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Hierarchy theory as a guide to mycorrhizal research on large-scale problems.
1991
O'Neill E.G. | O'Neill R.V. | Norby R.J.
Politique generale de protection de l' environnement en France en matiere de pollution atmospherique [actions du Ministere de l' Environnement, de l' Agence pour la Qualite de l' Air et du Ministere de la Sante].
1987
Legrand H. | Biren J.M. | Jouan M.
Deperissement des forets et pollution atmospherique [pluies acides, degats par region et par essence].
1987
Muller M. | Wunenburger R.
Institutions active in environmental science, research and technology in Italy.
1994
Facchetti S.
Protection of the environment has been of public concern for many years in Italy and many institutions here are involved in this field. However, the advantages offered by the improvement of the quality of the environment are not always considered in economic terms, even though a rigorous evaluation of the relationships between economy and environment should help us to better understand how protection of the environment is related to economic development and social benefits.
Afficher plus [+] Moins [-]Soil nutrients in a mature natural mixed forest exposed to elevated CO2
2002
Bucher-Wallin, I. K. | Schleppi, P. | Hagedorn, F. | Bucher, J. B. (Swiss Federal Research Institute WSL, Birmensdorf (Switzerland))
Elevated CO2 was shown to influence the nutritional status of exposed ecosystems. In an earlier experiment in model ecosystems in open-top chambers with young spruce and beech, the nitrate concentration of the soil solution was dramatically reduced after 4 years exposure to elevated CO2. This phenomenon was mainly interpreted as an immobilization of nitrogen in the soil. To test if such effects occur also in mature, undisturbed natural forests, we used facilities of the Swiss Canopy Crane project. Here in a mixed 120 years old forest the crowns of 30-35 m high broadleaved trees are fumigated with CO2 during the growing season since spring 2001. According to the results the soil is probably not yet much influenced by the fumigation of the tree crowns, and it is too early to estimate whether the observed nutrient effects are due to the CO2 treatment or to the natural variability of the soil
Afficher plus [+] Moins [-]Nutrient concentrations in the foliage of beech (Fagus sylvatica L.) and Norway spruce (Picea abies L. Karst.) plants of a model ecosystem in response to long-term exposure to atmospheric CO2 enrichment and increased N deposition
2002
Landolt, W. | Egli, P. | Pezzotta, D. | Bucher, J. B. (Swiss Federal Research Institute WSL, Birmensdorf (Switzerland))
The biological effects of both elevated CO2 and N deposition on model ecosystem were investigated in the Birmensdorf open-top chamber facility. Each of the 16 chambers was divided into two compartments with a ground area of 3 msub2 and filled with natural unfertilized forest soils from two sites (one acidic, the other calcareous). Elevated CO2 significantly increased O and Zn concentrations in beech leaves and those of Zn in spruce needles on the calcareous soils. Enhanced N deposition also led to a dilution of nutrients and increased N contents
Afficher plus [+] Moins [-]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
Afficher plus [+] Moins [-]Leaf morphology and gas exchange in holm oak (Quercus ilex L.) trees in different environments
2002
Lakso, K. (University of Oulu, (Finland). Department of Biology) | Paoletti, E. | Huttunen, S.
Two holm oak (Quercus ilex L.) sites in Tuscany, Central Italy, were studied in July 2000. Leaf morphological characteristics (area, dry weight, specific dry weight, water content, epicuticular wax amount, stomatal density) and leaf fluorescence were measured. Ozone flux into the leaves was calculated on a stomatal conductance basis. Among the measured parameters, only stomatal density and wax amount significantly differed between the sites. This response might indicate an adaptation to air pollutants, of which tropospheric ozone might be of the greatest importance
Afficher plus [+] Moins [-]Needle traces of Scots pine as air pollution indicators
2002
Konopka, B. (Forest Research Institute, Zvolen (Slovak Republic))
Needle retention, needle density, height and radial increments were surveyed on Scots pine (Pinus sylvestris L.) in four forest regions, In the each forest region research was conducted on seven about 45-year-old pines. The Needle Trace Method (NTM) was used to determine needle retention and needle density along the main stem retrospectively for the last four decades. The NTM invented by Kurkela and Jalkanen is based on the examination of the vascular bundles connecting the needles and shoot pith. There are presented the long-term average values of needle retention in the particular forest regions, their differences. Needle retention and needle density reflected air pollution stress on the pines
Afficher plus [+] Moins [-]Foliar elements of Scots pine across the transect from the ammonia emission source (1995-1998)
2002
Kupcinskiene, E. (University of Agriculture of Lithuania, Kaunas (Lithuania). Kaunas-Akademia)
Significant correlations (p0.05) were found between the concentration of elements in the c needles and the distance of the sites from nitrogen ferilizer factory (NFF): the amounts of C, K, Mg, Zn, and Rb in the c+1 needles were increasing, whereas concentrations of N, P, Al, Mn, Cu, Ni, Sr and Cd were decreasing alongside the transect from NFF. Statistical analyses performed on logarithms and estimation of components of variance by maximum likelihood has shown that the age of the needles and the sites were the most important, while year of sampling was much smaller source of variance. Only a few significant differences were found comparing the amount of elements in Scots pine needles collected in four-year space
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