The Selenge River Basin(SRB)in Mongolia has faced ecosystem degradation because of climate change and overloading.The dynamics of the pastoral system and the extent of overload under future scenarios have not been doc...The Selenge River Basin(SRB)in Mongolia has faced ecosystem degradation because of climate change and overloading.The dynamics of the pastoral system and the extent of overload under future scenarios have not been documented.This study aims to answer the following questions:Will the typical soums in the SRB become more overgrazed in the future?What optimal strategy should be implemented?Multisource data were integrated and utilized to model the pastoral system of typical soums using a system dynamics approach.Future scenarios under three SSP-RCPs were projected using the model.The conclusions are as follows:(1)From upstream to downstream,rational scenarios for pastoral system transferred from SSP1-RCP2.6 to SSP2-RCP4.5,which reflect improved productivity at the expense of ecosystem stability.(2)Compared with that during the historical period of 2000-2020,the projected carrying capacity of the soums decreases by 15.2%-37.3%,whereas the number of livestock continues to increase.Consequently,the stocking rate is expected to increase from 0.32-1.16 during 2000-2020 to 1.26-2.02 during 2021-2050,indicating that rangeland will become more overloaded.(3)A livestock reduction strategy based on future livestock stock and grassland carrying capacity scenarios was proposed to maintain a dynamic forage-livestock equilibrium.It is suggested that reducing livestock is a practical option for harmonizing grassland conservation with livestock husbandry development.展开更多
[Objective] The aim was to study the biological activity of insecticidal components of Seleng Wormwood on cabbage butterfly （Pieris rapae）.[Method] With the assisted condition of microwave heating,ethanol,ethyl ethe...[Objective] The aim was to study the biological activity of insecticidal components of Seleng Wormwood on cabbage butterfly （Pieris rapae）.[Method] With the assisted condition of microwave heating,ethanol,ethyl ether,water and methylbenzene were selected as solvents to extract Seleng Wormwood,and the antifeedant,stomach toxicity,contact toxicity and fumigation activities of various solvent extracts against cabbage butterfly were determined.[Result] Various solvent extracts all showed certain antifeedant,stomach toxicity,contact toxicity and fumigation activity against the larvae of cabbage butterfly,and the biological activity of ethanol extract was the strongest.[Conclusion]The results could provide reference for development and utilization of botanical pesticides of Seleng Wormwood.展开更多
基金National Natural Science Foundation of China,No.32161143025,No.42371283,No.W2412155National Key R&D Program of China,No.2022YFE0119200。
文摘The Selenge River Basin(SRB)in Mongolia has faced ecosystem degradation because of climate change and overloading.The dynamics of the pastoral system and the extent of overload under future scenarios have not been documented.This study aims to answer the following questions:Will the typical soums in the SRB become more overgrazed in the future?What optimal strategy should be implemented?Multisource data were integrated and utilized to model the pastoral system of typical soums using a system dynamics approach.Future scenarios under three SSP-RCPs were projected using the model.The conclusions are as follows:(1)From upstream to downstream,rational scenarios for pastoral system transferred from SSP1-RCP2.6 to SSP2-RCP4.5,which reflect improved productivity at the expense of ecosystem stability.(2)Compared with that during the historical period of 2000-2020,the projected carrying capacity of the soums decreases by 15.2%-37.3%,whereas the number of livestock continues to increase.Consequently,the stocking rate is expected to increase from 0.32-1.16 during 2000-2020 to 1.26-2.02 during 2021-2050,indicating that rangeland will become more overloaded.(3)A livestock reduction strategy based on future livestock stock and grassland carrying capacity scenarios was proposed to maintain a dynamic forage-livestock equilibrium.It is suggested that reducing livestock is a practical option for harmonizing grassland conservation with livestock husbandry development.
基金Supported by Doctoral Research Fund of Yangtze UniversityEducational Commission of Hubei Province of China(Q200712003)~~
文摘[Objective] The aim was to study the biological activity of insecticidal components of Seleng Wormwood on cabbage butterfly （Pieris rapae）.[Method] With the assisted condition of microwave heating,ethanol,ethyl ether,water and methylbenzene were selected as solvents to extract Seleng Wormwood,and the antifeedant,stomach toxicity,contact toxicity and fumigation activities of various solvent extracts against cabbage butterfly were determined.[Result] Various solvent extracts all showed certain antifeedant,stomach toxicity,contact toxicity and fumigation activity against the larvae of cabbage butterfly,and the biological activity of ethanol extract was the strongest.[Conclusion]The results could provide reference for development and utilization of botanical pesticides of Seleng Wormwood.
