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51.
52.
B. G. Mackey H. A. Nix J. A. Stein S. E. Cork F. T. Bullen 《Biological conservation》1989,50(1-4):279-303
An assessment is made of the representativeness of the Wet Tropics World Heritage property of north-east Queensland, Australia. The relevance of this feature to the World Heritage criteria is discussed. Computer-based spatial data sets are used to provide a sample of the distribution of key environmental factors at both continental and regional scales. Numerical classification techniques are applied to generate environmental groups from pattens in the distribution of these environmental factors. An evaluation is presented of the representation of these groups within the World Heritage property, in the context of present and potential tropical forest cover. 相似文献
53.
Ulrich?F?rstnerEmail author Susanne?Heise René?Schwartz Bernhard?Westrich Wolfgang?Ahlf 《Journal of Soils and Sediments》2004,4(4):247-260
Background, Aims, and Scope
Data from the Elbe River and its tributaries indicate, despite extensive improvement in water quality during the last 15 years, that the respective sediment situation of many priority pollutants has not reached an acceptable level. For the coming decades, risks for downstream sites and stakeholders will persist, mainly due to secondary sources originating from historical pollution of soils and sediments in the catchment area. In practice, a catchment-wide assessment of historical contaminated soil and sediment should apply a three-step approach: (i) Identification of substances of concern (s.o.c.) and their classification into ’hazard classes of compounds’; (ii) identification of areas of concern (a.o.c.) and their classification into ‘hazard classes of sites’; (iii) identification of areas of risk (a.o.r.) and their assessment relative to each other with regard to the probability of polluting the sediments in the downstream reaches. The conversion of this concept has to consider the underlying philosophy of the EU Water Framework Directive, particularly with respect to the analysis and monitoring of priority substances in solid matrices. However, major deficiencies are still in the assessment and prognosis of resuspension processes, and potential approaches to fill this gap are described both in theory and from examples of the Elbe River. 相似文献54.
55.
Grassmann J Hippeli S Vollmann R Elstner EF 《Journal of agricultural and food chemistry》2003,51(26):7576-7582
The essential oil from Pinus mugo (PMEO) was tested on its antioxidative capacity. For this purpose, several biochemical test systems were chosen (e.g., the Fenton System, the xanthine oxidase assay, or the copper-induced oxidation of low-density lipoprotein (LDL)). The results show that there is moderate or weak antioxidative activity when tested in aqueous environments, like in the Fenton system, xanthine oxidase induced superoxide radical formation, or in the HOCl driven fragmentation of 1-aminocyclopropane-1-carboxylic acid (ACC). In contrast, when tested in more lipophilic environments (e.g., the ACC-cleavage by activated neutrophils in whole blood) the PMEO exhibits good antioxidative activity. PMEO does also show good antioxidative capacity in another lipophilic test system (i.e., the copper induced oxidation of LDL). Some components of PMEO (i.e., Delta(3)-carene, camphene, alpha-pinene, (+)-limonene and terpinolene) were also tested. As the PMEO, they showed weak or no antioxidant activity in aqueous environments, but some of them were effective antioxidants regarding ACC-cleavage by activated neutrophils in whole blood or copper-induced LDL-oxidation. Terpinolene, a minor component of PMEO, exhibited remarkable protection against LDL-oxidation. 相似文献
56.
Determination of a common forest life cycle assessment method for biodiversity evaluation 总被引:1,自引:0,他引:1
Forest biodiversity is highly linked with the occurrence of certain forest development phases (fdp) within the forest life cycle. Generally, the disintegration phase provides the highest biodiversity. The objective of the study was to test different existing forest life cycle assessment approaches aiming at developing a common reliable fdp assessment method. We tested and compared three approaches to record fdp in beech, mixed beech and spruce forests, in managed and unmanaged forests, and in four different plot sizes ranging from 125 to 2000 m2. The main results of the fdp comparison are as follows:
- (1)
- In approximately two thirds of the cases the three considered methods did not yield a corresponding fdp record.
- (2)
- Generally, the larger the plot sizes, the larger the average fdp deviation in forest reserves.
- (3)
- The fdp deviation is stronger in beech or spruce dominated forest reserves than in mixed beech forest reserves.
- (4)
- Plots of 500 m2 show most distinct numbers of microhabitats corresponding to the fdp sequence within the forest life cycle.
- (5)
- Furthermore, the managed forests mostly show lower fdp deviation than the forest reserves.
57.
58.
59.
H. G. Jones W. Sochanska J. Stein J. Roberge A. P. Plamondon J. Y. Charette 《Water, air, and soil pollution》1986,31(1-2):431-439
An integrated model (SNOQUALI) for the simulation of meltwater quality has been developed for a boreal forest site (Lake Laflamme, Québec). The model consists of a physical module and a chemical module; it has been validated for H+, NO3 and SO4 2? concentrations in discharge from the snowcover during the spring melt of 1984. Good agreement of simulated ion concentrations with those measured in the field were obtained for the strong acid anions NO3 ? and SO4 2?. Greater deviations of simulated concentrations from observed concentrations were recorded in the case of H+. These are attributed to ion exchange reactions between the ion and the organic debris which is deposited continously onto the snowcover from the forest canopy during the winter season. 相似文献
60.
Global Positioning System (GPS) measurements across the New Madrid seismic zone (NMSZ) in the central United States show little, if any, motion. These data are consistent with platewide continuous GPS data away from the NMSZ, which show no motion within uncertainties. Both these data and the frequency-magnitude relation for seismicity imply that had the largest shocks in the series of earthquakes that occurred in 1811 and 1812 been magnitude 8, their recurrence interval should well exceed 2500 years, longer than has been assumed. Alternatively, the largest 1811 and 1812 earthquakes and those in the paleoseismic record may have been much smaller than typically assumed. Hence, the hazard posed by great earthquakes in the NMSZ appears to be overestimated. 相似文献