Identification of biomes affected by marginal expansion of agricultural land use induced by increased crop consumption

In a previous study, the global agricultural expansion caused by wheat consumption in four different countries was modelled with the aim of establishing land use life cycle inventories. The previous study estimated the areas affected by expansion (in terms of square meters) but did not explain how to characterise these areas. The present study ascribes so-called biomes (natural potential vegetation) to the areas affected by agricultural expansion in order to provide a basis for assessing the environmental impacts from land use in the life cycle impact assessment (LCIA). The methodology builds on agricultural statistics and maps of global agricultural areas and the global distribution of biomes. The application of the method is illustrated with four examples. The results indicate that agricultural expansion on land suited for crop cultivation (cultivable land) typically affects forest biomes or potential grassland/steppe, whereas expansion on land suited for grazing but not for crop cultivation (grazable land) typically occurs on potential shrubland or a few other biomes depending on the region. Some uncertainty applies to the results but it is concluded that it is feasible to identify biomes affected by agricultural expansion and that the biomes can therefore be used as a starting point for land use LCIA.     

Environmental impacts of farm scenarios according to five assessment methods

It is not known to what extent the outcome of studies assessing the environmental impacts of agricultural systems depends on the characteristics of the evaluation method used. The study reported here investigated five well-documented evaluation methods (DIALECTE, Ecological Footprint, Environmental Management for Agriculture, FarmSmart, Life Cycle Assessment) by applying them to a case study of three pig farm scenarios. These methods differ with respect to their global objective (evaluation of impact versus evaluation of adherence to good practice), the number and type of environmental issues they consider, the way they define the system to be analysed, the mode of expression of results (for the farm as a whole, per unit area or per unit product) and the type of indicators used (pressure, state or impact indicators). The pig farm scenarios compared were conventional good agricultural practice (GAP), a quality label scenario called red label (RL) and organic agriculture (OA). We used the methods to rank the three scenarios according to their environmental impacts. The relative ranking of the three scenarios varied considerably depending on characteristics of the evaluation method used and on the mode of expression of results. We recommend the use of evaluation methods that express results both per unit area and per unit product. Environmental evaluation methods should be used with great caution, users should carefully consider which method is most appropriate given their particular needs, taking into consideration the method's characteristics.     

生物液体燃料发展的环境影响研究进展

第二代生物燃料生产技术已发展起来,有关生物液体燃料发展的环境影响研究,毁誉参半、争论激烈。论文在查阅大量国内外相关文献的基础上,评述了生物液体燃料的发展进程及其对温室气体减排、水土资源及生物多样性等方面的影响,并就生物液体燃料环境影响的研究趋势与发展方向进行了讨论。研究认为:①一些学者认为,就温室气体减排来看,尽管效益不同,但生物液体燃料均在一定程度上减轻了温室气体排放。也有学者认为生物液体燃料与化石燃料相比并没有减少温室气体排放,甚至更糟。②大规模的能源作物集约种植消耗了大量水资源,污染了地下水,破坏了土壤碳库,降低了土壤肥力,加剧了水土流失。此外,土地利用方式改变造成的潜在影响具有很大的不确定性。但也有研究表示选择合适的能源物种及科学的耕作方式也有可能对水土资源带来积极的影响。③生物液体燃料发展对生物多样性产生了危害,但恰当的管理方式亦可能带来正效益。导致研究结论差异巨大的原因主要在于研究角度与尺度不同、研究方法的复杂性和数据的精度及可获得性等。明确边界、统一路径,细化指标、规范标准,系统分析、定量评价应是生物液体燃料的环境影响研究的发展方向。     

城市化水文效应研究进展

受人类活动特别是城市化的影响,天然水文过程发生了显著变化。目前城市化的水文效应研究已经成为国际上的热点问题和前沿领域。文章回顾了国内外城市化过程所引起的水文效应研究现状,述评了现有研究方法和主要研究内容:①城市化对降水的影响具有地区差异和季节差异,其影响程度还存在争议,城市化降水效应机理有待研究;②城市化地区河网结构趋于简单,目前平原河网地区水系分级方法不明确;③不透水面变化改变长期径流量、水质以及暴雨洪水洪峰流量、洪峰过程,其定量关系的阈值需要确立;④变化下垫面条件下流域生态系统结构和功能,水文过程与生态过程耦合需要进一步研究。最后提出了存在问题和进一步研究的思路,以便作为城市水文学研究的参考。     

快速轨道交通规划环境影响评价方法及实例研究

规划环境影响评价属于战略环境影响评价的范畴,其评价方法尚处于发展之中.对现有的规划环境影响评价方法进行了概述,并以某城市快速轨道交通规划环境影响评价实例为基础,对规划环境影响评价方法进行探讨.在环境影响界定的基础上,初步建立了由土地与环境敏感区、噪声、振动、水资源和电磁辐射五方面构成的快速轨道交通线网规划环境影响评价指标体系.同时以振动为例,对情景分析法在环境影响预测中的应用进行了说明.      

澜沧江流域云南段土地利用格局变化及环境影响分析

应用1986与2000年TM遥感影像解译生成的澜沧江流域云南段土地利用现状图,在ArcGIS 8.3软件的支持下,进行图形叠加、空间分析和数据统计分析,获取该流域1986-2000年土地利用格局变化图和面积转换矩阵,揭示了该流域1986和2000年土地利用与土地覆被的空间分布规律及14年来的变化特征,并对澜沧江流域云南段14年来土地利用变化对环境产生的影响进行分析.结果表明,澜沧江流域云南段土地利用格局的变化引发了流域水土流失、生物多样性降低、景观破碎化等一系列环境问题.      

Method for assessing impacts on life support functions (LSF) related to the use of ‘fertile land’ in Life Cycle Assessment (LCA)

Degradation of soil quality is a major concern due to the scarcity of fertile land, and needs to be properly addressed in the environmental assessment of agro-forestry systems. This paper addresses the main issues arising in assessing the impacts of fertile land use on “Life Support Functions” in Life Cycle Assessment (LCA). These issues include the assessment of occupation and transformation impacts, the references against which such impacts should be measured, and the concept of natural relaxation versus backup technology for recovery from the impacts. The alternative (or reference) situation is defined using the concept of consequential LCA, which facilitates clarification of the allocation issues arising due to successive land uses. This paper presents soil organic matter (SOM) as a robust indicator for soil quality; even though it does not fully consider all aspects of soil functioning, SOM has been often recognised as the best stand-alone indicator for soil quality. Impacts on biodiversity are not included in this indicator and should be assessed in parallel. Alternative data sources for practical implementation of the method are suggested in a hierarchical way, including locally specific data sets describing changes in SOM; mechanistic models for the prediction of SOM evolution; and general data sources for simplified analyses. Thanks to its flexibility in data collection the method is applicable to any agricultural or forestry LCA to fill an important gap in Life Cycle Impact Assessment (LCIA) of land use.     

Mapping and modelling of changes in agricultural intensity in Europe

Spatial maps of agricultural intensity are needed for analyses of environmental issues, including biodiversity changes. We present a method to produce such maps for Europe. While most studies beyond farm level focus on land cover change only, this paper focuses on spatial variation in land use intensity and its dynamics.Our method defines agricultural land use intensity in terms of nitrogen input. For arable land, it combines field observations with administrative-level statistics to assess probability of occurrence for three land use intensity classes. For grassland, it uses maps of livestock density to assess probability of occurrence for two intensity classes. Agricultural land is spatially allocated to intensity classes using an algorithm that downscales intensity changes simulated with an agricultural economic model.Our results are 1 km² resolution maps of classified agricultural land use intensity in the year 2000. We illustrate the method by exploring changes in the spatial pattern of land use intensity for a financial policy reform scenario in the year 2025. Results indicate spatial heterogeneity in land use intensity across European countries, including large differences in intensity between countries, between regions, but also within regions.Our method could be improved with smaller-resolution agricultural statistics and broader intensity indicators.     

Biodiversity of the ground-dwelling spider fauna of afforestation habitats

The aim of this study was to assess spider diversity among habitats that are typically used for afforestation in Ireland, and to identify habitat parameters which could potentially be used as indicators of their biodiversity value. Ground-dwelling spiders were surveyed in 24 sites across Ireland, with eight sites of each of the following habitat types: improved grassland, wet grassland and peatland. The spiders were sampled using pitfall traps which were located within the major vegetation types present in each site as well as within supplementary habitat features which may add to biodiversity value of the whole site such as hedgerows, flushes and the edges of ditches and streams.Each habitat supported distinct spider assemblages that reflect major differences in both environmental conditions and management regime. The improved grasslands had low spider species richness and low variation in assemblage structure which is probably related to the intensive management of this habitat. In this case hedgerows maybe an important aspect of the spider diversity within agricultural landscapes. The peatlands, and to a lesser extent wet grasslands, supported a diverse and specialist spider fauna, including a number of rare species; this may be due to differences in soil moisture and plant architecture. Indicators of biodiversity value identified included wet flushes in the peatlands and low grazing pressure in the wet grasslands. This study suggests that in terms of biodiversity value improved grassland is the preferable habitat for afforestation, because of the poor baseline spider diversity. However, it may be unrealistic to expect land owners to afforest their most productive agricultural land, so the management and habitat indicators identified in this study may be of use for assessing habitat quality among the wet grassland and peatlands to allow sites with lower biodiversity value to be identified.     

Characterizing the change of land-use based on flora: application for EIA and LCA

The environmental impact of land-use can be expressed in terms of a change in biodiversity of flora. We present two models that characterize the negative effects of land-use: a model on the basis of species richness; a model on the basis of the rarity of ecosystems and their vascular plants. Each of those models may serve in the EIA (environmental impact assessment) of the urban and rural planning of expanding cities, industrial areas, road infrastructure, etc. Moreover, these models might be applied by Life Cycle Analysis (LCA) practitioners to incorporate the aspect of land-use in the environmental assessment of a specific product design. The results of both models have been applied in practice. Maps of The Netherlands are provided for both models. The map based on the rarity of ecosystems differentiates the best of what experts (biologists and ecologists) define as botanical quality of nature; the methodology is operational in The Netherlands and might be applied to other countries as well, however, detailed botanical information is required. The map based on species richness has a weaker compliance with the botanical quality of nature, however, the model can more easily be applied to a wider area of the world, since indicative data about species richness is available on a global scale. The so called ‘eco-costs of land conversion’ is proposed as a single indicator, being the marginal costs of prevention (or compensation) of the negative environmental effects on biodiversity caused by change of land-use. These ‘eco-costs of land conversion’ for the botanical aspects are part of the much broader model of the eco-costs/value ratio, which has recently been published in this journal [Vogtländer et al., Journal of Cleaner Production 2002;10:57–671].     

Ecological planning for land use and ruraldevelopment of Taojiang County

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乌鲁木齐都市圈空间变化及其发展模式研究

以乌鲁木齐都市圈为例，基于1989-2002年的LandsatTM/ETM＋卫星影像和多期城市用地信息，运用GIS空间分析功能研究了都市圈宏观与微观层次的空间变化，得出以下结论：①1989-2002年间研究区内面积增加的用地主要有农业用地、城镇用地、农村居民点与道路，增加的部分主要来源于裸地、天然植被和原有农业用地。农业用地、城镇、农村居民点和道路向北部冲积平原扩张的趋势明显，建设用地的迅速扩张在一定程度上加剧了干旱区景观的破碎化。②1998-2006年间，都市圈内各城市用地面积总体上增幅不大，但是每个城市在某些局部方位用地增幅显著，并且有向核心城市趋近的现象。核心城市乌鲁木齐主要功能用地具有一定的圈层分布特征，周边中小城市还未形成圈层结构，但是昌吉和米泉在城市外围已有较为成型的工业集中区。③都市圈在空间发展中存在核心城市拓展受限、脆弱的生态格局受到胁迫和用地不合理布局的问题，针对这些问题提出区域发展“一体化”、城镇格局“大聚小散”和职能空间“重组化”的构想。     

城市用地扩张、规模经济与经济增长质量

城市用地扩张不仅影响经济增长数量,还通过产业结构升级、城市化、生态环境变化和规模经济等路径影响区域经济增长质量。城市用地扩张,促进市场范围扩大,有利于区域内与区域间开展分工合作,提升城市的集聚经济效益与规模经济水平;但若城市用地扩张使区域突破最优规模经济状态后,因管理与服务成本、交通成本和环境成本等快速增加,城市规模效率会下降,对经济增长质量产生负影响。实证研究结果表明:在全国、中部和西部地区3个空间维度,城市用地扩张与规模效率间存在倒U型关系,而在东部地区此关系并不成立;在4个空间维度,城市用地扩张通过规模经济路径对全要素生产率的影响都为负,表明城市用地扩张已使各区域突破最优规模经济状态,土地要素投入存在冗余现象,与资本、劳动等要素配置比例非最优。研究结果还表明,人力资本、城市化、产业结构升级、基础设施等变量对经济增长质量有正影响。     

生态适宜的城市发展空间分析方法与案例研究

综合运用生态功能区划方法和土地建设适宜性分析技术,基于地理信息系统平台建立了生态适宜的城市发展空间区域(生态主导功能区)的划分方法,依据生态保护原则和土地开发适宜度,将城市生态主导功能区划分为禁止、限制、优化和重点开发区4种类型.介绍了该方法在大连市的应用.结果表明,大连市禁止、限制、优先和重点开发区面积分别占全市域土地面积的56%、19%、12%和13%.     

滇池流域主要农业产品水足迹空间格局及其环境影响测度

科学合理的评估农业产品水资源消耗及其环境影响对保护区域农业生产安全和水资源合理配置具有重要意义.本文以滇池流域为例,耦合水足迹和生命周期评价方法,对流域内2005—2011年主要农业产品水足迹空间格局进行分析,并对其环境影响进行测度.结果显示:滇池流域主要农作物和动物产品年平均水足迹分别为4.88×108m3·a-1和8.97×108m3·a-1,动物产品总水资源消耗大于农作物产品.动物产品水足迹的人类健康和生态系统质量总环境影响高于农作物,但资源消耗总环境影响要低于农作物,各区县产品水足迹环境影响值最大的为猪肉、水稻和玉米.各区县主要产品水足迹及其环境影响空间差异显著,嵩明县和晋宁县的产品水足迹环境影响最高,城区则较低.本文最后提出:评价一种产品对区域水资源的可持续性影响时,不仅要考虑产品耗水量也应考虑产品对水资源产生的潜在环境影响大小,应从水资源管理和生命周期角度综合考虑.水资源量少的地区,应侧重选择水资源消耗量小的产品,水量充沛地区则应选择对人类和生态产生影响小的产品.     

快速城市化对区域生态环境影响的时空过程及评价

综合景观生态学与地统计学方法,尝试构建基于"遥感(RS)数据分类→土地利用变化制图→景观格局分析→GIS地统计分析"的区域环境影响评价方法,定量研究了区域环境变化的时空变化特征.案例研究采用2000、2004和2006年遥感数据,监测快速城市化背景下连云港港湾地区城市用地扩张特征、盐田湿地损失、填海造地(港口扩建等)以及耕地退化等关键的区域环境变化,分析评价了区域景观格局特征和生态环境效应,进而评价了快速城市化背景下区域环境影响强度的时空分异.在城市规划和区域发展战略驱动下,整个区域环境影响强度分布及变化规律与城市扩张强度与方向基本一致,高环境影响强度区是受人类干扰最大、生态系统最脆弱以及环境被破坏程度最深的部分,也是当前和未来进行环境调控重点地区.     

Development of LCIA characterisation factors for land use impacts on biodiversity

The UNEP/SETAC life cycle initiative has recently proposed a framework for life cycle impact assessment (LCIA) of land use. Still, a lack of appropriate LCIA-methods for assessing land use impacts exist in life cycle assessment (LCA). Most existing methods are either too coarse-grained regarding the differentiation between different land use types (e.g. conventional farming versus organic farming), or they are too narrow regarding spatial coverage (e.g. only part of Europe). Therefore, the purpose of this article is to develop a method that overcomes these problems. A secondary goal is to develop a method for which it is possible to determine characterisation factors for any land use type in any region without the need for overwhelming data and data manipulation requirements. The developed method for LCIA of biodiversity focuses on species richness of vascular plants which can be determined from species–area curves. The category indicator is calculated as the multiplication of occupied area, the number of species affected per standard area (100 m²), the duration of occupation and renaturalisation from transformation, and a factor for ecosystem vulnerability. The main uncertainties of the method are related to the determination of renaturalisation times and the establishment species–area curves. The intention of the study presented in this article, i.e. to develop an applicable model with global coverage and no constraints on resolution regarding spatial and land use type differentiation, has widely been met. The limiting factor for applicability is the access to species richness surveys for the relevant regions and land use types. But still, the method shows that, with limited efforts, it is possible to calculate characterisation factors for a large range of land use types in different parts of the world.     

基于遥感的SDG 15.1.2生物多样性指标计算与分析:以长三角生态绿色一体化发展示范区为例

生物多样性评价为生物多样性保护提供重要的参考价值,联合国可持续发展目标(SDGs)中15.1.2指标对此提出了具体要求. 本研究借助遥感技术,以长三角生态绿色一体化发展示范区(简称“示范区”)为研究区,选取物种多样性层次、生态系统多样性层次和景观多样性层次的7个指标(生境质量指数、增强型植被指数、水网密度指数、生境面积百分比、辛普森多样性指数、景观分离度指数、蔓延度指数)构建生物多样性评价指标体系,实现了对研究区生物多样性的量化计算及生物多样性评估. 结果表明:①研究区生物多样性指数平均值为0.42,生物多样性高等级区域面积为526.65 km2,占研究区陆地面积的27.38%;研究区共28个乡镇,其中生物多样性高等级区域占乡镇陆地面积比例大于50%的乡镇有两个,分别是青浦区的华新镇和香花桥街道. ②探究了土地利用方式和城市不透水面占比对生物多样性的影响,生物多样性受人类活动干扰较为严重,不透水面占比与高等级生物多样性占比呈负相关,在植被稀少的城市和工业区域生物多样性等级较低. 研究显示,SDG 15.1.2指标区域得分为27.38分,距离实现2030年生物多样性可持续目标还面临一定的挑战;同时,该研究旨在构建县级区域生物多样性现状的评价指标体系,从而为SDGs指标本地化提供理论参考.      

城市土地置换过程中土壤有机污染物健康影响度评价

城市化过程中日益严峻的土壤污染已成为制约城市土地可持续开发利用的主要因素,而有机物已成为土壤中重要的污染物. 在我国目前缺乏相关环境质量标准的背景下,选择某区域土地置换开发为案例,尝试采用人体健康影响度评价法,对城市土地置换中土壤有机污染物可能给未来入住人群健康带来的潜在危害进行了分析与定量评价,识别出该区域土壤有机污染物以2,4-二硝基酚、五氯酚以及PAHs为主. 需要指出的是,参与评价的有机污染物仅为被检出有机污染物总量的一部分,因此评价结果中的健康影响度可能较实际数值偏低. 随着环境管理工作的深入进行,在城市土地置换过程中应逐步加强环境健康风险评价的研究. 