Annex 3.
KoL 09-2-7-6d
Open-top chambers have been widely used to investigate the effects of ozone on plants under fairly realistic
conditions. The atmospheric environment can be altered by filtration or addition of pollutants. The photo
shows ozone exposure in a wheat field at Östads Säteri, south-west Sweden, where a large number of opentop chamber experiments were conducted from the late 1980s to the early 2000s. Photo: Håkan Pleijel
Special issue of AMBIO “Ozone exposure and impacts on vegetation in
the Nordic and Baltic Countries”
2009-08-13
1. The significance of the ozone flux concept for abatement of negative ozone
impacts on vegetation in northern Europe (introductory article)
Karlsson, P.E., Pleijel, H., Simpson, D.
Type: Article
Not yet completed
Abstract
Not yet available
2. Near-ambient ozone concentrations reduce the vigor of Betula and Populus
species in Finland
Oksanen Elina1, Manninen Sirkku2, Vapaavuori Elina3, Holopainen Toini4
1University of Joensuu, Faculty of Biosciences, 80101 Joensuu, Finland
2University of Helsinki, Department of Biological and Environmental Sciences, 00014 Helsinki University,
Finland
3Finnish Forest Research Institute, Suonenjoki Research Unit, 77600 Suonenjoki, Finland
4University of Kuopio, Department of Environmental Science, 70211 Kuopio, Finland
Type: Article
Abstract:
In this review the main growth responses of Finnish birch (Betula pendula, Betula
pubescens) and aspen species Populus tremula and Populus tremuloides x P. tremula) are
correlated with ozone exposure, indicated as AOT40 value. Data are derived from 23
different laboratory, open-top chamber and free-air fumigation experiments. Our results
indicate that these tree species are sensitive to increasing ozone concentrations, though
high intra-specific variation exists. The roots are the most vulnerable targets in both
genera. These growth reductions, determined from trees grown under optimal nutrient
and water supply, were generally accompanied by increased visible foliar injuries, carbon
allocation towards defensive compounds, reduced carbohydrate contents of leaves,
impaired photosynthesis processes, disturbances in stomatal function and earlier autumn
senescence. Because both genera have shown complex ozone defence and response
mechanisms, which are modified by variable environmental conditions, a mechanistically
based approach is necessary for accurate ozone risk assessment.
3. IMPACT OF EXPERIMENTALLY ELEVATED OZONE ON SEED
GERMINATION AND GROWTH OF RUSSIAN PINE (PINUS SYLVESTRIS)
AND SPRUCE (PICEA SPP.) PROVENANCES
Nadezda Prozherina1, Elena Nakvasina2, Elina Oksanen3
1 Institute of Ecological Problems in the North UB RAS, Arkhangelsk, Russia
2Arkhangelsk State Technical University, Arkhangelsk, Russia
3 Faculty of Biosciences, University of Joensuu, PO Box 111, FI-80101 Joensuu, Finland
Type: Report
Abstract:
Impact of elevated ozone concentrations on early ontogenetic stages of pine (Pinus
sylvestris) and spruce (Picea abies, P. obovata, P. abies x P. obovata) seedlings originated
from different provenances in Russia were studied in the open-field ozone fumigation
system located in Kuopio, Finland, over two years. AOT40 was 11 ppm h per growing
season, being 1.4 times higher as compared to the ambient air concentration. The plants
were measured for germination rate, shoot increment, needle length, and dry mass of
needles, shoots and roots. Significant differences between pine and spruce provenance
response to ozone were found in all parameters. Ozone stress reduced immediately the
germination rate of Northern pine provenances, whereas biomass reductions became
evident during the second year of the exposure in all pine provenances. Spruce species
were more tolerant to elevated ozone concentrations. Our results indicate that seedling
development is vulnerable to increasing ozone concentrations and that attention has to be
paid to the provenance selection.
Reviewers:
4. Rising atmospheric CO2 concentration partially masks the negative effects of
elevated O3 in silver birch (Betula pendula Roth)
Vapaavuori, Elina1, Holopainen, Jarmo K.2, Holopainen, Toini2, Julkunen-Tiitto,
Riitta3, Kaakinen, Seija1, Kasurinen, Anne2, Kontunen-Soppela, Sari1,3, Kostiainen,
Katri1, Oksanen, Elina3, Peltonen, Petri1,3, Riikonen, Johanna1,2, Tulva, Ingmar4
1Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki, Finland
2Department of Environmental Science, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland
3Faculty of Biosciences, University of Joensuu, PO Box 111, FI-80101 Joensuu, Finland
4Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia
Type: Article
Abstract:
This review summarizes the main results from a 3-yr open top chamber experiment, with
two silver birch (Betula pendula Roth) clones (4 and 80) where impacts of 2x ambient
[CO2] (EC) and [O3] (EO) and their combination (EC+EO) were examined. Growth,
physiology of the foliage and root systems, crown structure, wood properties, and
biological interactions were assessed to understand the effects of a future climate on the
biology of silver birch. The clones displayed great differences to EC and EO. Growth in
clone 80 increased by 40% in EC and this clone also appeared O3-tolerant showing no
growth reduction. In contrast, growth in clone 4 was not enhanced by EC, and EO
reduced growth with root growth being most affected. The physiological responses of the
clones to EO were smaller than expected. We found no O3 effect on net photosynthesis in
either of the clones and many parameters indicated no change compared with chamber
controls suggesting active detoxification and defense in foliage. In EO, common for both
clones was the increased rhizospheric respiration over time and accelerated leaf
senescence. We assumed that elevated O3 offsets the positive effects of elevated CO2
when exposed to combined EC+EO treatment. In contrast, the responses in EC+EO
mostly resembled the ones in EC, at least partly due to stomatal closure and thus reduced
O3 flux to the leaves. However, clear cellular level symptoms of oxidative stress were
observed also in EC+EO. Thus, we conclude that EC masked most of the negative O3
effects during long exposure of birch to EC+EO. Biotic interactions were not heavily
affected. Only some early season defoliators may suffer from faster maturation of leaves
due to EO.
5. Ambient Ozone Concentration and Its Impact on Forest Vegetation in Lithuania
Rasa Girgždienė1, Brigita Serafinavičiūtė2, Vidas Stakėnas2, Steigvilė Byčenkienė1
1 Institute of Physics, Savanoriu 231, LT-02300, Vilnius, Lithuania
2 Lithuanian Forest Research Institute, Liepu 1, LT-53101, Kaunas distr., Lithuania.
Type: Article.
Abstract
Continuous ozone concentration measurements at rural sites in Lithuania were performed
since 1982. Long-term ozone data show an increasing trend 0.4 ppb yr-1 in annual mean
concentrations during the period 1982-2008, although ozone peak values show an
insignificant tendency to decrease. Several studies were performed in order to evaluate
the ozone effect on the main plant species of Lithuanian forests. A strong positive
correlation was found between values for the AOT40 index and the defoliation of
Fraxinus excelsior trees in Lithuanian forests during 1991-2008. A strong correlation was
found between ozone exposure and the proportion of healthy Fraxinus excelsior, Betula
sp. and Alnus incana tress trees indicating that in Lithuania the deciduous species are
more sensitive to ozone than conifers, and that healthier trees may be better indicators of
the changing environment. The results of the studies suggest that the observed levels of
ozone are sufficiently high to have negative effects on the vegetation in Lithuania.
6. Observations of ground-level ozone and NO2 in northernmost Sweden, including
the Scandian Mountain Range
Jenny Klingberg1, Mats Björkman1,2, Gunilla Pihl Karlsson3, and Håkan Pleijel1
1 University of Gothenburg, Plant and Environmental Sciences, P.O. Box 461, SE-405 30 Göteborg,
Sweden
2 Norwegian Polar Institute, Polar Environmental Centre, 9296 Tromsø, Norway
3 Swedish Environmental Research Institute Ltd., P.O. Box 5302, SE-400 14 Göteborg, Sweden
Type: Report
Abstract
Ozone was measured using passive diffusion samplers at alpine Latnjajaure (980 m a.s.l.)
in the northern Scandian Mountain Range during spring and summer 2006-2008, and
year round at three further sites in northernmost Sweden 2004-2008. These observations
were compared with ozone concentrations from three permanent monitoring stations,
using UV absorption instruments. Ozone concentrations at Latnjajaure were higher than
at the closest monitoring site, illustrating the importance of high elevation for ozone. At
the northern sites the ozone spring peak was more pronounced, higher and earlier (April
maximum) compared to a site in south Sweden (May maximum). During summer, ozone
concentrations were higher in south Sweden. Presently, the growing season largely starts
after the ozone spring peak in north Sweden, but is likely to start earlier in the future
climate. This could lead to an increased risk for ozone effects on vegetation if the current
yearly ozone cycle persists.
7. Evidence for impacts of near-ambient ozone concentrations on vegetation in
southern Sweden
Per Erik Karlsson1, Håkan Pleijel2, Helena Danielsson1, Gunilla Pihl Karlsson1, Kristin
Piikki3, Johan Uddling2
1 IVL Swedish Environmental Research Institute Ltd , P. O. Box 5302, SE-400 14 Göteborg, Sweden
2 Department of Plant and Environmental Sciences, University of Gothenburg, P. O. Box 461, SE-405 30
Göteborg, Sweden
3 Swedish University of Agricultural Sciences, Department of Soil and Environment, Precision agriculture
and pedometrics, P.O. Box 234, SE-532 23 Skara
Type: Article
Status: Manuscript under revision
Abstract:
Substantial impacts of near-ambient ozone concentrations on agricultural crops, trees and
semi-natural vegetation are demonstrated for southern Sweden. Impacts of ambient ozone
levels (2-15 µL L-1 h annual AOT40) range from 2 – 10 % reduction for trees (leaf
chlorophyll, tree growth) and up to 15 % reduction for crops (yield, wheat/potato). Leaf
visible injury on bioindicator plants caused by ambient ozone levels has been clearly
demonstrated. The humid climatic conditions in Sweden, promote high rates of leaf
ozone uptake at a certain ozone concentration. This is likely to explain the comparatively
large ozone impacts found for vegetation in southern Sweden at relatively low air ozone
concentrations. It is important that the future methods used for the representation of
ozone impacts on vegetation across Europe are based on the leaf ozone uptake concept
and not on concentration based exposure indices such as AOT40.
8. Effects of the Nordic photoperiod on ozone sensitivity and repair in different
clover species studied using infrared
Cecilia M. Futsaether1, Ane V. Vollsnes1, Ole Mathis Opstad Kruse1, Eli Otterholt2,
Knut Kvaal1, Aud B. Eriksen3
1 Dept. of Mathematical Sciences and Technology, Norwegian University of Life Sciences, P.O. Box 5003,
N-1432 Ås, Norway
2 Faculty of Health Sciences, Oslo University College, Pilestredet 50, 0167 Oslo, Norway
3 Dept. of Biology, University of Oslo, P.O. Box 1066, 0316 Oslo, Norway
Type: Report.
Abstract
Plants in Nordic regions can be more ozone sensitive at a given ozone concentration than
plants at lower latitudes. A recent study shows that the Nordic summer photoperiod,
particularly the dim nighttime light, can increase visible foliar injury and alter leaf
transpiration in subterranean clover. Effects of photoperiod on the ozone sensitivity of
white and red clover cultivars adapted to Nordic conditions were investigated. Although
ozone induced visible foliar injury and leaf transpirational changes in white clover, the
effects were independent of photoperiod. In red clover, ozone combined with a long
photoperiod with dim nights (eight nights) induced more severe visible injuries than with
a short photoperiod. Furthermore, transpirational changes in red clover depended on
photoperiod. Thus, a long photoperiod can increase ozone sensitivity differently in clover
cultivars with different degrees of adaptation to northern conditions, suggesting that
ozone indices used in risk analysis should take this effect into account.
9. Northern Plants and Ozone
Sirkku Manninen1, Satu Huttunen2, Hans Tømmervik3, Lars R. Hole4 and Sverre
Solberg5
1 Department of Biological and Environmental Sciences, P.O. Box 56, 00014 University of Helsinki.
Finland
2 Botany Division, Department of Biology, P.O. Box 3000, 90014 University of Oulu, Finland
3 Norwegian Institute for Nature Research (NINA), The Polar Environmental Center, 9296 Tromsø,
Norway
4 Norwegian Institute for Air Research (NILU), Tromsø office, The Polar Environmental Center, 9296
Tromsø, Norway
5 Norwegian Institute for Air Research (NILU), P.O. Box 100, 2027 Kjeller, Norway
Type: Article.
Abstract
Forests in northern Fennoscandia are mainly composed of the O3-sensitive species Scots
pine and downy, mountain and silver birches. Semi-natural vegetation also contributes to
biodiversity, carbon cycling and ecosystem services as a part of forests, mires, meadows
and road verges. Fumigation experiments show that current O3 concentrations of 30-50
ppb reduce plant biomass production and reproduction. Visible foliar injury is attributable
to peak O3 concentrations and relates to fast phenological development and high growth
rate. Trees can acclimate to O3 induced water stress by producing more xeromorphic
leaves or needles. The direct effects of O3 on grassland vegetation also translate to
changes in the structure and size of soil microbial community, and ecosystem N cycling.
It is necessary to reduce the emission of O3 precursors and maintain high biodiversity to
protect northern ecosystems. Regular, systematic, countrywide monitoring and validation
as well as quantification of the effects of O3 on plants in the Nordic countries are also
necessary.
10. Climate and emission changes contributing to changes in near-surface ozone in
Europe over the coming decades - Results from model studies
Magnuz Engardt1, Robert Bergström1,2 and Camilla Andersson1
1 Swedish Meteorological and Hydrological Institute, Norrköping
2 Department of Chemistry, University of Gothenburg
Type: Article
Abstract
We used an offcurrent and future levels of near-surface ozone and AOT40 in Europe. To describe the
current situation and enable an evaluation of the model’s performance we simulated a
number of years around 2000. To assess changes in ozone concentrations due to possible
emission changes in Europe, the model was run with the meteorology of the early 2000s
and precursor emissions from a set of CAFE emissions scenarios. By extrapolation of the
observed increase in near-surface O3 at coastal locations in northwest Europe we
constructed model boundaries that were used to simulate the impact of increasing
hemispheric background in 2020. To assess changes in ozone concentrations due to
climate change, the model was run with recent (2000) emissions but using meteorology
from a regional climate model simulating a control (1961-1990) and a future (2021-2050)
climate. The results indicate that climate change will have a small impact on ozone
concentrations and AOT40 in the Nordic countries. Changes in hemispheric background
concentrations and changes in precursor emissions in Europe will have a larger effect on
ozone in Northern Europe. The situation is quite different in southern Europe where
climate change is expected to result in a very large increase in near-surface ozone
concentrations.
11. Synoptic weather types and long-range transport patterns for ozone precursors
during high-ozone events in southern Sweden
Lin Tang1, Per Erik Karlsson2, Yongfeng Gu1, Deliang Chen1, Peringe Grennfelt2
1 University of Gothenburg, Department of Earth Sciences, P.O. Box 460, SE-405 30 Gothenburg, Sweden
2 IVL Swedish Environmental Research Institute Ltd, P.O. Box 5302, SE-400 14 Gothenburg, Sweden
Type: Report
Abstract
In this study, long-range transport patterns and related weather types are studied in
relation to high-ozone events in southern Sweden. The aim is to deepen the understanding
of the relationship between Lamb-Jenkinson weather types and surface ozone
concentration variation, thus widening the application of the weather type analysis of air
quality at four sites in this region. The long-range transport patterns associated with highozone events were classified into trajectories from WE (Western Europe), EE (Eastern
Europe) and VIC (in the vicinity of southern Sweden). The VIC type, characterised by
short and whirling curves, represented more than 40% of the high-ozone events at the
studied rural sites. More than half of the high-ozone events occurred under high-pressure
conditions, belonging to weather type A (anticyclone). The high correlation coefficient
between annual counts of weather type A and those of long-range transport pattern VIC
confirmed the strong link between stagnant weather conditions and high-ozone events,
especially during the summer. Furthermore, a strong linear anti-correlation was detected
between high-ozone events and annual counts of cyclones (weather type C) during the
summer. This relationship implies that the frequency of weather type C is a useful
indicator for low risk of summertime high-ozone events in southern Sweden. Moreover,
the relationship between the weather type and high ozone risk may be useful in
examining the potential effect of climate change on the regional air quality.