Scientific grassland ecological compensation mechanism is favorable for improving the grassland ecological environment and promote the sustainable development of animal husbandry. Combined with actual situations of Ti...Scientific grassland ecological compensation mechanism is favorable for improving the grassland ecological environment and promote the sustainable development of animal husbandry. Combined with actual situations of Tibet,this paper discussed core issues in the design of grassland ecological compensation mechanism,including compensation purpose,compensation subject,compensation object,compensation standard,and compensation method. It pointed out that the design of mechanism is a complex and systematic project. Each issue is complex and varied. The government at all levels should be cautious and make scientific treatment,and should not apply a single solution for all issues.展开更多
It is well known that quackgrass is both very aggressive and persistent. In agriculture, many attempts have been made to eliminate this weed without success. Within the context of a sustainable agriculture, mechanical...It is well known that quackgrass is both very aggressive and persistent. In agriculture, many attempts have been made to eliminate this weed without success. Within the context of a sustainable agriculture, mechanical control of quackgrass represents an interesting alternative to chemical means. The use of a ＂C＂ shaped mounted tine cultivator, a rotary cross-harrow, and an ＂S＂ shaped trailed tine cultivator （alone or in combination） to control quackgrass in grassland was investigated. The rate of quackgrass present in each experimental plot was determined before and after the treatments using a one square meter quadrant. Also, the time required for each passage as well as the fuel consumption were computed. Results revealed that the fuel consumption and the time required by the ＂C＂ and ＂S＂ shaped tine cultivators to transport and expose the rhizomes to the sun on the soil surface highly depend on the quality of tillage during the first stubble passage. Also, subsequent tillage with the ＂C＂ shaped tine cultivator after a first passage with a rotary cross-harrow resulted in less fuel consumption and passage time. On the other hand, stubble and subsequent soil tillage with only the ＂C＂ shaped tine cultivator is the least successful method.展开更多
Grassland is one of the largest terrestrial biomes,providing critical ecosystem services such as food production,biodiversity conservation,and climate change mitigation.Global climate change and land-use intensificati...Grassland is one of the largest terrestrial biomes,providing critical ecosystem services such as food production,biodiversity conservation,and climate change mitigation.Global climate change and land-use intensification have been causing grassland degradation and desertification worldwide.As one of the primary medium for ecosystem energy flow and biogeochemical cycling,grassland carbon(C)cycling is the most fundamental process for maintaining ecosystem services.In this review,we first summarize recent advances in our understanding of the mechanisms underpinning spatial and temporal patterns of the grassland C cycle,discuss the importance of grasslands in regulating inter-and intra-annual variations in global C fluxes,and explore the previously unappreciated complexity in abiotic processes controlling the grassland C balance,including soil inorganic C accumulation,photochemical and thermal degradation,and wind erosion.We also discuss how climate and land-use changes could alter the grassland C balance by modifying the water budget,nutrient cycling and additional plant and soil processes.Further,we examine why and how increasing aridity and improper land use may induce significant losses in grassland C stocks.Finally,we identify several priorities for future grassland C research,including improving understanding of abiotic processes in the grassland C cycle,strengthening monitoring of grassland C dynamics by integrating ground inventory,flux monitoring,and modern remote sensing techniques,and selecting appropriate plant species combinations with suitable traits and strong resistance to climate fluctuations,which would help design sustainable grassland restoration strategies in a changing climate.展开更多
Shrub encroachment into arid and semi-arid grasslands has elicited extensive research attention worldwide under the background of climate change and increasing anthropogenic activities.Shrub encroachment may considera...Shrub encroachment into arid and semi-arid grasslands has elicited extensive research attention worldwide under the background of climate change and increasing anthropogenic activities.Shrub encroachment may considerably impact local ecosystems and economies,including the conversion of the structure and function of ecosystems,the shift in ambient conditions,and the weakness of local stock farming capacity.This article reviews recent research progresses on the shrub encroachment process and mechanism,shrub identification and dynamic monitoring using remote sensing,and modeling and simulation of the shrub encroachment process and dynamics.These studies can help to evaluate the ecological effect of shrub encroachment,and thus,practically manage and recover the ecological environment of degraded areas.However,the lack of effective measures and data for monitoring shrub encroachment at a large spatial scale severely limits research on the mechanism,modeling,and simulation of shrub encroachment,and the shrub encroachment stages can hardly be quantitatively defined,resulting in insufficient analysis and simulation of shrub encroachment for different spatiotemporal scales and stages shift.Improvement in remote sensingbased shrub encroachment dynamic monitoring might be crucial for analyzing and understanding the process and mechanism of shrub encroachment,and multi-disciplinary and multi-partnerships are required in the shrub encroachment studies.展开更多
基金Supported by Soft Science Project of Tibet Autonomous Region Department of Science and Technology"Study on Tibetan Grassland Ecological Compensation Mechanism Based on Conflict Management Theory"
文摘Scientific grassland ecological compensation mechanism is favorable for improving the grassland ecological environment and promote the sustainable development of animal husbandry. Combined with actual situations of Tibet,this paper discussed core issues in the design of grassland ecological compensation mechanism,including compensation purpose,compensation subject,compensation object,compensation standard,and compensation method. It pointed out that the design of mechanism is a complex and systematic project. Each issue is complex and varied. The government at all levels should be cautious and make scientific treatment,and should not apply a single solution for all issues.
文摘It is well known that quackgrass is both very aggressive and persistent. In agriculture, many attempts have been made to eliminate this weed without success. Within the context of a sustainable agriculture, mechanical control of quackgrass represents an interesting alternative to chemical means. The use of a ＂C＂ shaped mounted tine cultivator, a rotary cross-harrow, and an ＂S＂ shaped trailed tine cultivator （alone or in combination） to control quackgrass in grassland was investigated. The rate of quackgrass present in each experimental plot was determined before and after the treatments using a one square meter quadrant. Also, the time required for each passage as well as the fuel consumption were computed. Results revealed that the fuel consumption and the time required by the ＂C＂ and ＂S＂ shaped tine cultivators to transport and expose the rhizomes to the sun on the soil surface highly depend on the quality of tillage during the first stubble passage. Also, subsequent tillage with the ＂C＂ shaped tine cultivator after a first passage with a rotary cross-harrow resulted in less fuel consumption and passage time. On the other hand, stubble and subsequent soil tillage with only the ＂C＂ shaped tine cultivator is the least successful method.
基金supported by the National Natural Science Foundation of China (32125025 and 31988102)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA23080301 and XDA26010303)JMG acknowledges the support of the Israel Science Foundation (1796/19).
文摘Grassland is one of the largest terrestrial biomes,providing critical ecosystem services such as food production,biodiversity conservation,and climate change mitigation.Global climate change and land-use intensification have been causing grassland degradation and desertification worldwide.As one of the primary medium for ecosystem energy flow and biogeochemical cycling,grassland carbon(C)cycling is the most fundamental process for maintaining ecosystem services.In this review,we first summarize recent advances in our understanding of the mechanisms underpinning spatial and temporal patterns of the grassland C cycle,discuss the importance of grasslands in regulating inter-and intra-annual variations in global C fluxes,and explore the previously unappreciated complexity in abiotic processes controlling the grassland C balance,including soil inorganic C accumulation,photochemical and thermal degradation,and wind erosion.We also discuss how climate and land-use changes could alter the grassland C balance by modifying the water budget,nutrient cycling and additional plant and soil processes.Further,we examine why and how increasing aridity and improper land use may induce significant losses in grassland C stocks.Finally,we identify several priorities for future grassland C research,including improving understanding of abiotic processes in the grassland C cycle,strengthening monitoring of grassland C dynamics by integrating ground inventory,flux monitoring,and modern remote sensing techniques,and selecting appropriate plant species combinations with suitable traits and strong resistance to climate fluctuations,which would help design sustainable grassland restoration strategies in a changing climate.
基金supported by the National Natural Science Foundation of China[grant number 41571406]the Fund for Creative Research Groups of National Natural Science Foundation of China[grant number 41621061]the State Key Laboratory of Earth Surface Processes and Resource Ecology at Beijing Normal University[grant number 2015-ZDTD-011].
文摘Shrub encroachment into arid and semi-arid grasslands has elicited extensive research attention worldwide under the background of climate change and increasing anthropogenic activities.Shrub encroachment may considerably impact local ecosystems and economies,including the conversion of the structure and function of ecosystems,the shift in ambient conditions,and the weakness of local stock farming capacity.This article reviews recent research progresses on the shrub encroachment process and mechanism,shrub identification and dynamic monitoring using remote sensing,and modeling and simulation of the shrub encroachment process and dynamics.These studies can help to evaluate the ecological effect of shrub encroachment,and thus,practically manage and recover the ecological environment of degraded areas.However,the lack of effective measures and data for monitoring shrub encroachment at a large spatial scale severely limits research on the mechanism,modeling,and simulation of shrub encroachment,and the shrub encroachment stages can hardly be quantitatively defined,resulting in insufficient analysis and simulation of shrub encroachment for different spatiotemporal scales and stages shift.Improvement in remote sensingbased shrub encroachment dynamic monitoring might be crucial for analyzing and understanding the process and mechanism of shrub encroachment,and multi-disciplinary and multi-partnerships are required in the shrub encroachment studies.
