Emergy synthesis of a combined food and energy production system compared to a conventional wheat (Triticum aestivum) production system

It is a major challenge to produce food and energy sustainably for the ever increasing world population as today's conventional food production and energy needs are met by the fossil based resources, causing enormous environmental load. A novel, combined food and energy (CFE) agro-ecosystem, was designed for sustainable production of food, fodder and energy without chemical inputs (fertiliser, herbicide and fungicide). The objective was an emergy synthesis of the CFE system compared to a conventional wheat (Triticum aestivum) production system to assess resource use efficiency. The emergy indices, used to assess the environmental performance and sustainability, exhibited contrasting differences between the two production systems in terms of outputs (Y), total emergy use, solar transformity, relative use of local renewable resources, environmental loading ratio (ELR), emergy yield ratio (EYR) and emergy sustainability index (ESI). The Y in the CFE consisted of grain, straw, fodder and woodchip production of 4020, 3580, 6100 and 10,000 kg/ha/yr respectively whereas Y in the conventional wheat consisted of 7250 and 3770 kg grain and straw/ha/yr respectively. The Y in the CFE was 81% (2.80E+11 J/ha/yr) higher with 13.5 times (6.40E+03 seJ/J) lower solar transformity compared to the Y (1.54E+11 J/ha/yr) and solar transformity (8.63E+04 seJ/J) in the conventional wheat, exhibiting highly resource intensive production in conventional wheat. The local renewables constituted 19.2% and 2.6% of the total emergy input in the CFE and the conventional wheat respectively with a corresponding lower ELR (4.21) and 22.5% higher EYR (1.26) in CFE compared to conventional wheat. CFE was more reliant on local renewable emergy flows and compatible with the local environment with higher ESI (0.30) compared to conventional wheat (0.03), where 64.5% of the total emergy input constituted chemical inputs. The study demonstrated that the innovative agro-ecosystem, exemplified by CFE, is considerably less resource demanding and more amenable to sustainable production, whether defined in terms of outputs, solar transformity, relative use of local renewable resources, EYR, ELR or ESI.     

Emergy analysis of cassava chips-suitable feedstock for fuel ethanol in China

The theory and indices of Odum's concept of emergy are explained. The environmental and economic inputs and sustainability of cassava chips production system are evaluated by emergy methodology. The emergy indices of cassava chips production system were calculated as follows: Tr (transformity) was 6.85E + 11 sej/kg, EYR (emergy yield ratio) was 1.11, ELR (environmental loading ratio) was 1.75, EIR (emergy investment ratio) was 9.33, and ESI (emergy sustainability indice) was 0.63. The emergy indices of four kinds of feedstock for fuel ethanol—corn, wheat, sugarcane, and cassava chips—were compared. Least solar energy was consumed when taking cassava chips as feedstock for fuel ethanol. According to the emergy indices, using cassava chips as the feedstock of fuel ethanol is helpful for sustainable development in China.     

The emergy of metabolism in different ecosystems under the same environmental conditions in the agro-pastoral ecotone of northern China

The sustainability of ecosystem productivity and rules governing ecosystem development are important topics of scientific research. The emergy approach is an effective method for investigating these topics, especially when used to evaluate systems that have developed under the same environmental conditions, such as climate and soil. In this paper, emergy differences between terrestrial ecosystems were studied in Guyuan County, a region representative of the agro-pastoral ecotone in Hebei Province, China. A combination of field tests and a questionnaire survey were carried out between June and August 2015. The ecosystems studied included natural grassland, artificial grassland, field crops and commercial crops. These four ecosystems were further subdivided into a total of ten ecosystems. Natural grassland was divided into free-grazing and mowed ecosystems; artificial grassland consisted of oat, Chinese leymus and corn silage; field crops included naked oats, flax and wheat; and commercial crops consisted of cabbage and potatoes. The results showed that the rain input of 4.78 × 10¹⁴ seJ/ha/yr constituted the highest renewable natural resource emergy and that the purchased emergy inputs of the ten ecosystems ranged from 3.53 to 147.67 × 10¹⁴ seJ/ha/yr. Natural resource emergy input was the basic power to maintain the ecosystem, and purchased emergy input was the direct cause of the development of the ecosystems. Groundwater was the most important non-renewable purchased energy for the production of economic crops. The emergy investment ratios (EIR) for potatoes (27.81) and cabbage (19.03) were higher than those of the other ecosystems, but mowed and artificial Chinese leymus grassland had the higher emergy self-sufficiency rates (ESR). Natural grassland, artificial Chinese leymus grassland and traditional grain crops had a low environmental load and high sustainability, whereas potatoes and cabbage had a high environmental load and low sustainability. Overall, rain-fed artificial grassland has a high development potential from the perspective of environment and productivity.     

The emergy ecological footprint for small fish farm in China

Mariculture, especially cage aquaculture remains a growing, vibrant and important production sector for high protein food in coastal regions in China. A quantitative evaluation of the mariculture system is an essential step to documenting its’ sustainability. The method of emergy ecological footprint is applied to evaluate the environmental sustainability of an offshore small fish farm (Great Marine fish farm, GMFF) in the East China Sea. All input needed to support fish farming were accounted and converted into biological space, to estimate the natural capital demand for the rearing process in terms of global hectares. The emergy ecological footprint of GMFF was 1953.19 ha, meaning that nearly 2000 ha of ecologically productive lands were needed to support the fish framing. The largest component of emergy ecological footprint was forage (1183.64 ha), which took up 60.60% of the total footprint; the second and third largest footprint components were fingerlings and fuel. In a word, emergy ecological footprint can serve as a practical and meaningful tool for comparing and monitoring the environmental impact of fish farming. The strong dependence of external contributions of exploiting the wild fish resources affects strongly the level of environmental sustainability of fish farming.     

Feasibility of using constructed treatment wetlands for municipal wastewater treatment in the Bogotá Savannah,Colombia

The main water bodies in the Bogotá Savannah have been seriously polluted due to the mismanagement of domestic, agricultural, and industrial wastewater. While there are a number of wastewater treatment facilities in the region, most do not function properly. There is a great need for inexpensive and sustainable wastewater treatment systems that are not technologically sophisticated and that do not require intensive management. The main goal of this study was to quantify the performance and sustainability of treatment wetlands and existing wastewater treatment systems in this region. Using data from the literature, a treatment wetland model was developed, which focused on pollutant removal. The modeled performance was compared to a system of waste stabilization ponds and a sequencing batch reactor. The three systems were subject to cost analysis and an emergy evaluation, leading to the assessment of indicators of cost-benefit for comparison. The economic analysis suggested that the net annual cost of the treatment wetland was US$ 14,672, compared to US$ 14,201 for the stabilization ponds and US$ 54,887 for the batch reactor. The emergy evaluations show that the ponds have the lowest annual emergy flow (6.65 + 16 sej/yr), followed by the constructed wetland (2.88E+17 sej/yr) and the batch reactor (8.86E+17 sej/yr). These results were combined to estimate treatment ratios (contaminants removed per lifetime cost, and contaminants removed per total emergy), cost ratios (cost per volume of water, annual cost per capita, and construction cost per capita), and emergy ratios (treatment yield, renewable emergy, lifetime emprice, construction emprice, non-renewable emergy, empower density, environmental loading, total emergy per volume of water, and emergy per capita).     

An emergy evaluation of the sustainability of Chinese crop production system during 2000–2010

Crop production systems are the basis of human survival and development because they can produce grain and industrial raw materials. As one of the largest agricultural countries in the world, the sustainability of China's crop production system is being concerned widely with its economic development and increasing population. This study adopted emergy analysis to explore the comprehensive performance of this system. A set of emergy based indicator system was used to investigate its economic benefit, environmental pressure and sustainability from 2000 to 2010. The study results show that the purchased nonrenewable input makes the largest contribution to the total input (average value 60.73% of the total input), which mainly derived from agricultural mechanic equipments and chemical fertilizer; on the average, beans has the largest share (20.20%) to the total emergy output, next from rape seed (18.36%), then from peanuts (15.85%), fruits (15.74%), wheat (8.26%), rice (8.07%), corn (7.66%) and cotton (4.60%) accordingly, and the other four categories crops just have a contribution of 1.28%; the production efficiency of China's crop production system has been raised by 11.54% with decrease of the indicator unit emergy value of product (UEVP) from 1.82E09 sej/g to 1.61E09 sej/g, the dependence of this system on economic market has increased by 24.92% with growth of the indicator EIR from 6.22 to 7.77, its economic benefit has been reduced by 0.59% with decline of the indicator EYR from 1.69 to 1.68, and its environmental loading has raised by 57.89% with growth of the indicator ELR from 1.33 to 2.10; the sustainability of China's crop production system is reduced by 37.01% with decrease of the index ESI from 1.27 to 0.80, during this study period. Based on these study results, the following measures should be emphasized in future, including raising the efficiency of purchased non-renewable resources (especially agricultural mechanical equipments and chemical fertilizer), using other methods of cultivation inherently more sustainable (e.g. replacing chemical fertilizer with organic fertilizer, recycling organic wastes, biological control of agricultural pests, use of local renewable energy, and more), strengthening supervision of the related industrial processes and further promoting agricultural environmental protection.     

Agricultural non-point source pollution in the Yongding River Basin

More and more nitrogen and phosphorus chemical fertilizers are applied in the upstream of the Yongding River Basin. With the aid of convertibility between emergy and value, the calculated ESI (Environmental Sustainability Index) of basin agricultural production is 0.1056, indicating that local agriculture is seriously unsustainable. According to the different combining types of nitrate and ammonium salts with soil particles, soil nitrogen losses under the influence of rainfall-runoff are quantitatively evaluated from the perspective of the nitrogen cycle. By virtue of the content of dissolved and particulate phosphorus in soil, the calculation process for soil phosphorus loss is modeled according to the field runoff volume. The total nitrogen and total phosphorus losses from soil are 96 kg hm⁻² and 9 kg hm⁻², respectively. The calculation result of nitrogen and phosphorus losses in the basin is certainly reasonable. Finally, the research emphasis of calculation method for reducing basin agricultural non-point source pollution is represented from management level.     

Energy budgeting and emergy synthesis of rainfed maize–wheat rotation system with different soil amendment applications

Soil is a non-renewable resource and its preservation is essential for food security, ecosystem services and our sustainable future. Simultaneously, it is a major challenge to substitute non-renewable fossil based resources with renewable resources to reduce environmental load. In order to check soil erosion vis-a-vis degradation of sloppy lands of rainfed maize–wheat rotation system, fertilization with organic manure supplemented with inorganic fertilizers is required. In order to address these issues, substitution of 50% NPK through four organic manures viz. farmyard manure (FYM), vermicompost (VC), poultry manure (PM) and in situ green manuring (GM) of sunnhemp (Crotalaria juncea L.) were evaluated against 100% NPK through inorganic fertilizers and through FYM for energy budgeting and emergy synthesis during 2009–2014. Integrated use of FYM along with 50% NPK fertilizers could maintain the highest energy ratio (7.3), human energy profitability (142.4), energy productivity (0.22 kg MJ⁻¹), and energy profitability (6.3 MJ ha⁻¹) over other treatments. However, GM and inorganic fertilizers on equal NPK basis maintained the highest energy intensiveness (24.61 MJ US $⁻¹) and exhibited higher emergy yield ratio (2.66) and lower emergy investment ratio (0.60) and environmental loading ratio (3.74) which resulted into higher environmental sustainability index (0.71) over other treatments. Fertilization with organic manure (FYM) alone could not compete with other fertilized options to energy budgeting and emergy synthesis except specific energy. The study demonstrated that innovative integrated nutrient management of chemical fertilizers and organic manures particularly FYM for energy budgeting and GM for emergy synthesis may be considered as feasible and environment-friendly options for soil conservation, thereby benefiting a 50% saving on costly chemical fertilizers in non-OPEC countries which import most of its phosphorus and potassium fertilizers.     

Emergy and economic evaluations of four fruit production systems on reclaimed wetlands surrounding the Pearl River Estuary,China

Emergy and economic methods were used to evaluate and compare a traditional tropical fruit cultivation system, for bananas, and three newly introduced fruit cultivation systems, for papaya, guava and wampee, on reclaimed wetlands of the Pearl River Estuary, China. The goal of this study was to apply ecological engineering principles to fruit production system designs to maximize total emergy benefits and sustainability. The evaluations considered input structure, production efficiency, environmental impacts, economic viability and sustainability. The market effects on emergy exchange were assessed both for purchasing the inputs to production and for selling the fruit. These market effects were also considered in the evaluation of sustainability by using the Emergy Index for Sustainable Development (EISD), which was evaluated with and without taking the change in natural capital (i.e., soil organic matter) into consideration. The results showed that all three of the newly introduced systems are much more sustainable than the traditional banana production system. The guava production system had the highest value of the Emergy Sustainability Index (ESI = 0.40). The high price of wampee gave it the highest economic yield/cost ratio (4.87) and EISD (0.73). Emergy and economic evaluations are complementary methods, with emergy analysis shedding more light on environmental support and impacts of the production systems not considered in the market value, and economic analysis focusing on the effects of markets on fruit production. The Emergy Exchange Ratio (EER) was proposed as a bridge between emergy and economic evaluations for specific systems and/or processes.     

Ecological accounting for an integrated “pig–biogas–fish” system based on emergetic indicators

With the expansion of urbanization in China, the integrated biogas-utilization system has gained its popularity for both renewable energy production and multi-level utilization of organic waste. To appraise the ecological performance of the integrated biogas system, systematic accounting is undertaken for an integrated “pig–biogas–fish” system in Hubei province, China. Based on Odum's concept of embodied solar energy as a unified measure for environmental resources, human labors and purchased goods, a set of emergetic indicators are employed to quantify the system sustainability. The results reveal that in a 20-year designed lifetime scenario, 94.69% of the total emergy inputs for the “pig–biogas–fish” system are attributed to purchased social resources. Three kinds of products, namely pig, biogas, fish are taken into consideration, and transformity of the “pig–biogas–fish” system is calculated as 1.26E + 05 seJ/J. Compared with the Chinese conventional agriculture system, the integrated biogas system shows a higher sustainability. Given that most biogas systems have a lifespan less than 20 years, for the “pig–biogas–fish” system, six other scenarios with different lifespans are studied to investigate the impact of the lifespan on sustainability. The findings suggest that the “pig–biogas–fish” system should be well operated for at least 8 years to prove its advantage in ecological economy over the conventional agriculture system. This has essential policy implications that local government should strengthen subsequent management on biogas production to extend the practical service life of the biogas system.     

Emergy and exergy evaluation of a dike-pond project in the drawdown zone (DDZ) of the Three Gorges Reservoir (TGR)

The dike-pond system was a form of ecological engineering that was a component of successional dikes and ponds along the banks of the Pengxi River in the drawdown zone (DDZ) of the Three Gorges Reservoir (TGR). The application of science-based evaluation system was appropriate for the flows of emergy in this agricultural ecosystem. The Emergy Analysis (EmA) has the ability to transform different types of inputs to a common form to allow meaningful comparisons across different systems. This study made use of the emergy analysis that assessed two different types of farming methods in the DDZ of the TGR. One method was planning crops in a dike-pond system (model I), and the other method was conventional agriculture (model II). In addition, the Exergies of both yields of agriculture methods were calculated, and the Exergy and Emergy Density (ED) were combined to explore the quality of these methods. The results showed that the two models relied on different resources. The ED yield of both models were similar, but the emergy investment of model II was greater than that of model I. Model II also used less renewable energy input to the agricultural systems than model I. The agricultural emergy sustainability index (AESI) of model I system (AESI = 2.4 > 1) was greater than that of model II system (AESI = 0.5 < 1), which indicated that the sustainable development of model I was stronger than that of model II in the DDZ of the TGR. The ratio Exergy/Emergy density (R_ex/em) in the two models of different agricultural system were 121.52 × 10⁻³ J/sej (Model I) and 24.19 × 10⁻³ J/sej (model II). Model I was greater than model II, and the result intimated that the model I agricultural system was a new method in the DDZ, but it was older and closer to the steady state than model II. The Emergy and Exergy analysis certifies that model I has a more acceptable and more sustainable development potential and is more stabilized in the DDZ of the TGR.     

基于耕地能值-生态足迹的耕地休耕规模研究——以贵州省松桃县为例

区域耕地休耕规模测算是耕地休耕空间配置的重要组成部分,从资源承载力视角理解,其本质是将休耕空间布局于耕地资源承载力相对较低的区域。立足于从区域耕地生态经济系统探索耕地休耕规模,运用能值分析方法和生态足迹方法,以生态严重退化地区、国家第一批休耕试点县的贵州省松桃县为案例区,修正了耕地能值生态足迹改进模型（EC和EF,简称"修正模型"）与耕地能值可持续指数（ESI_cl）,测算了松桃县2016年休耕面积范围值。结果表明：（1）耕地能值生态盈亏可以作为乡镇是否应该休耕的判定标准,基于此测算的最大休耕面积关键在于测算生态耕地面积。总体来看,全县耕地能值生态赤字,应该安排耕地休耕;从分乡镇来看,有3个乡镇可以不休耕、25个乡镇应该休耕。按照全县平均统计（SCAL）和按照分乡镇统计（STL）,全县最大休耕面积分别19558.62hm²和17673.83hm²。最大休耕面积中等及以上等级的乡镇散布于4个区域的8个乡镇。（2）ESI_cl可以作为休耕乡镇时序的判定标准,其优先休耕乡镇的最大休耕面积之和即为全县最小休耕面积。全县ESI_cl偏低,应该适度休耕。优先休耕、适度休耕和暂不休耕的乡镇分别有2个、23个和3个。全县最小休耕面积1396.10hm²,占耕地面积的1.88%。按照全县平均统计（SCAL）,全县休耕面积范围值1396.10-19558.62hm²,占总耕地面积的1.88%-26.34%;按照分乡镇统计（STL）,全县休耕面积1396.10-17673.83hm²,占总耕地面积的1.88%-23.8%。修正模型和ESI_cl为测算区域休耕规模提供了更加科学的技术方法,以期为其他类似区域开展休耕实践提供借鉴。     

GIS-based integrated evaluation of environmentally sensitive areas (ESAs) for land use planning in Langkawi,Malaysia

Extensive economic growth, tourism activities and over-exploitation of resources have become the common causes of environmental degradation in Langkawi. The sudden development leap resulting from UNESCO's recognition of Langkawi Archipelago as a Global Geopark in 2007, leads to continuous conflicts between enhancing environmental protection and meeting tourism and development needs. Environmental sensitivity evaluation is a basis upon which the concept of environmentally sensitive areas (ESAs) can be practised in order to protect the environment, regulate development activities and promote sustainable land use planning. This study embarks on evaluating and classifying environmental sensitivity as well as comparing different ESA approaches applicable for land use planning in Langkawi. A GIS-based integrated evaluation model was performed on two assessment sets (Set A and Set B) using a standard grading system and weights determined with analytic hierarchy process (AHP) method. Of these sets, the former consists of selected indicators from the Malaysian integrated ESA instrument while the latter are derived from previous eco-environmental studies conducted in China. The projected final ESA maps of Langkawi indicate spatial distribution of four environmental sensitivity classes. More highly and moderately sensitive areas are observed in Set A, accounting for 339.15 km² or 72.24% of the total land area compared to Set B with only 259.04 km² or 55.18% respectively. The results also reveal large proportion of low sensitivity areas in Set A, covering areas of 117.42 km² (25.01%). In contrast, more areas with non-sensitivity are widely distributed in Set B, occupying areas of 123.02 km² (26.20%). Taking into consideration the natural and cultural characteristics of the islands, it is suggested that Set A is a better approach to portray current environmental concerns and to coordinate future land use planning as well as fits Langkawi's aspiration in becoming a sustainable, world-class Global Geopark. This study provides beneficial information and opportunity for reasonable rearrangement of zoning and development guidelines and strategies within sensitivity areas. It promotes effective utilization of the natural resources, minimizes negative tourism impacts and adequately highlights ecosystem functions to prosper local socio-economic growth. It also represents an early step for the design of universal ESA instruments to regulate local development activities and promote sustainable land use planning in vulnerable areas at global levels.     

Monitoring the sustainability and equity of socioeconomic development: A comparison of emergy indices using Macao, Italy and Sweden as examples

The concept of sustainability involves factors related to society, economy, and ecology. The modern context of sustainability also includes a requirement for equitable consumption of materials and energy to sustain the quality of life while still protecting the environment. To evaluate the environmental sustainability of socioeconomic activities, emergy (embodied energy) is an important tool because it can measure real wealth by accounting for both natural and socioeconomic flows using a common set of units. However, different emergy indices provide different insights, and not all are equally suitable for every situation. Using traditional emergy-based indices, an integrated environmental sustainability index (ESI), and two measures of emergy storage, we analyzed emergy flows and related indices for three typical human-influenced ecosystems: those of Macao, Italy, and Sweden. The performance of each ecosystem was compared using several emergy-based indices to assess their levels of sustainable development and demonstrate how different indices provide different insights. Based on the principle that equitability is an essential component of sustainability, we suggest that a positive and low net emergy ratio is desirable, since this means that the system does not capture excessive amounts of resources from external systems and thereby damage its external life-support systems.     

The prediction of ecological potential for developing salt-tolerant oil plants on coastal saline land in Sheyang Saltern,China

The current energy crisis is a worldwide problem, and developing energy from biomass is considered an effective partial solution. Sheyang Saltern is located in a coastal area in East China. The administration of saltern cooperated with our Halophyte Research Lab to create a Five-year Plan of Biomass Energy on Saline Land. In this plan, 3330 ha of salt-tolerant oil plants will be planted on the coastal saline land in Sheyang Saltern, including 2664 ha of Ricinus communis and 666 ha of Kosteletzkya virginica (L.) presl. These plants will produce biomass energy from land that is not fit for common crops, and thus this plan will not affect crop production. Moreover, the biomass of plants will be fully utilized in a hierarchical way, guided by an ecological engineering design. Thus, more outputs and more profits will be gained by applying this plan. This study uses the emergy analysis to predict and analyze the saltern ecosystem's ecological potential and compare it with an existing system founded in 2007, a 33.3 ha field of the two plants in the saltern. Four main emergy indices of the two ecosystems, EYR, EIR, ELR and ESI, are calculated and compared. To better show the system's ecological potential, we establish a new emergy index-potential yield ratio (PYR). PYR is designed to measure artificial ecosystems’ potential output capacity. It reflects a system's potential to transform stored emergy into output emergy using ecological engineering technology. The value of the predicted system's PYR is as great as 225, indicating that the system has a bright future to develop salt-tolerant oil plants. The system's future ecological potential and additional ways to utilize the two plants – the use of ricin and tuberous roots, etc. are also discussed in this paper. Our results will be helpful to the government's policy making, and provides useful information for enterprises.     

Ecosystem, environmental quality and ecotechnology in the Taipei metropolitan region

The “self-design” capability of a natural environment is ignored in currently practiced environmental technology and urban planning professionals. Therefore, we propose an ecological engineering approach to conduct scenarios for environmental management in the metropolitan region of Taipei. Ecological energetic analysis is applied to assess the ecological economic status and the role and contribution of solid waste and water resources in the Taipei metropolitan region. The benefit of an ecological engineering approach to the environmental quality and sustainable development of the metropolitan region is evaluated using emergy synthesis. The results indicate that Taipei metropolitan region operates its activity mainly on the imported fuels and goods and services, which account for 90% of total emergy used. The treatment of waste as resources and the use of the self-design capability of the natural environment according to the ecological engineering approach can generate positive contribution and aid the environmental quality and productive potential of the ecological economic system. It is concluded that ecological sustainability should be used as a reference of environmental quality for urban development policy.     

Renewability and emergy footprint at different spatial scales for innovative food systems in Europe

Food production is increasingly being challenged by limited resources of energy and land as well as by growing demand for food. In a future with less availability of fossil fuels, land area will become very important for capturing the flow-limited renewable resources. Emergy assessment has been applied to calculate scale dependent indicators, which account for the land area needed, if agricultural systems were to be supported solely on renewable sources. These indicators are designated emergy footprints (EmFs) and expand the concept of support area defined previously in emergy accounting. The EmF (in ha) is calculated based on renewable empower densities which convert resource use into area equivalents able to capture renewable flows. The spatial division between on-site, local and non-local land areas applied in this study, identifies where the support area is located in order to apply a site-specific renewable empower density. A new indicator applying the EmF is the emergy overshoot factor, which estimates the ratio between EmF and the geographical system boundary (in ha). We apply this approach on three innovative food supply systems in Europe located at farms characterised by combining high diversity, reduced use of resources, nutrient cycling and local sales. The question is whether this type of food system may be considered sustainable from a resource use point of view measured as resource use efficiency by means of unit emergy value (UEV), renewability (R_on-site and R_global), direct and indirect occupation of land on different spatial scales (EmF and Emergy overshoot factor) and productivity per ha of the directly observed areas and the EmF area, respectively. Labour inputs constituted between 13 and 80% of the total emergy flow. The proportion of resource use from renewable sources was between 31 and 60% when excluding the inputs of direct labour. The food system with the lowest UEV, excluding direct labour, had the highest emergy overshoot factor, which even exceeded the global average of seven. However, this system had the highest productivity. The system with the highest UEV, excluding direct labour, had the lowest overshoot factor. In conclusion, each food system strategy has its pros and cons and it depends on the priorities, which is judged the most sustainable from an emergy point of view.     

Sustainable biomass production: A comparison between Gross Energy Requirement and Emergy Synthesis methods

In this paper two methods for energy analysis and environmental accounting (Gross Energy Requirement and Emergy Synthesis) are critically discussed in order to explore their ability to provide a comprehensive evaluation of the performance and environmental sustainability of human-dominated production processes. In order to allow a quantitative comparison, two cropping systems, namely 1 ha of corn production in Italy, and 1 ha of willow production in Sweden, are investigated by means of the parallel application of both methods. The case studies are carried out by performing a quantitative inventory of both natural and economic input flows to the investigated cropping systems. Such input flows are then converted into embodied energy (MJ) as well as emergy (seJ) units. Finally, performance indicators representative for each method are calculated. Results provided by the two methods and their respective theoretical features are compared and discussed in order to point out limits and potentialities of both approaches. The study shows that the two methods account for different – although complementary – categories of input flows, use different conversion factors, and answer to different questions and concerns. Gross Energy Requirement focuses on fossil fuel use and is capable to support the development of more efficient use of commercial energy. Emergy Synthesis uses broader spatial and time frames and accounts for both natural and economic resources. In so doing, it takes into consideration different forms of energy, materials, human labor and economic services on a common basis, offering larger potentiality to explore the sustainable interplay of environment and economy.     

Procrustes analysis as a tool for land management

Generalized Procrustes analysis (GPA) is a multivariate technique that involves transformations of data matrices to provide optimal comparability. We propose GPA to quantify the concordance among sets of variables that characterize natural, human and productive subsystems. When the land use fits in with the physical support of agricultural production, people's well-being should be evident in a high concordance between the land use and the social conditions. In a situation of instability each set of variables operates in diverse directions resulting in lower resilience and sustainability. Two GPA were performed, between physical support and land use data sets (concordance = 67.4%), and between land use and social conditions data sets (concordance = 65.3%). The interplay between the pair of concordance values constitutes a bi-dimensional index which serves as an ecological indicator. Based on bootstrap confidence interval, the 49 counties of the Pampa Ecoregion, Argentina, were classified in medium, high or low concordance. The lack of concordance is an indicator of imbalances which may contribute to guide environmental management.     

Criteria and indicator approach of global sustainability assessment system for sustainable landscaping using native plants in Qatar

The present study focuses on the importance and need to identify criteria and indicators (C&I) for sustainable landscaping using native plants in Qatar. The conditions for operationalizing the criteria and indicators approach are being incorporated into sustainable development practices and management planning in Qatar. This paper aims to develop criteria and related indicators for strengthening the global sustainability assessment system (GSAS) in order to provide a holistic approach for sustainable environmental assessment and the enhancement of ecosystem services. A total of 50 potentially native plant species were prioritized and categorized based on the following different parameters: weather conditions tolerated (temperature, humidity, and rainfall), multiple use value (ecological, economical, and medicinal), standard crown size (≤50 cm and ≥50 cm) and water requirement (moist, moderate, and dry). Diverse local stakeholders as well as international experts were consulted to rank the plant species, and concluded that these prioritized native species are fit for sustainable landscaping as opposed to the exotic plant species which are imported from different geo-climatic zones. Environmental, social, economic, human, and policy sustainability aspects were considered, along with 12 criteria and 49 related indicators which were identified by promoting the use of potential native plants for sustainable landscaping in Qatar.