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Input capacity constraints means a firm cannot make its output decision based on the first - order optimal condition of profit maximization because it does not have enough inputs. Input capacity constraints have a significant effect on production quality and firm competition, especially on food safety management. This paper tries to provide a new perspective for quality operation in supply chain management. It also designs a new mechanism for quality regulation. After distinguishing between quantity-sensitive input capacity constraints and quality-sensitive input capacity constraints, this paper demonstrates a theoretical analysis about the impact of input capacity constraints on food quality and quality regulation by game theory. The results show that both kinds of capacity input constraints lead to a lower level of output, quality and consumer surplus, but a higher level of prices. In this study, we design a quality regulation to stimulate the growth of high quality food products. More importantly, this paper proves that reward is more effective in food quality guarantee programs than punishment or fine based programs. The conclusions are helpful for addressing food safety problems for both the supervisors and firms. [ABSTRACT FROM AUTHOR]

• Build a multi-objective method for improving LEN functional and structural connectivity. • Identify key locations for improving structural connectivity based on graph theory. • Introduce "integral index of probable connection" into network link additional technique. • Search corridor paths with maximum functional connectivity using greedy algorithm. • Use hierarchical rules with different priorities to set the greedy algorithm. By building connectivity between ecological spaces, the landscape ecology network (LEN) can effectively prevent further habitat fragmentation and loss in urbanizing areas. The existing LEN construction method fails to consider the multiple optimization goals of improving network structural and functional connectivity. This paper aimed to provide a novel method to improve connectivity for existing LENs in urbanizing areas. We took an urbanizing area in China as an example and extract existing LEN based on ecological priorities. On this basis, from the dimension of structural connectivity optimization, we used the network link additional technique based on "integral index of probable connection" to identify 50 optimal locations of additional corridors that could significantly improve the network structural connectivity. From the dimension of functional connectivity enhancement, we applied the greedy algorithm based on hierarchical rules with different priorities to search for corridor paths with maximum ecological function and low ecological and construction resistance. The optimized LEN contained 43 ecological sources and 74 ecological corridors. The dual dimension method proposed in this paper can improve the functional and structural connectivity of existing LEN, and greatly save the optimization time and efficiency of the network, to provide targeted ecological space protection schemes for urbanizing areas. [ABSTRACT FROM AUTHOR]

• The ecohydraulic modeling framework is a valuable tool for assessing fish ecology in dammed rivers. • Cascade dam construction could fragment spawning site habitats and reduce fish population abundance in the tailwater zone of the main stream. • Spawning site habitats would improve, leading to an increase in fish population abundance in the backwater zone of tributaries. • The effects of cascade dam construction on endemic fish habitat and population status depend on spawning site location, fish species, and life stages. Cascade dam constructions will alter the habitat of spawning sites and affect fish population in the Lancang River basin. This paper examines the impacts of cascade dam construction on four spawning sites, focusing on two co-distributed and endemic fish species: Schizothorax prenanti and Schizothorax davidi. An ecohydraulic modeling framework that combined hydro-morphodynamic, habitat, and population models was used to investigate changes in habitat quality and fish population under two scenarios: no-dam and with-dam. Fish habitat quality was evaluated using the habitat suitability index, and population fluctuations were assessed by the abundance and density of fish populations at all life stages. The simulation results indicated that cascade dam construction would fragment the spawning site habitat in the tailwater zone of the main stream and result in a decrease in fish population abundance and density. Conversely, spawning site habitats in backwater zone of tributaries would improve, and fish population abundance and density would increase. Additionally, the simulation results showed that the magnitude of fish population variations varied by species and life stages. These results highlight the different responses of spawning site location, fish species, and life stages to dam construction, which can help identify areas of the habitat with higher potential for finer-scale endemic fish conservation and recovery efforts. This study provides a comprehensive framework tool for fish ecological evaluation in dammed rivers, which has the potential to assist decision-makers involved in river ecosystem ecological conservation. [Display omitted] [ABSTRACT FROM AUTHOR]

The re-interpretation of the urban development acts as both a sink of entropy transfer and as a source of releasing negative effects into the environment. It is a major step towards the design of urban sustainable development schemes. Presented in this paper is an integrated ecological economic assessment considering the economic and ecological losses and a sustainability policy-making framework for 31 typical Chinese cities in view of spatial variations based on thermodynamic analysis. The economic and ecological loss varies significantly across cities both in total sum due to diversities of geographic features, economic development levels and local energy use availability. The results revealed the metropolises (including Beijing, Shanghai, Guangzhou, etc) and cities along the Yangzi river (e.g., Changsha) have the lowest Emergy-based Sustainability Index (ESI) values, thus suggesting that emissions greatly reduced the sustainability of the urban socioeconomic system by pulling resources for damage repair and for replacement of lost natural and human-made capital. The investment of the waste treatment investment, which acts as a balanced system for entropy turbulence, should be encouraged. The spatial hierarchy theory in emergy synthesis can be derived from the developing pattern of cities. This paper provides a reference towards how the urban environmental impacts drive economic policy and sustainability. [Copyright &y& Elsevier]

Abstract: In recent years, many methods have been proposed to cope with eutrophication, a serious ecological problem in estuaries. Many of these problems have resulted from the new production of non-siliceous algae. In this paper, a runoff optimized regulation model for eutrophication control was developed to limit the potential of new non-siliceous algae production, which, in this paper, is defined as eutrophication potential. At the beginning of the model, a formula of silicon flux was modified by adding a dam retention coefficient and a turbidity maximum zone (TMZ) retention coefficient. Afterwards, the formula was used to improve the expression of the ICEP (indicator of coastal eutrophication potential) for a more exact result. The ICEP (treated as an ecology objective to limit the potential of sustaining new production of non-siliceous algae), harmonious index, and cost function were then integrated into the optimization model, at which point the ICOA (immune clone optimization algorithm) was proposed to solve this model. We then chose the Yangtze Estuary as a case study to verify the performance of the optimization model, and used an uncertainty analysis, a comparative analysis, and a sensitivity analysis to assess the model''s performance. The results show the best combination of weight factors for integrating objectives is λ 1 =0.48, λ 2 =0.32, λ 3 =0.2. The optimized runoff performs well at keeping the value of the ICEP within reasonable limits while at the same time meeting the goal of economy and society in the Yangtze Estuary. Finally, we discuss transfer rates in different exceedance probabilities, illustrating that the optimized runoff is feasible for this study area, and the results can then be used as a point of reference regarding water transfer decisions. [Copyright &y& Elsevier]

Conservation investments are increasingly being implemented through payments for ecosystem services (PES) for the protection and restoration of ecosystem services around the world. Previous studies suggested that social norms have substantial impacts on environmental behaviors of humans, including enrollment of PES programs. However, it is still not well understood how social norms are affected by the design of PES programs and how the evolution of social norms may affect the efficiency of conservation investments. In this paper, we developed an agent-based simulation model to demonstrate the evolution and impacts of social norms on the enrollment of agricultural land in a PES program. We applied the model to land plots that have been enrolled in China's Grain-to-Green Program (GTGP) to examine reenrollment in an alternative payment program when the current payments ceased. The study was conducted in Wolong Nature Reserve where several thousand plant and animal species, including giant pandas, may benefit from the reenrollment. We found that over 15% more GTGP land can be reenrolled at the same payment if social norms were leveraged by allowing more than 10 rounds of interactions among landholders regarding their reenrollment decisions. With only three rounds of interactions, an additional 7.5% GTGP land was reenrolled at the same payment due to the effects of social norms. In addition, the effects of social norms were largest at intermediate payments and were smaller at much higher or much smaller payments. Even in circumstances where frequent interactions among landholders about their enrollment decisions are not feasible, policy arrangements that divide households into multiple waves for sequential enrollment can enroll over 11% more land at a given payment level. The approach presented in this paper can be used to improve the efficiency of existing PES programs and many other conservation investments worldwide. [Copyright &y& Elsevier]

This paper takes environmental complexity to task by offering a way to understand the heterogeneity of an ecosystem in terms of its components’ relations rather than in terms of individuals (disaggregate) or wholes (aggregate). To do so, we use Escobar's notion of redes (networks) and Deleuze and Guatteria's ideas about human/environment relations as they relate to understanding the practical, political and emotional complexities of change in Fanjingshan National Nature Reserve (FNNR), Guizhou Province, China. A critical issue in the reserve relates to the resource-use relations between local farmers and an endangered snub-nosed monkey species, Rhinopithecus brelichi. Deleuze and Guattari point to understanding complexity through affective ecologies, while Escobar's work is particularly useful in connecting local activism, eco-tourism, and community networks in an attempt to contest globalized hegemonic discourses that do not necessarily support sustainability at the local level. The 21,000 farmers within FNNR have an intimate knowledge of their local environment that derives from day-to-day living and, for some farmers, from generations living in a particular area. The paper discusses some of the actions of local farmers that are variously connected to, and emotionally charged around, sustainability and the preservation of the snub-nosed monkey. [Copyright &y& Elsevier]

• This study constructed an urban nexus accounting framework based on Multi-Scale Input Output model. • Shanghai is a net consumer city mainly imports embodied energy and water from domestic and developing regions. • Energy water nexus characteristics of industrial sectors can offer different ways to tackle environmental challenges. Large scale urbanization and industrial development has resulted in serious environmental challenges for China. Both energy and water are considered key to urban sustainability and for that matter resource accounting and tracing are drawing growing attention in the economy. This paper focuses on energy-water nexus of urban sectors in Shanghai (referred to year 2010) using multi-regional input-output (MRIO) analysis. This study outcome revealed that overall Shanghai is a net consumer city mainly imports embodied energy and water from domestic and developing regions of the world and exports little to developed regions. In depth analysis indicated that, except S17, S7, S10, S15 and S8 all other industrial sectors were net inflows of energy in Shanghai. Similarly, except S15, all other industrial sectors were net water consumers in Shanghai. The S16 (18.96 Mtce), S20 (11.06 Mtce) and S12 (7.71 Mtce) were ranked highest as net importer making up about 60.48% of total net inflows of embodied energy, whereas S1 (18053.48 Mt), S3 (6865.16 Mt) and S19 (2320.62 Mt) were ranked highest as net importer making up about 74.99% of total net inflows of embodied water. The developed nexus strength indicator uncovered the sectoral energy-water linkages. From a production perspective, the S15 exhibited high nexus strength level up to 1 with 50% contribution by each resource to the nexus. While from a consumption perspective, the S1 revealed high nexus strength level and water was the most frequent resource node contributing about 84% to the energy-water nexus. The energy-water nexus characteristics of industrial sectors can offer different ways to tackle environmental challenges. This study can provide a reference to policy makers in identifying key sectors that requires more focus in terms of easing environmental stress to achieve sustainability in urban development. In addition, called for coordination and regulating urban industrial trade structure in the future. [ABSTRACT FROM AUTHOR]

It is important to investigate the sustainability nexus using composite ecological efficiency (eco-efficiency) indicators from quantitative and computational modeling perspectives. To provide a more comprehensive measure of eco-efficiency, this paper develops three data envelopment analysis (DEA) models incorporating metafrontier and undesirable outputs into a slacks-based measure (SBM), an epsilon-based measure (EBM), and minimum distance to weak efficient frontier (MinDW), respectively, named Meta-U-SBM, Meta-U-EBM, and Meta-U-MinDW. We show theoretically: if a decision-making unit (DMU) is being Meta-U-SBM-efficient, it is also being Meta-U-EBM-efficient and Meta-U-MinDW-efficient, and vice versa. For each DMU, its score measured by Meta-U-MinDW is the highest, while its score measured by Meta-U-SBM is the lowest. Using the proposed models, we make a first empirical attempt at measuring the eco-efficiency of the Key Environmental Protection prefecture-level cities in China from 2003 to 2015. The results show that: (1) the eco-efficiency of eastern cities performs the best, followed by central cities and western cities. Cities not listed as resource-based (RB) outperform RB cities; (2) eastern cities are closer to metafrontier than central and western cities; and (3) efficiency change and technological progress dominate the basic trend of the eco-efficiency growth. Results derived from the proposed methodologies can help managers and policymakers in the city to assess sustainability development quantitatively and comprehensively, they can also provide implications for the environmental management of sustainability development at city level. Policy implementations are presented based on the empirical results. [ABSTRACT FROM AUTHOR]

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]

In ecological network theory, network efficiency and resilience are two essential but complementary attributes of the network structure, and a balance between these factors is critical for an ecosystem's long-term sustainability. Our paper introduces this method and related concepts into water use systems to provide a new angle for sustainability quantification. In this paper, we investigate the meanings of network efficiency and resilience in the context of sustainable development of water use systems, and define sustainable systems based on the optimal balance between network efficiency and resilience. With the consideration of complex artificial characteristics of water use, we propose an optimal water use network and quantify its flows. By ascendency calculation, the balanced network structure can be determined. We then use the four sub-basins of China's Haihe River as a case study to illustrate how the optimal network can be constructed and how the optimal balance for each scenario can be calculated. The results show that the optimal balance for the sub-basins has ascendency values ranging from 0.5970 to 0.7161. By analyzing the contribution of each water use activity to network's balance structure, the location of the optimal balance in water use systems can be better understood. This research represents the first attempt to explore the balance between a network structure's efficiency and resilience as a way to quantify the sustainability of water use systems, and builds a foundation for future studies on the assessment, regulation, and management of water resources. [Copyright &y& Elsevier]

The two major aims of watershed management are regional economic development and watershed ecosystem protection. In this paper, constructed wetland (CW) technology is employed to examine watershed ecosystem protection under a certain regional economic load. The Chaohu Lake watershed in China was chosen as the target study area and fuzzy random variables used to describe the uncertainties. Then, a bi-level optimization model for watershed-scale CW planning was developed and applied to the Chaohu Lake watershed with the aim of protecting ecosystem health. To solve the model, a fuzzy random simulation-based nested simulated annealing algorithm was designed. The results showed that there was a “finite sum game” relationship between economic development and ecosystem health within the Chaohu Lake watershed. Under a probability and possibility of 0.9, to achieve the ecological goal F 1 = 70, it was estimated that a 348.19 (ha) CW needed to be constructed. The impacts of environmental policies and economic development on the watershed ecosystem were found to be significant. One of the key practical results indicated that: in the Chaohu Lake watershed, the water environmental treatment of rivers should take precedence over that of lakes; a result which could be of assistance to local government policy making. [ABSTRACT FROM AUTHOR]

Based on sustainable development theory and the method of system dynamics and multi-agent simulation, the environment-economy-society relationship model of Liaohe River Basin is constructed by coupling the system dynamics model with the multi-agent model in the software-NetLogo. This paper selects the Qinghe, Fanhe and Puhe River of Liaohe River Basin which are located in Shenyang and Tieling City as the study boundary, then the overall situation of environment, economy and society development is analyzed. At the same time, in order to simulate and predict the overall operation of the model under different policies, three kinds of development scenarios are established by changing some key variables including pollution abatement investment, fixed assets investment and industrial waste water production of ten thousand yuan industrial output value. The results show that the development under different policies can be simulated and predicted by this model, which will provide support for macroeconomic regulation and control the sustainable development strategy of Liaohe River Basin. [ABSTRACT FROM AUTHOR]

• We compared the structural characteristics of 18 urban agglomerations in China. • Our framework contained analysis of 3 different scales based on 4 elements' flows. • Guangdong-Hong Kong-Macao urban Agglomeration had the greatest average flow (5.15). • Shandong Peninsula Urban Agglomeration had the best performance in overall network. • Cities with high centrality were in the bidirectional or main spillover subgroups. Flows of different elements among cities can affect urban organizational structures, leading to specific links between and roles for cities within urban agglomerations. Previous studies have mainly focused on flows produced by specific elements in a single urban agglomeration, and they cannot reveal differences in organizational structures affected by multiple elements among different urban agglomerations. Therefore we selected 18 typical urban agglomerations in China and explored their structural characteristics under comprehensive effects of four elements: economy, resources, population and technology, with gravity model and social network analysis. Guangdong-Hong Kong-Macao Urban Agglomeration had a maximum flow intensity of 5.15, this concentration range was the largest from 0.65 to 3.75, indicating that more elements flowed internally. Shandong Peninsula Urban Agglomeration had the largest network density at 0.412, the lowest efficiency at 0.567, and the lowest hierarchy at 0.000, showing that intercity relationships within SP were the tightest among the18 urban agglomerations. Geographical proximity and topological structure of subgroups proved that connections among subgroups were not complex, and cities of different provinces lacked close interactions. Furthermore, most of the key cities with high centrality indexes were municipalities directly under the Central Government or provincial capitals; these cities played important roles in networks and were distributed into "main spillover" and "bidirectional spillover" subgroups. This paper provides a unified analytical framework aimed at urban agglomerations that accounts for flows of multiple types of elements and explores urban organizational structures, and our results could provide scientific guidance for promoting the coordinated and sustainable development of urban agglomerations. [ABSTRACT FROM AUTHOR]

During the past century Chinese agriculture has been struggling to produce more food to support the ever growing population, while dealing with the increased degradation of air, water and soil quality in the agricultural regions. Lessons learnt from the long-term efforts indicated that scientifically sound methodology could play a crucial role in understanding the complex interactions among climate, soil, water and farming management practices, all of which collectively control the agroecosystem services including crop yield, greenhouse gas emissions, nutrient loading and other environmental issues. Therefore, the development of a more process-based approach is needed. The process-based model, DNDC (Denitrification-Decomposition) has been widely used internationally to simulate detailed carbon and nitrogen biogeochemical cycles occurring in agricultural systems. However, this model is not fully suitable for China as it lacks a number of features which are crucial for representing Chinese agro-ecosystems, including paddy rice cultivation, complex and multiple cropping systems, and intensive management practices, etc. Recently a new version of DNDC, China-DNDC, was developed. The new model improved its capability of predicting the fluxes of all three terrestrial greenhouse gases: nitrous oxide (N 2 O), carbon dioxide (CO 2 ), and methane (CH 4 ), as well as other important indicators such as crop phenology, soil C sequestration, and nutrient leaching from different cropping systems across all the major agricultural regions in China. This paper reported how China-DNDC was developed, tested and applied for sustaining Chinese agriculture. And then, it identified the weaknesses and potential improvements for the model. [ABSTRACT FROM AUTHOR]

• An ABM for socio-ecological simulation in small-scale coupled human-nature systems. • A microeconomic basis for heterogeneous agents with partial rationality. • A rich set of mechanisms of two-way human-nature interactions. • Low data demand, and broad implementability in developing countries. • A case study in Wolong, China showing the validity of the model. The tension between economic development and ecological conservation has always been a hotly debated topic, especially in critical ecologically sensitive areas such as nature reserves in the developing world. Complexity modeling methods, such as Agent-based Models (ABM), are a feasible way to study such Coupled Human and Nature Systems (CHANS). This paper presents an ABM named Socio-Econ-Ecosystem Multipurpose Simulator (SEEMS) for small-scale CHANS, with particular focus on biological conservation hotspots areas under developmental pressures. The model highlights a microeconomic basis tailored for research objects of the kind featuring heterogeneous agents with partial rationality, and integration of various mechanisms of two-way human-nature interaction such as ecological succession, and farmland fallowing. These features, together with merits in low data and computational requirements and convenient extendibility, make SEEMS an easy-to-apply approach in CHANS modeling. A case study in China's Wolong National Reserve for Giant Pandas not only validates the model's capacity of accurately simulate the real-world demographic, social, economic, and ecological situations, but also demonstrates nonlinear outcomes that might not otherwise emerge in statistical models. Subsequent studies may benefit from these features of SEEMS to investigate theoretical problems in the human-nature relationship in biological conservation hotspots, or practical ones regarding conservative policy-making in such areas. [ABSTRACT FROM AUTHOR]

• Evaluated the static and dynamic urban eco-efficiency of the Beijing-Tianjin-Hebei region in China. • Described the spatial association network characteristics of the urban eco-efficiency. • Analyzed the impact of influencing factors on the spatial association network. • Suggestions for strengthening the spatial association of urban eco-efficiency. This paper uses the DEA-Malmquist model to measure the static and dynamic ecological efficiency of city and describes its spatial distribution characteristics. Then, we use social network analysis and the quadratic assignment procedure to analyze the spatial association network characteristics of ecological efficiency and its influencing factors. The results show that urban eco-efficiency is close being effective according to the DEA method but does not fully. The ecological total factor productivity of the city is increasing. The spatial distribution of technical progress is consistent with total factor productivity, which shows that the former is the main reason for the progress of the latter. The ecological efficiency spatial association network structure is obvious and shows the characteristics of multithreading and complexity. The changing trends of network density and associated relationships remain consistent. In general, there is an upward trend of volatility. Network connectedness, network hierarchy, and network efficiency show that the spatial association of ecological efficiency is inseparable. The overall network structure has better correlation and stability, but there are strict ecological efficiency spatial association network structural characteristics between cities. The analysis of individual network characteristics shows that the connection between cities is getting closer, but the spatial association needs strengthening. The correlation coefficients of green level, industrial structure, government financial support, and fixed asset investment are significantly positive, while the influence of economic level and opening up on the ecological efficiency spatial network are not significant. [ABSTRACT FROM AUTHOR]

The overall goal of this paper is to analyze the impacts of the urbanization on regional and national agricultural production through its impact on water use in agriculture in China. Given the historical trend of water use in agriculture and its correlation with urbanization, the change in agricultural water use due to urbanization is estimated. Then the impacts of this change on regional crop production are simulated based on the China Water Simulation Model (CWSM). Within CWSM, a positive mathematical programming (PMP) optimizes water allocation among crops and between irrigated and rainfed areas within a crop in each of ten river basins in China. The results show that water use in China has an obvious increasing trend, particularly in the industrial and domestic sectors, while the share of water use in agricultural sector has been dropping. A 1-percentage-point increase in urbanization can result in a 0.47 percentage-point decline in share of water use. Based on the model simulation, this will lead to the further decrease of irrigated areas and the increase of rainfed areas at both the national and river basin levels, particularly for water intensive crops (such as rice and wheat). Accordingly, average yields and total production will also decrease. A river basin with large production of either rice or wheat (or both) decreases more in irrigated area as urban area expands. Adaptation measures are recommended for both authorities and farmers to ensure food security, such as providing incentive for farmers to adopt water saving technology, implementing appropriate institutional and policy innovations (e.g., water use association, water pricing and water use rights). [ABSTRACT FROM AUTHOR]

The transfer of embodied exergy from one industry to another can be modeled using a network to help understand industrial characteristics and resource features of a specific area. In this paper, we build a weighted directed network of embodied exergy flows between Chinese industries based on the 135-sector input–output table from 2007. The density, connectedness and degree distribution are used to describe the overall performance of the network. The results show that the network has a low density and a high connectedness, indicating that the network has little influence on specific industries while individual industries have a strong impact on each other. The degree, weighted degree and betweenness centrality are used to determine the main industries in the network. Key industries are characterized by large degrees that play a key role in the network, of which the mining and washing of coal, the production and supply of electric and heat power, construction, and the rolling of steel have stronger influences on the network. Moreover, the production and supply of electric power and heat power, the manufacture of automobiles and farming are the intermediaries of the network. Finally, we use a block-modeling method to decompose the collection of 135 Chinese industries into seven communities. The community of coal-related industries is the core of the network, which transfers embodied exergy to every other community, whereas the community of steel-related industries is also important, forming the base of the rest of the network. [ABSTRACT FROM AUTHOR]

China's Shandong Lubei eco-industrial park was approved for construction in 2003, just after the first national eco-industrial demonstration parks were confirmed by China's State Environmental Protection Administration in 2002. It has therefore been recognized around the world as a successful example of an industrial symbiosis system. The park's success results from the harmonious and coordinated relationships among its members. Analyzing the ecological characteristics of these relationships and identifying the resulting advantages provide a basis for improving the park's efficiency and examining other parks. In this paper, we analyzed the flows of sulfur in the Lubei park (as an example of typical flows) using ecological network analysis to describe this industrial symbiosis system. The integrated analysis of the utility resulting from direct and indirect exchanges of byproducts and wastes can reflect the ecological relationships among members within the system. Based on these ecological relationships, members can be divided into producers, primary consumers, and secondary consumers; the integral flow weight for each level of the hierarchy can then be compared to reveal the system's overall ecological structure. By examining the exchanges of resources within the system, we can describe the ecological connotations of the symbiosis and how these ecological relationships influence the overall development and resource flows within the system. [ABSTRACT FROM AUTHOR]

To alter the sharply decreasing trend of biodiversity due to human disturbances, much emphasis has been placed on the ecological networks comprised of core areas with high ecological significance and corridors connecting them. The purpose of this paper is to introduce a novel viewpoint and method to identify, analyze and optimize the ecological network of Wuyishan City. The bidirectional least-cost distance model is applied to identify the landscape network in Wuyishan City for the year 1995 and 2005, which can incorportate digraph in ecological network modeling, overcome the limitation of failing to reflect the orientation of the species' dispersal process, and make the process of modeling more convincing by distinguishing flux orientation of “go” and “return” of two random patches. Three new metrics, i.e., network cyclicity, degree of cyclicity, and degree of connectedness, which can quantify the integrity and continuity of network and the relation between network organization and ecological process, are introduced to measure the presence and strength of cyclic pathways in a network and reflect the network's ability to transfer bio-flux. The results show that the ecological network of Wuyishan City in the year 1995 and 2005 have respectively a network size of 18 and 17, degree of connectedness of 1 and 0.7647, network cyclicity of 7.1378 and 8.2570, and degree of cyclicity of 0.3965 and 0.4857, which indicate that the network in Wuyishan City for the year 2005 has strong ability to transfer bio-flux, a high level of eco-process diversity, and a low level of integrity and continuity. It can be concluded that during the past 10 years, different areas of Wuyishan City have gone through landscape degradation and restoration. In the northeast, network components degraded severely and made several patches “isolated islands”, while in the southwest, the network has been developed because of landscape restoration. In particular, the linkages among the patches of natural reserve and its neighborhood increased remarkably, which directly increased the interaction strength and the whole network cyclicity. Then, via scenario analysis, we also identify the patches and linkages that make great contributions to the entire cyclicity and connectedness, such as patches [1,2,3,4,5,6] (Nature reserve and its neighborhood), [12] (bridging the north and west part) and [19] (bridging the south and west part), and linkages among the central patches. [ABSTRACT FROM AUTHOR]

Testing ecological models involves using independent data on model performance, which can be difficult or practically impossible to obtain. Individual based models of forest dynamics, or gap models, simulate the change of forests by computing the annual growth, birth and death of each tree at a location in a forest. The models are relatively simple and simulate results that can be translated to multiple response scales: Individual plant growth, population birth-death processes, stand environmental dynamics ( e.g ., evapotranspiration, element cycling, heat flux, etc .), landscape processes, and regional and global change. This paper reviews some of the approaches applied to testing gap models. Then, it demonstrates the testing of the performance of an individual-based gap model of forest dynamics, FAREAST, through comparison against independent data from China and across Russia. As part of this model testing, biomass simulation output for 93 locations is compared to independent field-collected inventory-data from 44 Russian forests, which span a broad range of forest types across Russia. FAREAST captures biomass dynamics and stabilization at specific locations bracketing the measured values. At Changbai Mountain, the model accurately predicts the community dynamics of complex mixed forest types present along an elevational gradient, as well as the broad regional compositional patterns across China and Russia. Validation of regional detailed landscape dynamics shows the model performs with fidelity with an average R2 value of 0.74 for 87 comparisons and an average root mean square error of 10.8 tC ha −1. Performance of the model for historical conditions implies the model's applicability across a broad region and suggests the usefulness of a detailed model for evaluating forest change to management and changing climate. [ABSTRACT FROM AUTHOR]

Based on emergy accounting rules, only the greater number between emergy inputs from the same source, e.g., solar radiation and rainfall, should be accounted in emergy analysis to avoid double-counting. Using a year or a season as time scale, the rainfall emergy is usually larger than that of solar energy and thus taken as the renewable emergy input to the ecosystem. However, using a day as time scale, on sunny days with no rain only the solar energy would be counted as the renewable emergy. Therefore, different time scales may affect renewable emergy accounting. In this paper, we explored the effects of four time scales (year, season, month, and day) on renewable emergy accounting of forest ecosystems in Southeast China, a humid area, and the Minqin Oasis in Northwest China, an arid area. The results show that annual renewable emergy increased with the decrease of time scale but were close to each other in Southeast China (i.e., 2.5% difference at most), but were up to 30% different in arid Northwest China. However, the water which is actually used by forests for ecological productivity is evapotranspiration (ET), which can be less than precipitation in humid areas, but higher than rainfall in arid areas where groundwater compensates. Thus, it is ET rather than the available rainfall which should be counted as the renewable emergy input to ecological productivity. Otherwise the emergy contribution of renewable natural resources to ecosystems may be overestimated or underestimated, e.g., 0.33-7.33 times to the forests in Southeast China, and 0.36 times to the oasis system in Northwest China. Furthermore, despite whether or not it rains, ET emergy is often larger than solar emergy in most cases. Therefore, the use of ET emergy not only improves the estimate of emergy input, but also helps avoid the effect of time scale on renewable emergy accounting. [ABSTRACT FROM AUTHOR]

• We propose a new forest prediction model and use actual deforestation data for optimization and verification. • Use the XGBoost method to reconstruct deforestation intensity data. • Deforestation hotspots in China are mainly concentrated in the southern and southeastern regions. • Our model provides certain reference information for forest disaster prevention and forest management. Forests are important for the global carbon cycle, hydrothermal balance, and climate change. Human activities can exert a significant impact on forest ecosystems, thereby having the potential to alter their physical and chemical properties and thus affecting carbon, water, and heat budgets, and climate change. The historical reconstruction of the disturbance of global forests can help us understand the processes and patterns of human activities and global change. In this paper, we construct a deforestation prediction model using a Spearman correlation coefficient and implement the XGBoost method, using Python 3.6, for the reconstruction of deforestation intensity data from 2000 to 2019. Secondly, the selection of the driver indicators is done by using extreme difference regularization to unify the magnitude, and the potential deforestation area risk index is calculated in the form of equal weights. Finally, the actual deforestation data were used for optimization and validation. The model shows that the deforestation hotspots are mainly concentrated in the southern and southeastern regions of China and that there are large differences in deforestation in different provinces. In the future, the fine spatial and temporal patterns of deforestation in China during the historical period can be quantitatively reconstructed, which can provide some reference information for forest disaster prevention and forest management in China. [ABSTRACT FROM AUTHOR]

Rapid economic growth and social development in China have led to serious water pollution problems and water resource shortages, limiting the sustainable and coordinated development that could support both the socio-economy and water environment (WE). However, the spatial heterogeneity and evolutionary characteristics of the coordination between economic development (ED) and WE have not been adequately explored in China's provinces. In this study, we use the spatial global (local) autocorrelation and geographically weighted regression (GWR) model to explore the relationship between ED and WE subsystems and its influencing factors in China's provinces from 2010 to 2019. The main results are as follows, (a) The coupling coordination degree (CCD) between the two subsystems in southern China is higher than that of northern China. Transitional development areas have gradually spread to the middle of China, and there has been an increase trend in the number of moderate and high coordination provinces. (b) The ED-led (WE lags behind ED) type is mainly concentrated in central and eastern China, and the WE-led (ED lags behind WE) type is concentrated in the northeastern and western regions. The areas with synchronous development are relatively small in number and are mainly concentrated in east coastal China. (c) There is an obvious spatial dependence of the coordination between ED and WE from the perspective of global correlation, but this dependence is weakened with increasing geographical distance. The local mode of agglomeration shows a trend towards the evolution of high-high clustering in the eastern region. (d) The GWR analysis indicates that the factors of population density, energy consumption, fixed investment, and research and development (R&D) expenditure significantly influence the coordination between ED and WE. Fixed investment and R&D expenditure are mainly positive driving factors, while the impacts of population density and energy consumption vary among different regions as time evolves. Changes in driving force in a region can extend spatial effects to adjacent regions through the spatial transmission mechanism. Finally, we close the paper by recommending the different policy implications according to the GWR results. [ABSTRACT FROM AUTHOR]

Long-term water supplies are needed to address wetland degradation and the expansion of cones of depression, but this use of water is seldom considered in conventional reservoir operating models. In this paper, a new reservoir operating model is proposed to effectively direct water supply to wetlands, cones of depression, and humans. For ecological water provision to wetlands, the reservoir space is divided into two zones to maintain either the basic ecological water level in the wetland or the preferred ecological water level. The division provides reservoir operators with improved flexibility for balancing water supplies between wetlands and other users. The timing and rate of water release to alleviate cones of depression is triggered by the reservoir''s water level. The division of reservoir space for water supply to wetlands and the specified reservoir water level and release rates to cones of depression are optimized based on the overall water availability and the planned water supply to each user. The proposed model is applied to China''s Xidayang Reservoir to demonstrate its effectiveness for addressing the problems of water supplies for multiple ecological and socio-economic uses. The results demonstrate that this model effectively provides water supply to wetlands and cones of depression, while satisfying socio-economic water requirements. [Copyright &y& Elsevier]

Alteration of hydrological regime due to reservoir operation has significant impacts on the river ecosystem, in particular for diversion-type hydropower stations that make part of the natural river channel considerably de-watered. Maintaining ecological flow is considered an effective way to remediate the damages. However, it may jeopardize the socio-economic benefit of reservoirs, for example reduction of power production. The conflicting objectives bring a dilemma to water managers in defining the reservoir operation policy. This study considers two cascaded reservoirs in the Yalong River, and develops an optimization model to explore trade-offs between hydropower generation and ecological flow requirement. The objective function of the model is the total power production. In addition to conventional constraints on the water level and discharge, the model takes into account downstream ecological flow requirement, defined as a hydrograph representing the daily flow requirement to conserve the habitats of the indigenous fish Schizothorax chongi (S. chongi). The optimization model allows establishing a relation between the target of fish habitat conservation and the corresponding loss of hydropower production, so as to propose compromise solutions. Although the model has only been applied in the paper to one case study, its generic formulation allows applying it to a broad range of cascaded reservoir configurations. Moreover, extensions towards cases with ecological flow requirements for more than one species are straightforward. [Copyright &y& Elsevier]

The Pearl River Estuary (PRE) is a tropical estuary that was an important fishery ground in the South China Sea, where many other fisheries have also experienced substantial declines in productivity. In this study, we develop an ecological model constructed by Ecopath with Ecosim (EwE) software to explore the consequences of different fishing policies on the management of the PRE ecosystem. Scenarios are examined that maximise the net profits from the fishing activities, the jobs provided by the fisheries and the measures of ecosystem status. Then the trade-offs due to the ecosystem-scale optimisation of fishery management policies are analysed. The results indicate that optimising short-term economic and social (employment) goals in the PRE creates a depletion of the top predators and losses of biodiversity. Alternatively, focusing on the structure of the ecosystem leads to a reduction in fishing effort for almost all fleets and a corresponding increase in the biomass of most fishes at the expense of reduced profits and jobs provided by the fisheries. An ideal policy compromise is found when equal weight placed on profits, jobs and ecosystem structure, which leads to an overall increase in profits, jobs/catch value, ecosystem maturity and biodiversity. The effects of changing weights placed on profits, jobs/catch value and ecosystem maturity on ecosystem indices are examined and the parameters of vulnerabilities and discount rates are also analysed in this paper. [Copyright &y& Elsevier]

Ecological agriculture (eco-agriculture) is an approach to agriculture that seeks a balance between ecological and economic benefits to promote the sustainable development of both. This paper proposes a scientific method for analyzing the environmental and economic effects of eco-agriculture and simulating their long-term trend. Here, we focus on the eco-agriculture system of Kongtong District, Pingliang City, Gansu Province, China, and we build a system dynamics model named “AEP-SD” to evaluate the integrated effects of the system from 2009 to 2050. Under business as usual conditions, simulation results show rapid improvement until a peak is reached in 2027, after which the system will decline gradually. The model identifies some defects and disadvantages of the current agriculture system, such as the excessive increase of cattle slaughter, unstable production of methane, slow development of organic agriculture, and unsustainable energy structure. System improvement policies are offered and then proven by the model that they can indeed reduce the negative effects and eliminate the potential risks of system decline. [Copyright &y& Elsevier]

The implementation of systemic modeling methods to understand the variation of natural capital and ecosystem services in response to economic activities has huge significance for sound decision-making also at local scale. This paper reports the results of an investigation performed on the grassland ecosystem in North Xinjiang. The Emergy Synthesis method introduced by H.T. Odum in the 1980s was used to dynamically simulate the trend of grassland natural capital and its related ecosystem services. The simulation of natural capital was based on indexes of standing biomass, soil organic matter, soil nitrogen and soil water storages; ecosystem services were assessed by means of indexes of annual CO2 uptake, O2 release, forage supply as animal feed, food supply for human nutrition, and finally soil conservation. Results indicate that an upper limit of livestock carrying capacity in the region was reached in the year 1994; after that year the natural capital and main ecosystem services of the grassland ecosystem declined steadily. The emergy based currency equivalent value of the grassland ecosystem in terms of ecosystem services was higher than 87.3 billion Yuan RMB/yr in 1990. Such a value declined to 62.3 billion Yuan RMB/yr in 2010. Similarly, the total emergy based value of natural capital was about 331.7 billion Yuan RMB in 1990 and dropped to 155.6 billion Yuan RMB in 2010. According to the simulation model, the natural capital components such as biomass and soil stocks, the ecosystem services and the replacement value declined due to intensive herding and disturbance from human activities. Such trend is not sustainable because it exceeds the renewable carrying capacity of the area, but it is likely to continue until fundamental changes in human behavior and management of the grassland and animal husbandry occur or until the whole area is fully degraded. Social reasons prevent from simply decreasing the intensity of the livestock activities that provide living means to a large number of local farmers. As a consequence, the traditional low-productivity and environmental unfriendly grazing farming system should gradually be converted into a human-managed pasture based on farming higher productivity pasture crops in a small part of the local land, in order to decrease the grazing pressure on natural grassland of North Xinjiang. [Copyright &y& Elsevier]

The minimum ecological water requirements of an urban river system and water deployment are key elements in integrated water resources planning and urban ecological construction. Based on a review of ecological water requirement calculation methods and considering the different ecological functions of an urban river system, the ecological function method was used in this paper to calculate the components of the ecological water requirements of an urban river. An envelope curve-based method was proposed for assessing the minimum ecological water requirements of an urban river system. Water resources deployment strategies designed to meet the minimum ecological water requirements were described. Then, the minimum ecological water requirements of the urban river system in Beijing central region, selected as a case study, were investigated. The key parameters for assessing the minimum ecological water requirement in the Beijing urban river system were determined. Based on the ecological objectives and the current status of the different urban river systems within the Beijing central region, the minimum ecological water requirements were calculated. Different types of water sources, including rainwater, upstream water, and reclaimed water, were deployed to meet the ecological water requirements for the urban river system in the Beijing central region. [Copyright &y& Elsevier]

In this paper, we describe the development of a model for the sustainable release of e-flows from the regional water resource infrastructure (e.g., reservoirs, rivers with available water) for lake restoration and preservation, and use the model in a case study of Baiyangdian Lake, China. First, we define the sustainable environmental flows (e-flows), with an emphasis on the ecological importance of temporal variation in factors such as water level (depth). By analyzing historical data on the suitable range of water levels in the lake, we evaluated fluctuations using canonical correspondence analysis and frequency distribution analysis. The temporal variations required by the ecosystem of the lake were also assessed. Based on this approach, we developed an optimization model for sustainable release of e-flows. We used the adaptive genetic algorithm approach to solve the model and determine the required release of e-flows. Scenario analysis then provided a range of potential management strategies for the e-flows. The optimal results are helpful to the lake managers to establish sustainable e-flow release schemes for the lake restoration and preservation. [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]

In this paper, emergy accounting (EA) and life cycle assessment (LCA) methods are employed to investigate a typical urban wetland park, the Green Lake Urban Wetland Park (GLUWP) of Beijing, in terms of its environmental and capital inputs, ecosystem services and organic matter yields, environmental support, and sustainability. The LCA method is also used to obtain a quantitative estimation of the environmental impact of discharges during the entire life cycle of the GLUWP. Various emergy-based indices, such as emergy yield ratio (EYR), environmental load ratio (ELR), emergy sustainability index (ESI), net economic benefit (Np), and environmental impacts of process-based LCA, including global warming potential (GWP), eutrophication (EU), nonrenewable resource depletion (RU), energy consumption (EN), acidification potential (AP), photochemical oxidant creation potential (POCP), particulate matter (PM) and wastes (W), are calculated. The results show that the GLUWP has higher proportions of renewable resource input, less pressure on the environment, more environmental support and better ecological and economic benefits, which can be considered as an environment-friendly and long-term sustainable ecological practice, compared with another constructed wetland in Beijing. Meanwhile, the dominant environmental impact is induced by POCP with the construction phase contributing the most on the entire life cycle. It is expected that increasing green area, extensively using environment-friendly materials, optimizing construction techniques and reducing power consumption can promote the sustainability of the GLUWP. [Copyright &y& Elsevier]

Taking 29 Chinese lakes and 29 Italian lakes as two separate case studies, the paper presented the variations of exergies and structural exergies along eutrophication gradients in Chinese and Italian lakes. The exergies (Ex) and structural exergies (Exst) were calculated based on phytoplankton biomass (BA) and zooplankton biomass (BZ). A trophic state index (TSI) scaling from 0 to 100 was developed to classify trophic status for Chinese and Italian lakes based on three indicators, chlorophyll-a concentration (Chl-a, in mg/m3), total phosphorus (TP in mg/m3) and transparency in Secchi disk depth (SD in m). The relationships between TSI and Ex, Exst, total biomass, BZ/BA ratios were analyzed. The following results were obtained: (1) with the increase of TSI in Chinese and Italian lakes, there is an increasing trend for Ex, and a decreasing trend for Exst, generally. The obvious negative correlations exist between TSI and Exst, at the significant level of 0.01 for Italian lakes, and 0.05 for Chinese lakes. The obvious positive correlations exist between TSI and Ex, at the significant level of 0.01 for Chinese lakes, and for Italian lakes in Spring, Autumn and the all-year. (2) The structural exergy is more dependent on the ratio of phytoplankton biomass to zooplankton biomass (BZ/BA) than the exergy, and the exergy is more dependent on total biomass than the structural exergy. (3) The phytoplankton biomass (BA) and zooplankton biomass (BZ) are increased with the increasing TSI in Chinese and Italian lakes, and phytoplankton biomass (BA) increases more rapidly then zooplankton biomass (BZ) does. This results in the definite decrease of BZ/BA ratio with the increasing trophic status index. Such changes of BA, BZ and BZ/BA ratio could explain successfully the variations of exergies and structural exergies along eutrophication gradients in Chinese and Italian lakes. From the two separate case studies of Chinese lakes and Italian lakes, it could be concluded that exergy and structural exergy are feasible to serve as the system-level ecological indicators to give appropriate information on the trophic status of different lakes. [Copyright &y& Elsevier]

Lake eutrophication leading to water pollution is a major global concern. In recent years, rapid economic growth and the increase in the intensity of resource exploitation in China have caused the influx of nitrogen and phosphorus into lakes. This in turn has led to more severe lake eutrophication, more frequent outbreaks of algal blooms, and the degradation of lake ecosystems. An effective plan balancing economic growth with the reduction of nitrogen and phosphorus emissions is greatly needed. The design and implementation of such a plan requires the collection and analysis of pertinent data. In this paper, we use the environmental computable general equilibrium (ECGE) model to identify the most effective way to balance economic growth with the reduction of nitrogen and phosphorus emissions. For the multiregional analysis, we use social accounting matrices (SAMs) and a provincial trade matrix based on the assumptions of the gravity model. We consider the Poyang Lake Watershed as a case study to illustrate the utility of the model. Based on present conditions in the Poyang Lake Watershed, restricting nitrogen and phosphorus emissions from sectors with the highest emissions is more effective for balancing economic growth and the reduction of nitrogen and phosphorus emissions than restricting nitrogen and phosphorus emissions from all sectors. [Copyright &y& Elsevier]

As a major ecosystem type, wetland provides invaluable ecological services. Environmental pollution, especially pesticides pollution should be paid more attention to keep wetlands healthy. Based on the risk quotient method, coupled with a probabilistic risk assessment model, this paper proposed a methodology suitable for ecological risk assessment of pesticide residues for wetland ecosystems. As an important industrializing and ecologically vulnerable area in China, the Taihu Lake wetland was chosen for the case study. The risks of eight pesticides in Taihu Lake wetland were assessed, as single substances and in mixtures. The assessment indicates that risks of the representative species are not significant. In general, the herbicide is found to be more toxic for algae, whereas insecticides pose more risks to zooplankton, insect and fish. For each pesticide in the wetland, the ecological risk it poses is acceptable. But the combined ecological risk posed by mixture can harm more than 10% of species of the wetland ecosystem, mainly dominated by dichlorvos, dimethoate and malathion contributions. These results imply that pesticide residues have been posing pressures on the ecosystem of the Taihu Lake wetland. It is recommended that proper countermeasures should be implemented to reduce the risks. [Copyright &y& Elsevier]

In this paper, a multi-objective optimization model has been developed for allocating freshwater to meet the environmental flow requirements of the restored wetlands in the Yellow River Delta, China. The model seeks a rational balance among appropriate water allocation for the wetlands, a healthy ecosystem, and optimum economic returns for the humans that use the wetlands to earn their livelihood, with the degree of ecosystem health represented by the difference between actual and ideal water levels. And then a holistic method has been used for satisfying multiple objectives to avoid the problem of decision-maker subjectivity, and then solved the resulting optimal allocation model for environmental flows of the wetlands using a genetic algorithm. With water from the Yellow River as the source, the model shows how the optimal monthly water release into the restored wetlands can be achieved in dry, average, and wet years. Using the model, 20–56% reductions in water use could be achieved compared with the current pattern of water release, and the optimal water level in each month would coincide better with the ideal value based on an indicator plant community (reeds). The results of the study demonstrate the capability of the multi-objective programming model to optimize ecological water allocation and management for the wetlands of the Yellow River Delta. [Copyright &y& Elsevier]

The suitable spectral mode in remote sensing is often desirable to facilitate the inversion of ecological environment and landscape. This paper put forward an optimizing model based on variable precision rough sets (VPRS) for the land cover discrimination in wetland inventory. In the case study of Lake Baiyangdian which has important ecological functions to the northern China, this model is established successfully according to the domain-experts knowledge. The procedure is as follows. First step is data collection, including remote-sensing data (e.g., Landsat-5 TM bands), the digitized relief maps, and statistical yearbooks. Second, the remote sensing imagery (RSI) and relief maps are co-registered into the same resolution. Third, a condition set, including various attributes is derived from spectral bands, band math or ratio indices based on previous studies, at the same time, the decision set is derived from true land types after investigation and validation. Then, the remote sensing decision table (RSDT) is constructed by linking condition set with decision set according to the sequential pixels in RSI. Fourth, we create one forward greedy searching algorithm based on VPRS to handle this RSDT. After adjusting parameters such as β and knowledge granularity diameter (KGD), we obtain the stable optimized results. Comparative experiments and evaluation show that the discrimination or retrieval accuracy of VPRS model is satisfying (overall accuracy: 87.32% and KHAT: 0.84) and better than original data. Moreover, data dimension has been decreased dramatically (from 12 to 3) and key attributes found by the model may be useful for specific retrieval in wetland inventories. [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]

Rapid land use transformation shaped by agriculture, industrialization and population urbanization has a great influence on ecological environment. Based on theory of ecosystem service functions, this study aims at revealing the response of ecological storage and conservation to each unit area of land use transformation. Taking Cishan Town, a mining town in China, as a case study, this paper estimates the “past-present-future” ecological storage impacted by the process, result and possibility of land use transformation. The local land use and industrial distribution show that the active areas of land use transformation are also the areas of concentration of human (industrial) activities. Ecological storage shows the different responses to land use ways. And then this study combines the ecological storage indices with the indices of ecosystem pattern and land condition into the“5A” framework (active state, active degree, active possibility, active balance and active condition) for grading ecological conservation, and then assigns all regions of Cishan Town into different grades through membership functions for complex mapping of ecological conservation. The research results show that the ecological conservation in Cishan goes toward two extreme grades (best grade and worst grade). Uneven and unbalanced land use transformation is the main cause of that. Hence, rational and timely reflection of impact of land use transformation on ecological storage and conservation can assist land use planners and local government in adjusting land use ways and balancing regional ecology and economy. [Copyright &y& Elsevier]

Since the construction of the Gezhouba Dam in the 1980s, the number of Chinese sturgeon in the Yangtze River has been rapidly declining. The Gezhouba Dam has cutoff the migration path of these sturgeon, resulting in an overall reduction of suitable sturgeon habitat. This paper describes a habitat suitability index model that is used to evaluate the impacts of the Gezhouba Dam and Three Gorges Project on Chinese sturgeon spawning sites. Based on research concerning the reproduction characteristics of Chinese sturgeon, ten major ecological factors that influence reproduction were analyzed, including: water temperature, velocity, water depth, substrate, suspended sediment concentration, and the amount of egg predatory fish. The suitability index (SI) curves based on these ten ecological factors were obtained, and a habitat suitability function was developed. A two-dimensional mathematical model was also created to simulate and predict physical habitat situation (such as hydraulic, sediment, and substrate) of the Chinese sturgeon. By coupling the habitat suitability function and a two-dimensional mathematical model, a habitat suitability index model for Chinese sturgeon was established. The habitat suitability index model was validated by comparing measured data with predictions from the model. These comparisons showed that the computed results agreed well with the measured results, and the high calculated habitat suitability index (HSI) corresponded to high measured quantity of eggs per unit (1000m3) discharge (CPUEd). The calculated habitat suitability index for Chinese sturgeon also showed that the habitat suitability index was better in 1999, before the impoundment of the Three Gorges Project, compared with the habitat suitability in 2003. Simulation results of different discharges from Gezhouba Dam predicted that flow discharges between 10,000 and 30,000m3/s were most suitable for sturgeon spawning. [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]

This paper describes the development of a land use model coupling ecosystem processes. For a given land use pattern in a region, a built-in regional ecosystem model (TESim) simulates leaf physiology of plants, carbon and nitrogen dynamics, and hydrological processes including runoff generation and run-on re-absorption, as well as runoff-induced soil erosion and carbon and nitrogen loss from ecosystems. The simulation results for a certain period from 1976 to 1999 were then used to support land use decisions and to assess the impacts of land use changes on environment. In the coupling model, the land use type for a land unit was determined by optimization of a weighted suitability derived from expert knowledge about the ecosystem state and site conditions. The model was applied to the temperate crop-pasture band in northern China (CCPB) to analyze the interactions between land use and major ecosystem processes and functions and to indicate the added value of the feedbacks by comparing simulations with and without the coupling and feedbacks between land use module and ecosystem processes. The results indicated that the current land use in CCPB is neither economical nor ecologically judicious. The scenario with feedbacks increased NPP by 46.78gCm−2 a−1, or 32.23% of the scenario without feedbacks, also decreased soil erosion by 0.65kgm−2 a−1, or 23.13%. Without altering the regional land use structure (proportions of each land use type). The system developed in this study potentially benefits both land managers and researchers. [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]

• Dynamic yield prediction with the integral regression model at any time intervals. • Remote sensing-based TVDI replaces precipitation to represent the actual amount of water available to crops. • We couple the three types of factors (sunshine hours, temperature, and precipitation/TVDI) into a comprehensive factor for yield prediction. • The combination of sunshine hours, temperature, and TVDI has better dynamic yield prediction results. This paper describes integrating remote sensing and meteorological data for dynamic winter wheat yield prediction at fixed date intervals with an integral regression model. In most cases, both rainfall and irrigation supply the water needs of crops. We postulated that meteorological precipitation could not fully represent the actual amount of water available to crops, whereas the temperature vegetation dryness index (TVDI) can represent actual water, which monitors soil moisture. According to this, meteorological and remote-sensing data based on sunshine hours, temperature, and TVDI formed a light–temperature–water data combination, which are the three most fundamental and critical factors related to crop growth. The new data combination was used as the input variables of the integral regression model, which could predict the crop yield at a fixed date interval of any length. The dynamic results were then compared with that of the meteorology data combination (sunshine hours, temperature, and precipitation). We selected a total of seven county-level areas in semi-humid and arid regions in China. The proposed dynamic prediction approach achieved good results at the county level from March 21 to maturity at 16-day intervals with predicted R2 > 0.94 and root mean squared error range of 15.54–121.01 kg ha−1 between predicted and actual yield with leave-one-year-out cross-validation for each prediction date. The trend of dynamic prediction accuracy had a relatively stable state. In addition, TVDI contained more crop water information, and prediction results using TVDI and meteorology were generally superior to that using only meteorology for semi-humid and arid areas, with the best results for arid regions. Thus, integrating meteorology and TVDI could effectively dynamically predict yield at county level for most agroclimatic regions, and particularly for arid regions. The work has implications for dynamic yield prediction and improving prediction accuracy and can be extended to other areas. [ABSTRACT FROM AUTHOR]

Abstract: Grassland ecosystems play an important role in Chinese terrestrial ecosystems. However, great demand and excessive utilization of human beings on grassland resources have made it more susceptible to rapid degeneration in ecosystem properties and soil carbon levels. Among them, grazing is one of the key factors to make grassland ecosystems degraded. Therefore, it is very important to graze sustainably on grassland for preventing the degradation of grasslands. In this paper, as a case study, we simulated the potential changes of soil organic carbon (SOC) and net primary productivity (NPP) of meadow steppe dominated by Leymus chinensis under different grazing intensities based on CENTURY model (V4.0) in order to evaluate the effects of different grazing intensities and to pursue for optimal grazing intensity. The results showed that NPP and SOC of meadow steppe dominated by Leymus chinensis were very sensitive to grazing intensity. The optimal grazing intensity could be expressed by live shoots, and it should be less than 40% of whole live shoots per month, in order to mitigate the degradation of Leymus chinensis grassland and maintain its sustainable development. [Copyright &y& Elsevier]

Cellular automata (CA) have been increasingly used to simulate complex urban systems. Empirical data can be used to calibrate CA models so that realistic urban patterns can be generated. Traditionally, the calibration procedure employs linear regression methods, e.g., multicriteria evaluation. However, the evolution of urban systems often manifests the complexity of non-linear features, for which the linear transition rules are insufficient. This paper proposes to use the kernel-based learning techniques to acquire non-linear transition rules for CA. The kernel-based approach maps the original data vectors to an implicit high-dimensional feature space, through which complex non-linear problems are translated into simple linear problems. Compared with a widely used non-linear method, neural network, the kernel method is more mathematically “transparent” and therefore the results are easier to be analyzed. A case study of simulating the expansion of Guangzhou, a fast growing city in China, shows that the kernel-based CA even achieves a slightly higher accuracy than a neural-network-based CA. [Copyright &y& Elsevier]

The plateau pika is a keystone species of the Qinghai-Xizang plateau. We ought to intensify the inspection and management about its population dynamics in order to bring it to appropriate spatio-temporal distribution, play the role of keystone species, and do not destroy the alpine grasslands. In this paper, a cellular automata model for dispersal of plateau pika has been established. Concept of dispersal force based on this model has been presented. Through simulating the insight into dispersal mechanism of the plateau pika has been obtained. [Copyright &y& Elsevier]

Abstract: As economic and ecological support systems become more interdependent, new disciplines are needed to “bridge the gap” between human and nature. “Emergy” created by H.T. Odum is a new method for evaluating natural capital and ecosystem services. The “ecological footprint” created by Wackernagel and Rees has been promoted as a policy and planning tool for sustainability. The aim of this paper is to show a modified form of ecological footprint calculation by combining emergy analysis with conventional ecological footprint form of calculations. Our new method starts from the energy flows of a system in calculating ecological footprint and carrying capacity. Through a study of the energy flows, and using the method of emergy analysis, the energy flows of a system are translated into corresponding biological productive units. To demonstrate the mechanics of this new method, we compared our calculations with that of an original calculation of ecological footprint of a regional case. We select Gansu province in western China, as an example for application of our study. In this case the same conclusions were drawn using both methods: that Gansu province runs an ecological deficit. [Copyright &y& Elsevier]