经济快速增长区城市用地空间扩展对生态安全的影响

目前我国正处于经济快速发展、城市化进程加快阶段,承受着生态环境恶化的巨大压力,大多数城市已为环境污染、空间拥挤、绿化率低、秩序混乱等严重的城市问题所困扰.昆山市作为我国经济发展最为活跃的地区之一,其城市化过程与生态环境安全之间的矛盾更为突出.在总结国内外生态安全和城市生态研究的基础上,分析城市用地扩展对城市生态安全产生的影响.昆山市城市用地空间扩张经历了缓慢发展期(1949～1977年)、老城区改造期(1977～1985年)、新区开发期(1985～1999年)和快速扩展期(1999年至今)4个阶段,针对城市土地利用变化特征及其城市土地利用存在的问题,对昆山市城市用地空间扩展进程和模式及扩展的主要特征方面进行剖析.从城市废水、废气和固废排放量几个方面分析了昆山城市用地空间扩展过程中生态环境变化情况,指出高速工业化、城市化过程,快速增长的经济可能威胁到昆山城市的生态安全.同时建立城市生态安全评价模式,构建城市生态安全评价的指标体系,探讨城市生态安全评价的方法,评价了昆山市1985～2004年的城市生态安全,最后对昆山市未来城市生态安全进行预警.为维护昆山市的生态安全,实现可持续发展提供科学依据.     

基于乡镇尺度的土地生态安全时空格局评价研究——以博尔塔拉蒙古自治州为例

近年来,国内外学者已做了大量区域土地生态安全评价的研究,但大多针对流域或县级以上行政单元,乡镇尺度的土地生态安全评价研究甚少。因此,选择地处我国西北干旱生态脆弱区的博尔塔拉蒙古自治州为研究区,以"3S"技术和数学统计方法为支撑,结合研究区自然地理特征和社会经济状况,构建博尔塔拉蒙古自治州乡镇级压力-状态-响应(Pressure-StateResponses,P-S-R)土地生态安全评价模型,并对其土地生态安全空间格局特征及成因进行诊断性分析。结果表明:(1)2014年博州土地生态安全较2011年有所恶化,Ⅲ级向Ⅳ级转化的面积最大,高达2555.33 km~2,主要在温泉县境内,其次是Ⅴ级区域向Ⅳ级转化1356.53 km~2,主要发生在精河县的茫丁乡和托托乡;(2)博州大部分乡镇的土地生态安全状况处于Ⅲ级水平,区域生态结构不稳定,亟待调整;(3)博州土地生态安全状况具有明显地域性分布的特征,低值区多集中于博州东部荒漠地区,高值区多集中在博州中部绿洲区域和湖区。研究结果可为乡镇级土地生态安全评价提供参考,为区域生态保护协调推进与乡镇可持续发展提供理论指导。     

Ecological intensification to mitigate impacts of conventional intensive land use on pollinators and pollination

Worldwide, human appropriation of ecosystems is disrupting plant–pollinator communities and pollination function through habitat conversion and landscape homogenisation. Conversion to agriculture is destroying and degrading semi‐natural ecosystems while conventional land‐use intensification (e.g. industrial management of large‐scale monocultures with high chemical inputs) homogenises landscape structure and quality. Together, these anthropogenic processes reduce the connectivity of populations and erode floral and nesting resources to undermine pollinator abundance and diversity, and ultimately pollination services. Ecological intensification of agriculture represents a strategic alternative to ameliorate these drivers of pollinator decline while supporting sustainable food production, by promoting biodiversity beneficial to agricultural production through management practices such as intercropping, crop rotations, farm‐level diversification and reduced agrochemical use. We critically evaluate its potential to address and reverse the land use and management trends currently degrading pollinator communities and potentially causing widespread pollination deficits. We find that many of the practices that constitute ecological intensification can contribute to mitigating the drivers of pollinator decline. Our findings support ecological intensification as a solution to pollinator declines, and we discuss ways to promote it in agricultural policy and practice.     

An ecological network analysis of the structure,development and sustainability of China’s natural gas supply system security

Mitigating the impacts of climate change and ensuring energy supply security has compelled China’s policy makers to maximise the use of alternative and low carbon fuels. Use and production of natural gas (an energy source with low carbon emissions) has experienced remarkable growth in China during the last decade, making China the third largest consumer and importer in the world. This study applied a powerful system-oriented ecological network analysis (ENA) technique to study China’s natural gas policies as they pertain to guarantee supply security. Several indicators based on the ENA were measured to analyse the degree of connectivity, the contributions of different compartments, resource utilisation (aggradation), development (ascendancy) and sustainability of China’s natural gas supply system. It was found that China’s source and route diversification policy have caused the natural gas supply system to exhibit considerable network complexity, demonstrating the high level of development, flexibility and diversity of China’s natural gas supply system. However, the policy also has caused a decrease in the aggradation and sustainability from the perspective of an ecological system network. The most important compartments in terms of their contribution to China’s natural gas supply system were found to be domestic natural gas production and transit compartments.     

Food consumption and related water resources in Nordic cities

Many modern cities have strongly invested in the sustainability of their urban water management system. Nordic cities like Stockholm or Copenhagen are amongst pioneers in investments towards integrated urban water management. However, cities can never be fully self-sufficient due to their dependency on external (water) resources. In this paper, we quantify this water dependency with respect to food consumption in nine cities located in the five Nordic countries (Sweden, Denmark, Finland, Norway and Iceland), by means of the water footprint concept. Detailed urban water footprint assessments are scarce in the literature. By analysing national nutrition surveys, we find that urban food intake behaviour differs from national food intake behaviour. In large Nordic cities people eat generally less potatoes, milk products (without cheese), meat and animal fats and they drink less coffee than outside city borders. On the other hand, they generally eat more vegetables and vegetable oils and they drink more tea and alcoholic beverages. This leads consistently – for the six large Nordic cities Stockholm, Malmö, Copenhagen, Helsinki, Oslo and Reykjavik – to slightly smaller food related urban water footprints (−2 to −6%) than national average values. We also analyse the water footprint for different diets based upon Nordic Nutrition Recommendations (NNR) for these cities. We assessed three healthy diet scenarios: 1) including meat (HEALTHY-MEAT), 2) pesco-vegetarian (HEALTHY-PESCO-VEG) and 3) vegetarian (HEALTHY-VEG). This shows that Nordic urban dwellers 1) eat too many animal products (red meat, milk and milk products) and sugar and drink too much alcohol and 2) they eat not enough vegetables, fruit and products from the group pulses, nuts and oilcrops. Their overall energy and protein intake is too high. A shift to a healthy diet with recommended energy and protein intake reduces the urban WF related to food consumption substantially. A shift to HEALTHY-MEAT results in a reduction of −9 to −24%, for HEALTHY-PESCO-VEG the reduction is −29 to −37%, for HEALTHY-VEG the reduction is −36 to −44%. In other words, Nordic urban dwellers can save a lot of water by shifting to a healthy diet.     

Identifying ecologically valuable and sensitive areas: a case study analysis from China

The expansion of artificial constructs with the rapid economic development in China has led to ecological and environmental emergencies. The extent of the decline in natural resources and environmental conditions has recently been recognized. Identifying “ecological protection redlines”, i.e. ecological limits, to guarantee ecological baselines for natural resources and ecosystem service functions would therefore help to coordinate economic development and to protect ecological resources in the coming years. We used remotely sensed and climatic data to delimit the ecological protection redlines for Zibo, a typical and important city in Shandong province, as an example to illustrate the principles and methodology of ecological protection redlines. The area of the ecological protection redlines for Zibo encompassed 1132.26 km², accounting for 18.98% of the total area of Zibo, were mainly distributed in the southern regions of the municipality, and consisted of extremely important areas of ecosystem service functions, including water conservation, both soil and water conservation, windbreaks and sand fixation, and the conservation of biodiversity. This area is extremely sensitive, and development is forbidden. Strict measures of management and control should be implemented to protect the long-term effectiveness of ecological protection redlines.     

基于焦点物种的北京市生物保护安全格局规划

快速城市化进程中,城市及周边地区生物栖息地的丧失和破碎化对生物多样性保护构成严重威胁。如何在景观尺度上判别对于生物保护具有重要意义的栖息地及其空间格局成为了重要问题。选取快速城市化的典型地区——北京市作为研究对象,将焦点物种和景观安全格局方法相结合,对北京市生物保护安全格局进行判别和规划。根据焦点物种的定义和选取标准,将在栖息地类型、生物学特征等各方面具有代表性的大白鹭(Casmerodius albus)、绿头鸭(Anas platyrhynchos)、环颈雉(Phasianus colchicus)选作北京市的焦点物种,应用最小阻力模型和GIS空间分析技术,对焦点物种的栖息地适宜性进行分析,并建立物种运动的等阻力面,根据阻力面的空间特征对北京市生物保护安全格局进行规划。结果显示:规划后的安全格局的斑块数量、分离度、邻近距离显著下降,平均斑块面积和最大斑块指数显著上升;该格局用约60%的土地,保护了北京市主要生境类型及关键性空间格局,可有效缓解栖息地丧失和破碎化的问题,从而达到保护整体生物多样性的目的。这一研究方法和成果可为北京市生物多样性保护和城乡生态建设提供决策依据,也对同类研究具有借鉴价值。     

我国珍稀濒危植物保护红线的划定

本文依据《国家生态保护红线——生态功能基线划定技术指南(试行)》原则和植物保护的具体情况, 探讨了我国珍稀濒危植物保护红线划定的原则与方法。研究选取《国家重点保护野生植物名录》中收录的所有物种作为研究对象。将其定义为红线保护植物, 其中的I级保护植物定义为红线关键植物, 并基于文献资料及标本记录等数据建立了我国植物的属性数据库和地理分布数据库。在GIS支持下, 以建立的数据库为基础研究了我国红线保护植物的地理分布特征; 基于保护生物学理论, 结合我国自然保护区的就地保护现状进行了分析和评价; 以热点地区和GAP分析为理论基础, 在其分布地中识别具有代表性的热点区域以及不同属性植物分布的重点区域, 进而结合土地利用和人类干扰因素, 划定我国珍稀濒危植物生境整体保护的红线。通过在全国尺度上的分析, 得出我国珍稀濒危植物的整体保护红线面积为71.63万km², 占陆域国土面积的7.45%。植物生境保护红线划定的原则、方法和划定方案的研究对于更准确地划定生态安全预警红线具有重要意义, 同时可以为我国国土生态安全格局的构建提供依据。