Ameliorating waste treatment by technological improvements affects the economic and the ecological-environment benefits of intensive pig production. The objective of the research was to develop and test a method to de...Ameliorating waste treatment by technological improvements affects the economic and the ecological-environment benefits of intensive pig production. The objective of the research was to develop and test a method to determine the technical optimization to ameliorate waste treatment methods and gain insight into the relationship between technological options and the economic and ecological effects. We developed an integrated bio-economic model which incorporates the farming production and waste disposal systems to simulate the impact of technological improvements in pig manure treatment on economic and environmental benefits for the case of a pilot farm in Beijing, China. Based on different waste treatment technology options, three scenarios are applied for the simulation analysis of the model. The simulation results reveal that the economic-environmental benefits of the livestock farm could be improved by reducing the cropland manure application and increasing the composting production with the current technologies. Nevertheless, the technical efficiency, the waste treatment capacity and the economic benefits could be further improved by the introduction of new technologies. It implies that technological and economic support policies should be implemented comprehensively on waste disposal and resource utilization to promote sustainable development in intensive livestock production in China.展开更多
The expansion of non-industrial private forests (NIPF) in Ireland is unique in the European context in which the almost doubling of forest cover within the last thirty years has taken place largely on farmland. This i...The expansion of non-industrial private forests (NIPF) in Ireland is unique in the European context in which the almost doubling of forest cover within the last thirty years has taken place largely on farmland. This is not surprising as Ireland has some of the highest growth rates for conifers in Europe and also has a large proportion of land which is marginal for agriculture but highly productive under forests. However, in recent years, afforestation in Ireland as in many European countries has fallen well short of policy targets. As the farm afforestation decision essentially involves an inter-temporal land use change, farmers need comprehensive information on forest market returns under different environmental conditions and forest management regimes. This paper describes the systematic development of a cohort forest bio-economic model which examines financially optimal afforestation and management choices. Simulating a range of productivity and harvesting scenarios for Sitka spruce, we find that different objectives result in different outcomes. We see substantial differences between the biologically optimal rotation, the reduced rotation in common usage and the financially optimal rotation which maximises net present value and find that the results are particularly sensitive to the choice of management and methodological assumptions. Specifically, we find that better site productivity and thin versus no-thin options result in shorter rotations across all optimisations, reinforcing the usefulness of this type of financial modelling approach. This information is critical for future policy design to further incentivise afforestation of agricultural land.展开更多
The neon flying squid(Ommastrephes bartramii)in the Northwest Pacific Ocean is one economically important cephalopod,largely exploited by squid jigging fleets from Chinese Mainland,Japan,and Chinese Taibei.In this stu...The neon flying squid(Ommastrephes bartramii)in the Northwest Pacific Ocean is one economically important cephalopod,largely exploited by squid jigging fleets from Chinese Mainland,Japan,and Chinese Taibei.In this study,a Bayesian Bio-economic model was developed using fishery data from Chinese Mainland,Japan,and Chinese Taibei,and relevant fishery economic data from Chinese Mainland.The stock assessment and risk analysis of alternative management strategies for O.bartramii were carried out.Three prior distributions(i.e.,uniform,normal and logarithmic normal)for model parameters were assumed in different scenarios.The results showed that the estimated model parameters and reference points such as maximum sustainable yield(MSY),maximum economic yield(MEY),bio-economic balance point(BE)and fishing mortality were similar in the scenarios of normal and logarithmic normal prior assumptions.However,the estimates were larger in the scenario of uniform prior assumption.The fishing mortalities and annual catches from 1996 to 2008 were lower than the reference points F_(0.1) and MSY in all the three scenarios,indicating that O.bartramii stock is at sustainable exploited level.The results of decision analysis indicated that under the same harvest rate,the catch and biomass in 2023 from the uniform assumption were the highest.However,the highest probability of the collapse was found for squid resources after 2023.Our findings suggested that the harvest rate of 0.4 appeared to be the best management regulation under the uniform assumption,and the MSY would be 200 thousand tons.In addition,the harvest rate of 0.5 would be the best management regulation under the other two assumptions,and the MSY would be 180 thousand tons,which balanced the desire for high yields and the healthy population.The results of this study could be used to provide management suggestions for neon flying squid in the Northwest Pacific Ocean.展开更多
In this paper,we study a class of singular stochastic bio-economic models described by differential-algebraic equations due to the influence of economic factors.Simplifying the model through a stochastic averaging met...In this paper,we study a class of singular stochastic bio-economic models described by differential-algebraic equations due to the influence of economic factors.Simplifying the model through a stochastic averaging method,we obtained a two-dimensional diffusion process of averaged amplitude and phase.Stochastic stability and Hopf bifurcations can be analytically determined based on the singular boundary theory of diffusion process,the Maximal Lyapunov exponent and the invariant measure theory.The critical value of the stochastic Hopf bifurcation parameter is obtained and the position of Hopf bifurcation drifting with the parameter increase is presented as a result.Practical example is presented to verify the effectiveness of the results.展开更多
论文以内蒙古沙漠化地区为例,运用Bioe-conom ic M odel,比较自由放牧与耕垦、禁牧与禁垦、控制放牧规模与禁垦的土地利用政策情景下,引进舍饲养牛技术与信贷服务和增加非农就业机会对农户土地利用决策及其家庭收入的影响,据此探讨中国...论文以内蒙古沙漠化地区为例,运用Bioe-conom ic M odel,比较自由放牧与耕垦、禁牧与禁垦、控制放牧规模与禁垦的土地利用政策情景下,引进舍饲养牛技术与信贷服务和增加非农就业机会对农户土地利用决策及其家庭收入的影响,据此探讨中国北方地区沙漠化发展的人文驱动机制以及生态重建的环境政策。结果表明:实施控制放牧规模与禁垦的环境政策,同时引进舍饲养牛技术能够有效地促进生态重建并提高农户收入;引进舍饲养牛技术需要启动基金,提供信贷服务和增加非农就业机会是贫困农户引进该技术的前提。因此,迫切需要调整宏观环境政策,提高农业集约化经营水平和城乡联系力度,从而提高农户家庭收入、减轻农民对环境的依赖性和促进农村的可持续发展。展开更多
This study analyzes the vegetative and soil degradation,measured as biomass and soil loss,for Arnigad micro-watershed located in Indian Himalayan state of Uttarakhand,in systems framework by using dynamic linear progr...This study analyzes the vegetative and soil degradation,measured as biomass and soil loss,for Arnigad micro-watershed located in Indian Himalayan state of Uttarakhand,in systems framework by using dynamic linear programming bio-economic model.The focus is at investigating the effects of alternate policy regimes,i.e.,introduction of improved energy sources for cooking along with substitution of existing local livestock breeds with improved breed,reduction in human population growth and introduction of high yielding varieties of main crops including paddy,maize and wheat.The model horizon extended over a period of 25 years,i.e.,from 2006 to 2030.It was found that the model scenario incorporating increased use of improved energy sources along with substitution of local cows by improved cows could be the most effective policy option in reducing vegetative and soil degradation.The vegetative biomass density declined to 19.76% compared to 35.24% in the BASE scenario and soil erosion loss was also lowered by 29.13%.Also,the reduction of population growth rate to half of the BASE scenario led to minor improvements in degradation.Introduction of high yielding varieties of main crops slightly increased vegetative degradation but reduced soil loss(8.35%) with respect to the BASE scenario.Such a phenomenon could be explained in terms of changed crop mix resulting in reduced amount of crop by-products requiring increased lopping of tree branches for animal fodder.The policy option of the increased use of improved energy sources along with substitution of improved breed of cows resulted in 9.58% higher income.Introduction of high yielding varieties of crops led to 1.92% increase in income,but the income decreased by 1.25 % when population growth was reduced to half.The usefulness of the model lies in analyzing the systems behavior in its entirety where the results can predict the possible direction of change as a result of manipulation in alternate economic regimes.展开更多
Background：In mid hills of Western Himalayas,Himachal Pradesh India,growth,yield and economics of Solanum khasianum as a potential medicinal herb under Pinus roxburghii（Chir pine） plantation has been studied for tw...Background：In mid hills of Western Himalayas,Himachal Pradesh India,growth,yield and economics of Solanum khasianum as a potential medicinal herb under Pinus roxburghii（Chir pine） plantation has been studied for two consecutive years to assess the performance of Solanum khasianum in undercanopy of Pinus roxburghii for developing Solanum khasianum and Pinus roxburghii based innovative silvi-medicinal system.Methods：Growth parameters such as plant height,number of branches per plant and leaf area index followed by yield were estimated after Solanum khasianum was grown on three topographical aspects as;Northern,North- western and Western at a spacing of 45 cm x 45 cm,followed by three tillage depths as;minimum（0 cm）,medium（up to 10 cm）and deep tillage（up to 15 cm）,in open and below canopy conditions treatment.The study was conducted to explore the possibility of using Solanum khasianum based silvi-medicinal system to utilize the below canopy of Chir pine forest for enhancing the productivity of forests besides the conservation of the medicinal herb.Results：The growth parameters such as plant height,number of branches per plant and leaf area index were nonsignificantly affected by topographical aspects and tillage practices,both below canopy and open conditions except fresh weight and dry weight of berries during harvesting stage.The maximum yield（0.61 t·ha^（-1）） was observed on Western aspect in open conditions as compared to below canopy of Chir pine.The highest gross returns were observed for the crop cultivated on Western aspect under deep tillage in open conditions than other aspect and tillage combinations.However the positive net returns from the crops raised in below canopy of Chir pine indicates its possible economic viability under agroforestry system as the gross returns was higher than the cost of cultivation.Conclusion：Solanum khasianum when grown in below canopy of Pinus roxburghii,its growth and yield indicated positive net returns.Solanum khasianum and Pinus roxburghii based silvi-medicinal system has the potential to enhance the overall productivity of Chir pine forest.This silvi-medicinal system gives scope for utilizing floor Chir pine forests for growth and production of Solanum khasianum beside conservation of the medicinal herb.展开更多
基金supported by the International Cooperation Project of Ministry of Science and Technology of China(MOST:2009DFA32710,BMBF(FKZ):0330847F)the Natural Science Foundation of Zhejiang Province,China(Y13G030168)
文摘Ameliorating waste treatment by technological improvements affects the economic and the ecological-environment benefits of intensive pig production. The objective of the research was to develop and test a method to determine the technical optimization to ameliorate waste treatment methods and gain insight into the relationship between technological options and the economic and ecological effects. We developed an integrated bio-economic model which incorporates the farming production and waste disposal systems to simulate the impact of technological improvements in pig manure treatment on economic and environmental benefits for the case of a pilot farm in Beijing, China. Based on different waste treatment technology options, three scenarios are applied for the simulation analysis of the model. The simulation results reveal that the economic-environmental benefits of the livestock farm could be improved by reducing the cropland manure application and increasing the composting production with the current technologies. Nevertheless, the technical efficiency, the waste treatment capacity and the economic benefits could be further improved by the introduction of new technologies. It implies that technological and economic support policies should be implemented comprehensively on waste disposal and resource utilization to promote sustainable development in intensive livestock production in China.
文摘The expansion of non-industrial private forests (NIPF) in Ireland is unique in the European context in which the almost doubling of forest cover within the last thirty years has taken place largely on farmland. This is not surprising as Ireland has some of the highest growth rates for conifers in Europe and also has a large proportion of land which is marginal for agriculture but highly productive under forests. However, in recent years, afforestation in Ireland as in many European countries has fallen well short of policy targets. As the farm afforestation decision essentially involves an inter-temporal land use change, farmers need comprehensive information on forest market returns under different environmental conditions and forest management regimes. This paper describes the systematic development of a cohort forest bio-economic model which examines financially optimal afforestation and management choices. Simulating a range of productivity and harvesting scenarios for Sitka spruce, we find that different objectives result in different outcomes. We see substantial differences between the biologically optimal rotation, the reduced rotation in common usage and the financially optimal rotation which maximises net present value and find that the results are particularly sensitive to the choice of management and methodological assumptions. Specifically, we find that better site productivity and thin versus no-thin options result in shorter rotations across all optimisations, reinforcing the usefulness of this type of financial modelling approach. This information is critical for future policy design to further incentivise afforestation of agricultural land.
基金This work was funded by Natural Science Foundation of China(41876141)the Funding Scheme for Training Young Teachers in Shanghai Colleges and the Shanghai Leading Academic Discipline Project(Fisheries Discipline).
文摘The neon flying squid(Ommastrephes bartramii)in the Northwest Pacific Ocean is one economically important cephalopod,largely exploited by squid jigging fleets from Chinese Mainland,Japan,and Chinese Taibei.In this study,a Bayesian Bio-economic model was developed using fishery data from Chinese Mainland,Japan,and Chinese Taibei,and relevant fishery economic data from Chinese Mainland.The stock assessment and risk analysis of alternative management strategies for O.bartramii were carried out.Three prior distributions(i.e.,uniform,normal and logarithmic normal)for model parameters were assumed in different scenarios.The results showed that the estimated model parameters and reference points such as maximum sustainable yield(MSY),maximum economic yield(MEY),bio-economic balance point(BE)and fishing mortality were similar in the scenarios of normal and logarithmic normal prior assumptions.However,the estimates were larger in the scenario of uniform prior assumption.The fishing mortalities and annual catches from 1996 to 2008 were lower than the reference points F_(0.1) and MSY in all the three scenarios,indicating that O.bartramii stock is at sustainable exploited level.The results of decision analysis indicated that under the same harvest rate,the catch and biomass in 2023 from the uniform assumption were the highest.However,the highest probability of the collapse was found for squid resources after 2023.Our findings suggested that the harvest rate of 0.4 appeared to be the best management regulation under the uniform assumption,and the MSY would be 200 thousand tons.In addition,the harvest rate of 0.5 would be the best management regulation under the other two assumptions,and the MSY would be 180 thousand tons,which balanced the desire for high yields and the healthy population.The results of this study could be used to provide management suggestions for neon flying squid in the Northwest Pacific Ocean.
基金National Natural Science Foundation of China under Grant No.61673099.
文摘In this paper,we study a class of singular stochastic bio-economic models described by differential-algebraic equations due to the influence of economic factors.Simplifying the model through a stochastic averaging method,we obtained a two-dimensional diffusion process of averaged amplitude and phase.Stochastic stability and Hopf bifurcations can be analytically determined based on the singular boundary theory of diffusion process,the Maximal Lyapunov exponent and the invariant measure theory.The critical value of the stochastic Hopf bifurcation parameter is obtained and the position of Hopf bifurcation drifting with the parameter increase is presented as a result.Practical example is presented to verify the effectiveness of the results.
文摘论文以内蒙古沙漠化地区为例,运用Bioe-conom ic M odel,比较自由放牧与耕垦、禁牧与禁垦、控制放牧规模与禁垦的土地利用政策情景下,引进舍饲养牛技术与信贷服务和增加非农就业机会对农户土地利用决策及其家庭收入的影响,据此探讨中国北方地区沙漠化发展的人文驱动机制以及生态重建的环境政策。结果表明:实施控制放牧规模与禁垦的环境政策,同时引进舍饲养牛技术能够有效地促进生态重建并提高农户收入;引进舍饲养牛技术需要启动基金,提供信贷服务和增加非农就业机会是贫困农户引进该技术的前提。因此,迫切需要调整宏观环境政策,提高农业集约化经营水平和城乡联系力度,从而提高农户家庭收入、减轻农民对环境的依赖性和促进农村的可持续发展。
基金a part of research project:An Interdisciplinary Approach to Analyze the Dynamics of Forest and Soil Degradation and to Develop Sustainable Agro-ecological Strategies for Fragile Himalayan Watersheds,funded by the European Union
文摘This study analyzes the vegetative and soil degradation,measured as biomass and soil loss,for Arnigad micro-watershed located in Indian Himalayan state of Uttarakhand,in systems framework by using dynamic linear programming bio-economic model.The focus is at investigating the effects of alternate policy regimes,i.e.,introduction of improved energy sources for cooking along with substitution of existing local livestock breeds with improved breed,reduction in human population growth and introduction of high yielding varieties of main crops including paddy,maize and wheat.The model horizon extended over a period of 25 years,i.e.,from 2006 to 2030.It was found that the model scenario incorporating increased use of improved energy sources along with substitution of local cows by improved cows could be the most effective policy option in reducing vegetative and soil degradation.The vegetative biomass density declined to 19.76% compared to 35.24% in the BASE scenario and soil erosion loss was also lowered by 29.13%.Also,the reduction of population growth rate to half of the BASE scenario led to minor improvements in degradation.Introduction of high yielding varieties of main crops slightly increased vegetative degradation but reduced soil loss(8.35%) with respect to the BASE scenario.Such a phenomenon could be explained in terms of changed crop mix resulting in reduced amount of crop by-products requiring increased lopping of tree branches for animal fodder.The policy option of the increased use of improved energy sources along with substitution of improved breed of cows resulted in 9.58% higher income.Introduction of high yielding varieties of crops led to 1.92% increase in income,but the income decreased by 1.25 % when population growth was reduced to half.The usefulness of the model lies in analyzing the systems behavior in its entirety where the results can predict the possible direction of change as a result of manipulation in alternate economic regimes.
文摘Background：In mid hills of Western Himalayas,Himachal Pradesh India,growth,yield and economics of Solanum khasianum as a potential medicinal herb under Pinus roxburghii（Chir pine） plantation has been studied for two consecutive years to assess the performance of Solanum khasianum in undercanopy of Pinus roxburghii for developing Solanum khasianum and Pinus roxburghii based innovative silvi-medicinal system.Methods：Growth parameters such as plant height,number of branches per plant and leaf area index followed by yield were estimated after Solanum khasianum was grown on three topographical aspects as;Northern,North- western and Western at a spacing of 45 cm x 45 cm,followed by three tillage depths as;minimum（0 cm）,medium（up to 10 cm）and deep tillage（up to 15 cm）,in open and below canopy conditions treatment.The study was conducted to explore the possibility of using Solanum khasianum based silvi-medicinal system to utilize the below canopy of Chir pine forest for enhancing the productivity of forests besides the conservation of the medicinal herb.Results：The growth parameters such as plant height,number of branches per plant and leaf area index were nonsignificantly affected by topographical aspects and tillage practices,both below canopy and open conditions except fresh weight and dry weight of berries during harvesting stage.The maximum yield（0.61 t·ha^（-1）） was observed on Western aspect in open conditions as compared to below canopy of Chir pine.The highest gross returns were observed for the crop cultivated on Western aspect under deep tillage in open conditions than other aspect and tillage combinations.However the positive net returns from the crops raised in below canopy of Chir pine indicates its possible economic viability under agroforestry system as the gross returns was higher than the cost of cultivation.Conclusion：Solanum khasianum when grown in below canopy of Pinus roxburghii,its growth and yield indicated positive net returns.Solanum khasianum and Pinus roxburghii based silvi-medicinal system has the potential to enhance the overall productivity of Chir pine forest.This silvi-medicinal system gives scope for utilizing floor Chir pine forests for growth and production of Solanum khasianum beside conservation of the medicinal herb.
