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Biodiesel from non-grain feedstock has been considered as one of the proper substitutes for fossil fuels associated with a series of activities emerging in China in order to meet the resource shortage and develop the energy crops. This paper presents an ecological accounting framework based on embodied energy, emergy, and CO2 emission for the whole production chain of biodiesel made from Jatropha curcas L. (JCL) oil. The energy and materials invested in and CO2 emission from the whole process, including cropping, transportation, extraction, and production, are accounted and calculated. Also, EmCO2, the ratio of real CO2 released to the emergy-based sustainability indicator per joule biodiesel, is proposed in this paper to present a new goal function for low-carbon system optimization. Finally, the results are compared with those of the bioethanol (wheat) production in Henan Province, China, and bioethanol (corn) production in Italy in view of the indices of embodied energy, emergy and CO2 emissions and EmCO2. [Copyright &y& Elsevier]

This paper presented a thermodynamic synthesis that involved resource accounting, evaluation and modeling of urban ecosystems based on embodied cosmic exergy (EcE), which redefined embodied exergy with the cosmic microwave background radiation (CMBR) as the reference for solar exergy. In a case study of the Beijing urban ecosystem, the major resources supporting the urban ecosystem, both from free natural resources and from the economy, were accounted for, analyzed and evaluated in the same units, Cosmic Joules (Jc). These indicators revealed the current performance of the Beijing urban ecosystem by considering five aspects of the system: EcE sources, EcE intensity, EcE welfare, environmental impacts and economic efficiency. Moreover, through the combination of the EcE synthesis with a systems dynamics, this research constructed an embodied cosmic exergy-based urban system model (EESM) using Beijing as an example of urban development. The results show that the 10 years from 2010 to 2020 will be very critical for the sustainable development of Beijing because many key factors, such as water resources, wastes and urban assets, might be confronted with great changes during this period. These changes will inevitably transform the urban system not only in its external circumstances but also in its inner structure and may lead to serious consequences. Of all the necessary resources, the most sensitive factor is water supply. [Copyright &y& Elsevier]

Wetlands research and restoration has become one of the critical concern due to their importance in providing ecosystem services. This study proposes a holistic methodology to assess the wetland ecosystem based on cosmic exergy as a thermodynamic orientor. This new approach is applied to two typical wastewater treatment facilities (an activated sludge system and a cyclic activated sludge system) and to a constructed wetland ecosystem in Beijing for comparison. Results show that the Beijing wetland ecosystem gains positive net present ecological value of 3.08E+14 J c regarding its total life cycle. Comparison with the activated sludge system and cyclic activated sludge system, shows that the wetland ecosystem has greater dependencies on local resources (22% vs. 0% vs. 0%) and renewable resources (67% vs. 38% vs. 31%) as well as a larger ecological sustainability index (0.64157 vs. 0.00005 vs. 0.00008). This implies that the wetland ecosystem is more environmentally friendly and sustainable method for water treatment. [Copyright &y& Elsevier]

Ecological network analysis (ENA) is introduced in this paper as a promising approach to study water use systems. Information indices from ENA involving total system throughput (TST), ascendency and overhead are calculated here. Two related aspects including organization inherent in system structures and synthesized water use intensity related with sustainable development of water use systems are analyzed. The indices of ascendency and overhead are applied for analyzing and characterizing water use network organization. For comparison of sustainability of water use systems from integrated aspects of environment, society and economy and based on TST, a new indicator termed as total system throughput intensity (TSTI) is constructed incorporating parameters of land, precipitation, population, GDP and environmental flow, which can be used as a measure of sustainability in terms of synthesized water use intensity. The Yellow River Basin in China during 1998–2006 is chosen as the case study and divided into subsystems according to the six river sections as from source to Lanzhou (S1-L1), Lanzhou to Toudaoguai (L1-T), Toudaoguai to Longmen (T-L2), Longmen to Sanmenxia (L2-S2), Sanmenxia to Huayuankou (S2-H) and Huayuankou to the mouth of Bo Sea (H-B). The results show that (i) the organization levels of L1-T and H-B are better than those of S1-L1 and T-L2, with those of L2-S2 and S2-H the worst; (ii) the synthesized water use intensity has been improving, of which T-L2, L2-S2 and S2-H are at the highest levels while H-B the lowest. In addition, the comparison between TSTI and other metrics and the relationship between ascendency and TSTI are discussed, from which the importance of TSTI is reflected and the optimization criterions for sustainable development of six subsystems are derived. It can be concluded that the application of ENA in water use systems can provide new angles for water resource management to address the challenges of assessing and optimizing options to obtain more sustainable water use. [Copyright &y& Elsevier]

Abstract: Water footprint is an indicator showing the consumption impact on environment with water equivalent, which allows a detailed quantification of water use directly and indirectly in sectors for the domestic and abroad final consumption. This paper presents a framework of calculating national water footprint (NWF) with input–output method on China 2002. The results indicated that the NWF of China was 381m3/capyr in 2002. A new indicator termed as national water footprint intensity (NWFI) is also derived from NWF to evaluate the water consumption intensities of different sectors. Then the evaluation of virtual water trade in sectors is followed, the results of which give a detailed quantification of net virtual water import of sectors, verifying that China is a net virtual water exporter concerning the whole national sectors, which is different from the previous studies. Finally, it is suggested that the sectors with high NWFI and volume of net virtual water export should be regarded as the priority of Chinese water-saving strategy. [Copyright &y& Elsevier]

Abstract: The resource consumption of the Chinese society from 1981 to 2001 is investigated using ecological footprint (EF) and emergetic ecological footprint (EEF). The latter is a newly development modification of ecological footprint based on ecological thermodynamics. Individual sectors in society are described in detail corresponding to the EF and EEF components based on different views of ecological production. The EF and EEF intensities are also presented to depict the resource consumption level corresponding to unit economic output. Finally, EEF is suggested to serve as a modified indicator of EF to illustrate the resource, environment, and population activity, and thereby reflecting the ecological overshoot of the general ecological system. [Copyright &y& Elsevier]

Abstract: The resource accounting of the Chinese economy in 2000 is presented based on exergy as a unified quantifier for natural resources. Major resources entering the economic production include sunlight, wind power, tidal power, wave power, geothermal power, nuclear power, biomass, straw, hydropower, coal, oil, natural gas, wood, ores, agricultural and aquatic products. The resource conversion embracing the paper, food, iron and steel, nonferrous metal, chemical and other industries as well as transportation, household and commerce sectors are illustrated. The efficiencies of the thermal conversion procedures including lighting, mechanical work, space heating, cooking, water heating and process heating are also estimated. The total exergy input of the Chinese economy was 64.76 EJ, which was 51.0 GJ/cap, whereas the total exergy output contained 12.8 EJ or 10.1 GJ/cap, indicating the exergy efficiency was 20%. The present study illustrates the possibilities of increasing exergy efficiencies of different conversion sectors and provides theoretical foundation for policymakers in establishing effective regulatory mechanism of economic production. [Copyright &y& Elsevier]

Consumption demands in China’s megacities not only cause energy resource extraction within their own jurisdictional boundaries, but also impose huge energy resource requirements to other regions via interregional supply chains. This paper presents a multi-regional input–output analysis of energy uses embodied in final demand and interregional trade of China’s four direct-controlled municipalities, with the recently available Chinese 2007 multi-regional input–output table. The total embodied energy uses (EEUs) of Beijing, Tianjin, Shanghai and Chongqing are 59.1, 60.0, 136.7 and 50.4 Mtce in 2007, respectively. Shanghai has the highest per capita EEUs with an amount of 7.4 tce, followed by Tianjin (5.4 tce), Beijing (3.6 tce) and Chongqing (1.8 tce). Investment is the leading final demand category and accounts for respectively 53.1% and 55.8% of the total EEUs in Beijing and Chongqing. Meanwhile, the shares of energy uses embodied in exports are especially high in Tianjin and Shanghai, due to their location advantages and great economic openness. 98.9%, 92.1%, 51.2% and 35.6% of the EEUs in Shanghai, Beijing, Tianjin and Chongqing are imported from China’s other regions, respectively. Shanxi, Inner Mongolia, Hebei, Shaanxi, Heilongjiang and Xinjiang are the important “energy-saving helpers” for these megacities. The largest interregional net embodied energy-import sector is construction for all the four municipalities. Considering the embodied energy uses in urban ecosystems is important for policy makers to recognize visible and hidden energy uses within city boundaries and along the entire supply chains and address cross-boundary potentials for energy saving at the regional, national and global supply chains. [ABSTRACT FROM AUTHOR]

A structurally dynamic model was developed based on the software Pamolare II for the plant-dominated Baiyangdian Lake in North China. The model was applied to forecast the ecological health condition under different scenarios of removing submerged plants. The indicators for ecosystem health included phytoplankton biomass, ratio of zooplankton to phytoplankton biomass, eco-exergy and structural eco-exergy. The results showed that the lake''s health degraded following the decrease of removal of submerged plants. Meanwhile, the ecological health improved when the removal of submerged plants increased to 1.5 times the normal level. Finally, based on the model results, the biomass of submerged plants is recommended to be reduced to 140–180g/m2, which may provide reasonable reference for regulating and controlling submerged plants in Baiyangdian Lake. [Copyright &y& Elsevier]

Analyzing the structure and functioning of the urban system revealed ways to optimize its structure by adjusting the relationships among compartments, thereby demonstrating how ecological network analysis can be used in urban system research. Based on the account of the extended exergy utilization in the sector of urban socio-economic system, which is considered as the composition of extraction (Ex), conversion (Co), agriculture (Ag), industry (In), transportation (Tr), tertiary (Te) and households (Do) sectors, an urban ecological network model is constructed to gain insights into the economic processes oriented to sustainable urban development. Taking Beijing city as the case, the network accounting and related ecological evaluation of a practical urban economy are carried out in this study in the light of flux, efficiency, utility and structure analysis. The results showed that a large quantity of energy and resources have to be consumed to maintain the structure and function of a city. The thermodynamic efficiencies of individual sector in Beijing remain at a low level. The social system in Beijing is a highly competitive network, and there are 8 competitive relations and only two mutualistic ones. The Domestic and Agricultural sector are the major controlling factors of the system. Moreover, the assessment results of Beijing are compared with the other three socio-economic systems, Norway, UK and Italy, and the ecological network function and structure comparisons are correspondingly illuminated and discussed. The conclusions indicate that the exergy-based network analysis can be refined to become an integrative tool for evaluation, policy-making and regulation for urban socio-economic system management concerning structure and efficiency at urban levels. [Copyright &y& Elsevier]

Thermodynamic indicators, including eco-exergy and structural eco-exergy, have been widely applied to lake ecosystem health assessment in recent decades. In this paper, the index system, including phytoplankton biomass, microzooplankton biomass, trophic state index (TSI), eco-exergy, structural eco-exergy and ecological buffer capacity to total phosphorus for phytoplankton, were applied to assess the health states of fourteen typical water areas in the plant-dominated Baiyangdian Lake. Different types of organisms, including zooplankton, benthonic animals and macrophytes with various denotative meanings, were differentiated to some extent and the latest weighting factors, were used in the eco-exergy and structural eco-exergy calculations for a better characterization of health state. The results showed that only the water area in site 4, with relatively high eco-exergy, structural eco-exergy, ecological buffer capacity and low phytoplankton biomass, microzooplankton biomass and TSI, is in healthy state. Health states of the other water areas were all deteriorated at various degrees due to the human disturbances. The health states of the northeast and southeast water areas were better than those of the northern, central and southern water areas with aquaculture and villages and western water areas close to the Fu River. For the plant-dominated Baiyangdian Lake, combining eco-exergy with structural eco-exergy could better characterize the health state of ecosystem with macrophytes hypermorphosis and meanwhile based on the distinguishing of various organism components, specifically benthonic animals, to some extent for eco-exergy and structural eco-exergy calculations, spatial variations of health state obtained better description, which indicated eco-exergy and structural eco-exergy were the robust indicators for ecosystem health assessment of the plant-dominated lake. [Copyright &y& Elsevier]

Regarding various energy and materials flowing in the urban ecosystem and the merit of emergy as an embodied energetic equivalent for integrated ecological economic evaluation, an evaluation framework of emergy-based urban ecosystem health indicators (UEHIem) was established in view of five aspects including vigor, structure, resilience, ecosystem service function maintenance and environmental impact to depict the urban ecosystem health states. Further, set pair analysis (SPA) was employed to assess the urban ecosystem health level based on the UEHIem, by which the approximate degree of real index set to the optimal one was defined and evaluated to describe the relative health state of the concerned urban ecosystems. Choosing twenty typical Chinese cities in 2005 as cases, we evaluated and compared their urban ecosystem health levels based on UEHIem and SPA. The results showed that health levels of Xiamen, Qingdao, Shenzhen and Shanghai are pretty well, while those of Wuhan, Harbin, Yinchuan, Beijing and Urumchi are relatively weak. Moreover, the relative health levels were analyzed by SPA to discern the influences of the mentioned five aspects on the UEHIem. It is concluded that emergy synthesis combined with SPA can serve as an effective relative-measure to compare different ecosystem health levels of urban ecosystems. [Copyright &y& Elsevier]

The objective of this study is to measure and evaluate the ecosystem health levels of 31 Chinese capital cities in 2004 through an emergy synthesis framework. A system of indicators was developed corresponding to the four factors of urban ecosystem health including efficiency, structure, impact and flux. Furthermore, combined with individual indices, an emergy-based urban ecosystem health index (EUEHI) was proposed to measure and evaluate the health levels among various typical cities in China, which offers an integrated evaluation tool in view of urban production, trade and consumption. The results showed that there are intrinsic differences among six clusters associated with driving mechanisms distinguishing the rankings of urban health levels. After lining the cities of similar health levels with cluster map, the spatial distribution of the urban health is found to be arch-shaped, increasing initially and then decreasing from coast to inner land. This kind of spatial hierarchy is per se compatible and consistent with the hierarchical theory of emergy synthesis. The results also revealed double restrictions of urban health between economy and environment. Moreover, the interaction analysis was used for mirroring the driving mechanism of urban ecosystem health. Three conclusions were arrived at. Firstly, environmental health is inversely related to the economic health in China, indicating that cities cannot achieve win–win between environment and economy in the current urban development mode. Secondly, based on economy-driven mode, four quadrants were divided in the city division map, wherein 43.33% of the concerned cities developed in high economy-restriction mode, which means low economic level is still an important limiting factor for the major cities of China. Finally, based on environment-driven mode, two sections were divided, of which weak environmental dominance mode expounds the special characteristics of urban environment with obvious fragility. 23.33% of the 30 cities were in the intermediate state, which means a few correspondingly unhealthy cities should develop concrete polices for the urban ecosystem restoration. [Copyright &y& Elsevier]

Highlights: [•] We model forest carbon fluxes of a 63km2 boreal landscape with five process models. [•] Results are compared to measured fluxes and long-term forest inventory. [•] A meta-analysis is used to identify similarities among model results. [•] We use these results to relate net primary productivity to spring temperature. [•] This simple relationship could be used to make inventory models climate sensitive. [Copyright &y& Elsevier]

Abstract: Flow and environmental dispersion are essential to ecological risk assessment and ecological restoration associated with wetlands. Presented in this paper is an analytical study for effect of wind on contaminant dispersion in a wetland flow dominated by free-surface effect. Based on the momentum transport equation generally adopted for wetland flow, the solution for velocity distribution in a free-surface wetland flow under wind is rigorously derived, with a limiting case covering the known solution of flow in the absence of wind. The thickness of inverse flow layer, maximum velocity, and its location are obtained. By use of Aris''s method of concentration moments, the expression for environmental dispersivity in the free-surface wetland flow under wind is derived, and that in the absence of wind can be included as a special case. The direction and intensity of wind can influence greatly the environmental dispersivity at a stable stage. The time scale for environmental dispersivity to approach the stable stage is independent of wind. Analytical solution of mean concentration is derived and illustrated for a pulsed contaminant emission into a wetland flow dominated by free-surface effect under wind. For typical pollutant Pb, the length and duration of influence region with contaminant concentration beyond given standard level of water quality are illustrated. [Copyright &y& Elsevier]

The eleven symposia organized for the 2009 conference of the International Society for Ecological Modelling (ISEM 2009) held in Quebec City, Canada, October 6–9, 2009, included facilitated discussion sessions following formal presentations. Each symposium focused on a specific subject, and all the subjects could be classified into three broad categories: theoretical development, population dynamics and ecosystem processes. Following discussions with the symposia organizers, which indicated that they all shared similar issues and concerns, the facilitated discussions were task-oriented around four basic questions: (1) key challenges in the research area, (2) generating and sharing new ideas, (3) improving collaboration and networking, and (4) increasing visibility to decision-makers, partners and clients. Common challenges that emerged from the symposia included the need for improved communication and collaboration among different academic disciplines, further progress in both theoretical and practical modelling approaches, and accentuation of technology transfer. Regarding the generation and sharing of new ideas, the main issue that emerged was the type of positive interactions that should be encouraged among potential collaborators. The usefulness of the Internet, particularly for the sharing of open-source software and conducting discussion forums, was highlighted for improving collaboration and networking. Several communication tools are available today, and it is important for modellers to use them more intensively. Visibility can be increased by publishing professional newsletters, maintaining informal contacts with the public, organizing educational sessions in primary and secondary schools, and developing simplified analytical frameworks and pilot studies. Specific issues raised in each symposium are also discussed. [Copyright &y& Elsevier]

In this study, a mixed integer fuzzy interval-stochastic programming model was developed for supporting the improvement of eco-resilience to floods in wetlands. This method allows uncertainties that are associated with eco-resilience improvement and can be presented as both probability distributions and interval values to be incorporated within a general modeling framework. Also, capacity-expansion plans of eco-resilience can be addressed through introducing binary variables. Moreover, penalties due to ecological damages which are associated with the violation of predefined targets can be effectively incorporated within the modeling and decision process. Thus, complexities associated with flood resistance and eco-resilience planning in wetlands can be systematically reflected, highly enhancing robustness of the modeling process. The developed method was then applied to a case of eco-resilience enhancement planning in three ecologically vulnerable regions of a wetland. Interval solutions under different river flow levels and different ecological damages were generated. They could be used for generating decision alternatives and thus help decision makers identify desired eco-resilience schemes to resist floods without causing too much damages. The application indicates that the model is helpful for supporting: (a) adjustment or justification of allocation patterns of ecological flood-resisting capacities, (b) formulation of local policies regarding eco-resilience enhancement options and policy interventions, and (c) analysis of interactions among multiple administrative targets within a wetland. [Copyright &y& Elsevier]

Based on the thermodynamic concept of exergy as a unified measure for environmental resources and economic products, a framework for systems assessment is presented for ecological economies. With a typical systems diagram devised for a general ecological economy with four arm fluxes for free local natural resources, purchased economic investment, environmental impact and economic yield, system indices of the renewability index, exergy yield ratio, exergy investment ratio, environmental resource to yield ratio, system transformity and environmental stress index are defined for a congregated systems ecological assessment with essential implications to sustainability. As a detailed case study to the Chinese agriculture from 1980 to 2000 with cropping, forestry, stockbreeding and fishery sectors, extensive exergy account and systems assessment are carried out with emphasis on annual and structural variations against social political transitions. For the overall agriculture as a congregated ecological stage, the value of the system transformity is found around 10, the typical value for the general ecological hierarchy as well devised by Odum associated with Lindeman''s Tenth Law. [Copyright &y& Elsevier]