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1.
Pooja Sharma James Humphreys Nicholas M. Holden 《The International Journal of Life Cycle Assessment》2018,23(1):26-40
Purpose
System modelling and life cycle assessment (LCA) were used to assess the climate change, acidification and eutrophication impacts of milk production using spring calving pasture-based system. The objective of the study was to evaluate the effect of climate and soil resources on the environmental impact per unit milk produced at the farm gate from low-cost, grass-based rotational-grazing dairy production.Methods
A dairy system model, Dairy_sim, designed to identify optimum grass-based spring calving production systems considering the interaction between climate and soil resources was tested using the Irish National Dairy Blueprint and then used to assess regional differences of system management with well, moderately, mixed moderately-poorly and poorly drained soil resources available. Life cycle assessment was used to quantify environmental impacts of climate and soil drainage status. The Dairy_sim output was used as activity data for the LCA model.Results and discussion
Differences were found in the management tactics influenced by climate and drainage resource. The impact of poor drainage reduced stocking rate, increased housing time and had greater need for later cut silage and more reliance on silage. Climate change, acidification and eutrophication impacts were greater for optimum management on poorly drained soil. The climate change ranged from 1.06 kg CO2 eq./kg (well drained) to 1.18 kg CO2 eq./kg (poorly drained) of energy corrected milk (ECM). The acidification and eutrophication ranged from 3.87 to 6.85 g SO2 eq./kg ECM and 2.69 to 3.64 g PO4 eq./kg ECM, respectively. Around 50% of poorly drained soil resource can be easily accommodated in dairy systems with little increase in environmental impact, where poor drained portion is utilised for silage.Conclusions
LCA combined with a system optimization model revealed how dairy farm management practises constrained by poor land resource increased the environmental impact per unit product.2.
Yanan Zhang Guiping Hu Robert C. Brown 《The International Journal of Life Cycle Assessment》2014,19(7):1371-1381
Purpose
This life cycle assessment evaluates and quantifies the environmental impacts of renewable chemical production from forest residue via fast pyrolysis with hydrotreating/fluidized catalytic cracking (FCC) pathway.Methods
The assessment input data are taken from Aspen Plus and greenhouse gases, regulated emissions, and energy use in transportation (GREET) model. The SimaPro 7.3 software is employed to evaluate the environmental impacts.Results and discussion
The results indicate that the net fossil energy input is 34.8 MJ to produce 1 kg of chemicals, and the net global warming potential (GWP) is ?0.53 kg CO2 eq. per kg chemicals produced under the proposed chemical production pathway. Sensitivity analysis indicates that bio-oil yields and chemical yields play the most important roles in the greenhouse gas footprints.Conclusions
Fossil energy consumption and greenhouse gas (GHG) emissions can be reduced if commodity chemicals are produced via forest residue fast pyrolysis with hydrotreating/FCC pathway in place of conventional petroleum-based production pathways. 相似文献3.
Donal O’Brien Padraig Brennan James Humphreys Eimear Ruane Laurence Shalloo 《The International Journal of Life Cycle Assessment》2014,19(8):1469-1481
Purpose
Life cycle assessment (LCA) studies of carbon footprint (CF) of milk from grass-based farms are usually limited to small numbers of farms (<30) and rarely certified to international standards, e.g. British Standards Institute publicly available specification 2050 (PAS 2050). The goals of this study were to quantify CF of milk from a large sample of grass-based farms using an accredited PAS 2050 method and to assess the relationships between farm characteristics and CF of milk.Materials and methods
Data was collected annually using on-farm surveys, milk processor records and national livestock databases for 171 grass-based Irish dairy farms with information successfully obtained electronically from 124 farms and fed into a cradle to farm-gate LCA model. Greenhouse gas (GHG) emissions were estimated with the LCA model in CO2 equivalents (CO2-eq) and allocated economically between dairy farm products, except exported crops. Carbon footprint of milk was estimated by expressing GHG emissions attributed to milk per kilogram of fat and protein-corrected milk (FPCM). The Carbon Trust tested the LCA model for non-conformities with PAS 2050. PAS 2050 certification was achieved when non-conformities were fixed or where the effect of all unresolved non-conformities on CF of milk was?<?±5 %.Results and discussion
The combined effect of LCA model non-conformities with PAS 2050 on CF of milk was <1 %. Consequently, PAS 2050 accreditation was granted. The mean certified CF of milk from grass-based farms was 1.11 kg of CO2-eq/kg of FPCM, but varied from 0.87 to 1.72 kg of CO2-eq/kg of FPCM. Although some farm attributes had stronger relationships with CF of milk than the others, no attribute accounted for the majority of variation between farms. However, CF of milk could be reasonably predicted using N efficiency, the length of the grazing season, milk yield/cow and annual replacement rate (R 2?=?0.75). Management changes can be applied simultaneously to improve each of these traits. Thus, grass-based farmers can potentially significantly reduce CF of milk.Conclusions
The certification of an LCA model to PAS 2050 standards for grass-based dairy farms provides a verifiable approach to quantify CF of milk at a farm or national level. The application of the certified model highlighted a wide range between the CF of milk of commercial farms. However, differences between farms’ CF of milk were explained by variation in various aspects of farm performance. This implies that improving farm efficiency can mitigate CF of milk. 相似文献4.
Daniel Maga Markus Hiebel Christian Knermann 《The International Journal of Life Cycle Assessment》2013,18(4):861-871
Purpose
Information communication technology (ICT) offers the chance of enhancing the efficiency of public services and economic processes. The use of server-based computing is supposed to reduce the energy and material consumption in ICT services. This hypothesis will be investigated and quantified looking at the whole life cycle of the products. In this paper, server-based computing in combination with thin clients (SBCTC) is compared to a typical desktop PC (DPC) workplace over a time period of 5 years.Materials and methods
The LCA method used in this paper is focused on the impact category of global warming potential. The calculations were performed using the Microsoft® Excel-based methodology for ecodesign of energy-related products tool. This tool includes the requirements of energy-related products (Directive 2009/125/EC). Moreover, an input-orientated method—material input per service unit (MIPS)—is applied which allows for an additional comparison between the two ICT solutions.Results and discussion
Electricity consumption could be identified as a crucial environmental impact factor of DPC and SBCTC with both methods. Depending on the user behavior, more than 200 kg CO2e can be saved by switching from DPC to SBCTC. Over 80 kg CO2e can be saved in the material and extraction life cycle stage. The largest savings are achieved in the material category electronics (about 70 kg CO2e). A correlation analysis between the results of global warming potential (GWP) and the MIPS category “air” shows that both indicators GWP and air lead to the same conclusions when evaluating life cycle stages and ICT material categories.Conclusions
Taking into account all assumptions made in this paper, SBCTC saves more than 65 % of greenhouse gas emissions compared to DPC during the entire life cycle. To ensure further profound comparisons of the ICT solutions, current data on the energy demand and detailed information on the composition of the IT products should be made available by industry. 相似文献5.
S. Richard O. Williams Peter D. Fisher Tony Berrisford Peter J. Moate Keith Reynard 《The International Journal of Life Cycle Assessment》2014,19(1):69-78
Purpose
To consider whether feed supplements that reduce methane emissions from dairy cows result in a net reduction in greenhouse gas (GHG) intensity when productivity changes and emissions associated with extra manufacturing and management are included.Methods
A life cycle assessment was undertaken using a model farm based on dairy farms in Victoria, Australia. The system boundary included the creation of farm inputs and on-farm activities up to the farm gate where the functional unit was 1 L of fat and protein corrected milk (FPCM). Electricity and diesel (scaled per cow), and fertiliser inputs (scaled on farm size) to the model farm were based on average data from a survey of farms. Fertiliser applied to crops was calculated per area of crop. Animal characteristics were based on available data from farms and literature. Three methane-reducing diets (containing brewers grain, hominy or whole cotton seed) and a control diet (cereal grain) were modelled as being fed during summer, with the control diet being fed for the remainder of the year in all cases.Results and discussion
Greenhouse gas intensity (kg CO2-eq/L FPCM) was lower than the control diet when the hominy (97 % compared with control) and brewers grain (98 %) diets were used but increased when the whole cottonseed diet was used (104 %). On-farm GHG emissions (kg CO2-eq) were lower than the control diet when any of the methane-reducing diets were used (98 to 99.5 % of emissions when control diet fed). Diesel use in production and transport of feed supplements accounted for a large portion (63 to 93 %) of their GHG intensity (kg CO2-eq/t dry matter). Adjusting fertiliser application, changing transport method, changing transport fuel, and using nitrification inhibitors all had little effect on GHG emissions or GHG intensity.Conclusions
Although feeding strategies that reduce methane emissions from dairy cows can lower the GHG emissions up to the farm gate, they may not result in lower GHG intensities (g CO2-eq/L FPCM) when pre-farm emissions are included. Both transport distance and the effect of the feed on milk production have important impacts on the outcomes. 相似文献6.
Nitrogen deposition promotes ecosystem carbon accumulation by reducing soil carbon emission in a subtropical forest 总被引:1,自引:0,他引:1
Houbao Fan Jianping Wu Wenfei Liu Yinghong Yuan Rongzhen Huang Yingchun Liao Yanyan Li 《Plant and Soil》2014,379(1-2):361-371
Background and aims
Tropical and subtropical forests are experiencing high levels of atmospheric nitrogen (N) deposition, but the responses of such forests ecosystems to N deposition remain poorly understood.Methods
We conducted an 8-year field experiment examining the effect of experimental N deposition on plant growth, soil carbon dioxide efflux, and net ecosystem production (NEP) in a subtropical Chinese fir forest. The quantities of N added were 0 (control), 60, 120, and 240 kg ha?1 year?1.Results
NEP was lowest under ambient conditions and highest with 240 kg of N ha?1 year?1 treatment. The net increase in ecosystem carbon (C) storage ranged from 9.2 to 16.4 kg C per kg N added in comparison with control. In addition, N deposition treatments significantly decreased heterotrophic respiration (by 0.69–1.85 t C ha?1 year?1) and did not affect plant biomass. The nitrogen concentrations were higher in needles than that in fine roots.Conclusions
Our findings suggest that the young Chinese fir forest is carbon source and N deposition would sequester additional atmospheric CO2 at high levels N input, mainly due to reduced soil CO2 emission rather than increased plant growth, and the amount of sequestered C depended on the rate of N deposition. 相似文献7.
Steve Wallbridge Anthony Banford Adisa Azapagic 《The International Journal of Life Cycle Assessment》2013,18(5):990-1008
Purpose
Full life cycle assessment (LCA) impacts from decommissioning have rarely been assessed, largely because few sites have been decommissioned so that the impacts of decommissioning are currently uncertain. This paper presents the results of an LCA study of the ongoing decommissioning of the Magnox power plant at Trawsfynydd in the UK. These results have been used to estimate the potential environmental impacts for the whole UK Magnox fleet of 11 reactors that will have to be decommissioned during this century.Methods
The functional unit is defined as ‘decommissioning one Magnox power plant’. The system boundary considers all stages in the life cycle of decommissioning, including site management, waste retrieval, plant deconstruction, packaging and storage of intermediate- and low-level wastes (ILW and LLW). High-level waste, i.e. waste fuel is excluded as it was being removed from the site to be reprocessed at Sellafield. The environmental impacts have been estimated using the CML 2001 methodology. Primary data have been sourced from the Trawsfynydd site and the background from Ecoinvent.Results and discussion
Most impacts from decommissioning are due to the plant deconstruction (25–75 %) and ILW storage and disposal (25–70 %). For the example of global warming potential (GWP), estimated at 241 kt CO2 eq./functional unit, or 3.5 g CO2 eq./kWh of electricity generated during the lifetime of the plant, 55 % of the impact is from plant deconstruction and 30 % from ILW disposal. The results for the whole UK Magnox fleet indicate that the impacts vary greatly for different sites. For example, the GWP ranges from 0.89 to 7.14 g CO2 eq./kWh. If the impacts from storage of waste fuel at Sellafield are included in the estimates, the GWP increases on average by four times. Overall, decommissioning of the UK Magnox reactors would generate 2 Mt of CO2 eq. without and 11 Mt of CO2 eq. with the waste from Sellafield. This represents 0.4 and 2 % of the total UK annual emissions, respectively.Conclusions
The impacts of decommissioning can vary greatly at different sites depending on the amount of waste and electricity generated by the plants. Delaying decommissioning to allow the energy system to decarbonise could reduce the environmental impacts, e.g. GWP could be reduced by 50 %. The impacts could also be reduced by reducing the volume of waste and increasing recycling of materials. For example, recycling 70 % of steel would reduce the impacts on average by 34 %. 相似文献8.
Hannah H. E. van Zanten Herman Mollenhorst Jerke W. de Vries Corina E. van Middelaar Heleen R. J. van Kernebeek Imke J. M. de Boer 《The International Journal of Life Cycle Assessment》2014,19(1):79-88
Purpose
The livestock sector has a major impact on the environment. This environmental impact may be reduced by feeding agricultural co-products (e.g. beet tails) to livestock, as this transforms inedible products for humans into edible products, e.g. pork or beef. Nevertheless, co-products have different applications such as bioenergy production. Based on a framework we developed, we assessed environmental consequences of using co-products in diets of livestock, including the alternative application of that co-product.Methods
We performed a consequential life cycle assessment, regarding greenhouse gas emissions (including emissions related to land use change) and land use, for two case studies. Case 1 includes increasing the use of wheat middlings in diets of dairy cattle at the expense of using it in diets of pigs. The decreased use of wheat middlings in diets of pigs was substituted with barley, the marginal product. Case 2 includes increasing the use of beet tails in diets of dairy cattle at the expense of using it to produce bioenergy. During the production of biogas, electricity, heat and digestate (that is used as organic fertilizer) were produced. The decrease of electricity and heat was substituted with fossil fuel, and digestate was substituted with artificial fertilizer.Results and discussion
Using wheat middlings in diets of dairy cattle instead of using it in diets of pigs resulted in a reduction of 329 kg CO2 eq per ton wheat middlings and a decrease of 169 m2 land. Using beet tails in diets of dairy cattle instead of using it as a substrate for anaerobic digestion resulted in a decrease of 239 kg CO2 eq per ton beet tails and a decrease of 154 m2 land. Emissions regarding land use change contributed significantly in both cases but had a high uncertainty factor, ±170 ton CO2 ha?1. Excluding emissions from land use change resulted in a decrease of 9 kg CO2 eq for case 1 ‘wheat middlings’ and an increase of 50 kg CO2 eq for case 2 ‘beet tails’.Conclusions
Assessing the use of co-products in the livestock sector is of importance because shifting its application can reduce the environmental impact of the livestock sector. A correct assessment of the environmental consequences of using co-products in animal feed should also include potential changes in impacts outside the livestock sector, such as the impact in the bioenergy sector. 相似文献9.
Soil carbon dioxide and methane fluxes as affected by tillage and N fertilization in dryland conditions 总被引:1,自引:0,他引:1
Daniel Plaza-Bonilla Carlos Cantero-Martínez Javier Bareche José Luis Arrúe Jorge Álvaro-Fuentes 《Plant and Soil》2014,381(1-2):111-130
Background and aims
The effects of tillage and N fertilization on CO2 and CH4 emissions are a cause for concern worldwide. This paper quantifies these effects in a Mediterranean dryland area.Methods
CO2 and CH4 fluxes were measured in two field experiments. A long-term experiment compared two types of tillage (NT, no-tillage, and CT, conventional intensive tillage) and three N fertilization rates (0, 60 and 120 kg N ha?1). A short-term experiment compared NT and CT, three N fertilization doses (0, 75 and 150 kg N ha?1) and two types of fertilizer (mineral N and organic N with pig slurry). Aboveground and root biomass C inputs, soil organic carbon stocks and grain yield were also quantified.Results
The NT treatment showed a greater mean CO2 flux than the CT treatment in both experiments. In the long-term experiment CH4 oxidation was greater under NT, whereas in the short-term experiment it was greater under CT. The fertilization treatments also affected CO2 emissions in the short-term experiment, with the greatest fluxes when 75 and 150 kg organic N ha?1 was applied. Overall, the amount of CO2 emitted ranged between 0.47 and 6.0 kg CO2?equivalent kg grain?1. NT lowered yield-scaled emissions in both experiments, but these treatment effects were largely driven by an increase in grain yield.Conclusions
In dryland Mediterranean agroecosystems the combination of NT and medium rates of either mineral or organic N fertilization can be an appropriate strategy for optimizing CO2 and CH4 emissions and grain yield. 相似文献10.
Ivan T. Herrmann Andreas Jørgensen Sander Bruun Michael Z. Hauschild 《The International Journal of Life Cycle Assessment》2013,18(2):418-430
Purpose
Several factors contribute to the current increased focus on alternative fuels such as biodiesel, including an increasing awareness of the environmental impact of petrochemical (PC) oil products such as PC diesel, the continuously increasing price of PC oil, and the depletion of PC oil. For these reasons, the European Union has enacted a directive requiring each member state to ensure that the share of energy from renewable sources in transport be at least 10 % of the final consumption of energy by 2020 (The European Parliament and the Council 2009). This LCA study assesses the specific environmental impacts from the production and use of biodiesel as it is today (real-time), based on rapeseed oil and different types of alcohols, and using technologies that are currently available or will be available shortly. Different options are evaluated for the environmental improvement of production methods. The modeling of the LCA is based on a specific Danish biodiesel production facility.Methods
The functional unit is “1,000 km transportation for a standard passenger car.” All relevant process stages are included, such as rapeseed production including carbon sequestration and N2O balances, and transportation of products used in the life cycle of biodiesel. System expansion has been used to handle allocation issues.Results and discussion
The climate change potential from the production and use of biodiesel today is 57 kg CO2-eq/1,000 km, while PC diesel is 214 kg CO2-eq/1,000 km. Options for improvement include the increased use of residual straw from rapeseed fields for combustion in a power plant where carbon sequestration is considered, and a change in transesterification from a conventional process to an enzymatic process when using bioethanol instead of PC methanol. This research also evaluates results for land use, respiratory inorganics potential, human toxicity (carc) potential, ecotoxicity (freshwater) potential, and aquatic eutrophication (N) potential. Different sources for uncertainty are evaluated, and the largest drivers for uncertainty are the assumptions embedded into the substitution effects. The results presented should not be interpreted as a blueprint for the increased production of biodiesel but rather as a benchmarking point for the present, actual impact in a well-to-wheels perspective of biodiesel, with options for improving production and use.Conclusions
Based on this analysis, we recommend investigating additional options and incentives regarding the increased use of rape straw, particularly considering the carbon sequestration issues (from the perspective of potential climate change) of using bioalcohol instead of PC alcohol for the transesterification process. 相似文献11.
Makoto Watanabe Qiaozhi Mao Eka Novriyanti Kazuhito Kita Kentaro Takagi Fuyuki Satoh Takayoshi Koike 《Trees - Structure and Function》2013,27(6):1647-1655
Key message
Elevated CO 2 enhances the photosynthesis and growth of hybrid larch F 1 seedlings. However, elevated CO 2 -induced change of tree shape may have risk to the other environmental stresses.Abstract
The hybrid larch F1 (Larix gmelinii var. japonica × L. kaempferi) is one of the most promising species for timber production as well as absorption of atmospheric CO2. To assess the ability of this species in the future high CO2 environment, we investigated the growth and photosynthetic response of hybrid larch F1 seedlings to elevated CO2 concentration. Three-year-old seedlings of hybrid larch F1 were grown on fertile brown forest soil or infertile volcanic ash soil, and exposed to 500 μmol mol?1 CO2 in a free-air CO2 enrichment system located in northern Japan for two growing seasons. Regardless of soil type, the exposure to elevated CO2 did not affect photosynthetic traits in the first and second growing seasons; a higher net photosynthetic rate was maintained under elevated CO2. Growth of the seedlings under elevated CO2 was greater than that under ambient CO2. We found that elevated CO2 induced a change in the shape of seedlings: small roots, slender-shaped stems and long-shoots. These results suggest that elevated CO2 stimulates the growth of hybrid larch F1, although the change in tree shape may increase the risk of other stresses, such as strong winds, heavy snow, and nutrient deficiency. 相似文献12.
The nitrification inhibitor 3,4-dimethylpyrazole-phosphat (DMPP) - quantification and effects on soil metabolism 总被引:1,自引:0,他引:1
Gero Benckiser Elke Christ Tobias Herbert Achim Weiske Johannes Blome Martin Hardt 《Plant and Soil》2013,371(1-2):257-266
Aims
Nitrification inhibitors (NI) formulated on granulated ammonium sulphate nitrate (ASN) are an option to minimize nitrate leaching into ground waters and emissions of the greenhouse gas N2O. This paper focuses (a) on the development of an analytic enabling to extract and quantify the NI 3,4-dimethylpyrazolephosphate (DMPP), marketed since 1999. The efficiency of DMPP has been studied in laboratory and field soils. Here the DMPP analytic and the behaviour of a nitrifying bacterial consortium enriched from a field soil and exposed to zero, field applied and a 10 fold higher DMPP concentration than the recommended one for field application are in the focus.Methods
For extracting DMPP quantitatively from soils a method connected to a HPLC analytic has been developed by us and was standardized in laboratory experiment with a silt clay field soil (allochtone Vega). The method is detailed described here. Its reliability has been tested in a 3 years field trial under varying cropping systems and climatic conditions asides the influence of DMPP on CO2?, CH4? and N2O- emissions, measured by the closed chamber method. Parallel a nitrifying bacterial consortium of the silty clay field soil was enriched and subjected to 0, the recommended DMPP concentration for field applications and a 10 times higher one. In incubation experiments the conversion of ammonium to nitrite and nitrate in presence and absence of DMPP was spectrophotometer determined and pH-shifts with a scaled litmus paper. In sacrificed flasks at the end of incubation morphological changes of the bacteria involved were studied by transmission electron microscope (TEM).Results
The ammonium, nitrite and nitrate determinations and the TEM pictures show that in presence of the field applied DMPP concentration the nitrifying activity returned around 30 days later than in the control and the cells were slightly enlarged. In presence of a 10 times higher DMPP concentration a recovery was prevented. DMPP prolongs, compared with dicyandiamide (DCD), the period of nitrifiers’ inhibition and reduced N2O? and CO2? the emissions (Weiske et al., Biol Fertil Soils 34:109–117, 2001a, Nutr Cycl Agroecosys 60:57–64, b).Conclusions
With the method developed by us the stability of DMPP in agricultural soils can be satisfyingly and reproducible studied down to a detection limit of 0.01 μg DMPP g?1 dry soil. The morphological changes in the nitrifying consortium due to DMPP concentrations are in agreement with the recovery rate found by nitrite and nitrate formation. 相似文献13.
Nasir Anka Garba Les John Duckers William John Hall 《The International Journal of Life Cycle Assessment》2014,19(4):806-813
Purpose
The purpose of this study is to assess and calculate the potential impacts of climate change on the greenhouse gas (GHG) emissions reduction potentials of combined production of whole corn bioethanol and stover biomethanol, and whole soybean biodiesel and stalk biomethanol. Both fuels are used as substitutes to conventional fossil-based fuels. The product system includes energy crop (feedstock) production and transportation, biofuels processing, and biofuels distribution to service station.Methods
The methodology is underpinned by life cycle thinking. Crop system model and life cycle assessment (LCA) model are linked in the analysis. The Decision Support System for Agrotechnology Transfer – crop system model (DSSAT-CSM) is used to simulate biomass and grain yield under different future climate scenarios generated using a combination of temperature, precipitation, and atmospheric CO2. Historical weather data for Gainesville, Florida, are obtained for the baseline period (1981–1990). Daily minimum and maximum air temperatures are projected to increase by +2.0, +3.0, +4.0, and +5.0 °C, precipitation is projected to change by ±20, 10, and 5 %, and atmospheric CO2 concentration is projected to increase by +70, +210, and +350 ppm. All projections are made throughout the growing season. GaBi 4.4 is used as primary LCA modelling software using crop yield data inputs from the DSSAT-CSM software. The models representation of the physical processes inventory (background unit processes) is constructed using the ecoinvent life cycle inventory database v2.0.Results and discussion
Under current baseline climate condition, net greenhouse gas (GHG) emissions savings per hectare from corn-integrated biomethanol synthesis (CIBM) and soybean-integrated biomethanol synthesis (SIBM) were calculated as ?8,573.31 and ?3,441 kg CO2-eq. ha?1 yr?1, respectively. However, models predictions suggest that these potential GHG emissions savings would be impacted by changing climate ranging from negative to positive depending on the crop and biofuel type, and climate scenario. Increased atmospheric level of CO2 tends to minimise the negative impacts of increased temperature.Conclusions
While policy measures are being put in place for the use of renewable biofuels driven by the desire to reduce GHG emissions from the use of conventional fossil fuels, climate change would also have impacts on the potential GHG emissions reductions resulting from the use of these renewable biofuels. However, the magnitude of the impact largely depends on the biofuel processing technology and the energy crop (feedstock) type. 相似文献14.
Verónica Parra-Vega Begoña Renau-Morata Alicia Sifres José M. Seguí-Simarro 《Plant Cell, Tissue and Organ Culture》2013,112(3):353-360
Production of doubled haploids (DHs) is a convenient tool to obtain pure lines for breeding purposes. Until now, the easiest and most useful approach to obtain pepper DHs is via anther culture. However, this method has an associated possibility of producing calli from anther wall tissues that would be coexisting in the anther locule with embryos derived from microspores. Using two established protocols for anther culture, Dumas de Vaulx et al. (Agronomie 2:983–988, 1981) and Supena et al. (Sci Hort 107:226–232, 2006a; Plant Cell Rep 25:1–10, 2006b) callus and embryo development was assessed in four sweet pepper cultivars. For all genotypes tested, the protocol of Dumas de Vaulx et al. (Agronomie 2:983–988, 1981) promoted both embryo development and callus growth, whereas the protocol of Supena et al. (Sci Hort 107:226–232, 2006a; Plant Cell Rep 25:1–10, 2006b) produced no callus but only embryos. However, differences in embryo production were observed among these genotypes. In parallel, anthers were exposed to a 35 °C inductive heat shock for 4, 8, 12 and 16 days, prior to culture at 25 °C. The duration of the heat shock had significant effects in embryo production, but also in callus generation. Callus generation increased with prolonged exposures to 35 °C. Embryo and callus origin was analyzed by flow cytometry, light microscopy and molecular markers. Tests conducted demonstrated a gametophytic origin for all of the embryos tested, and a sporophytic origin for all of the calli. Together, our results reveal that culture conditions have a significant influence on the presence of calli derived from anther walls, which could be minimized by reducing heat shock exposure and/or using a shed-microspore approach. 相似文献
15.
Background and purpose
Rapid increases in atmospheric carbon dioxide concentration ([CO2]) may increase crop residue production and carbon: nitrogen (C:N) ratio. Whether the incorporation of residues produced under elevated [CO2] will limit soil N availability and fertilizer N recovery in the plant is unknown. This study investigated the interaction between crop residue incorporation and elevated [CO2] on the growth, grain yield and the recovery of 15N-labeled fertilizer by wheat (Triticum aestivum L. cv. Yitpi) under controlled environmental conditions.Methods
Residue for ambient and elevated [CO2] treatments, obtained from wheat grown previously under ambient and elevated [CO2], respectively, was incorporated into two soils (from a cereal-legume rotation and a cereal-fallow rotation) 1 month before the sowing of wheat. At the early vegetative stage 15N-labeled granular urea (10.22 atom%) was applied at 50 kg?N ha?1 and the wheat grown to maturity.Results
When residue was not incorporated into the soil, elevated [CO2] increased wheat shoot (16 %) and root biomass (41 %), grain yield (19 %), total N uptake (4 %) and grain N removal (8 %). However, the positive [CO2] fertilization effect on these parameters was absent in the soil amended with residue. In the absence of residue, elevated [CO2] increased fertilizer N recovery in the plant (7 %), but when residue was incorporated elevated [CO2] decreased fertilizer N recovery.Conclusions
A higher fertilizer application rate will be required under future elevated [CO2] atmospheres to replenish the extra N removed in grains from cropping systems if no residue is incorporated, or to facilitate the [CO2] fertilization effect on grain yield by overcoming N immobilization resulting from residue amendment. 相似文献16.
Syndhia Mathe 《The International Journal of Life Cycle Assessment》2014,19(8):1506-1514
Purpose
This article discusses the choice of stakeholder categories and the integration of stakeholders into participatory processes to define impact categories and select indicators.Methods
We undertook a literature review concerning the roles and the importance of stakeholders in participatory processes, and the use of such processes in environmental and social LCAs (Biswas et al. Int J Life Cycle Assess 3(4):184-190, 1998; Sonnemann et al. Int J Life Cycle Assess 6(6):325-333, 2001; Baldo Int J Life Cycle Assess 7(5):269-275, 2002; James et al. Int J Life Cycle Assess 7(3):151-157, 2002; Bras-Kapwijk Int J Life Cycle Assess 8(5):266-272, 2003; Mettier et al. Int J Life Cycle Assess 11(6):468-476, 2006). As part of the French National Research Agency Piscenlit project, we adapted the Principle, Criteria, Indicator (PCI) method (Rey-Valette et al. 2008), which is an assessment method of sustainable development, as a way to integrate the participatory approach into Social Life Cycle Assessment (SLCA) methodology, mainly at the impact definition stage.Results and discussion
Different views of participation were found in the literature; there is no consensual normative approach for the implication of stakeholders in LCA development. Some attempts have been made to integrate stakeholders into environmental LCAs but these attempts have not been generalized. However, they strongly emphasize the interrelationship between research on the growing integration of stakeholders and on the choice of stakeholders. We then propose criteria from stakeholder theory (Freeman 1984; Mitchell et al. Acad Manage Rev 22(4):853-886, 1997; Geibler et al. Bus Strat Environ 15:334-346, 2006) in order to identify relevant stakeholders for SLCA participatory approach. The adaptation of the PCI method to Principles, Impacts, and Indicators (PII) enables stakeholders to express themselves and hence leads to definitions of relevant social indicators that they can appropriate. The paper presents results regarding the selection of stakeholders but no specific results regarding the choice of impact categories and indicators.Conclusions and recommendations
Integrating a participatory approach into SLCAs is of interest at several levels. It enables various factors to be taken into account: plurality of stakeholder interests, local knowledge, and impact categories that make sense for stakeholders in different contexts. It also promotes dialogue and simplifies the search for indicators. However, it requires a multidisciplinary approach and the integration of new knowledge and skills for the SLCA practitioners. 相似文献17.
María José Amores Fernando Daniel Mele Laureano Jiménez Francesc Castells 《The International Journal of Life Cycle Assessment》2013,18(7):1344-1357
Purpose
The production of bioethanol in Argentina is based on the sugarcane plantation system, with extensive use of agricultural land, scarce use of fertilizers, pesticides, and artificial irrigation, and burning of sugarcane prior to harvesting. The objective of this paper is to develop a life cycle assessment (LCA) of the fuel ethanol from sugarcane in Tucumán (Argentina), assessing the environmental impact potentials to identify which of them cause the main impacts.Methods
Our approach innovatively combined knowledge about the main impact pathways of bioethanol production with LCA which covers the typical emission-related impact categories at the midpoint life cycle impact assessment. Real data from the Argentinean industry subsystems have been used to perform the study: S1—sugarcane production, S2—milling process, S3—sugar production, and S4—ethanol production from molasses, honey, or sugarcane juice.Results and discussion
The results are shown in the three alternative pathways to produce bioethanol. Different impact categories are assessed, with global warming potential (GWP) having the highest impact. So, the production of 1 kg of ethanol from molasses emitted 22.5 kg CO2 (pathway 1), 19.2 kg CO2 from honey (pathway 2), and 15.0 kg CO2 from sugarcane juice (pathway 3). Several sensitivity analyses to study the variability of the GWP according to the different cases studied have been performed (changing the agricultural yield, including economic and calorific allocation in sugar production, and modifying the sugar price).Conclusions
Agriculture is the subsystem which shows the highest impact in almost all the categories due to fossil fuel consumption. When an economic and calorific allocation is considered to assess the environmental impact, the value is lower than when mass allocation is used because ethanol is relatively cheaper than sugars and it has higher calorific value. 相似文献18.
Background and aims
Combination of rewetting and wetland crop cultivation (paludiculture) is pursued as a wider carbon dioxide (CO2) mitigation option in drained peatland. However, information on the overall greenhouse gas (GHG) balance for paludiculture is lacking. We investigated the GHG balance of peatlands grown with reed canary grass (RCG) and rewetted to various extents.Methods
Gas fluxes of CO2, methane (CH4) and nitrous oxide (N2O) were measured with a static chamber technique for 10 months from mesocosms sown with RCG and manipulated to ground water levels (GWL) of 0, ?10, ?20, ?30 and ?40 cm below the soil surface. Gross primary production (GPP) was estimated from the above ground biomass yield.Results
The mean dry biomass yield across all water table treatments was 6 Mg ha?1 with no significant differences between the treatments. Raising the GWL to the surface decreased both the net ecosystem exchange (NEE) of CO2 and N2O emissions whereas CH4 emissions increased. Total cumulative GHG emissions (for 10 months) corresponded to 0.08, 0.13, 0.61, 0.68 and 0.98 kg CO2 equivalents m?2 from the GWL treatments at 0, ?10, ?20, ?30 and ?40 cm below the soil surface, respectively.Conclusions
The results showed that a reduction in total GHG emission can be achieved without losing the productivity of newly established RCG when GWL is maintained close to the surface. Further studies should address the practical constrains and long-term productivity of RCG cultivation in rewetted peatlands. 相似文献19.
Greenhouse gas emissions from forestry in East Norway 总被引:1,自引:0,他引:1
Volkmar Timmermann Janka Dibdiakova 《The International Journal of Life Cycle Assessment》2014,19(9):1593-1606
Purpose
So far no calculations have been made for greenhouse gas (GHG) emissions from forestry in East Norway. This region stands for 80 % of the Norwegian timber production. The aim of this study was to assess the annual GHG emissions of Norwegian forestry in the eastern parts of the country from seed production to final felling and transport of timber to sawmill and wood processing industry (cradle-to-gate inventory), based on specific Norwegian data.Methods
The life cycle inventory was conducted with SimaPro applying primary and secondary data from Norwegian forestry. GHG emissions of fossil-related inputs from the technosphere were calculated for the functional unit of 1 m3 timber extracted and delivered to industry gate in East Norway in 2010. The analysis includes seed and seedling production, silvicultural operations, forest road construction and upgrading, thinning, final felling, timber forwarding and timber transport on road and rail from the forest to the industry. Norwegian time studies of forestry machines and operations were used to calculate efficiency, fuel consumption and transport distances. Due to the lack of specific Norwegian data in Ecoinvent, we designed and constructed unit processes based on primary and secondary data from forestry in East Norway.Results and discussion
GHG emissions from forestry in East Norway amounted to 17.893 kg CO2-equivalents per m3 of timber delivered to industry gate in 2010. Road transport of timber accounted for almost half of the total GHG emissions, final felling and forwarding for nearly one third of the GHG emissions. Due to longer road transport distances, pulpwood had higher impact on the climate change category than saw timber. The construction of forest roads had the highest impact on the natural land transformation category. The net CO2 emissions of fossil CO2 corresponded to 2.3 % of the CO2 sequestered by 1 m3 of growing forest trees and were compared to a calculation of biogenic CO2 release from the forest floor as a direct consequence of harvesting.Conclusions
Shorter forwarding and road transport distances, increased logging truck size and higher proportion of railway transport may result in lower emissions per volume of transported timber. A life cycle assessment of forestry may also consider impacts on environmental categories other than climate change. Biogenic CO2 emissions from the soil may be up to 10 times higher than the fossil-related emissions, at least in a short-term perspective, and are highly dependent on stand rotation length. 相似文献20.
In this paper, we assessed the quantum mechanical level of theory for prediction of linear and nonlinear optical (NLO) properties of push-pull organic molecules. The electric dipole moment (μ), mean polarizability (〈α〉) and total static first hyperpolarizability (βt) were calculated for a set of benzene, styrene, biphenyl and stilbene derivatives using HF, MP2 and DFT (31 different functionals) levels and over 71 distinct basis sets. In addition, we propose two new basis sets, NLO-V and aNLO-V, for NLO properties calculations. As the main outcomes it is shown that long-range corrected DFT functionals such as M062X, ωB97, cam-B3LYP, LC-BLYP and LC-ωPBE work satisfactorily for NLO properties when appropriate basis sets such as those proposed here (NLO-V or aNLO-V) are used. For most molecules with β ranging from 0 to 190 esu, the average absolute deviation was 13.2 esu for NLO-V basis sets, compared to 27.2 esu for the standard 6-31 G(2d) basis set. Therefore, we conclude that the new basis sets proposed here (NLO-V and aNLO-V), together with the cam-B3LYP functional, make an affordable calculation scheme to predict NLO properties of large organic molecules. Figure
Calculated values for total static first hyperpolarizability (βt) for 4-amino-4′-nitrostilbene at cam-B3LYP/basis set level. Experimental from Cheng et al. [1, 2]. 相似文献