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Physiological ozone responses of birch (Betula pendula Roth) differ between soil-growing trees in a multi-year exposure and potted saplings in a single-season exposure
2002
Oksanen, E. (University of Kuopio, Kuopio (Finland). Department of Ecology and Environemntal Science)
Increased ozone sensitivity of larger soil-growing trees with growth in the multi-year exposure was a result of several interactive senescence-related physiological factors: lower net photosynthesis to stomatal conductance ratio at the end of the growing season promoted high ozone uptake and low photosynthetic carbon gain, leading to onset of visible injuries and impaired bud formation. This was expected to affect negatively the early growth of the next year foliage, This clone showed a major change in allocation pattern during the early ontogeny at the expense of foliage growth towards the stem height increase
Show more [+] Less [-]Conditions of natural regeneration of Norway spruce ecosystems in the Krkonose mountains
2002
Cudlin, P. (Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Institute of Landscape Ecology) | Godbold, L. | Bonifacio, E. | Egli, S. | Fritz, H. W. | Chmelikova, E. | Kowalik, P. | Martinotti, M. G. | Moravec, I. | Nicolotti, G. | Zanini, E.
The aim of the international EU project was to characterize the status, conditions, and constraints for natural regeneration of Norway spruce (Picea abies [L.] Karst.) ecosystems in different stage of forest decline on three permanent research plots in the Giant Mts., to assess whether the biotechnological measures are necessary to support a natural regeneration at each plot. There were not ascertained any fundamental differences in basic soil types of three permenent research plots. No significant differences were observed in diversity of fungal and bacterial rhizospheric populations, including ectomycorrhizal symbionts
Show more [+] Less [-]Critical loads and exceedances for eutrophication and acidification in Flanders
2002
Neirynck, J. | Langouche, D. | Ridder, K. de | Wiedman, T. | Roskams, P. (Institute for Forestry and Game Management, Geraardsbergen, (Belgium))
Critical loads were estimated for over more than 1400 receptors supporting forest vegetation in northern Belgium using simple mass balance method. Necessary data were derived from old historical soil database, recent data from forest surveys, meteo data, level I and II plots and regional studies concerning elemental sequestration in woody biomass. Deposition estimates were performed with the OPS-model, which had been validated with deposition measurements of N and S in 6 level II plots over the period 1994-1998. In addition, an edge enhancement factor was calculated to account for enhanced deposition in plots situated in forest edges
Show more [+] Less [-]Quality assurance (QA) procedures in the Italian network for forest health monitoring; a six-years experience
2002
Cozzi, A. (Linnaea-ambiente, Firenze (Italy)) | Bussotti, F. | Ferretti, M.
The results indicate that it is possible to reach a good level of reproducibility in a relatively short time. However, quality assurance procedures allow to know the real status of reliability of the field data. More attention must be given to the Level II indices, to select the really useful and informative ones, and to concentrate on these the didactic efforts
Show more [+] Less [-]European oak decline (Quercus robur and Q. petraea) and population genetic structures
2002
Hertel, H. | Zaspel, I. (Institute for Forest Genetics and Forest Tree Breeding, Waldsieversdorf (Germany). Federal Research Centre for Forestry and Forest Products)
Phenotypical differentiation between and within populations was observed. During the last decade, vitality decreased for both species in the observation plots in accordance with the general trend in Germany. Differences between the species were detected for single symptomatic traits like bark necroses. The genetic analyses with isozyme markers as well as cpDNA haplotypes resulted in remarkable differences between species
Show more [+] Less [-]Neutron activation analyses for air pollution studies: some preliminary results of the European moss-survey 2000
2002
Ermakova, E. | Frontasyeva, M. (Joint Institute for Nuclear Research, Dubna (Russia). Frank Laboratory of Neutron Physics)
Instrumental neutron activation analysis (INAA) at the Joint Institute for Nuclear Research is presently being used in several projects on air pollution studies supported by the International Atomic Energy Agency and the Plenipotentiaries of the country members of JINR. They involve moss and lichen biomonitoring techniques and GIS technology for constructing geographical maps of atmospheric deposition patterns of key heavy metals and a number of additional elements. Multi-element INAA is considered to be a reference analytical technique providing most reliable results for the bulk elemental content due to the non-destructive way of sample preparation for analysis
Show more [+] Less [-]Norway spruce crown structure changes under long-term multiple stress impact in Central European mountains
2002
Moravec, I. | Cudlin, P. (Institute of Landscape Ecology, Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Department of Forest Ecology) | Polak, T.
Results obtained by crown status estimation and branch structure transformation assessment methods are also applicable at forest stand level. By means of these methods we can reconstruct a scheme of probable stress response history for individual trees with possibility to distinguish three different types of stress response behaviour. The goal of our study was to describe a stress response history of single trees and corresponding forest stands, diverse in different level of multiple stress impact, and to localize investigated trees in the stress response scheme
Show more [+] Less [-]Long-term effects of air pollution on spruce forests in the Tatra Mts. - ozone and vegetation studies
2002
Godzik, B. (Polish Academy of Sciences, Krakow (Poland). Institute of Botany) | Fleischer, P. | Grodzinska, K.
Wet-deposited - sulphur and nitrogen pollutants and ambient ozone are important anthropogenic factors affecting forest health. Regular assessment of chemistry of throughfall and precipitation water based on two-week sampling started in 1997. Passive samplers for detection of ozone concentration have been exposed on a network of monitoring stations during vegetation periods since 1998. In addition, in selected locations, UV absorption monitors for continuous O3 measurements were installed in 1999
Show more [+] Less [-]Unaccounted spatial variability may bias site-related estimates of ozone-like foliar symptoms
2002
Maccherini, S. (Universita di Siena, Siena (Italy). Dipartimento Scienze Ambientali) | Betti, G. | Cozzi, A. | Ferretti, M. | Grohmann, F. | Savini, P.
The assessment of O3-like foliar symptoms is increasingly considered in monitoring programs aimed at evaluating air pollution effects on forests. The results showed considerable spatial and temporal variation of O3-like foliar symptoms: year, subplot adn the interaction between year and plot were found significant factors. Symptoms resulted lower in 2001; there were differences of foliar symptoms between different subplot and overall the variation between years are considerably different according to the plot being considered. These findings suggest that O3-like foliar symptoms recorded on a small plot selected without a formal statistical approach and with no consideration of the apparently high variability of symptoms expression risk to introduce a serious bias in the evaluation of the potential ozone impact at a given site and its trend
Show more [+] Less [-]Ponderosa pine response to elevated CO2 and nitrogen
2002
Johnson, D.W. (University of Nevada, Reno (USA). Environmental and Resource Sciences) | Ball, J.T. | Hoylman, A.M. | Walker, R.F.
This paper summarizes the data on growth response and N uptake in open-top chambers planted with ponderosa pine (Pinus ponderosa Laws.) treated with both N (0, 10, and 20 g N msub-2 yrsub-1 as ammonium sulfate ) and CO2. Both N and elevated CO2 caused increased growth. The effects of N on growth response to elevated CO2 were assessed in various ways and various interpretations could be drawn depending on which metric was used, including a negative effect of N on growth response to CO2. These calculations suggest that expressing growth as percentages can be misleading, especially when done on a grams per tree basis
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