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Response of coniferous ecosystems to reduction of SO2 and NOx emission in last decade in Poland
2002
Staszewski, T. (Institute for Ecology of Industrial Areas, Katowice (Poland)) | Uzieblo, A. | Kubiesa, P. | Lukasik, W. | Szdzuj, J.
Five permanent plots in pine and spruce stands were established at beginning of the 90s. The sites were situated in a gradient of air pollution level, from the south to the north of Poland. There are presented changes in SO2 and NO2 concentration in the air as well as loads of acidic compounds and the exceedance of critical loads in the period of 1993-2001. Response of the forest ecosystems was evaluated by changes in health status of trees and changes in biodiversity at forest permanent plots. The comparative study revealed an improvement in the health condition of trees and a tendency of ecosystems to regenerate due to greater than 30% decrease in emission in the last decade
Afficher plus [+] Moins [-]The role of roots and mycorrhizas in C-sequestration under elevated CO2 (popface)
2002
Lukac, M. | Godbold, D.L. (University of Wales, Bangor (United Kingdom). SAFS)
The need to assess the role of terrestrial ecosystems in the global C cycle and the potential change of this role as the atmospheric concentration of CO2 increases attracted considerable scientific attention over the recent decade. In order to assess ecosystem responses as a whole and to evaluate the potential role of forests and tree communities as a carbon sinks, the below-ground response to increasing levels of CO2 must be addressed
Afficher plus [+] Moins [-]Moderation of CO2 induced gas exchange and growth responses by elevated tropospheric O3
2002
Karnosky, D. F. (Michigan Technological University, Houghton (USA). School of Forestry and Wood Products) | Sober, A. | Sharma, P. | Kubiske, M. | Isebrands, J.G.
Stimulation of photosynthesis by elevated CO2 has been consistently found for aspen but not for maple. Similar responses have been shown for growth. In contrast, O3 causes decreased levels of photosynthesis and growth in aspen but does not appear to impact sugar maple significantly. When the pollutants co-occur, CO2 induced enhancements in photosynthesis and growth are moderated so that trees in CO2 and O3 treatments respond similarly to those in control rings. In this presentation, we will provide a physiological interpretation of our results in modelling growth response under future atmospheric conditions
Afficher plus [+] Moins [-]Soil microorganisms suppressed by emissions of a magnesite plant in the Slovak Republic
2002
Kautz, G. (University of Cologne, Cologne (Germany). Institute of Zoology) | Zimmer, M. | Zach, P.: Kulfan, J. | Topp, W. | Zelinkova, D.
Soil microorganisms are important for plant growth and beneficial for the nutrition and the development of a variety of soil animals. Together with soil invertebrates they also improve nutrients availability in soils. Although not frequent in Europe , magnesite emissions can affect the nutritional status of the vegetation and the survival of soil microorganisms as well as other biota locally, and thus may be crucially responsible for the quality of the entire biotic system. The observed gradients of soil microbial characteristics reflect the physico-chemical properties of soils around the magnesite plant and may be used to predict transitory changes during amelioration
Afficher plus [+] Moins [-]The effect of nitrogen fertilization on fungistatic phenolic compounds in roots of beech (Fagus sylvatica L.) and Norway spruce (Picea abies L. [Karst.])
2002
Tomova, L. | Braun, S. | Fluckiger, W. (Institute for Applied Plant Biology, Schonenbuch, (Switzerland))
The phenolic compounds showed different responses to fertilization. Fine roots of beech showed a significant decrease of (-) epicateching (84-99%) and pecatannol (78-98%) with nitrogen fertilization. Fine roots of fertilized Norway spruce showed decreased concentrations of 4-hydroxyacetophenone (33-48%), p-coumaric acid (44-64%), and pecatannol (36-61%). Concentration of p-hydroxybenzoic acid and protocatechuic acid were significantly higher in no fertilized roots. However in both tree species fertilization had no effect on vanillin and quercetin concentration in fine roots. It is suggested that roots of beech and Norway spruce are more susceptible to attacks of pathogens when they are exposed to impact of nitrogen
Afficher plus [+] Moins [-]Throughfall and canopy interactions in five different tree species in Denmark
2002
Hansen, K. | Bastrup-Birk, A. | Hovmand, M.F. (Danish Forest and Landscape Research Institute, Hoersholm (Denmark))
Acidification of forest soils is dependent on the tree species for several reasons. One reason is that the deposition to deciduous tree species normally is considered lower than to coniferous tree species. This study therefore considers the differences in deposition to different tree species in Denmark. Canopy throughfall and precipitation were collected during the period 1986 to 1999 at three trial species experimental sites in Denmark. At each site the species Norway spruce, sitka spruce, Douglas fir, beech and oak were studied. The paper presents and discusses the differences in canopy exchange processes and dry deposition in different tree species and at different locations
Afficher plus [+] Moins [-]Soil acidification in Swiss forest ecosystems
2002
Braun, S. (Institute for Applied Plant Biology, Schonenbuch, (Switzerland)) | Kurz, D. | Fluckiger, W.
Soil water measurements in Swiss forest plots show a decrease of the ratio between base cations and aluminium within last 4 years. The decrease is significant in at least one soil layer in 12 of 14 plots and is strongest in areas with high acid deposition. In some of the soils the critical ratio of 1 is being reached today. The development is compared with model estimates. In Switzerland, 80% of acid deposition is made up by nitrogen compounds
Afficher plus [+] Moins [-]The Sikfokut forest dirt study: early results from a successful LTER/ILTER cross-site collaboration
2002
Vanderbilt, K. (University of New Mexico, Albuquerque (USA). Department of Biology) | Toth, J. A. | Caldwell, B. | Bowden, R. | Lajtha, K.
A DIRT (Detritus Input and Removal Treatments) experiment was initiated at the Sikfokut Forest LTER site in Hungary in November 2000. This study was designed to evaluate how sources and quantities of litter inputs control nutrient cycling and carbon storage in forest soils across sites with different climate, C and N status. Sikfokut Forest was selected for its high N deposition rate compared the Harvard Forest LTER, Bousson Forest and Andrews Forest LTER DIRT experiment sites in the United States. Trends in soil enzyme phosphatase and beta-glucosidase activity at Sikfokut indicate that the microbial community there is already clearly responding to reduced litter availability after only two years of treatment
Afficher plus [+] Moins [-]Elemental composition of lime wood response to atmospheric deposition
2002
Mankovska, B. (Forest Research Institute, Zvolen (Slovak Republic)) | Popierova, D. | Florek, M. | Frontasyeva, V. | Yermakova, L. | Antoni, J.
Instrumental neutron activation analysis was used for determination of element concentration in 10 year old segments of lime wood in extremely polluted area in Central Spis. We found the highest concentrations of Al, As, Au, Br, Cl, K, Na, Rb, Sb and Sm in the oldest 80-90 year old forest. The same elements were determined in atmospheric deposition with moss bio-monitoring technique. In the area of Central Spis we found in comparison with Norwegian limit values exceeded levels for the elements as given similarly for comparison with Magnitogorsk in Ural Mountains
Afficher plus [+] Moins [-]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
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