Increasing interannual and altitudinal ozone mixing ratios in the Catalan Pyrenees

Díaz-de-Quijano M., Peñuelas J., Ribas A. (2009) Increasing interannual and altitudinal ozone mixing ratios in the Catalan Pyrenees. Atmospheric Environment. 43: 6049-6057.
Enllaç
Doi: 10.1016/j.atmosenv.2009.08.035

Resum:

Interannual, seasonal, daily and altitudinal patterns of tropospheric ozone mixing ratios, as well as ozone phytotoxicity and the relationship with NOx precursors and meteorological variables were monitored in the Central Catalan Pyrenees (Meranges valley and Forest of Guils) over a period of 5 years (2004-2008). Biweekly measurements using Radiello passive samplers were taken along two altitudinal transects comprised of thirteen stations ranging from 1040 to 2300 m a.s.l. Visual symptoms of ozone damage in Bel-W3 tobacco cultivars were evaluated biweekly for the first three years (2004-2006). High ozone mixing ratios, always above forest and vegetation protection AOT40 thresholds, were monitored every year. In the last 14 years, the AOT40 (Apr-Sept.) has increased significantly by 1047 μg m-3 h per year. Annual means of ozone mixing ratios ranged between 38 and 67 ppbv (38 and 74 ppbv during the warm period) at the highest site (2300 m) and increased at a rate of 5.1 ppbv year-1. The ozone mixing ratios were also on average 35-38% greater during the warm period and had a characteristic daily pattern with minimum values in the early morning, a rise during the morning and a decline overnight, that was less marked the higher the altitude. Whereas ozone mixing ratios increased significantly with altitude from 35 ppbv at 1040 m-56 ppbv at 2300 m (on average for 2004-2007 period), NO2 mixing ratios decreased with altitude from 5.5 ppbv at 1040 m-1 ppbv at 2300 m. The analysis of meteorological variables and NOx values suggests that the ozone mainly originated from urban areas and was transported to high-mountain sites, remaining aloft in absence of NO. Ozone damage rates increased with altitude in response to increasing O3 mixing ratios and a possible increase in O3 uptake due to more favorable microclimatic conditions found at higher altitude, which confirms Bel-W3 as a suitable biomonitor for ozone concentrations during summer time. Compared to the valley-bottom site the annual means of ozone mixing ratios are 37% larger in the higher sites. Thus the AOT40 for the forest and vegetation protection threshold is greatly exceeded at higher sites. This could have substantial effects on plant life at high altitudes in the Pyrenees. © 2009 Elsevier Ltd. All rights reserved.

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Airborne trace element pollution in 11 European cities assessed by exposure of standardised ryegrass cultures

Klumpp A., Ansel W., Klumpp G., Breuer J., Vergne P., Sanz M.J., Rasmussen S., Ro-Poulsen H., Ribas Artola A., Peñuelas J., He S., Garrec J.P., Calatayud V. (2009) Airborne trace element pollution in 11 European cities assessed by exposure of standardised ryegrass cultures. Atmospheric Environment. 43: 329-339.
Enllaç
Doi: 10.1016/j.atmosenv.2008.09.040

Resum:

Within a European biomonitoring programme, Italian ryegrass (Lolium multiflorum Lam.) was employed as accumulative bioindicator of airborne trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, V, Zn) in urban agglomerations. Applying a highly standardised method, grass cultures were exposed for consecutive periods of four weeks each to ambient air at up to 100 sites in 11 cities during 2000-2002. Results of the 2001 exposure experiments revealed a clear differentiation of trace element pollution within and among local monitoring networks. Pollution was influenced particularly by traffic emissions. Especially Sb, Pb, Cr, Fe, and Cu exhibited a very uneven distribution within the municipal areas with strong accumulation in plants from traffic-exposed sites in the city centres and close to major roads, and moderate to low levels in plants exposed at suburban or rural sites. Accumulation of Ni and V was influenced by other emission sources. The biomonitoring sites located in Spanish city centres featured a much higher pollution load by trace elements than those in other cities of the network, confirming previously reported findings obtained by chemical analyses of dust deposition and aerosols. At some heavily-trafficked sites, legal thresholds for Cu, Pb, and V contents in foodstuff and animal feed were reached or even surpassed. The study confirmed that the standardised grass exposure is a useful and reliable tool to monitor and to assess environmental levels of potentially toxic compounds of particulate matter. © 2008 Elsevier Ltd. All rights reserved.

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Disseny i aplicació d’una proposta d’aprenentatge cooperatiu dels continguts de l’àrea d’Ecologia mitjançant l’estudi de casos. En “Cap a l’espai europeu d’educació superior. Experiències docents innovadores de la UAB en ciències experimentals i tecnol

Rodrigo A, Martínez-Vilalta J, Piñol J, Lloret F, Ribas A, Retana J, Losarcos J (2008) Disseny i aplicació d’una proposta d’aprenentatge cooperatiu dels continguts de l’àrea d’Ecologia mitjançant l’estudi de casos. En “Cap a l’espai europeu d’educació superior. Experiències docents innovadores de la UAB en ciències experimentals i tecnol ogies i en ciències de la salut”. Servei de Publicacions UAB. Bellaterra

Climate change effects on Mediterranean forests: from observations to experimentation, from genetics to remote sensing.

Peñuelas J., Estiarte M, Ogaya R, Filella I, Jump A, Garbulsky M, Sardans J., Llusià J, Seco R, Alessio G., Hunt J, Owen S, Asensio D, Prieto P, Ribas A, Carrillo B, Blanch S, Coll M, Kefauer S, Stefanescu C, Lloret F, Terradas J (2007) Climate change effects on Mediterranean forests: from observations to experimentation, from genetics to remote sensing. Afforestation and sustainable forests as means to combat desertification. 16-19 April Jerusalem, Israel, p. 50.

Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

Klumpp A., Ansel W., Klumpp G., Calatayud V., Garrec J.P., He S., Peñuelas J., Ribas À., Ro-Poulsen H., Rasmussen S., Sanz M.J., Vergne P. (2006) Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities. Environmental Pollution. 139: 515-522.
Enllaç
Doi: 10.1016/j.envpol.2005.05.021

Resum:

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone #4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. © 2005 Elsevier Ltd. All rights reserved.

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Ozone pollution and ozone biomonitoring in European cities. Part I: Ozone concentrations and cumulative exposure indices at urban and suburban sites

Klumpp A., Ansel W., Klumpp G., Calatayud V., Pierre Garrec J., He S., Peñuelas J., Ribas A., Ro-Poulsen H., Rasmussen S., Sanz M.J., Vergne P. (2006) Ozone pollution and ozone biomonitoring in European cities. Part I: Ozone concentrations and cumulative exposure indices at urban and suburban sites. Atmospheric Environment. 40: 7963-7974.
Enllaç
Doi: 10.1016/j.atmosenv.2006.07.017

Resum:

In the frame of a European research project on air quality in urban agglomerations, data on ozone concentrations from 23 automated urban and suburban monitoring stations in 11 cities from seven countries were analysed and evaluated. Daily and summer mean and maximum concentrations were computed based on hourly mean values, and cumulative ozone exposure indices (Accumulated exposure Over a Threshold of 40 ppb (AOT40), AOT20) were calculated. The diurnal profiles showed a characteristic pattern in most city centres, with minimum values in the early morning hours, a strong rise during the morning, peak concentrations in the afternoon, and a decline during the night. The widest amplitudes between minimum and maximum values were found in central and southern European cities such as Düsseldorf, Verona, Klagenfurt, Lyon or Barcelona. In the northern European cities of Edinburgh and Copenhagen, by contrast, maximum values were lower and diurnal variation was much smaller. Based on ozone concentrations as well as on cumulative exposure indices, a clear north-south gradient in ozone pollution, with increasing levels from northern and northwestern sites to central and southern European sites, was observed. Only the Spanish cities did not fit this pattern; there, ozone levels were again lower than in central European cities, probably due to the direct influence of strong car traffic emissions. In general, ozone concentrations and cumulative exposure were significantly higher at suburban sites than at urban and traffic-exposed sites. When applying the newly established European Union (EU) Directive on ozone pollution in ambient air, it was demonstrated that the target value for the protection of human health was regularly surpassed at urban as well as suburban sites, particularly in cities in Austria, France, northern Italy and southern Germany. European target values and long-term objectives for the protection of vegetation expressed as AOT40 were also exceeded at many monitoring sites. © 2006 Elsevier Ltd. All rights reserved.

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Ozone pollution and ozone biomonitoring in European cities Part II. Ozone-induced plant injury and its relationship with descriptors of ozone pollution

Klumpp A., Ansel W., Klumpp G., Vergne P., Sifakis N., Sanz M.J., Rasmussen S., Ro-Poulsen H., Ribas A., Peñuelas J., Kambezidis H., He S., Garrec J.P., Calatayud V. (2006) Ozone pollution and ozone biomonitoring in European cities Part II. Ozone-induced plant injury and its relationship with descriptors of ozone pollution. Atmospheric Environment. 40: 7437-7448.
Enllaç
Doi: 10.1016/j.atmosenv.2006.07.001

Resum:

Within the scope of a biomonitoring study conducted in twelve urban agglomerations in eight European countries, the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was employed in order to assess the occurrence of phytotoxic ozone effects at urban, suburban, rural and traffic-exposed sites. The tobacco plants were exposed to ambient air for biweekly periods at up to 100 biomonitoring sites from 2000 to 2002. Special emphasis was placed upon methodological standardisation of plant cultivation, field exposure and injury assessment. Ozone-induced leaf injury showed a clearly increasing gradient from northern and northwestern Europe to central and southern European locations. The strongest ozone impact occurred at the exposure sites in Lyon and Barcelona, while in Edinburgh, Sheffield, Copenhagen and Düsseldorf only weak to moderate ozone effects were registered. Between-site differences within local networks were relatively small, but seasonal and inter-annual differences were strong due to the variability of meteorological conditions and related ozone concentrations. The 2001 data revealed a significant relationship between foliar injury degree and various descriptors of ozone pollution such as mean value, AOT20 and AOT40. Examining individual sites of the local monitoring networks separately, however, yielded noticeable differences. Some sites showed no association between ozone pollution and ozone-induced effects, whereas others featured almost linear relationships. This is because the actual ozone flux into the leaf, which is modified by various environmental factors, rather than ambient ozone concentration determines the effects on plants. The advantage of sensitive bioindicators like tobacco Bel-W3 is that the impact of the effectively absorbed ozone dose can directly be measured. © 2006 Elsevier Ltd. All rights reserved.

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Surface ozone mixing ratio increase with altitude in a transect in the Catalan Pyrenees

Ribas A., Peñuelas J. (2006) Surface ozone mixing ratio increase with altitude in a transect in the Catalan Pyrenees. Atmospheric Environment. 40: 7308-7315.
Enllaç
Doi: 10.1016/j.atmosenv.2006.06.039

Resum:

Tropospheric ozone mixing ratios and their phytotoxicity and NO2 mixing ratios were measured along an altitudinal gradient at the Meranges valley in the Catalan Pyrenees. Biweekly measurements using Radiello passive samplers were taken along a transect of seven stations ranging from 1040 to 2400 m ASL from May to December 2004. As well, at each station biweekly evaluations were made of the visual symptoms of ozone damage in Bel-W3 and Bel-B tobacco cultivars. Whereas ozone mixing ratios increased with altitude, NO2 mixing ratios decreased from the valley floor upwards. Ozone damage rates were found to vary with time and space depending on local environmental and meteorological conditions, although the highest ozone damage to foliage was found in the stations at greatest altitude, especially wherever altitudinal micrometeorological conditions enhanced plant sensitivity. © 2006 Elsevier Ltd. All rights reserved.

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Using plant biomonitors and flux modelling to develop O 3 dose-response relationships in Catalonia

Filella I., Peñuelas J., Ribas A. (2005) Using plant biomonitors and flux modelling to develop O 3 dose-response relationships in Catalonia. Environmental Pollution. 134: 145-151.
Enllaç
Doi: 10.1016/j.envpol.2004.07.007

Resum:

We used tobacco Bel-W3 biomonitoring data and ozone flux modelling (WINDEP model) with the aim of developing the absorbed dose-response relationship, and comparing this approach with the most commonly used AOT40 (the sum of hourly ozone concentrations above a cut-off of 40 ppb during daylight hours, when global radiation exceeds 50 W m -2) in the estimation of exposure-damage curves. Leaf damage values were more related to OAD 15 days, potential (potential ozone absorbed dose calculated over 15 consecutive days) than to AOT40 in all the studied stations. An OAD 15 days, potential of 180 mg m -2 was found to be the threshold for damage to the most sensitive species in this region under well watered conditions. The results show the applicability of the flux approach for risk assessment at the local scale, the improvement of the ozone damage estimation when the potential absorbed dose is modelled and used instead of just the ozone exposure, and finally, the possibilities opened by the use of biomonitoring networks. Modelling of biomonitors ozone absorbed dose improves damage estimation in comparison with exposure indices such as AOT40. © 2004 Elsevier Ltd. All rights reserved.

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Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

Ribas A., Peñuelas J., Elvira S., Gimeno B.S. (2005) Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species. Environmental Pollution. 134: 291-300.
Enllaç
Doi: 10.1016/j.envpol.2004.07.026

Resum:

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O 3) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb v of O 3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of δ 13C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in δ 15N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, δ 15N, chlorophyll, leaf area, LMA and biomass occurred at ambient O 3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. Ozone induces species-specific leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species. © 2004 Elsevier Ltd. All rights reserved.

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