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781.
Photosynthetically fixed energy from the sun, in the form of net primary production, ultimately supports the majority of life
on earth. Given the importance of this energy source, we calculate the human appropriation of net primary production (HANPP)
for the province of Nova Scotia, Canada. We find that over 25% of potentially available production is appropriated by humans
through harvest (forestry and agriculture) and land cover change. The level of appropriation in Nova Scotia is close to the
global average, when methodological differences between studies are taken into account, but substantially less than in Austria
and India where detailed surveys have also been conducted. Furthermore, HANPP is not distributed evenly throughout the province,
but is instead concentrated in the north-central counties, where appropriation reaches 50%. We discuss the implications of
these results, and the novel method used to obtain them, in the context of biophysical assessment and the species-energy hypothesis. 相似文献
782.
文章论述了城市生态化及其发展对策 ,提出可持续城市发展的概念及其生态原则 ,以期推动我国城市生态化和可持续城市建设工作的开展 相似文献
783.
--A region
surrounding Qinghai Lake was chosen as thestudy area and nine ecological landscape types
that were recognizedbased on Landsat TM image classification of land cover/use typesalong
with the ancillary data, and their ecological features andthe measures dealing with the
eco-environmental problems arepresented in this paper. The study has shown that using
thisapproach the ecological landscape types in a region like the studyarea can be readily
recognized and their ecological features can berather accurately derived. Moreover, the
deterioration in near alllandscape ecological types in the area is quite serious.
Therefore,effective and proper measures have to be taken in order to realizea sustainable
development of the region. 相似文献
784.
Leo Baas 《Journal of Cleaner Production》1998,6(3-4)
This article opens briefly with the recent discussions about the effectiveness of pollution prevention. As pollution prevention and cleaner production are important elements of industrial ecology, the different definitions and approaches of industrial ecology as a term also need clarity. The major part of this article reflects the first results of the cleaner production and industrial ecology concepts, applied in an industrial ecosystem project (INES) in the Rotterdam harbour area. In this industrial area with many refineries and (petro)chemical facilities, the possibilities for companies to reuse waste streams, by-products and energy from each other was researched. The project was initiated by an industrial association. Sixty-nine members of the industrial association joined the INES project and provided confidential information about their resources, products and waste streams to the research team. Based on this information, 15 projects were designed. The selected three projects for further feasibility studies showed the potency to reduce the use of energy, water and bio sludge significantly. 相似文献
785.
Integrating the Metapopulation and Habitat Paradigms for Understanding Broad-Scale Declines of Species 总被引:2,自引:0,他引:2
DOUG P. ARMSTRONG 《Conservation biology》2005,19(5):1402-1410
Abstract: Caughley (1994) argued that researchers working on threatened populations tended to follow the "small population paradigm" or the "declining population paradigm," and that greater integration of these paradigms was needed. Here I suggest that two related paradigms exist at the broader spatial scale, namely the metapopulation paradigm and habitat paradigm, and that these two paradigms also need to be integrated if we are to provide sound management advice. This integration is not trivial, and I outline five problems that need to be addressed: (1) habitat variables may not measure habitat quality, so site-specific data on vital rates are needed to resolve the effects of habitat quality and metapopulation dynamics; (2) measurements of vital rates may be confounded by movements; (3) vital rates may be density dependent; (4) vital rates may be affected by genotype; and (5) vital rates cannot be measured in unoccupied patches. I reviewed papers published in Conservation Biology from 1994 to 2003 and found 41 studies that analyzed data from 10 or more sites to understand the factors limiting species' distributions. Five of the analyses presented were purely within the metapopulation paradigm, 14 were purely within the habitat paradigm, 17 involved elements of both paradigms, and 7 were theoretically ambiguous (2 papers presented 2 distinct analyses and were counted twice). This suggests that many researchers appreciate the need to integrate the paradigms. Only one study, however, used data on vital rates to resolve the effects of habitat quality and metapopulation dynamics (problem 1), and this study did not address problems 2–5. I conclude that more intensive research incorporating site-specific data on vital rates and movement is needed to complement the numerous analyses of distributional data being produced. 相似文献
786.
787.
研究了臭氧和光合细菌联合处理景观水体,结果表明,在控制水体pH值为7.5,按照1 L样品通臭氧25 min(每h产生1.5 g)后,在向其中加入4亿个光合细菌大约静置5 d,景观污水将得到较好的净化效果。根据目前的臭氧制取技术,每制取1 kg臭氧约耗电在20 kW·h,按照每分解1 kg COD需要3 kg的臭氧计算,则每处理1 kg COD需要28元左右。较高的运行费用也是这一技术未能大规模应用的主要因素之一。但是该实验利用臭氧和光合细菌联合处理景观水的方法每处理1 kg COD只需要16.5元左右,大大节约了成本,还提高了效率。因此通过臭氧和光合细菌联合处理技术,净化景观水体中的有机物污染和改善景观水体水质,既节约了成本,又达到了很好的效果。 相似文献
788.
789.
不同溶解氧条件下A/O系统的除碳脱氮效果和细菌群落结构变化 总被引:5,自引:3,他引:2
应用一个在不同的溶解氧(3、2、1和0.5 mg·L-1)浓度下长期运行的缺氧/好氧(A/O)小试系统考察了溶解氧浓度的变化对系统的除碳和脱氮效果以及细菌群落结构的影响.结果表明,A/O系统的除碳和脱氮效果不随溶解氧(DO)的降低而降低,在低溶解氧(0.5 mg·L-1)条件下,系统仍具有很好的除碳和脱氮效果,即化学需氧量(COD)、氨氮(NH+4-N)和总氮(TN)的去除率分别为89.7%、98.3%和88.0%.通过PCR-DGGE方法,对系统中的细菌群落结构随DO浓度的变化规律进行了分析,结果表明,微生物群落结构随DO浓度的变化有所不同,高DO和低DO环境中的细菌群落结构差异较大,但是与高DO条件下系统内的细菌群落相比,在低DO条件下系统内细菌群落仍具有较高的生物多样性.在低DO条件下,系统内的优势细菌主要被鉴定为Proteobacteria. 相似文献
790.