Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods f...Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.展开更多
Phytocenoses in the ecosystems contact zones are characterized by a rather complex structural and dynamical more than one features and by specific development characters under definite physical and geographical condit...Phytocenoses in the ecosystems contact zones are characterized by a rather complex structural and dynamical more than one features and by specific development characters under definite physical and geographical conditions. Unlike zonal vegetation, such phytocenoses respond to all environment changes more rapidly. The structure of such phytocenoses allows to determine the way this or that scenarios of climate change would develop at any level of more than one ecosystems. A possibility to use the notion “paragenese” for characterization of phytocenoses under contrast conditions is considered. Paragenese is the development of phytocenoses which are not related to zonal vegetation types by their composition and structure. Probably, the communities from ecosystems contact zones are to be related to a particular “type” of vegetation. Phytocenoses in the contact of light coniferous taiga and extrazonal steppes, as well as relations between zonal forest-steppe at main areas of Lake Baikal basin served as examples for justification of use of the notion “paragenese” to characterize the development of such communities.展开更多
A clear understanding of the relationships among multiple ecosystem services(ESs) is the foundation for sustainable urban ecosystem management. Quantitatively identifying the factors that influence ES trade-offs and s...A clear understanding of the relationships among multiple ecosystem services(ESs) is the foundation for sustainable urban ecosystem management. Quantitatively identifying the factors that influence ES trade-offs and synergies can contribute to deepening ES research, from knowledge building to decision making. This study simulated soil conservation, water yield and carbon sequestration in Beijing, China, from 2015–2018. The spatial trade-offs and synergies of these three ESs within the five major river basins in Beijing were explored using geographically weighted regression. Furthermore, geographical detector was applied to quantitatively identify the driving mechanism of the environmental factors for the ES trade-offs and synergies. The results show the following:(1) the spatial relationships between soil conservation and water yield, as well as between water yield and carbon sequestration, were mainly trade-offs. There was a spatial synergy between soil conservation and carbon sequestration.(2) Regarding the spatial trade-off/synergy between soil conservation and water yield in Beijing, the dominant influencing factor was temperature/elevation, and the dominant interactions of the spatial trade-off and synergy between these two ESs in Beijing and the Chaobai River Basin are all manifested in the superposition of precipitation and potential evapotranspiration, temperature, and elevation.(3) Topographic factors were the dominant factors influencing the spatial relationship between soil conservation and carbon sequestration in Beijing and its five major river basins. As a result of the distribution of water systems and hydrological characteristics of the basins, differences were observed in the effects of different combinations of interaction factors on the spatial relationship between these two ESs in different basins.(4) Temperature had the strongest explanatory power in terms of the spatial trade-offs and synergies between water yield and carbon sequestration. The interactions between precipitation and temperature and between precipitation and elevation were the dominant interactions affecting the spatial relationship between water yield and carbon sequestration in Beijing. Overall, the explanatory power of influencing factors on the trade-offs and synergies and the degree of interaction between factors coexist in different basins with consistency and differences. Therefore, understanding the quantitative characteristics of basin-scale spatial trade-offs and synergies between ESs is important for ecosystem management and the promotion of synergy in different basins.展开更多
Land degradation is one of the most ubiquitous environmental challenges affecting the semi-arid ecosystems of the world and the Sokoto-Rima basin is not immune to this. In this study, we evaluated vulnerability of the...Land degradation is one of the most ubiquitous environmental challenges affecting the semi-arid ecosystems of the world and the Sokoto-Rima basin is not immune to this. In this study, we evaluated vulnerability of the Sokoto-Rima basin to land degradation by combining remote sensing and geographic information system technologies. An appraisal model was developed for the identified nine variables, whose weights were ascertained by the analytical hierarchy process. Using this model, we examined the spatiotemporal distribution of vulnerability to land degradation stimulated by climate change from 2002 to 2015. Largely, the basin is extremely vulnerable to land degradation with roughly 88% of the land area in 2002, 2012 and 2015 while areas with low vulnerability were just 1.52%, 1.48% and 1.51% respectively. Geographically, there exists a north-south vulnerability index dichotomy as the index increases northwards. Also, integrated vulnerability index showed that the entire basin is getting exposed to the vagaries of climate change that stimulates land degradation. Large-scale resilience projects such as greening and integrated shelter-belts and woodlots can be implemented in the long run as existing ones are inadequate to address the observed degradation.展开更多
Water supply services(WSSs) are critical for the regional water balance and water circulation, but relevant studies have not established the relationship between WSSs and human well-being. This research identifies the...Water supply services(WSSs) are critical for the regional water balance and water circulation, but relevant studies have not established the relationship between WSSs and human well-being. This research identifies the scope of areas that benefit from WSSs from an ecosystem service flow perspective. Moreover, the path and quantity of the flow of WSSs are simulated to provide a scientific theoretical basis for ecosystem service management and ecological compensation. The Dongjiang Lake Basin is a national priority river basin in China where ecological compensation pilot programmes concerning water resources are top priorities. Dongjiang Lake Basin experienced an increase and then a decrease in the overall supply of water, with an average net water supply of 1096–1500 mm for the years 1995, 2000, 2005 and 2010. The water demand increased each year in service beneficiary areas(SBAs), varying from 387 to 580 mm. Overall, Dongjiang Lake Basin met the net water demands of the actual SBAs in the lower reaches, but a gap in the water supply and demand emerged gradually. This research provides an understanding of the functional mechanisms for the provision, demand and flow of WSSs and provides a scientific theoretical basis for ecosystem service management and ecological compensation.展开更多
In this paper, the effects of land cover changes on the climate of the La Plata Basin in southern South America are investigated using the Weather and Research Forecasting （WRF） Model configured on a 30/10- km two-w...In this paper, the effects of land cover changes on the climate of the La Plata Basin in southern South America are investigated using the Weather and Research Forecasting （WRF） Model configured on a 30/10- km two-way interactive nested grid. To assess the regional climate changes resulting from land surface changes, the standard land cover types are replaced by time-varying Ecosystem Functional Types （EFTs）, which is a newly devised land-cover classification that characterizes the spatial and interannual variability of surface vegetation dynamics. These variations indicate that natural and anthropogenic activities have caused changes in the surface physical parameters of the basin, such as albedo and roughness length, that contributed to regional climate changes. EFTs are obtained from functional attributes of vegetation computed from properties of the Normalized Difference Vegetation Index （NDVI） to represent patches of the land surface with homogeneous energy and gas exchanges with the atmosphere. Four simulations are conducted, each experimental period ranging from September to November in two contrasting years, 1988 and 1998. The influence of an identical EFT change on the surface heat fluxes, 2-m temperature and humidity, 10-m winds, convective instabilities and large-scale moisture fluxes and precipitation are explored for 1988 （a dry year） and 1998 （a wet year）. Results show that the surface and atmospheric climate has a larger response to the same EFT changes in a dry year for 2-m temperature and 10-m wind; the response is larger in a wet year for 2-m water vapor mixing ratio, convective available potential energy, vertically integrated moisture fluxes and surface precipitation. For EFTs with high productivity and a weak seasonal cycle, the near- surface temperature during the spring of 1988 and 1998 increased by as much as I^C in the central and western portions of La Plata Basin. Additionally, for higher productivity EFTs, precipitation differences were generally positive in both dry and wet years, although the patterns are not uniform and exhibit certain patchiness with drier conditions.展开更多
The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectivel...The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectively were quantified and examined in study area in Huailai Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soils of shrubland site. Corg, Ntotal, Navail and Pavail were between 1.18 and 3.90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the Ptotal concentration was lower in shrubland soils than in overgrazed rangeland soils, the Pavail concentration, however, was significantly greater in the soils of shrubland site, and increased by 59.1% and even 289.6% in the soils of shrubland site comparing to those in the soils of range-land and millet field sites. Among the three sites, CV exceeding 40% were found for SO4, Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO4 ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO4 ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of desertified ecosystems.展开更多
On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic be...On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.展开更多
Water provides the origin of human survival and prosperity,and the basic resource for the maintenance of terrestrial eco-systems,their biodiversity,productivity and ecological services.With China’s recent,rapid growt...Water provides the origin of human survival and prosperity,and the basic resource for the maintenance of terrestrial eco-systems,their biodiversity,productivity and ecological services.With China’s recent,rapid growth both in population and economic development,the water shortage has become one of the most constraints on its ecological restoration and socio-economic development,especially in the arid inland regions of northwest China.At first glance,this water shortage in China appears to be a resource crisis.But second,an in-depth analysis reveals that the water shortage crisis arises mainly resulting from the poor water management system and operating mechanism that cannot facilitate fair allocation and efficient utilization of water resources both regionally and nationally and thus is viewed as a crisis of water manage-ment.The solution of China’s water shortage and low-efficient utilization problem will,in particular,require a fundamen-tal and substantial reform or innovation of the existing water management system and operating mechanism.In this paper,we address explicitly the problems existed in the current water management system,explore the basic theory of water re-sources management and provide some insights into the way how to establish a river basin based integrated water re-sources management system in China.展开更多
基金Project supported by the China Scholarship Council and the National Basic Research Program (973) of China (No. 2002CCA00300).
文摘Ecosystem risk is a new concept in understanding environmental problems. It is important to study and develop quantitative methods for regional ecosystem risk analysis. In this study, some new indicators and methods for measuring oasis ecosystem risk were established using reliability theory. These indicators are linked to water resource, which is the key restricting factor in arid area oasis ecosystems. They have clear meanings and can also be compared in different arid area oases. A case study in the Liangzhou oasis of the Shiyang River Basin in China shows how to calculate these ecosystem risk indicators. The results of the case study are as follows： the reliability indicator, risk indicator, stability indicator, and integrated loss indicator of the Liangzhou oasis are 0.686, 0.314, 0.743, and 0.301, respectively. This means that the reliability degree of the oasis＇s ecosystem safety is 68.6%; the degree of risk that it is unsafe is 31.4%; the stability degree is 74.3%; and 30.1% of the oasis＇s area is supported by over-exploiting underground water and damaging the lower reaches of the ecosystem. This result can be used as a guide in controlling and managing ecosystem risk in the research area.
文摘Phytocenoses in the ecosystems contact zones are characterized by a rather complex structural and dynamical more than one features and by specific development characters under definite physical and geographical conditions. Unlike zonal vegetation, such phytocenoses respond to all environment changes more rapidly. The structure of such phytocenoses allows to determine the way this or that scenarios of climate change would develop at any level of more than one ecosystems. A possibility to use the notion “paragenese” for characterization of phytocenoses under contrast conditions is considered. Paragenese is the development of phytocenoses which are not related to zonal vegetation types by their composition and structure. Probably, the communities from ecosystems contact zones are to be related to a particular “type” of vegetation. Phytocenoses in the contact of light coniferous taiga and extrazonal steppes, as well as relations between zonal forest-steppe at main areas of Lake Baikal basin served as examples for justification of use of the notion “paragenese” to characterize the development of such communities.
基金National Natural Science Foundation of China,No.41671098, No.42071288National Key Research and Development Program of China,No.2018YFC1508900, No.2018YFC1508801Beijing Environmental Quality Monitoring Project (2018),No.Y88M1800AL。
文摘A clear understanding of the relationships among multiple ecosystem services(ESs) is the foundation for sustainable urban ecosystem management. Quantitatively identifying the factors that influence ES trade-offs and synergies can contribute to deepening ES research, from knowledge building to decision making. This study simulated soil conservation, water yield and carbon sequestration in Beijing, China, from 2015–2018. The spatial trade-offs and synergies of these three ESs within the five major river basins in Beijing were explored using geographically weighted regression. Furthermore, geographical detector was applied to quantitatively identify the driving mechanism of the environmental factors for the ES trade-offs and synergies. The results show the following:(1) the spatial relationships between soil conservation and water yield, as well as between water yield and carbon sequestration, were mainly trade-offs. There was a spatial synergy between soil conservation and carbon sequestration.(2) Regarding the spatial trade-off/synergy between soil conservation and water yield in Beijing, the dominant influencing factor was temperature/elevation, and the dominant interactions of the spatial trade-off and synergy between these two ESs in Beijing and the Chaobai River Basin are all manifested in the superposition of precipitation and potential evapotranspiration, temperature, and elevation.(3) Topographic factors were the dominant factors influencing the spatial relationship between soil conservation and carbon sequestration in Beijing and its five major river basins. As a result of the distribution of water systems and hydrological characteristics of the basins, differences were observed in the effects of different combinations of interaction factors on the spatial relationship between these two ESs in different basins.(4) Temperature had the strongest explanatory power in terms of the spatial trade-offs and synergies between water yield and carbon sequestration. The interactions between precipitation and temperature and between precipitation and elevation were the dominant interactions affecting the spatial relationship between water yield and carbon sequestration in Beijing. Overall, the explanatory power of influencing factors on the trade-offs and synergies and the degree of interaction between factors coexist in different basins with consistency and differences. Therefore, understanding the quantitative characteristics of basin-scale spatial trade-offs and synergies between ESs is important for ecosystem management and the promotion of synergy in different basins.
文摘Land degradation is one of the most ubiquitous environmental challenges affecting the semi-arid ecosystems of the world and the Sokoto-Rima basin is not immune to this. In this study, we evaluated vulnerability of the Sokoto-Rima basin to land degradation by combining remote sensing and geographic information system technologies. An appraisal model was developed for the identified nine variables, whose weights were ascertained by the analytical hierarchy process. Using this model, we examined the spatiotemporal distribution of vulnerability to land degradation stimulated by climate change from 2002 to 2015. Largely, the basin is extremely vulnerable to land degradation with roughly 88% of the land area in 2002, 2012 and 2015 while areas with low vulnerability were just 1.52%, 1.48% and 1.51% respectively. Geographically, there exists a north-south vulnerability index dichotomy as the index increases northwards. Also, integrated vulnerability index showed that the entire basin is getting exposed to the vagaries of climate change that stimulates land degradation. Large-scale resilience projects such as greening and integrated shelter-belts and woodlots can be implemented in the long run as existing ones are inadequate to address the observed degradation.
基金Under the auspices of National Key Research and Development Program of China(No.2016YFC0503706 2016YFC0503403)+1 种基金National Natural Science Foundation of China(No.31400411)Technical Support Program of the Ministry of Science and Technology of China(No.2013BAC03B05)
文摘Water supply services(WSSs) are critical for the regional water balance and water circulation, but relevant studies have not established the relationship between WSSs and human well-being. This research identifies the scope of areas that benefit from WSSs from an ecosystem service flow perspective. Moreover, the path and quantity of the flow of WSSs are simulated to provide a scientific theoretical basis for ecosystem service management and ecological compensation. The Dongjiang Lake Basin is a national priority river basin in China where ecological compensation pilot programmes concerning water resources are top priorities. Dongjiang Lake Basin experienced an increase and then a decrease in the overall supply of water, with an average net water supply of 1096–1500 mm for the years 1995, 2000, 2005 and 2010. The water demand increased each year in service beneficiary areas(SBAs), varying from 387 to 580 mm. Overall, Dongjiang Lake Basin met the net water demands of the actual SBAs in the lower reaches, but a gap in the water supply and demand emerged gradually. This research provides an understanding of the functional mechanisms for the provision, demand and flow of WSSs and provides a scientific theoretical basis for ecosystem service management and ecological compensation.
基金supported by NSF Grant ATM0646856NASA Grant NNX08AE50Gthe Inter American Institute for Global Change Research (IAI) through the Cooperative Research Network (CRN)-2094
文摘In this paper, the effects of land cover changes on the climate of the La Plata Basin in southern South America are investigated using the Weather and Research Forecasting （WRF） Model configured on a 30/10- km two-way interactive nested grid. To assess the regional climate changes resulting from land surface changes, the standard land cover types are replaced by time-varying Ecosystem Functional Types （EFTs）, which is a newly devised land-cover classification that characterizes the spatial and interannual variability of surface vegetation dynamics. These variations indicate that natural and anthropogenic activities have caused changes in the surface physical parameters of the basin, such as albedo and roughness length, that contributed to regional climate changes. EFTs are obtained from functional attributes of vegetation computed from properties of the Normalized Difference Vegetation Index （NDVI） to represent patches of the land surface with homogeneous energy and gas exchanges with the atmosphere. Four simulations are conducted, each experimental period ranging from September to November in two contrasting years, 1988 and 1998. The influence of an identical EFT change on the surface heat fluxes, 2-m temperature and humidity, 10-m winds, convective instabilities and large-scale moisture fluxes and precipitation are explored for 1988 （a dry year） and 1998 （a wet year）. Results show that the surface and atmospheric climate has a larger response to the same EFT changes in a dry year for 2-m temperature and 10-m wind; the response is larger in a wet year for 2-m water vapor mixing ratio, convective available potential energy, vertically integrated moisture fluxes and surface precipitation. For EFTs with high productivity and a weak seasonal cycle, the near- surface temperature during the spring of 1988 and 1998 increased by as much as I^C in the central and western portions of La Plata Basin. Additionally, for higher productivity EFTs, precipitation differences were generally positive in both dry and wet years, although the patterns are not uniform and exhibit certain patchiness with drier conditions.
文摘The soil constituents and relations between the variation of soil resources and plant communities in three adjacent sites representing the overgrazing, reclamation and comparatively undisturbed communities respectively were quantified and examined in study area in Huailai Basin, Hebei Province, China. There have been significantly greater constituent of C, N, P in the soils of shrubland site. Corg, Ntotal, Navail and Pavail were between 1.18 and 3.90 times more concentrated in the soils of shrubland site in comparison with the other two sites. Although the Ptotal concentration was lower in shrubland soils than in overgrazed rangeland soils, the Pavail concentration, however, was significantly greater in the soils of shrubland site, and increased by 59.1% and even 289.6% in the soils of shrubland site comparing to those in the soils of range-land and millet field sites. Among the three sites, CV exceeding 40% were found for SO4, Cl, and F ion. The CV of organic carbon also exceeded 40% but only in the soils of millet field site. The highest CV were found for F, SO4 ion in the soils of shrubland and overgrazed rangeland sites, while for Cl and SO4 ion in those of millet field site. The results also showed that the introductions of shrubs are of vital importance for the accumulation of soil nutrients and maintenance of soil fertilities, and also for the restoration and reconstruction of desertified ecosystems.
文摘On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.
基金supported by the National Basic Research Program (973) of China (2009CB421302)the CAS/SAFEA International Partnership Program for Creative Research Teams "The Basic Research on Water Issues of the Arid Inland Basin Regions in China" (CXTD-Z2005-2-4)
文摘Water provides the origin of human survival and prosperity,and the basic resource for the maintenance of terrestrial eco-systems,their biodiversity,productivity and ecological services.With China’s recent,rapid growth both in population and economic development,the water shortage has become one of the most constraints on its ecological restoration and socio-economic development,especially in the arid inland regions of northwest China.At first glance,this water shortage in China appears to be a resource crisis.But second,an in-depth analysis reveals that the water shortage crisis arises mainly resulting from the poor water management system and operating mechanism that cannot facilitate fair allocation and efficient utilization of water resources both regionally and nationally and thus is viewed as a crisis of water manage-ment.The solution of China’s water shortage and low-efficient utilization problem will,in particular,require a fundamen-tal and substantial reform or innovation of the existing water management system and operating mechanism.In this paper,we address explicitly the problems existed in the current water management system,explore the basic theory of water re-sources management and provide some insights into the way how to establish a river basin based integrated water re-sources management system in China.
