خيارات البحث
النتائج 1 - 10 من 121
Caracterisation de l' environnement atmospherique en zone forestiere. Station laboratoire du Donon.
1987
Biren J.M. | Elichegaray C. | Vidal J.P.
De la foret polluee a la foret deperissante.
1986
Garrec J.P.
Etude des pluies recueillies en trois points a proximite de Besancon.
1986
Dole S. | Guyetant R. | Martin D. | Remy F. | Reyle R. | Rouault J.Y. | Valero L. | Vidonne A.
Acidity status of surface waters in Massachusetts.
1992
Walk M.F.I. | Godfrey P.J. | Ruby A. III | Zajicek O.T. | Mattson M.
Metal-pollution index (MPI) - proposal for freshwater monitoring
1999
Teodorovic, I. (Univerzitet u Novom Sadu, Novi Sad (Yugoslavia). Prirodno-matematicki fakultet, Institut za biologiju) | Djukic, N. | Maletin, S. | Miljanovic, B.
MPI - Metal Pollution Index is being proposed with an aim improving the freshwater pollution control, monitoring and classification based on fish metal body burden. This is a simple mathematical model which enables presentation of Cd, Pb, Cu, Zn and Al fish liver concentration as a single value. After thorough studies of bioaccumulation, biomagnification and tissue distribution patterns, liver of Carassius auratus gibelio has been chosen as sentinel organ. Normal distribution and biological variation assessment is being achieved by using normalizers - reference values (liver concentrations of selected elements in fish from reference sites Vruje and Moharac micro water reservoirs, Serbia (Yugoslavia)). Selected representative sites have been evaluated according to new classification of freshwater ecosystem based on MPI values.
اظهر المزيد [+] اقل [-]The Vlasina river [Serbia, Yugoslavia] - water quality, environmental quality assessment and preservation
1999
Paunovic, M. | Kalafatic, V. | Martinovic, J. | Jakovcev, D. | Martinovic-Vitanovic, V. (Institut za bioloska istrazivanja "Sinisa Stankovic", Beograd (Yugoslavia))
The paper presents results of the hydroecological investigations of the Vlasina river basin, Serbia (Yugoslavia). The researches were performed in May and September 1996, as a part an annual investigation cycle. Samples were collected from five localities on the Vlasina river, and on two spots on its main tributaries - the Gradska river and Luznica, just before entering into the Vlasina. Qualitative and quantitative data on composition of phyto- and zooplankton, periphytic and benthic communities together with data obtained from physico-chemical water examinations were analysed to assess water quality of examined water courses. The results of performed monitoring were compared with informations on the sources of pollution, as well as with the data on hydrology, geomorphology, demographic variations, and recent development of tourism and industry in the Region in order to assess environmental quality of aquatic ecosystem and to suggest the conservation strategy.
اظهر المزيد [+] اقل [-]Science and policy - to what extent does long-term monitoring of forest ecosystems contribute to policy relevant air pollution issues?
2002
Haussmann, T. (Federal Ministry of Consumer Protection, Food and Agriculture, Bonn (Germany)) | Fischer, R. | Riebau, A.
Following the objective to provide an overview on the spatial and temporal variation in forest condition on a European scale, an extensive systematic survey on more than 6000 so called Level I plots throughout Europe is carried out. Results show a recuparation of crown condition in the mid nineties and a resuming deterioration with nearly a quarter of the sample trees classified as damaged in 2001. Results of statistical evaluations explain the observed variation mainly by weather extremes, insects, fungi and indirect effects of air pollutants via soil acidification or changes in the nutritional status of trees
اظهر المزيد [+] اقل [-]Impact of regional pollution load on tree condition and interpretation of assessment methods
2002
Augustaitis, A. (Lithuanian University of Agriculture, Kaunas (Lithuania). Forest Monitoring Laboratory)
Investigation of air pollution impact on tree condition indicates the greatest correlation between pine defoliation and SO2, SO4 and NH4 concentration in the air, NH4 load with precipitation and its pH in the eastern part of Lithuania. In the southern part significant correlation was found between defoliation and SO4 concentration in the air and SO4, NH4 load with precipitation and its pH. No significant correlation was found in the western region of the country, which includes seaside part. Tree age and tree development classes have an essential effect on the correlation significance
اظهر المزيد [+] اقل [-]An empirical method to estimate ozone AOT40 values from measurements by passive samplers
2002
Gerosa, G. (Universita di Milano, Milano (Italy)) | Ferretti, M. | Buffoni, A. | Petriccione, B. | Pompei, E.
Passive samplers offer considerable advantages for measuring ozone (O3) concentrations in remote areas. Measurements with passive samplers typically result in data about weekly-to-monthly O3 concentrations, which are not consistent with the definitions of cumulative indices currently being used to estimate the exposure of vegetation to O3. For this reason, attempts were and are being made to develop statistical and empirical methods to estimate exposure indices like the AOT40 adopted in Europe (O3 Accumulated Over Threshold 40 ppb) starting from mean concentrations obtained from passive samplers. This paper describes an empirical method adopted in Italy to estimate 1996-2000 AOT40 values at 20 forest sites of the Italian network of intensive monitoring of forest ecosystems
اظهر المزيد [+] اقل [-]