Chengdu City is in the period of rapid urbanization and industrialization, and the disturbance derived from human activities on environment is increasing remarkablely in recent 20 years. The pressure on environment, e...Chengdu City is in the period of rapid urbanization and industrialization, and the disturbance derived from human activities on environment is increasing remarkablely in recent 20 years. The pressure on environment, economy and population is also increasing and land use in Chengdu has changed enormously. As struc- ture and function of land ecological system change obviously, sustainable development of land productivity has been an important goal and strategic task from now on, and it is necessary to systematically research land ecological carrying capacity based on ecological footprint. The ecological footprint of Chengdu City in the past ten years was calculated and analyzed from the spatial and temporal aspects according to statistical data from 1998 to 2008, as per ecological footprint method, ecological carrying capacity and the GIS spatial analysis method, and regression analysis method. The ecological footprint and ecological carrying capacity values from 2009 to 2019 in Chengdu City were predicted through calculation results in the past ten years. The results show that the ecological footprint and ecological deficit of land use from 1998 to 2008 increased in Chengdu City. The ecological deficit of land use within the city center was in high levels in the past ten years, and the ecological footprint kept raising, especially in areas, such as Shuangliu, Chongzhou, Qingyang among 9 city areas, 4 counties and 6 districts in Chengdu City. There is fanlike distribution of ecological deficit of land use. Analysis shows that the social and natural ecological system is uneven distribution, which is not in sustainable de- velopment situation. The results of the study show that the economic, social and natural ecological system in Chengdu City is not sustainable, and the ecological foot- print is uneven distribution. The analysis of the dynamic change of land ecological carrying capacity in Chengdu City is very important for city government in the pro- cess of the vigorous development in new Tianfu Xinqu, and redevelopment in the northern part of this city.展开更多
Aim In vitro dissolution test and pharmacokinetics in beagle dogs wereconducted to assess the formulation of tretinoin in self-emulsifying systems. Methods Theconcentrations of tretinoin were determined by HPLC. A cro...Aim In vitro dissolution test and pharmacokinetics in beagle dogs wereconducted to assess the formulation of tretinoin in self-emulsifying systems. Methods Theconcentrations of tretinoin were determined by HPLC. A crossover study was performed in four fastingbeagle dogs with the formulation of self-emulsifying systems and commercial capsules. Results Theresults showed that the dissolution rate in 15 min of tretinoin in self-emulsifying systems washigher than 80% while that of the commercial capsules was lower than 5% . The area under the plasmaconcentration-time curve (AUC) of the self-emulsifying formulation was significantly higher andC_(max) was approximately two times greater than those of commercial capsule, respectively, Inaddition, the time taken to reach peak was shorter (2 h to 1.25 h) for self-emulsifying formulationof tretinoin. Conclusion The self-emulsifying drug delivery systems.can significantly increasetretinoin in vitro dissolution and in vivo absorption.展开更多
[Objective] This study aimed to provide referential basis for ecosystem study of Hebei Province in the new decade of 21st century, by investigating the correlation between natural subsystem and economic subsystem. [Me...[Objective] This study aimed to provide referential basis for ecosystem study of Hebei Province in the new decade of 21st century, by investigating the correlation between natural subsystem and economic subsystem. [Method] The correlation between natural subsystem and economic subsystem in ecosystem was discussed by means of the canonical correlation, and the correlation between variables was explored with statistical data. [Result] The canonical correlation between the two subsystems could be explained by three groups of typical variables, Le., the canonical correlation between crop production and consumption; the canonical correlation between agricultural crop production, aquaculture and scientific research development funds; and the canonical correlation between forest area and GDP per capita. With the growth of economy and revenue and the steady development of agricultural production, there are still some serious problems, including the change of residents consumption is out of proportion to its material consumption; the socio-economic development depends on consuming of forests more heavily, which destroy the balance between the economic growth and environmental protection. [Conclusion] The results provide referential basis for the ecosystem study of Hebei Province.展开更多
Human beings have had a tremendous i mpact on natural ecosystems and are n ow the principal power to change the biosphere.It is logical t hat we should pay close attention to t he interaction between human system s an...Human beings have had a tremendous i mpact on natural ecosystems and are n ow the principal power to change the biosphere.It is logical t hat we should pay close attention to t he interaction between human system s and environ-mental systems.Taking Minqin basin,Gansu Province,as a case,this paper focuses on the evolution of regional physi-cal environments and the cultural sy stems by which people maintain their relationships with those environme nts.This pa-per presents the conceptual framewo rk for the man-land system.Expectin g to accelerate the regional sustain able develop-ment,it also analyses the evolution ary mechanism of regional man-land s ystem.On the basis of reviewing and a nalyzing the evolution of man-land system in Minqin basin,the paper also brings fo rward an adjusting mode for the studi ed area,which consists of three aspects:to b uild up a concept that economic growt h must harmonize with environmental quality’s and land productivity’s improvemen t;to make a whole planning and management in the drainage area;and to push for-ward the technique of water-saving i rrigation and establish water-saving agricultural system.It’s meanin gful for resource exploitation and sustainable development of Chinese northwestern arid area,which is represented by Minqin basin,by under-standing what great changes the basin has experienced and is experiencin g at the global background,and studying its time order and territorial structure,th e system’s character and law of evolu tion,trend and the regulating ways t o improve man-land relationship.展开更多
The Himalaya represents a vast mountain system and globally valued for its significant role in regulation of global as well as regional climate that has direct impact on biodiversity and ecosystem services crucial for...The Himalaya represents a vast mountain system and globally valued for its significant role in regulation of global as well as regional climate that has direct impact on biodiversity and ecosystem services crucial for sustenance of millions of people in Himalaya and adjoining areas. However, mountain regions worldwide are impacted by climate change and at the same time represent distinctive area for the assessment of climate related impacts. Climate change impacts in Himalayan region have its implications on food production, natural ecosystems,retreat of glacier, water supply, human and animal health and overall human well being. The livelihood and food security of the people inhabited in region largely depend on climate sensitive sectors i.e.agriculture, livestock, forestry and their interlinkages with each other, and has the potential to break down food and nutritional security as well as livelihood support systems. People's perception and understanding of climate can be an important asset when it comes to adaptation to climate change impact;however it is not taken into consideration for the development of policy design and implementation of modern mitigation and adaptation strategies by governments and other civil society organizations.The knowledge of local people and farming communities for rural landscape management and sustainable use of bioresources is gaining credence as a key strategy to cope up with the climate change.Therefore, the present study analyzes the indigenous knowledge of local people and their perceptions on climate change, and also documented adaptation approaches at local level in mountain ecosystem of western Himalaya. The study could be useful to policy makers to design appropriate adaptation strategies to cope up with the impacts of climate change.展开更多
Landscape ecology provides new theoretical frameworks and methodologies for understanding complex ecological phenomena at multiple scales.Studies of landscape ecology focus on understanding the dynamics of eco-logical...Landscape ecology provides new theoretical frameworks and methodologies for understanding complex ecological phenomena at multiple scales.Studies of landscape ecology focus on understanding the dynamics of eco-logical patterns and processes,and highlight the integration of multiple disciplines.In this paper,we discussed the problems and challenges that landscape ecology is currently facing,emphasizing the limitations of current methods used to describe dynamic landscape patterns and processes.We suggested that the focus should be on the integration of ground-based observation,mobile monitoring,transect survey,and remote-sensing monitoring,as well as improved coupling of experimental and model simulations.In addition,we outlined the research frontiers in landscape ecology,including scaling,integrated pattern and process modeling,and regional synthesis.Lastly,a brief review of pat-tern-process-scale coupling studies in China was provided.We concluded by pointing out that pattern-process-scale interactions,correlations between natural,economic,and social processes,and the coupling of human and natural systems will be major research areas in landscape ecology in the future.展开更多
Soil respiration (SR) is the second-largest flux in ecosystem carbon cycling. Due to the large spatio-temporal variability of environmental factors, SR varied among different vegetation types, thereby impeding accur...Soil respiration (SR) is the second-largest flux in ecosystem carbon cycling. Due to the large spatio-temporal variability of environmental factors, SR varied among different vegetation types, thereby impeding accurate estimation of CO2 emissions via SR. However, studies on spatio-temporal variation of SR are still scarce for semi-arid regions of North China. In this study, we conducted 12-month SR measurements in six land-use types, including two secondary forests (Populus tomentosa (PT) and Robinia pseudoacacia (RP)), three artificial plantations (Armeniaca sibirica (AS), Punica granatum (PG) and Ziziphusjujuba (Z J)) and one natural grassland (GR), to quantify spatio-temporal variation of SR and distinguish its controlling factors. Results indicated that SR exhibited distinct sea- sonal patterns for the six sites. Soil respiration peaked in August 2012 and bottomed in April 2013. The temporal coefficient of variation (CI0 of SR for the six sites ranged from 76.98% to 94.08%, while the spatial CV of SR ranged from 20.28% to 72.97% across the 12-month measurement. Soil temperature and soil moisture were the major controlling factors of temporal variation of SR in the six sites, while spatial variation in SR was mainly caused by the differences in soil total nitrogen (STN), soil organic carbon (SOC), net photosynthesis rate, and fine root biomass. Our results show that the annual average SR and Q10 (temperature sensitivity of soil respira- tion) values tended to decrease from secondary forests and grassland to plantations, indicating that the conversion of natural ecosystems to man-made ecosystems may reduce CO2 emissions and SR temperature sensitivity. Due to the high spatio-temporal variation of SR in our study area, care should be taken when converting secondary forests and grassland to plantations from the point view of accurately quantifying C02 emissions via SR at regional scales.展开更多
Characterization of the vertical distribution of soil organic carbon(C), nitrogen(N), and phosphorus(P) may improve our ability to accurately estimate soil C, N, and P storage. Based on a database of 21 354 records in...Characterization of the vertical distribution of soil organic carbon(C), nitrogen(N), and phosphorus(P) may improve our ability to accurately estimate soil C, N, and P storage. Based on a database of 21 354 records in 74 long-term monitoring plots from 2004 to 2013 in the Chinese Ecosystem Research Network(CERN), we built fitting functions to quantify the vertical distribution of soil C, N, and P(up to 100 cm depth) in the typical Chinese terrestrial ecosystems. The decrease of soil C, N, and P content with depth can be well fitted with various mathematical functions. The fitting functions differed greatly between artificial(agriculture) and natural(desert, forest, and grassland) ecosystems, and also differed with respect to soil C, N, and P content. In both the artificial and natural ecosystems, the best fitting functions were exponential functions for C, quadratic functions for N, and quadratic functions for P. Furthermore, the stoichiometric ratios of soil C, N, and P were ranked in descending order: grassland > forest > agriculture > desert, and were also associated with climate. This study is the first to build the fitting functions for the profile distribution of soil C, N, and P in China at a national scale. Our findings provide a scientific basis to accurately assess the storage of C, N, and P in soils at a large scale, especially for the integrative analysis of historical data.展开更多
As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achiev...As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.展开更多
Contrast with artificial environment, the multi-level self-organizational system of nature has great gain. Sustain-able material environment should respect nature: non-rubbish and super-cycle quality of natural ecosys...Contrast with artificial environment, the multi-level self-organizational system of nature has great gain. Sustain-able material environment should respect nature: non-rubbish and super-cycle quality of natural ecosystem offers the material source of human development, fractal structure of nature offers new field of space and information source to this high-density and information-based society, dissipative structure of nature links the new system of energy with whole ecosystem organi-cally, and life-chain regulation is the base of sustainable life environment. Nature guarantees the physical healthy environ-ment by its all-dimension healthy factor, constructs the mental healthy environment by its quality of co-ordinate and chaos, so that guarantees the whole emergence of sustainable develop-ment on the 'super-science' level. In the view of sustainable development, construction, green economy and human health are basic fields. With the concept of ecosystem regulation, we can relate these fields organically and fulfill the task of human health, welfare and sustainable development. Ecosystem regulation is the base of sustainable development's new para-digm.展开更多
Whether it is necessary to reduce nitrogen(N) and/or phosphorus(P) input to mitigate lake eutrophication is controversial. The controversy stems mainly from differences in time and space in previous studies that suppo...Whether it is necessary to reduce nitrogen(N) and/or phosphorus(P) input to mitigate lake eutrophication is controversial. The controversy stems mainly from differences in time and space in previous studies that support the contrasting ideas. To test the response of phytoplankton to various combinations of nutrient control strategies in mesocosms and the possibility of reflecting the conditions in natural ecosystems with short-term experiments, a 9-month experiment was carried out in eight 800-L tanks with four nutrient level combinations(+N+P,-N+P, +N-P, and-N-P), with an 18-month whole-ecosystem experiment in eight ~800-m^2 ponds as the reference. Phytoplankton abundance was determined by P not N, regardless of the initial TN/TP level, which was in contrast to the nutrient limitation predicted by the N/P theory. Net natural N inputs were calculated to be 4.9, 6.8, 1.5, and 3.0 g in treatments +N+P,-N+P, +N-P, and-N-P, respectively, suggesting that N deficiency and P addition may promote natural N inputs to support phytoplankton development. However, the compensation process was slow, as suggested by an observed increase in TN after 3 weeks in-N+P and 2 months in-N-P in the tank experiment, and after 3 months in-N?+P and ~3 months in-N-P in our pond experiment. Obviously, such a slow process cannot be simulated in short-term experiments. The natural N inputs cannot be explained by planktonic N-fixation because N-fixing cyanobacteria were scarce, which was probably because there was a limited pool of species in the tanks. Therefore, based on our results we argue that extrapolating short-term, small-scale experiments to large natural ecosystems does not give reliable, accurate results.展开更多
The importance attached to the need for sustainable development in the coastal areas is increasing. A management plan is required to minimize the environmental destruction resulting from the complexity of the property...The importance attached to the need for sustainable development in the coastal areas is increasing. A management plan is required to minimize the environmental destruction resulting from the complexity of the property in coastal areas, of human activities and of natural systems and to utilize the coastal resources effectively. The utilization of coasts, besides becoming very important particularly in views of tourism, has faced pressures caused by huge. These areas are mostly self-contradictory demands for the environmental protection. The project is an EU Life Long Learning Programme Project and the project duration is 24 months. The aim of the CoastLearn in Black Sea (CLBS) is to mobilize the human resources in the tourism and coastal management sector in Black Sea in general and notably Sinop, Varna and Constanta by raising awareness among the local decision making mechanisms of the integrated coastal zone management in order to encourage people to utilize the coastal resources in a coherent and balanced way.展开更多
Large oilfields are often coincidentally located in major river deltas and wetlands,and potentially damage the structure,function and ecosystem service values of wetlands during oil exploration.In the present study,th...Large oilfields are often coincidentally located in major river deltas and wetlands,and potentially damage the structure,function and ecosystem service values of wetlands during oil exploration.In the present study,the effects of crude oil contamination during oil exploration on soil physical and chemical properties were investigated in marshes of the Momoge National Nature Reserve in Jilin Province,China.The concentrations of total petroleum hydrocarbons in the marsh soil near the oil wells are significantly higher than those in the adjacent control marsh.Soil water contents in oil-contaminated marshes are negatively correlated with soil temperature and are significantly lower than those in the control area,especially in fall.Crude oil contamination significantly increases the soil pH up to8.0,and reduces available phosphorus concentrations in the soil.The concentrations of total organic carbon are significantly different among sampling sites.Therefore,crude oil contamination could potentially alkalinize marsh soils,adversely affect soil fertility and physical properties,and cause deterioration of the marshes in the Momoge National Nature Reserve.Phyto-remediation by planting Calamagrostis angustifolia has the potential to simultaneously restore and remediate the petroleum hydrocarbon-contaminated wetlands.Crude oil contamination affects the soil physical and chemical properties,so developing an effective restoration program in the Momoge wetland is neccesary.展开更多
基金Supported by National High-tech R&D Program of China(863Program)(2009AA12Z-140)National Natural Science Foundation of China(40771144,40575035)Scientific Research Foundation of Sichuan Normal University(SXK11002)~~
文摘Chengdu City is in the period of rapid urbanization and industrialization, and the disturbance derived from human activities on environment is increasing remarkablely in recent 20 years. The pressure on environment, economy and population is also increasing and land use in Chengdu has changed enormously. As struc- ture and function of land ecological system change obviously, sustainable development of land productivity has been an important goal and strategic task from now on, and it is necessary to systematically research land ecological carrying capacity based on ecological footprint. The ecological footprint of Chengdu City in the past ten years was calculated and analyzed from the spatial and temporal aspects according to statistical data from 1998 to 2008, as per ecological footprint method, ecological carrying capacity and the GIS spatial analysis method, and regression analysis method. The ecological footprint and ecological carrying capacity values from 2009 to 2019 in Chengdu City were predicted through calculation results in the past ten years. The results show that the ecological footprint and ecological deficit of land use from 1998 to 2008 increased in Chengdu City. The ecological deficit of land use within the city center was in high levels in the past ten years, and the ecological footprint kept raising, especially in areas, such as Shuangliu, Chongzhou, Qingyang among 9 city areas, 4 counties and 6 districts in Chengdu City. There is fanlike distribution of ecological deficit of land use. Analysis shows that the social and natural ecological system is uneven distribution, which is not in sustainable de- velopment situation. The results of the study show that the economic, social and natural ecological system in Chengdu City is not sustainable, and the ecological foot- print is uneven distribution. The analysis of the dynamic change of land ecological carrying capacity in Chengdu City is very important for city government in the pro- cess of the vigorous development in new Tianfu Xinqu, and redevelopment in the northern part of this city.
文摘Aim In vitro dissolution test and pharmacokinetics in beagle dogs wereconducted to assess the formulation of tretinoin in self-emulsifying systems. Methods Theconcentrations of tretinoin were determined by HPLC. A crossover study was performed in four fastingbeagle dogs with the formulation of self-emulsifying systems and commercial capsules. Results Theresults showed that the dissolution rate in 15 min of tretinoin in self-emulsifying systems washigher than 80% while that of the commercial capsules was lower than 5% . The area under the plasmaconcentration-time curve (AUC) of the self-emulsifying formulation was significantly higher andC_(max) was approximately two times greater than those of commercial capsule, respectively, Inaddition, the time taken to reach peak was shorter (2 h to 1.25 h) for self-emulsifying formulationof tretinoin. Conclusion The self-emulsifying drug delivery systems.can significantly increasetretinoin in vitro dissolution and in vivo absorption.
文摘[Objective] This study aimed to provide referential basis for ecosystem study of Hebei Province in the new decade of 21st century, by investigating the correlation between natural subsystem and economic subsystem. [Method] The correlation between natural subsystem and economic subsystem in ecosystem was discussed by means of the canonical correlation, and the correlation between variables was explored with statistical data. [Result] The canonical correlation between the two subsystems could be explained by three groups of typical variables, Le., the canonical correlation between crop production and consumption; the canonical correlation between agricultural crop production, aquaculture and scientific research development funds; and the canonical correlation between forest area and GDP per capita. With the growth of economy and revenue and the steady development of agricultural production, there are still some serious problems, including the change of residents consumption is out of proportion to its material consumption; the socio-economic development depends on consuming of forests more heavily, which destroy the balance between the economic growth and environmental protection. [Conclusion] The results provide referential basis for the ecosystem study of Hebei Province.
文摘Human beings have had a tremendous i mpact on natural ecosystems and are n ow the principal power to change the biosphere.It is logical t hat we should pay close attention to t he interaction between human system s and environ-mental systems.Taking Minqin basin,Gansu Province,as a case,this paper focuses on the evolution of regional physi-cal environments and the cultural sy stems by which people maintain their relationships with those environme nts.This pa-per presents the conceptual framewo rk for the man-land system.Expectin g to accelerate the regional sustain able develop-ment,it also analyses the evolution ary mechanism of regional man-land s ystem.On the basis of reviewing and a nalyzing the evolution of man-land system in Minqin basin,the paper also brings fo rward an adjusting mode for the studi ed area,which consists of three aspects:to b uild up a concept that economic growt h must harmonize with environmental quality’s and land productivity’s improvemen t;to make a whole planning and management in the drainage area;and to push for-ward the technique of water-saving i rrigation and establish water-saving agricultural system.It’s meanin gful for resource exploitation and sustainable development of Chinese northwestern arid area,which is represented by Minqin basin,by under-standing what great changes the basin has experienced and is experiencin g at the global background,and studying its time order and territorial structure,th e system’s character and law of evolu tion,trend and the regulating ways t o improve man-land relationship.
基金Task Force 3‘Forest Resources and Plant Biodiversity’under National Mission for Sustaining Himalayan Ecosystem(NMSHE)funded by Department of Science and Technology(DST),Govt.of India for financial support(DST/SPLICE/CCP/NMSHE/TF/GBPIHED/2014[G]dated 2/09/14)to conduct the study
文摘The Himalaya represents a vast mountain system and globally valued for its significant role in regulation of global as well as regional climate that has direct impact on biodiversity and ecosystem services crucial for sustenance of millions of people in Himalaya and adjoining areas. However, mountain regions worldwide are impacted by climate change and at the same time represent distinctive area for the assessment of climate related impacts. Climate change impacts in Himalayan region have its implications on food production, natural ecosystems,retreat of glacier, water supply, human and animal health and overall human well being. The livelihood and food security of the people inhabited in region largely depend on climate sensitive sectors i.e.agriculture, livestock, forestry and their interlinkages with each other, and has the potential to break down food and nutritional security as well as livelihood support systems. People's perception and understanding of climate can be an important asset when it comes to adaptation to climate change impact;however it is not taken into consideration for the development of policy design and implementation of modern mitigation and adaptation strategies by governments and other civil society organizations.The knowledge of local people and farming communities for rural landscape management and sustainable use of bioresources is gaining credence as a key strategy to cope up with the climate change.Therefore, the present study analyzes the indigenous knowledge of local people and their perceptions on climate change, and also documented adaptation approaches at local level in mountain ecosystem of western Himalaya. The study could be useful to policy makers to design appropriate adaptation strategies to cope up with the impacts of climate change.
基金Under the auspices of National Natural Science Foundation of China (No.40930528)State Forestry Administration of China (No.201004058)
文摘Landscape ecology provides new theoretical frameworks and methodologies for understanding complex ecological phenomena at multiple scales.Studies of landscape ecology focus on understanding the dynamics of eco-logical patterns and processes,and highlight the integration of multiple disciplines.In this paper,we discussed the problems and challenges that landscape ecology is currently facing,emphasizing the limitations of current methods used to describe dynamic landscape patterns and processes.We suggested that the focus should be on the integration of ground-based observation,mobile monitoring,transect survey,and remote-sensing monitoring,as well as improved coupling of experimental and model simulations.In addition,we outlined the research frontiers in landscape ecology,including scaling,integrated pattern and process modeling,and regional synthesis.Lastly,a brief review of pat-tern-process-scale coupling studies in China was provided.We concluded by pointing out that pattern-process-scale interactions,correlations between natural,economic,and social processes,and the coupling of human and natural systems will be major research areas in landscape ecology in the future.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060600)National Natural Science Foundation of China(No.51378306)
文摘Soil respiration (SR) is the second-largest flux in ecosystem carbon cycling. Due to the large spatio-temporal variability of environmental factors, SR varied among different vegetation types, thereby impeding accurate estimation of CO2 emissions via SR. However, studies on spatio-temporal variation of SR are still scarce for semi-arid regions of North China. In this study, we conducted 12-month SR measurements in six land-use types, including two secondary forests (Populus tomentosa (PT) and Robinia pseudoacacia (RP)), three artificial plantations (Armeniaca sibirica (AS), Punica granatum (PG) and Ziziphusjujuba (Z J)) and one natural grassland (GR), to quantify spatio-temporal variation of SR and distinguish its controlling factors. Results indicated that SR exhibited distinct sea- sonal patterns for the six sites. Soil respiration peaked in August 2012 and bottomed in April 2013. The temporal coefficient of variation (CI0 of SR for the six sites ranged from 76.98% to 94.08%, while the spatial CV of SR ranged from 20.28% to 72.97% across the 12-month measurement. Soil temperature and soil moisture were the major controlling factors of temporal variation of SR in the six sites, while spatial variation in SR was mainly caused by the differences in soil total nitrogen (STN), soil organic carbon (SOC), net photosynthesis rate, and fine root biomass. Our results show that the annual average SR and Q10 (temperature sensitivity of soil respira- tion) values tended to decrease from secondary forests and grassland to plantations, indicating that the conversion of natural ecosystems to man-made ecosystems may reduce CO2 emissions and SR temperature sensitivity. Due to the high spatio-temporal variation of SR in our study area, care should be taken when converting secondary forests and grassland to plantations from the point view of accurately quantifying C02 emissions via SR at regional scales.
基金under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05050702)National Natural Science Foundation of China(No.31270519,31470506)Kezhen Distinguished Talents in Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences(No.2013RC102)
文摘Characterization of the vertical distribution of soil organic carbon(C), nitrogen(N), and phosphorus(P) may improve our ability to accurately estimate soil C, N, and P storage. Based on a database of 21 354 records in 74 long-term monitoring plots from 2004 to 2013 in the Chinese Ecosystem Research Network(CERN), we built fitting functions to quantify the vertical distribution of soil C, N, and P(up to 100 cm depth) in the typical Chinese terrestrial ecosystems. The decrease of soil C, N, and P content with depth can be well fitted with various mathematical functions. The fitting functions differed greatly between artificial(agriculture) and natural(desert, forest, and grassland) ecosystems, and also differed with respect to soil C, N, and P content. In both the artificial and natural ecosystems, the best fitting functions were exponential functions for C, quadratic functions for N, and quadratic functions for P. Furthermore, the stoichiometric ratios of soil C, N, and P were ranked in descending order: grassland > forest > agriculture > desert, and were also associated with climate. This study is the first to build the fitting functions for the profile distribution of soil C, N, and P in China at a national scale. Our findings provide a scientific basis to accurately assess the storage of C, N, and P in soils at a large scale, especially for the integrative analysis of historical data.
基金Under the auspices of National Natural Science Foundation of China (No.40635028,40801066)State Key Laboratory of Earth Surface Processes and Resource Ecology of China (No.2008-KF-04)
文摘As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.
文摘Contrast with artificial environment, the multi-level self-organizational system of nature has great gain. Sustain-able material environment should respect nature: non-rubbish and super-cycle quality of natural ecosystem offers the material source of human development, fractal structure of nature offers new field of space and information source to this high-density and information-based society, dissipative structure of nature links the new system of energy with whole ecosystem organi-cally, and life-chain regulation is the base of sustainable life environment. Nature guarantees the physical healthy environ-ment by its all-dimension healthy factor, constructs the mental healthy environment by its quality of co-ordinate and chaos, so that guarantees the whole emergence of sustainable develop-ment on the 'super-science' level. In the view of sustainable development, construction, green economy and human health are basic fields. With the concept of ecosystem regulation, we can relate these fields organically and fulfill the task of human health, welfare and sustainable development. Ecosystem regulation is the base of sustainable development's new para-digm.
基金Supported by the State Key Laboratory of Freshwater Ecology and Biotechnology(Nos.2014FB14,2011FBZ14)Science and Technology Support Program of Hubei Province(No.2015BBA225)the Youth Innovation Association of Chinese Academy of Sciences(No.2014312)to WANG Haijun
文摘Whether it is necessary to reduce nitrogen(N) and/or phosphorus(P) input to mitigate lake eutrophication is controversial. The controversy stems mainly from differences in time and space in previous studies that support the contrasting ideas. To test the response of phytoplankton to various combinations of nutrient control strategies in mesocosms and the possibility of reflecting the conditions in natural ecosystems with short-term experiments, a 9-month experiment was carried out in eight 800-L tanks with four nutrient level combinations(+N+P,-N+P, +N-P, and-N-P), with an 18-month whole-ecosystem experiment in eight ~800-m^2 ponds as the reference. Phytoplankton abundance was determined by P not N, regardless of the initial TN/TP level, which was in contrast to the nutrient limitation predicted by the N/P theory. Net natural N inputs were calculated to be 4.9, 6.8, 1.5, and 3.0 g in treatments +N+P,-N+P, +N-P, and-N-P, respectively, suggesting that N deficiency and P addition may promote natural N inputs to support phytoplankton development. However, the compensation process was slow, as suggested by an observed increase in TN after 3 weeks in-N+P and 2 months in-N-P in the tank experiment, and after 3 months in-N?+P and ~3 months in-N-P in our pond experiment. Obviously, such a slow process cannot be simulated in short-term experiments. The natural N inputs cannot be explained by planktonic N-fixation because N-fixing cyanobacteria were scarce, which was probably because there was a limited pool of species in the tanks. Therefore, based on our results we argue that extrapolating short-term, small-scale experiments to large natural ecosystems does not give reliable, accurate results.
文摘The importance attached to the need for sustainable development in the coastal areas is increasing. A management plan is required to minimize the environmental destruction resulting from the complexity of the property in coastal areas, of human activities and of natural systems and to utilize the coastal resources effectively. The utilization of coasts, besides becoming very important particularly in views of tourism, has faced pressures caused by huge. These areas are mostly self-contradictory demands for the environmental protection. The project is an EU Life Long Learning Programme Project and the project duration is 24 months. The aim of the CoastLearn in Black Sea (CLBS) is to mobilize the human resources in the tourism and coastal management sector in Black Sea in general and notably Sinop, Varna and Constanta by raising awareness among the local decision making mechanisms of the integrated coastal zone management in order to encourage people to utilize the coastal resources in a coherent and balanced way.
基金Under the auspices of National Natural Science Foundation of China(No.31170476)Chinese Academy of Sciences/State Administration of Foreign Experts Affairs International Partnership Program for Creative Research Teams(No.KZZD-EW-TZ-07)+1 种基金Major Program of Science and Technology of Jilin Province(No.20075014)Fundamental Research Funds for the Central Universities of China(No.11GJHZ002)
文摘Large oilfields are often coincidentally located in major river deltas and wetlands,and potentially damage the structure,function and ecosystem service values of wetlands during oil exploration.In the present study,the effects of crude oil contamination during oil exploration on soil physical and chemical properties were investigated in marshes of the Momoge National Nature Reserve in Jilin Province,China.The concentrations of total petroleum hydrocarbons in the marsh soil near the oil wells are significantly higher than those in the adjacent control marsh.Soil water contents in oil-contaminated marshes are negatively correlated with soil temperature and are significantly lower than those in the control area,especially in fall.Crude oil contamination significantly increases the soil pH up to8.0,and reduces available phosphorus concentrations in the soil.The concentrations of total organic carbon are significantly different among sampling sites.Therefore,crude oil contamination could potentially alkalinize marsh soils,adversely affect soil fertility and physical properties,and cause deterioration of the marshes in the Momoge National Nature Reserve.Phyto-remediation by planting Calamagrostis angustifolia has the potential to simultaneously restore and remediate the petroleum hydrocarbon-contaminated wetlands.Crude oil contamination affects the soil physical and chemical properties,so developing an effective restoration program in the Momoge wetland is neccesary.