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The evidence of detrimental effects of ozone on vegetation in Europe, and the need to develop international control policies to reduce ozone exposures which are based on the effects of the pollutant, has led to attempts to define so-called critical levels of ozone above which adverse effects on trees, crops and natural vegetation may occur. This review is a(More)
This overview of experimentally induced effects of ozone aims to identify physiological and ecological principles, which can be used to classify the sensitivity to ozone of temperate grassland communities in Europe. The analysis of data from experiments with single plants, binary mixtures and multi-species communities illustrates the difficulties to relate(More)
Research on the effects of ozone on agricultural crops and agro-ecosystems is needed for the development of regional emission reduction strategies, to underpin practical recommendations aiming to increase the sustainability of agricultural land management in a changing environment, and to secure food supply in regions with rapidly growing populations. Major(More)
We investigated the relationship between the δ13C signal in current-year and 1-year-old needle bulk material, starch extracts, and early- or late-wood in mature spruce trees (Picea abies) to identify the modifying influence of climatic conditions on the different δ13C signals. Seasonal patterns of δ13C were determined in total bulk needle material from 1998(More)
A field experiment was established at 2000 m above sea level (asl) in the central Swiss Alps with the aim of investigating the effects of elevated ozone (O(3)) and nitrogen deposition (N), and of their combination, on above-ground productivity and species composition of subalpine grassland. One hundred and eighty monoliths were extracted from a species-rich(More)
Ozone is the most important regional-scale air pollutant causing risks for vegetation and human health in many parts of the world. Ozone impacts on yield and quality of crops and pastures depend on precursor emissions, atmospheric transport and leaf uptake and on the plant’s biochemical defence capacity, all of which are influenced by changing climatic(More)
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate–carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO 2 exchange with the atmosphere(More)
Seasonal trends in leaf gas exchange and ozone-induced visible foliar injury were investigated for three ozone sensitive woody plant species. Seedlings of Populus nigra L., Viburnum lantana L., and Fraxinus excelsior L. were grown in charcoal-filtered chambers, non-filtered chambers and open plots. Injury assessments and leaf gas exchange measurements were(More)
Brown knapweed (Centaurea jacea L.) has been suggested as a potential bioindicator for tropospheric ozone (O3), but little is known about the intra-specific variation in O3 sensitivity in this wild species. The aim of this study was to quantify the differences in O3 sensitivity among and within five populations, and to relate the differences to(More)