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1.
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.  相似文献   
2.
We respond to a reaction of the Global Footprint Network/GFN on our 8-point criticism of the ecological footprint. We also refer to, and comment on, an associated debate in this journal between Giampietro and Saltelli, 2014a, Giampietro and Saltelli, 2014b, on the one hand, and Goldfinger et al. (2014), on the other. We conclude that criticism on the footprint is accumulating and coherent across the various studies and disciplines and among the different authors. This was the first time that Wackernagel/GFN systematically responded to our criticisms. Hence, our response contains several original elements and the resulting exchange can be seen to add value to the existing literature. It ultimately allows readers to better make up their mind about the different viewpoints on the ecological footprint.  相似文献   
3.
啮齿类取食的物种偏好与时空格局   总被引:2,自引:1,他引:1  
沈泽昊  唐圆圆  李道兴 《生态学报》2008,28(12):6018-6024
通过强烈消耗土壤种子库,动物取食种子对植物种群更新和群落动态产生深远的影响。一般认为种子被食概率的空间格局取决于种子密度和离母树的距离,而环境(如地形)异质性的影响则一直没有得到足够的关注,与此相关的机制及其影响程度亦不清楚。研究设计在野外埋放种子以模拟种子扩散后的情形,监测啮齿类对种子的取食,以检验种子取食受埋藏生境、时间及动物对种子种类的偏好等因素的影响。结果表明,经过1a实验,8种落叶阔叶树种子的累计取食概率为0~48.25%,平均值为20%;山顶部位的取食概率大致是其它部位概率的3倍;埋放在凋落物层中的种子被食概率大约为埋放在土壤层中概率的2倍。利用logistic回归模型进行统计分析表明,种子被食概率变化的45%可以被上述因素解释。其中,物种偏好是影响种子被取食概率的首要因素,其后依次是地形、埋藏时间和深度。啮齿类明显喜好较大的种子;其取食行为在山脊部位明显较其它部位更频繁和剧烈;对埋藏种子的取食从3月份开始加剧,到7月份以后平息下来。种子埋放深度对啮齿类的取食概率有显著影响。  相似文献   
4.
The distribution patterns of the leathery sea anemone, Heteractis crispa, which contains an algal endosymbiont (zooxanthellae) and anemonefish, were investigated in relation to size distribution on a shallow fringing reef (3.2 ha, 0–4 m depth) in Okinawa, Japan. Individual growth and movements were also examined. Large individuals (>1,000 cm2) inhabited reef edges up to a depth of 4 m, while small anemone (<500 cm2) inhabited shallow reefs including inner reef flats. Individuals rarely moved, and their sizes were significantly correlated with their water depths. Growth of small anemones was negatively correlated with their distance from the reef edge, suggesting that reef edges provide more prey and lower levels of physiological stress. This study suggested that deep reef edges are suitable habitats for H. crispa. Large anemones were inhabited by large Amphiprion perideraion or large Amphiprion clarkii, both of which are effective defenders against anemone predators. Anemones that settle in deep reef edges may enjoy a higher survival rate and attain a large size because of their symbiotic relationship with anemonefish. However, early settlers do not harbor anemonefish. Their mortality rate would be higher in the deep edges than in shallow edges, the complicated topography of which provides refuge.  相似文献   
5.
Trap sampling over reefs in deep (mean = 20 m) and shallow (mean = 10 m) waters along c. 1500 km of coastline in tropical north‐western Australia during both day and night and in wet and dry periods yielded 23 377 fishes, representing 32 families, 58 genera and 119 species. Individuals of the Serranidae, Lutjanidae, Lethrinidae and Carangidae contributed 88·9% to the total catch. The ichthyofaunal compositions of the Kimberley, Canning and Pilbara bioregions were relatively discrete. Species composition was influenced far more by location (latitude) than by water depth, period and time of day, and underwent a gradational change southwards. The latter change reflected differences in the trends exhibited by the relative abundances of certain species with increasing latitude and the confinement of other species largely to particular regions. The three most abundant species, i.e. Lethrinus sp. 3, Lutjanus carponotatus and Lethrinus laticaudis contributed 34·8, 20·8 and 11·6% to the total catch, respectively. The first species was rarely recorded in the two most northern locations and was abundant in the four most southern locations, whereas the last two species were relatively more abundant in northern than in southern locations. Lutjanus bitaeniatus and Lutjanus johnii were found exclusively at the two locations in the Kimberley region, whereas Abalistes stellatus, Pentapodus emeryii and Lethrinus nebulosus were not caught in this region but were found in both locations of the Canning and Pilbara regions. The species composition in deep and shallow waters at each location almost invariably differed significantly between day and night and between dry and wet periods, with species such as L. bitaeniatus, L. johnii, Lutjanus sebae and A. stellatus being more abundant over deep reefs, whereas L. carponotatus, L. laticaudis, Siganus fuscescens and Lethrinus lentjan were more numerous over shallow reefs. Species such as L. johnii and Lethrinus atkinsoni were relatively more important in night‐time than daytime catches, whereas the reverse applied to Lethrinus lentjan, L. laticaudis and Choerodon cyanodus. Lethrinus sp. 3 and L. laticaudis were relatively more important in catches during the dry than wet period.  相似文献   
6.
真光层深度的遥感反演及其在富营养化评价中的应用   总被引:2,自引:0,他引:2  
乐成峰  李云梅  查勇  孙德勇  王莉珍 《生态学报》2008,28(6):2614-2614~2621
真光层深度直接影响水体中浮游植物的分布和初级生产力以及水体生态环境,是水生态研究的一个重要参数.利用2006年10月24日~11月2日太湖水下实测光谱数据和光合有效辐射(PAR)数据,通过数据的处理和分析,尝试建立真光层深度与水面以下遥感反射率的关系模型,并利用真光层深度与透明度的关系,建立水体富营养化真光层深度评价模型.研究结果表明:真光层深度与归一化遥感反射率具有很好的相关性;选用特定波段的归一化反射率作为变量,建立两者的关系模型能较好的反演真光层深度,所建立的模型算法中,指数模型拟合方程的综合效果好于其他模型,波段比值算法反演精度要好于单波段算法;利用利用真光层深度进行富营养化评价具有一定的应用价值,利用该模型对太湖水体进行富营养化评价,得出太湖西部湖区大部分已富营养化,东部湖区处于中营养化和轻度富营养化状态.  相似文献   
7.
A rCHO cell line of DUKX origin 26*-320, producing recombinant antibody against the human platelet, was cultivated in a two-stage depth filter perfusion system (DFPS) for 20 days in order to attain high recombinant antibody concentration. The productivity of the first stage DFPS bioreactor reached 53 times that of the batch culture in a controlled stirred tank reactor and was showed 12.1 mg/L antibody concentration at a perfusion rate of 6.0 d−1. Glucose concentration in the first DFPS was maintained at 1.5 g/L to avoid cell damage in the perfusion culture. A second stage DFPS system was attached to the first DFPS, which resulted in a low glucose concentration of 0.02 g/L and a high antibody concentration of 23.9 mg/L. The two-stage depth filter perfusion culture yielded 60% higher product concentration than the batch and 49-fold higher productivity of 69.3 mg/L/d in comparison with that (1.4 mg/L/d) in a batch system. Furthermore, antibody concentration of the second stage was 97% higher than that of the first stage, and the antibody productivities were comparable to that of the first stage. This two-stage DFPS system also showed potential for higher titer production of recombinant antibody and high volumetric productivity for long-term culture of bio-pharmaceutical substances.  相似文献   
8.
赵志强    李双成    高阳 《生态学报》2008,28(5):2220-2220~2231
对生态经济复合系统综合评价是实现区域可持续发展首先要面对的科学问题.针对传统生态足迹模型的系统封闭性和空间互斥性等不合理假设,利用从系统论出发并具有基于流量算法优点的能值分析理论,对传统生态足迹模型加以改进,同时将人类劳务纳入系统评价.改进后的模型仍然从供给与需求角度分析区域消费足迹与承载力,强调区域资源进出口,分析开放系统条件下区域发展状况,并将人类的作用纳入可持续发展评价范畴.以深圳市2006年发展状况为例对改进模型进行实证分析.计算结果显示:研究区域具有48.08ghm2的人均潜在生态承载力;在生物生产账户上存在3.60ghm2的人均生态赤字,需进口来弥补,而在工业产品账户上3.14ghm2的人均盈余,可供出口;具有约4.87ghm2的人均净承载力出口,为其他区域的发展做出了贡献;人力资源是深圳市可持续发展的重要保障,至少提供相当5.20ghm2的人均生态承载力;发展高新技术产业、低能耗的清洁工业,产出高能值转换率的产品,实现区域本地产品在能量系统等级的提升,是提升本地承载力的现实途径.结果表明,改进后模型突破了传统生态足迹模型偏生态的弱可持续性评价局限,成为综合反映区域生态经济发展状况的可持续性评价模型.  相似文献   
9.
Wavefront shaping can compensate the wavefront distortions in deep tissue focusing, leading to an improved penetration depth. However, when using the backscattered signals as the feedback, unexpected compensation bias may be introduced, resulting in focusing position deviations or even no focus in the illumination focal plane. Here we investigated the reliability of wavefront shaping based on coherent optical adaptive technique in deep tissue focusing by measuring the position deviations between the foci in the illumination focal plane and the epi‐detection plane. The experimental results show that when the penetration depth reaches 150 μm in mouse brain tissue (with scattering coefficient ~22.42 mm?1) using a 488 nm laser and an objective lens with 0.75 numerical aperture, the center of the real focus will deviate out of one radius range of the Airy disk while the optimized focus in the epi‐detection plane maintained basically at the center. With the penetration depth increases, the peak to background ratio of the focus in the illumination focal plane decreases faster than that in the epi‐detection plane. The results indicate that when the penetration depth reaches 150 μm, feedback based on backscattered signals will make wavefront shaping lose its reliability, which may provide a guidance for applications of non‐invasive precise optogenetics or deep tissue optical stimulation using wavefront shaping methods. A, Intensity distribution in the epi‐detection plane and the illumination focal plane before and after correction, corresponding to brain sections with 250 and 300 μm thickness, respectively. Scale bar is 2 μm. B, Averaged focusing deviations in the epi‐detection plane (optimized) and the illumination focal plane (monitored) after compensation. The unit of the ordinate is one Airy disk diameter. Black dashed line represents one Airy disk radius. Bars represent the SE of each measurement set.   相似文献   
10.
生态足迹模型的争论与发展   总被引:9,自引:0,他引:9  
陈成忠  林振山 《生态学报》2008,28(12):6252-6263
生态足迹模型自William Rees1992年提出、Mathis Wackemagel 1996年推广应用以来,在众多研究者的质疑和争论中不断发展、完善。目前,国内已有许多综述文章详细介绍了其理论假设、基本概念、计算方法、实证应用、一些缺陷改进等。在这些综述成果基础上,结合近2~3年的研究新进展,概括了10a来对其理论假设、均衡因子、产量因子、计算方法、过于静态性、缺乏预测性、结论单一性等方面存在的主要争论,聚焦了在概念发展、计算方法、均衡因子、产量因子、应用领域、时间序列、非线性科学研究方法、与其他社会经济指标相结合等方面进行的改进及发展,并指出今后生态足迹模型研究将要在计算方法改进、加强实践操作及市场化运作、与可持续发展政策的有机联系、与非线性科学研究方法相结合、长时间序列动态评估、单项指标等方面取得重要进展。这些争论、改进的综述及发展方向的提出,目的在于引发国内对生态足迹模型研究的新思考,推动生态足迹模型理论的进一步完善和发展。  相似文献   
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