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941.
M. R. Theobald U. Dragosits C. J. Place J. U. Smith M. Sozanska L. Brown D. Scholefield A. Del Prado J. Webb P. G. Whitehead A. Angus I. D. Hodge D. Fowler M. A. Sutton 《Water, Air, & Soil Pollution: Focus》2004,4(6):135-142
The distribution and impacts of different nitrogen pollutants are inextricably linked. To understand the problem fully, the interactions between the different pollutants need to be taken into account. This is particularly important when it comes to abatement techniques, since measures to reduce emissions of one nitrogen pollutant can often lead to an increase in another. This project represents a step towards greater understanding of these issues by linking together new and existing nitrogen flux models into a larger framework. The modelling framework has been constructed and some of the nitrogen flows between fields, farms and the atmosphere have been modelled for a UK study area for typical farm management scenarios. 相似文献
942.
Davey L. Jones John F. Farrar Kevin K. Newsham 《Water, Air, & Soil Pollution: Focus》2004,4(6):169-175
Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO–3 and NH+4). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed. 相似文献
943.
Ed Gidman Royston Goodacre Bridget Emmett Lucy J. Sheppard Ian D. Leith Dylan Gwynn-Jones 《Water, Air, & Soil Pollution: Focus》2004,4(6):251-258
The potential for metabolic fingerprinting via Fourier-transform infrared (FT-IR) spectroscopy to provide a novel approach for the detection of plant biochemical responses to N deposition is examined. An example of spectral analysis using shoot samples taken from an open top chamber (OTC) experiment simulating wet ammonium deposition is given. Sample preparation involved oven drying and homogenisation via mill grinding. Slurries of a consistent dilution were then prepared prior to FT-IR analysis. Spectra from control, 8 and 16 kg N ha–1 yr–1 treatments were then subjected to cross-validated discriminant function analysis. Ordination diagrams showed clear separation between the three N treatments examined. The potential for using Calluna vulgaris (L.) Hull as a bioindicator of N deposition is further evident from these results. The results also clearly demonstrate the power of FT-IR in discriminating between subtle phenotypic alterations in overall plant biochemistry as affected by ammonium pollution. 相似文献
944.
Impact of Land Use on Soluble Organic Nitrogen in Soil 总被引:5,自引:0,他引:5
Victoria B. Willett James J. Green Andrew J. Macdonald John A. Baddeley Georg Cadisch Steven M. J. Francis Keith W. T. Goulding Gary Saunders Elizabeth A. Stockdale Christine A. Watson David L. Jones 《Water, Air, & Soil Pollution: Focus》2004,4(6):53-60
Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO
3
–
, NH
4
+
) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention.
SAFRD, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU, U.K. 相似文献
945.
946.
947.
珠江三角洲经济区污水系统设计原则 总被引:2,自引:0,他引:2
分析了珠江三角洲经济区水环境现状;阐述了城市污水分散处理与集中处理的利弊;指出污水深度处理与回用是形成良性水循环的有效途径,更是经济可持续发展的必然要求;通过对已建排水系统存在问题的分析,探讨了珠江三角洲经济开发区污水系统的设计原则,认为污水系统规划要改变传统设计方法,应方便再生水回用,由经济、技术、地理等综合因素确定排水分区、污水厂厂址与数量,选择适合各排水区域水质水量的工艺流程,预留污水厂与再生水回用管线分期发展的空间,应优先选用国产污水处理设备,尽可能维持城市河涌自然生态。 相似文献
948.
罗布泊野骆驼自然保护区的建设及生物多样性保护 总被引:1,自引:0,他引:1
新疆罗布泊野骆驼自然保护区位于我国西部极旱荒漠带 ,以保护世界濒危物种———野双峰驼为主要对象 ,同时也保护当地特有的地貌、盐泉、丝绸之路遗迹及其他珍稀动植物物种 ,面积 7 8× 10 4km2 。该保护区在世界生物多样性保护中有重大作用。由于周边地区经济的发展 ,对该保护区的影响逐渐扩大 ,威胁到野生动植物的生存安全 ,急需加强宣传、建卡、检查、巡护等保护管理措施 ,同时需要提高周边贫困社区人民生活水平 ,强化管制非法采矿业 相似文献
949.
生态移民在保护自然生态环境中的重要作用及实施建议 总被引:1,自引:0,他引:1
在西部大开发中,生态环境保护与建设要先行,而生态移民则是落实该项政策的一项极重要措施。将自然保护区、交通和通讯不发达的边缘区、生态环境脆弱区和地质灾区的农牧民,移往自然环境条件较好,公路交通及通讯发达,接近城镇的地区,不但可改善和提高这些居民的生活水平,更重要的是对迁出区的自然生态环境保护,特别是珍稀野生动植物的生存和自然繁殖有十分积极的作用。而工业生产移民则是环境保护必要手段。该项政策的实施,不但具有重大社会政治、生态环境及经济效益,而且在我国自然保护史上是个重大创举。 相似文献
950.
红外光度法测定石油类和动植物油常见问题探讨 总被引:2,自引:0,他引:2
根据石油类在波数为2930cm-1、2960 cm-1、3030 cm-1全部或部分谱带处有物征吸收的原理,采用红外光度测油仪和水样絮凝富集技术测定石油类、动植物油。 相似文献