysis(RDA) were used...Based on the observed data in monitored drainage areas and GIS spatial analysis tools,watershed basic database of Shitoukoumen Reservoir Basin was built.The multivariate analysis and redundancy analysis(RDA) were used to analyze the spatial and temporal variations of water quality,identify the key environmental factors and their patterns influencing the spatial variation of water quality,and determine the main types and forms of the non-point source(NPS) pollutant export controlled by the key environmental factors.The results show that different patterns of environmental factors lead to great changes in water quality at spatial and seasonal scales.All selected environmental factors explain 64.5% and 68.2% of the spatial variation of water quality over dry season and rainy season,respectively,which shows clear seasonal difference.Over dry season,residential land is the most important environmental factor,which possesses 35.4% of the spatial variation,and drainage area is the second key environmental factor,which possesses 17.0% of spatial variation in the total variance.Over rainy season,slope length and drainage area are the key environmental factors,which possess 29.3% of the spatial variation together.Residential land influences nitrogen export by changing NH4+-N and particulate organic nitrogen(PON) discharge over dry season,and drainage area controls phosphorus export by regulating dissolved phosphorus(DP) drainage over dry season and phosphorus associated particulate(PAP) loss over rainy season,respectively.Although slope length is an important environmental factor,it does not influence NPS pollutant export.It is interesting that soil organic matter,as a minor environmental factor,highly determines phosphorus and nitrogen export by enhancing the DP,PAP and PON loss.展开更多
From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which inclu...From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which included 31 resident and 24 migratory species. With statistics methodology, we analyzed the avian communities with 10 major environmental factors covering the park area, water percentage, vegetation species, canopy cover, shrub cover, grass cover, hill number, location condition, human quantity, path width, the study results indicated that: (1) the following 7 environmental factors were important to impact the structures of the avian community, they were park area, vegetation species, shrub coverage, grass coverage, hill number, location condition of the parks and path width; (2) the avian community of theses urban parks tended to deteriorate in the bird number and diversity; the man-made lake which was currently promoted in the park designing and planning process would not be good to attract the birds.展开更多
Abundance and distribution of jumbo flying squid(Dosidicus gigas)are evidently influenced by the changes of marine environment.In this study,the maximum entropy(MaxEnt)model was applied to examine the impacts of marin...Abundance and distribution of jumbo flying squid(Dosidicus gigas)are evidently influenced by the changes of marine environment.In this study,the maximum entropy(MaxEnt)model was applied to examine the impacts of marine environmental variables on its potential distribution,and identified habitat hotspots of D.gigas in summer and autumn along the coast of Chile.The MaxEnt model was constructed by using the fisheries data of D.gigas from summer to autumn during 2011–2017 combined with critical environmental factors including mixed layer depth(MLD),sea surface salinity(SSS),sea surface height(SSH)and water temperature at depths of 0 m,25 m,50 m,100 m,150 m,200 m,300 m,400 m and 500 m.Results showed that the actual fishing efforts of D.gigas in summer and autumn were mostly distributed in the suitable habitat,indicating that the MaxEnt model can well predict the habitat hotspots of D.gigas off Chile.The key environmental factors and their suitable ranges for D.gigas showed significant intermonthly changes from December to May.The critical environmental factors of D.gigas off Chile were MLD,SSH,water temperature at different depths in summer(Temp_25 m in December,Temp_300 m in January and Temp_400 m in February)and SSH,SSS,Temp_400 m in autumn.Our findings suggest that selecting the key environmental factors is vital to study the potential distribution of D.gigas off Chile in each month to explore its habitat hotspots.展开更多
基金Under the auspices of Cooperation Program of Chinese Academy of Sciences and Jilin Province (No 2006SYHZ0025)Knowledge Innovation Programs of Chinese Academy of Sciences (No KZCX2-YW-126,KZCX2-YW-Q06-2)
文摘Based on the observed data in monitored drainage areas and GIS spatial analysis tools,watershed basic database of Shitoukoumen Reservoir Basin was built.The multivariate analysis and redundancy analysis(RDA) were used to analyze the spatial and temporal variations of water quality,identify the key environmental factors and their patterns influencing the spatial variation of water quality,and determine the main types and forms of the non-point source(NPS) pollutant export controlled by the key environmental factors.The results show that different patterns of environmental factors lead to great changes in water quality at spatial and seasonal scales.All selected environmental factors explain 64.5% and 68.2% of the spatial variation of water quality over dry season and rainy season,respectively,which shows clear seasonal difference.Over dry season,residential land is the most important environmental factor,which possesses 35.4% of the spatial variation,and drainage area is the second key environmental factor,which possesses 17.0% of spatial variation in the total variance.Over rainy season,slope length and drainage area are the key environmental factors,which possess 29.3% of the spatial variation together.Residential land influences nitrogen export by changing NH4+-N and particulate organic nitrogen(PON) discharge over dry season,and drainage area controls phosphorus export by regulating dissolved phosphorus(DP) drainage over dry season and phosphorus associated particulate(PAP) loss over rainy season,respectively.Although slope length is an important environmental factor,it does not influence NPS pollutant export.It is interesting that soil organic matter,as a minor environmental factor,highly determines phosphorus and nitrogen export by enhancing the DP,PAP and PON loss.
文摘From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which included 31 resident and 24 migratory species. With statistics methodology, we analyzed the avian communities with 10 major environmental factors covering the park area, water percentage, vegetation species, canopy cover, shrub cover, grass cover, hill number, location condition, human quantity, path width, the study results indicated that: (1) the following 7 environmental factors were important to impact the structures of the avian community, they were park area, vegetation species, shrub coverage, grass coverage, hill number, location condition of the parks and path width; (2) the avian community of theses urban parks tended to deteriorate in the bird number and diversity; the man-made lake which was currently promoted in the park designing and planning process would not be good to attract the birds.
基金supported by the National Key R&D Program of China(No.2019YFD0901405)the National Natural Science Foundation of China(Nos.41906073,31900333)the Natural Science Foundation of Shanghai(No.19ZR1423000).
文摘Abundance and distribution of jumbo flying squid(Dosidicus gigas)are evidently influenced by the changes of marine environment.In this study,the maximum entropy(MaxEnt)model was applied to examine the impacts of marine environmental variables on its potential distribution,and identified habitat hotspots of D.gigas in summer and autumn along the coast of Chile.The MaxEnt model was constructed by using the fisheries data of D.gigas from summer to autumn during 2011–2017 combined with critical environmental factors including mixed layer depth(MLD),sea surface salinity(SSS),sea surface height(SSH)and water temperature at depths of 0 m,25 m,50 m,100 m,150 m,200 m,300 m,400 m and 500 m.Results showed that the actual fishing efforts of D.gigas in summer and autumn were mostly distributed in the suitable habitat,indicating that the MaxEnt model can well predict the habitat hotspots of D.gigas off Chile.The key environmental factors and their suitable ranges for D.gigas showed significant intermonthly changes from December to May.The critical environmental factors of D.gigas off Chile were MLD,SSH,water temperature at different depths in summer(Temp_25 m in December,Temp_300 m in January and Temp_400 m in February)and SSH,SSS,Temp_400 m in autumn.Our findings suggest that selecting the key environmental factors is vital to study the potential distribution of D.gigas off Chile in each month to explore its habitat hotspots.
