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在实地考察和标本采集鉴定的基础上,对辽宁棋盘山森林公园种子植物的组成、分布类型和区系特征进行了分析研究.结果表明,棋盘山森林公园共有种子植物69科187属264种,其中裸子植物4科9属23种,被子植物65科178属241种;植被类型多样,区系地理成分复杂,具有强烈的温带性质;区内具有一定数量的重点保护植物,但特有现象不... 相似文献
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Seungdo?KimEmail author Bruce?DaleEmail author 《The International Journal of Life Cycle Assessment》2005,10(4):294-304
Goal and Scope This study estimates the life cycle inventory (LCI) of the electricity system in the United States, including the 10 NERC (North American Electric Reliability Council) regions, Alaska, Hawaii, off-grid non-utility plants and the US average figures. The greenhouse gas emissions associated with the United States electricity system are also estimated. Methods The fuel mix of the electricity system based on year 2000 data is used. The environmental burdens associated with raw material extraction, petroleum oil production and transportation for petroleum oil and natural gas to power plants are adopted from the DEAMTM LCA database. Coal transportation from a mining site to a power plant is specified with the data from the Energy Information Administration (EIA), which includes the mode of transportation as well as the distance traveled. The gate-to-gate environmental burdens associated with generating electricity from a fossil-fired power plant are obtained from the DEAMTM LCA database and the eGRID model developed by the United States Environmental Protection Agency. For nuclear power plants and hydroelectric power plants, the data from the DEAMTM LCA database are used.Results and Discussion Selected environmental profiles of the US electricity system are presented in the paper version, while the on-line version presents the whole LCI data. The overall US electricity system in the year 2000 released about 2,654 Tg CO2 eq. of greenhouse gas emissions based on 100-year global warming potentials with 193 g CO2 eq. MJe1 as an weighted average emission rate per one MJ electricity generated. Most greenhouse gases are released during combusting fossil fuels, accounting for 7895% of the total. The greenhouse gas emissions released from coal-fired power plants account for 81% of the total greenhouse gas emissions associated with electricity generation, and natural gas-fired power plants contribute about 16% of the total. The most significant regions for the total greenhouse gas emissions are the SERC (Southeastern Electric Reliability Council) and ECAR (East Central Area Reliability Coordination Agreement) regions, which account for 22% and 21% of the total, respectively. A sensitivity analysis on the generation and consumption based calculations indicates that the environmental profiles of electricity based on consumption are more uncertain than those based on generation unless exchange data from the same year are available because the exchange rates (region to region import and export of electricity) vary significantly from year to year.Conclusions and Outlook Those who are interested in the LCI data of the US electricity system can refer to the on-line version. When the inventory data presented in the on-line version are used in a life cycle assessment study, the distribution and transmission losses should be taken into account, which is about 9.5% of the net generation [1]. The comprehensive technical information presented in this study can be used in estimating the environmental burdens when new information on the regional fuel mix or the upstream processes is available. The exchange rates presented in this study also offer useful information in consequential LCI studies. 相似文献
106.
Hans-J?rg?AlthausEmail author Mischa?ClassenEmail author 《The International Journal of Life Cycle Assessment》2005,10(1):43-49
Goal, Scope and Background The ecoinvent database provides harmonised generic life cycle inventories for metal production and processing. They can be used as background data for different LCA applications. The goal of this paper is to provide an overview of the metals inventoried in ecoinvent. Beside, some methodological background information is given. The focus lies on a new methodology developed to inventorying joint resources. The implementation is shown in a case study of the production of primary copper on a global average. The respective process is assessed with Eco-indicator 99 (H,A) to identify dominant impacts within the production chain.Methods In ecoinvent, a coupled production is inventoried in multi output unit processes. For database calculation, an allocation by economic revenue is applied. Elementary flows for resources, especially joint resources, include information on type and quality of the resources.Results and Conclusion With the presented method, the extraction of resources can be valuated based on the cost of restoration or the change in the future impact due to the extraction of a specific resource. The case study indicates, for copper / molybdenum production, that the mineral extraction is of minor importance compared to the metallurgical step according to the LCIA results. Air emissions of heavy metals are identified as main impacts. Also, the resource depletion shows a notable impact. The environmental impacts of metals from sulphidic ores, however, are underestimated by neglecting emissions from tailings for lack of reliable data.Recommendation and Perspective Impact assessment methods will have to be updated to account for different grades of ore. The ecoinvent database should be enlarged by more inventories of technically important metals and alloys, e.g. by gold, silver, solders, etc. for the electronics industry and by specific steel and aluminium alloys. Reliable composition data of sulphidic tailings and transfer coefficients for their disposal considering Acidic Rock Drainage (ARD) are to be developed as well. 相似文献
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Michael?SpielmannEmail author Roland?ScholzEmail author Olaf?Tietje Peter de?Haan 《The International Journal of Life Cycle Assessment》2005,10(5):325-335
Background Tools and methods able to cope with uncertainties are essential for improving the credibility of Life Cycle Assessment (LCA)
as a decision support tool. Previous approaches have focussed predominately upon data quality.
Objective and Scope. An epistemological approach is presented conceptualising uncertainties in a comparative, prospective, attributional
LCA. This is achieved by considering a set of cornerstone scenarios representing future developments of an entire Life Cycle
Inventory (LCI) product system. We illustrate the method using a comparison of future transport systems.
Method Scenario modelling is organized by means of Formative Scenario Analysis (FSA), which provides a set of possible and consistent
scenarios of those unit processes of an LCI product system which are time dependent and of environmental importance. Scenarios
are combinations of levels of socio-economic or technological impact variables. Two core elements of FSA are applied in LCI
scenario modelling. So-called impact matrix analysis is applied to determine the relationship between unit process specific
socio-economic variables and technology variables. Consistency Analysis is employed to integrate unit process scenarios, based
on pair-wise ratings of the consistency of the levels of socio-economic impact variables of all unit processes. Two software
applications are employed which are available from the authors.
Results and Discussion The study reveals that each possible level or development of a technology variable is best conceived of as the impact of
a specific socio-economic (sub-) scenario. This allows for linking possible future technology options within the socio-economic
context of the future development of various background processes. In an illustrative case study, the climate change scores
and nitrogen dioxide scores per seat kilometre for six technology options of regional rail transport are compared. Similar
scores are calculated for a future bus alternative and an average Swiss car.
The scenarios are deliberately chosen to maximise diversity. That is, they represent the entire range of future possible developments.
Reference data and the unit process structure are taken from the Swiss LCA database 'ecoinvent 2000'. The results reveal that
rail transport remains the best option for future regional transport in Switzerland. In all four assessed scenarios, four
technology options of future rail transport perform considerably better than regional bus transport and car transport.
Conclusions and Recommendations. The case study demonstrates the general feasibility of the developed approach for attributional prospective
LCA. It allows for a focussed and in-depth analysis of the future development of each single unit process, while still accounting
for the requirements of the final scenario integration. Due to its high transparency, the procedure supports the validation
of LCI results. Furthermore, it is well-suited for incorporation into participatory methods so as to increase their credibility.
Outlook and Future Work. Thus far, the proposed approach is only applied on a vehicle level not taking into account alterations in
demand and use of different transport modes. Future projects will enhance the approach by tackling uncertainties in technology
assessment of future transport systems. For instance, environmental interventions involving future maglev technology will
be assessed so as to account for induced traffic generated by the introduction of a new transport system. 相似文献
108.
Arpad Horvath 《The International Journal of Life Cycle Assessment》2006,11(4):229-239
Goal, Scope and Background This study provides a life cycle inventory of air emissions (CO2, NOx, PM10, and CO) associated with the transportation of
goods by road, rail, and air in the U.S. It includes the manufacturing, use, maintenance, and end-of-life of vehicles, the
construction, operation, maintenance, and end-of-life of transportation infrastructure, as well as oil exploration, fuel refining,
and fuel distribution.
Methods The comparison is performed using hybrid life cycle assessment (LCA), a combination of process-based LCA and economic input-output
analysis-based LCA (EIO-LCA). All these components are added by means of a common functional unit of grams of air pollutant
per ton-mile of freight activity.
Results and Discussion Results show that the vehicle use phase is responsible for approximately 70% of total emissions of CO2 for all three modes.
This confirms that tailpipe emissions underestimate total emissions of freight transportation as infrastructure, pre-combustion,
as well as vehicle manufacturing and end-of-life account for a sizeable share of total emissions. Differences between tailpipe
emissions and total system wide emissions can range from only 4% for road transportation's CO emissions to an almost ten-fold
difference for air transportation's PM10 emissions.
Conclusion Rail freight has the lowest associated air emissions, followed by road and air transportation. Depending on the pollutant,
rail is 50-94% less polluting than road. Air transportation is rated the least efficient in terms of air emissions, partly
due to the fact that it carries low weight cargo. It emits 35 times more CO2 than rail and 18 times more than road transportation
on a ton-mile basis. It is important to consider infrastructure, vehicle manufacturing, and pre-combustion processes, whose
life-cycle share is likely to increase as new tailpipe emission standards are enforced.
Recommendation and Outlook Emission factors, fuel efficiency, and equipment utilization contribute the most to uncertainty in the results. Further studies
are necessary to address all variables that influence these parameters, such as road grade, vehicle speed, and vehicle weight.
A focus on regional variation, end-of-life processes, fuel refining processes, terminals, as well as more accurate infrastructure
allocation between freight and passenger transportation would strengthen the model. 相似文献
109.
Leda Coltro Anna Mourad Paula Oliveira Jose Baddini Rojane Kletecke 《The International Journal of Life Cycle Assessment》2006,11(1):16-21
Goal, Scope and Background
Brazil is the world's biggest producer of coffee beans with approx. a 30% market share. Depending on climate conditions, approx. 30 million bags of coffee beans are exported annually from Brazil, while domestic consumption is around 10 million bags, which makes Brazil the world's third largest coffee-consuming country. Therefore, the goal of this paper is to present the LCA of green coffee produced in Brazil for the reference crops 2001/02 and 2002/03 in order to generate detailed production inventory data as well as to identify the potential environmental impacts of its tillage in order to realize how to reduce those impacts and increase the environmental sustainability of this product. Only the inputs and outputs relative to the coffee tillage were considered. The production of fertilizers, correctives and pesticides were not included in the boundary, but only their amounts. The functional unit selected for this study was 1,000 kg of green coffee destined for exportation.Methods
The LCI was performed according to the ISO 14040 standard series. All information considered in this study (use of water, fossil based energy, fertilizers and chemicals) were taken up in in-depth data collection and evaluation by questionnaires applied on a farm level and/or received by mail. Four Brazilian coffee producer regions were evaluated: Cerrado Mineiro, South of Minas Gerais State, the Marília and Alta Mogiana regions in São Paulo State. These regions have the following geographic coordinates: 44 to 50° W longitude and 18 to 24° S latitude. The data refer to a production of 420,000 coffee bean bags and a productive area of approx. 14,300 ha. The varieties of coffee beans considered in this study were Mundo Novo, Catuaí (yellow and red), Icatu (yellow and red), Catucaí (yellow and red) and Obatã. Farm specific data along with agricultural production data have been combined to elaborate a coffee cultivation inventory, which will be applied in an emissions estimation.Results and Conclusion
The production of 1,000 kg of green coffee in Brazil requires approx. 11,400 kg of water, 94 kg of diesel, 270 kg of fertilizers as NPK, 900 kg of total fertilizers, 620 kg of correctives, 10 kg of pesticides and 0.05 hectare of annual land use. Outputs related to these functional units are approx. 3,000 kg of waste water from coffee washing, 8,500 kg of waste water from the wet method and 750 kg of organic residue that is reincorporated to the tillage as fertilizer. The publication of an LCI of agricultural products is a fundamental step for understanding the potential environmental impacts of each tillage and then establishes the basis for product sustainability. In this way, this work is the first Brazilian initiative for applying LCA to coffee cultivation.Recommendation and Perspective
Different agricultural practices demonstrate different environmental profiles. The amount of agricultural pesticide is directly related to agricultural practices as tillage rotation, density of plants, etc. This study supplied important results for a better correlation of the agricultural practices and potential environmental impacts of coffee. Future updates of this study will show the evolution of the natural resource management such as land use, new agricultural practices, lower fertilizers and chemicals use. 相似文献110.
采用法瑞地植物学派的样地调查法记录了澜沧江中上游河谷中一独特的硬叶小叶常绿阔叶林类型——锈鳞木樨榄、清香木群丛。该群丛由南向北分布于1300~1900m的河谷下部,对群落外貌、生活型与生长型、植物种类科属的组成、分布区类型等进行了分析。结果表明:(1) 群落结构简单,物种数平均为18种;(2) 生活型以高位芽植物居多,生长型以草本居多;(3) 群落中计有维管植物116种,隶属于39科,84属;(4) 植物科级、属级水平上均显示出了热带性质,植物区系表现出一定的古老性,反映了与古地中海硬叶小叶林的历史渊源。该植物群丛适应澜沧江干热-干暖河谷气候,分布区域狭窄,是一类值得重点保护和深入研究的植被类型。 相似文献