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81.
Bussotti F Schaub M Cozzi A Gerosa G Novak K Hug C 《Environmental pollution (Barking, Essex : 1987)》2006,140(2):257-268
This paper aims to identify the problems regarding the evaluation of ozone (and ozone-like) symptoms, by examining the results of the 4th UN/ECE ICP-Forests Intercalibration Course for the assessment of ozone-induced visible symptoms. Trees, shrubs and herbaceous species were evaluated in a tree nursery, at Lattecaldo (Switzerland) and under open field conditions at Moggio (Italy). The main findings were: (i) the most expert surveyors tended to be grouped in the same cluster and, during the field exercises, they tended to assess in a more conservative manner compared to the less trained participants; (ii) the agreement was greater in assessing the absence rather than the presence of symptoms; (iii) typical interveinal stippling on the upper leaf surface was more accurately evaluated than discoloration; (iv) uncertainties resulted mainly for species which showed greater variability in their symptom manifestation, and for certain herbaceous species. 相似文献
82.
83.
Gilbert Kabelo Gaboutloeloe Shulin Chen Michael E. Barber Claudio O. Stöckle 《Water, Air, & Soil Pollution: Focus》2009,9(3-4):279-286
Nitrogen removal in wetlands is achieved through two pathways: (a) N cycling and (b) storage. N cycling is a permanent removal pathway. There has been an increasing interest in the development of technologies to alleviate permanent nitrogen removal limitation in constructed wetlands by ensuring prevalence of conditions enhancing N cycling. The purpose of this study is to review an emerging technology of vegetated submerged bed constructed wetland system aimed at improving nitrogen removal in wetlands through rational system design. The design and performance of this system type is evaluated. The oxygen transfer capacity and nitrogen removal mechanisms on system performance are evaluated. Constructed wetland combinations most commonly consist of vertical flow (VF) and horizontal flow (HF) beds where VF and HF are aimed at nitrification and denitrification, respectively. Nitrate nitrogen accumulation is the most limiting factor in typical VF based systems. 相似文献
84.
Philip A. Marcus 《环境质量管理》1996,6(2):11-21
An environmental management system (EMS) approach can improve overall corporate performance and demonstrate this improvement to top management in “dollars and cents” language. This article illustrates the importance of a financial management approach to justify investments in environmental, health, and safety (EH&S) excellence. It also describes in detail the elements of the EH&S management assessment and improvement process. 相似文献
85.
The use of terrestrial ecoregions as a regional-scale screen for selecting representative reference sites for water quality monitoring 总被引:3,自引:0,他引:3
A process has been developed to select watersheds that are representative of terrestrial ecoregions and that are relatively
undisturbed by human activity. Using an existing land classification system at two hierarchical levels of resolution, representative
subsets (ecodistricts) of large-scale ecoregions were selected, on the basis of their physiographic, biological, and climatological
attributes, to represent the ecoregions. This was achieved using a frequency distribution analysis of existing attribute data
and choosing the ecodistrict most closely resembling the most common set of conditions for that ecoregion. Within each ecodistrict,
river basins were selected through a best-judgement evaluation of land use, coupled with an assessment of the size and location
of each river basin, in order to meet the condition of minimal human impact. Preliminary assessment of water quality data
collected from six watersheds selected in this way suggests that the process is effective in targeting regional scale river
basins exhibiting the desired characteristics. 相似文献
86.
Aquatic toxicity due to the creation and mobilization of chemical constituents by fire has been little studied, despite reports of post-fire fish kills attributed to unspecified pyrogenic toxicants. We examined releases of cyanides from biomass burning and their effect on surface runoff water. In laboratory test burns, available cyanide concentrations in leachate from residual ash were much higher than in leachate from partially burned and unburned fuel and were similar to or higher than the 96-h median lethal concentration (LC50) for rainbow trout (45 microg/l). Free cyanide concentrations in stormwater runoff collected after a wildfire in North Carolina averaged 49 microg/l, again similar to the rainbow trout LC50 and an order of magnitude higher than in samples from an adjacent unburned area. Pyrogenic cyanide inputs, together with other fire-related stressors, may contribute to post-fire fish mortalities, particularly those affecting salmonids. 相似文献
87.
Godoy JM Carvalho ZL da Costa Fernandes F Danelon OM Ferreira AC Roldão LA 《Journal of environmental radioactivity》2003,70(3):193-198
The present work presents the results of 137Cs concentration in seawater, fish and sediments samples collect in 11 sampling points, crossing the Brazilian Southeastern coastal region, from Vitória (ES) to Santos (SP), on a routine basis from 1997 to 2002. This monitoring program was carried out by the Instituto de Radioproteção e Dosimetria (IRD/CNEN/MCT), in cooperation with the Instituto de Estudos do Mar Almirante Paulo Moreira (IEAPM/Brazilian Navy), aiming at determining artificial radionuclides in marine samples. Additionally to the 137Cs results, 90Sr concentrations in fish samples from 1998 to 2002 are also reported.The 137Cs in seawater follows a lognormal distribution, with a geometric mean of 1.8 Bq m-3 and a geometric standard deviation of 1.4 (n=54), decay corrected to June/2002. For 137Cs levels in fish samples a geometric mean of 0.19 Bq kg−1 and a geometric standard deviation of 2.9 (n=39), decay corrected to June/2002, with a range of 0.03 to 1.7 Bq kg−1, were obtained. Based on the 137Cs mean concentration in fish as well as in seawater, a transfer factor of 1 × 102 was calculated, which is quite in agreement with the recommended value found in the Safety Report Serie 19. 相似文献
88.
Robert M. Lent Marcus C. Waidron John C. Rader 《Journal of the American Water Resources Association》1998,34(2):439-450
ABSTRACT: A multivariate approach was used to analyze hydrologic, geologic, geographic, and water-chemistry data from small order watersheds in the Quabbin Reservoir Basin in central Massachusetts. Eighty three small order watersheds were delineated and landscape attributes defining hydrologic, geologic, and geographic features of the watersheds were compiled from geographic information system data layers. Principal components analysis was used to evaluate 11 chemical constituents collected bi-weekly for 1 year at 15 surface-water stations in order to subdivide the basin into subbasins comprised of watersheds with similar water quality characteristics. Three principal components accounted for about 90 percent of the variance in water chemistry data. The principal components were defined as a biogeochemical variable related to wet. land density, an acid-neutralization variable, and a road-salt variable related to density of primary roads. Three subbasins were identified. Analysis of variance and multiple comparisons of means were used to identify significant differences in stream water chemistry and landscape attributes among subbasins. All stream water constituents were significantly different among subbasins. Multiple regression techniques were used to relate stream water chemistry to landscape attributes. Important differences in landscape attributes were related to wetlands, slope, and soil type. 相似文献
89.
Martin Gullstrom Maricela de la Torre Castro Salomao O.Bandeira Mats Bjork Mattis Dahlberg Nils Kautsky Patrik Ronnback Marcus C.Ohman 《Ambio-人类环境杂志》2002,31(8)
海草是海洋被子植物,广泛分布在温带和热带的海岸带水域,是地球上水生生态系统中最具生产力的生物之一. 相似文献
90.