Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and thei...Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and their economic value from these two ecosystems can provide theoretical and practical basis for further development and utilization of these classical agricultural techniques. CH4 and N2O emissions from RD and RF ecological systems were measured in situ by using static chambers technique. Using global warming potentials （GWPs）, we assessed the greenhouse effect of CH4 and N2O and their economic value. Results showed that the peaks of CH4 emission fluxes from RD and RF appeared at full tillering stage and at heading stage, and the average emission fluxes were significantly （P〈 0.05） lower than that from CK. N2O fluxes remained low when the field is flooded and high after draining the water. Compared with CK, the total amount of N2O emissions was significantly （P〈0.05） higher and slightly lower than those from RD and RF, respectively. In 2006 and 2007, the total greenhouse effect of CH4 and N20 from RD and RF were 4 728.3 and 4 611 kg CO2 ha^-1, 4 545 and 4 754.3 kg CO2 ha^-1, respectively. The costs of greenhouse effect were 970.89 and 946.81 RMB yuan ha^-1, and 933.25 and 976.23 RMB yuan ha^-1, respectively, which were significant lower than those from CK （5 997.6 and 5 391.5 RMB yuan ha^-1）. Except for the environment cost of CH4 and N2O, the economic benefits from RD and RF were 2 210.64 and 4 881.92 RMB yuan ha^-1; 3 798.37 and 5 310.64 RMB yuan ha^-1, respectively, higher than those from CK. Therefore, RD and RF complex ecological planting and breeding models can effectively decrease and control CH4 and N2O emissions, and they are two of the effective strategies to reduce greenhouse gases from rice paddy fields and contribute in alleviating global warming. Thus, their adoption is important to the environment together with their economy benefits.展开更多
Using energy analysis,the quantifying evaluation and study method on production, living and ecology functions and their sustainability of rural settlement ecosystem in mountain area is established with these energy in...Using energy analysis,the quantifying evaluation and study method on production, living and ecology functions and their sustainability of rural settlement ecosystem in mountain area is established with these energy index such as export of labor and products, export of water resource, internal energy reserve, energy consumption for human living, net energy of ecosystem function and net internal reserve. Taking rural settlement Raosi Village in Hengduan Mountains as a case study, and on the basis of the synthetic research into the ecological process of the complex ecosystem, the study shows that energy costs of production, human living and ecology functions are separately taking 1.36%, 13.59% and 85. 05% of the gross ecosystem functions, and the exertions of production and human living functions are close to a high-point state on the present using level of energy in the settlement. The study also shows that the most important function of a rural settlement in mountain area is its ecological rather productive function.展开更多
Valuating the fimction of ecosystem services is crucial for accounting green GDP, making a conservation policy of ecological environment and the decision of regional development as well as sustainable development stra...Valuating the fimction of ecosystem services is crucial for accounting green GDP, making a conservation policy of ecological environment and the decision of regional development as well as sustainable development strategy. R ice-duck-fish symbiosis has been promoted in several developing countries as a way of increasing incomes for rice farmers, but investigations of its value have mainly focused on direct economic＇ benefits, such as food and raw material production. Few studies have been conducted on the estimation of indirect services provided by rice-duck-fish complex ecosystem. The gas regulation service and its economic values provided by rice-duck-fish complex ecosystem were studied in Wuhan, China. The major components of gas regulation are O2 emission and greenhouse gases （GHGs, CO2） regulation. The results show that O2 emission from different treatments （including rice-duck （RD）, rice-fish （RF）, rice-duck-fish （RDF） and rice （CK）） ranged from 26,370 kg/ha to 33,910 kg/ha per year. with an economic value of 10,050-12,920 yuan/ha per ）,ear （Chinese currency： 1 euro =10.2475 yuan, August 28, 2007）. The net GHGs exchange varied from 1,200 to 3,320 kg/ha per year; and its economic value ranged from 1,040 yuan/ha to 2,900 yuan/ha per year Consequently, the total economic value of gas regulation provided by symbiosis complex ecosystems ranged from 11,090 yuan/ha to 15,820 yuan/ha per year. and the maximum overall economic value of gas regulation was provided by RDF complex ecosystem. The work will be useful for further understanding of the functions of rice-duck-fish complex ecos.vstem services and supplying the theoretical references to agricultural policy.展开更多
The citrate metabolism has been extensively studied in lactic acid bacteria (LAB) for its aroma compound production. Among the 4-carbon (C4) by-products obtained from citrate fermentation, diacetyl is one of the bette...The citrate metabolism has been extensively studied in lactic acid bacteria (LAB) for its aroma compound production. Among the 4-carbon (C4) by-products obtained from citrate fermentation, diacetyl is one of the better known products for its contribution to the buttery aroma of dairy products. A lot of documents deal with ways to improve diacetyl concentration in food matrices. Apart from these organoleptic advantages, in a microbial ecosystem, the citrate metabolism gives selective advantages to citrate positive microorganisms. Citrate metabolism allows the LAB to use another carbon source for their growth, withstand acidic conditions and generate a “proton motive force” (PMF). Moreover, the citrate/glucid co-metabolism leads to the fast release of organic compounds known for having bacteriostatic effects. Under specific conditions, the C4?pathway liberates diacetyl which is bacteriostatic. In this review we first describe the citrate metabolism and the enzymes involved in the two homo- and heterofermentative LABLc diacetylactisandLeuconostocspp. Moreover, the way to shift the metabolic pathway toward the production of aromatic compounds is discussed for both of these fermentative types of bacteria. Finally, the selective advantages of citrate metabolism for LAB in complex microbial ecosystems are delineated.展开更多
The escalating ecological consequences of state transitions have attracted significant attention in both theoretical and experimental studies,with a focus on determining the stable or equilibrium points of dynamic sys...The escalating ecological consequences of state transitions have attracted significant attention in both theoretical and experimental studies,with a focus on determining the stable or equilibrium points of dynamic systems[1-5].Identifying equilibrium states not only reveals a system's current status but also offers insights into its evolutionary trajectory under specific environmental conditions[6].展开更多
Infrastructure mega-projects(IMP), which involve complex interactions and feedback, have more significant impact on economic, social, and other systems.This paper proposes a concept—the IMP complex ecosystem—to anal...Infrastructure mega-projects(IMP), which involve complex interactions and feedback, have more significant impact on economic, social, and other systems.This paper proposes a concept—the IMP complex ecosystem—to analyze IMP from a broad perspective of organic links across engineering, social, economic, and resource environments. Moreover, this paper proposes the theoretical concept, framework, and functions for the IMP complex ecosystem based on complex ecosystem theory.First, the coupling process between IMP complex ecosystem subsystems is analyzed through material flows, energy flows, information flows, and value streams.Second, a logistic model of the IMP complex ecosystem is proposed by analyzing the evolution conditions and motivations. Third, the evolution pattern of the IMP complex ecosystem is determined. Fourth, the positive evolution strategy of the IMP complex ecosystem based on dissipative structure theory and the influencing factors of the evolutionary process is introduced. Finally, the Hong Kong-Zhuhai-Macao Bridge and Sousa chinensis are used as the case study. This paper also analyzes the coupling structure on the complex ecosystem of the Hong KongZhuhai-Macao Bridge and investigates the coupling and evolution mechanism application of the IMP complex ecosystem on Sousa chinensis protection for the Hong Kong-Zhuhai-Macao Bridge project.展开更多
There is a need to find a comprehensive approach focusing on the conflicts between economical growth and environmental protection. Chinese scholars advocate a comprehensive ecosystem viewpoint named social-economic-na...There is a need to find a comprehensive approach focusing on the conflicts between economical growth and environmental protection. Chinese scholars advocate a comprehensive ecosystem viewpoint named social-economic-natural complex ecosystem(SENCE). The kernel of the concept lies in the hierarchical structure of SENCE, through which methods from ecological network can be useful to the compound system. The author gives a schema depicting its structure, following a made analysis to help understand the reliance of economy on ecosystem. It is obvious that more actions should be done to strive for sustainable development.展开更多
基金supported by Important National Science&Technoligy Specific Projects, China (2004BA520A02)
文摘Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and their economic value from these two ecosystems can provide theoretical and practical basis for further development and utilization of these classical agricultural techniques. CH4 and N2O emissions from RD and RF ecological systems were measured in situ by using static chambers technique. Using global warming potentials （GWPs）, we assessed the greenhouse effect of CH4 and N2O and their economic value. Results showed that the peaks of CH4 emission fluxes from RD and RF appeared at full tillering stage and at heading stage, and the average emission fluxes were significantly （P〈 0.05） lower than that from CK. N2O fluxes remained low when the field is flooded and high after draining the water. Compared with CK, the total amount of N2O emissions was significantly （P〈0.05） higher and slightly lower than those from RD and RF, respectively. In 2006 and 2007, the total greenhouse effect of CH4 and N20 from RD and RF were 4 728.3 and 4 611 kg CO2 ha^-1, 4 545 and 4 754.3 kg CO2 ha^-1, respectively. The costs of greenhouse effect were 970.89 and 946.81 RMB yuan ha^-1, and 933.25 and 976.23 RMB yuan ha^-1, respectively, which were significant lower than those from CK （5 997.6 and 5 391.5 RMB yuan ha^-1）. Except for the environment cost of CH4 and N2O, the economic benefits from RD and RF were 2 210.64 and 4 881.92 RMB yuan ha^-1; 3 798.37 and 5 310.64 RMB yuan ha^-1, respectively, higher than those from CK. Therefore, RD and RF complex ecological planting and breeding models can effectively decrease and control CH4 and N2O emissions, and they are two of the effective strategies to reduce greenhouse gases from rice paddy fields and contribute in alleviating global warming. Thus, their adoption is important to the environment together with their economy benefits.
文摘Using energy analysis,the quantifying evaluation and study method on production, living and ecology functions and their sustainability of rural settlement ecosystem in mountain area is established with these energy index such as export of labor and products, export of water resource, internal energy reserve, energy consumption for human living, net energy of ecosystem function and net internal reserve. Taking rural settlement Raosi Village in Hengduan Mountains as a case study, and on the basis of the synthetic research into the ecological process of the complex ecosystem, the study shows that energy costs of production, human living and ecology functions are separately taking 1.36%, 13.59% and 85. 05% of the gross ecosystem functions, and the exertions of production and human living functions are close to a high-point state on the present using level of energy in the settlement. The study also shows that the most important function of a rural settlement in mountain area is its ecological rather productive function.
基金the Key Research Pro-gram of Hubei Province (Grant No. 2005AA201B01)
文摘Valuating the fimction of ecosystem services is crucial for accounting green GDP, making a conservation policy of ecological environment and the decision of regional development as well as sustainable development strategy. R ice-duck-fish symbiosis has been promoted in several developing countries as a way of increasing incomes for rice farmers, but investigations of its value have mainly focused on direct economic＇ benefits, such as food and raw material production. Few studies have been conducted on the estimation of indirect services provided by rice-duck-fish complex ecosystem. The gas regulation service and its economic values provided by rice-duck-fish complex ecosystem were studied in Wuhan, China. The major components of gas regulation are O2 emission and greenhouse gases （GHGs, CO2） regulation. The results show that O2 emission from different treatments （including rice-duck （RD）, rice-fish （RF）, rice-duck-fish （RDF） and rice （CK）） ranged from 26,370 kg/ha to 33,910 kg/ha per year. with an economic value of 10,050-12,920 yuan/ha per ）,ear （Chinese currency： 1 euro =10.2475 yuan, August 28, 2007）. The net GHGs exchange varied from 1,200 to 3,320 kg/ha per year; and its economic value ranged from 1,040 yuan/ha to 2,900 yuan/ha per year Consequently, the total economic value of gas regulation provided by symbiosis complex ecosystems ranged from 11,090 yuan/ha to 15,820 yuan/ha per year. and the maximum overall economic value of gas regulation was provided by RDF complex ecosystem. The work will be useful for further understanding of the functions of rice-duck-fish complex ecos.vstem services and supplying the theoretical references to agricultural policy.
文摘The citrate metabolism has been extensively studied in lactic acid bacteria (LAB) for its aroma compound production. Among the 4-carbon (C4) by-products obtained from citrate fermentation, diacetyl is one of the better known products for its contribution to the buttery aroma of dairy products. A lot of documents deal with ways to improve diacetyl concentration in food matrices. Apart from these organoleptic advantages, in a microbial ecosystem, the citrate metabolism gives selective advantages to citrate positive microorganisms. Citrate metabolism allows the LAB to use another carbon source for their growth, withstand acidic conditions and generate a “proton motive force” (PMF). Moreover, the citrate/glucid co-metabolism leads to the fast release of organic compounds known for having bacteriostatic effects. Under specific conditions, the C4?pathway liberates diacetyl which is bacteriostatic. In this review we first describe the citrate metabolism and the enzymes involved in the two homo- and heterofermentative LABLc diacetylactisandLeuconostocspp. Moreover, the way to shift the metabolic pathway toward the production of aromatic compounds is discussed for both of these fermentative types of bacteria. Finally, the selective advantages of citrate metabolism for LAB in complex microbial ecosystems are delineated.
基金supported by the funds from the National Natural Science Foundation of China(42041005 and 32101313)the CAS Strategic Priority Research Programme(A)(XDA20050103)Science&Technology Fundamental Resources Investigation Program(2022FY100100)。
文摘The escalating ecological consequences of state transitions have attracted significant attention in both theoretical and experimental studies,with a focus on determining the stable or equilibrium points of dynamic systems[1-5].Identifying equilibrium states not only reveals a system's current status but also offers insights into its evolutionary trajectory under specific environmental conditions[6].
基金funded by the National Natural Science Foundation of China(Grant Nos.71771067 and 71390522)
文摘Infrastructure mega-projects(IMP), which involve complex interactions and feedback, have more significant impact on economic, social, and other systems.This paper proposes a concept—the IMP complex ecosystem—to analyze IMP from a broad perspective of organic links across engineering, social, economic, and resource environments. Moreover, this paper proposes the theoretical concept, framework, and functions for the IMP complex ecosystem based on complex ecosystem theory.First, the coupling process between IMP complex ecosystem subsystems is analyzed through material flows, energy flows, information flows, and value streams.Second, a logistic model of the IMP complex ecosystem is proposed by analyzing the evolution conditions and motivations. Third, the evolution pattern of the IMP complex ecosystem is determined. Fourth, the positive evolution strategy of the IMP complex ecosystem based on dissipative structure theory and the influencing factors of the evolutionary process is introduced. Finally, the Hong Kong-Zhuhai-Macao Bridge and Sousa chinensis are used as the case study. This paper also analyzes the coupling structure on the complex ecosystem of the Hong KongZhuhai-Macao Bridge and investigates the coupling and evolution mechanism application of the IMP complex ecosystem on Sousa chinensis protection for the Hong Kong-Zhuhai-Macao Bridge project.
文摘There is a need to find a comprehensive approach focusing on the conflicts between economical growth and environmental protection. Chinese scholars advocate a comprehensive ecosystem viewpoint named social-economic-natural complex ecosystem(SENCE). The kernel of the concept lies in the hierarchical structure of SENCE, through which methods from ecological network can be useful to the compound system. The author gives a schema depicting its structure, following a made analysis to help understand the reliance of economy on ecosystem. It is obvious that more actions should be done to strive for sustainable development.
