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Surface ozone influence on native vegetation: results based on ozone visible symptoms and stomatal flux
Matoušková, Leona ; Hůnová, Iva (advisor) ; Albrechtová, Jana (referee) ; Hovorka, Jan (referee)
Regarding the vegetation, the most affected areas by high levels of surface ozone (O3) are the mountain ridges. Our study has been carried out in the Jizerske hory Mts. High O3 levels together with the convenient environmental conditions for stomatal conductance could be a threat for the health of recovering ecosystems in this area. The aims of this study was both to assess the influence of O3 on vegetation in the Czech mountains and to provide recommendations and outlooks for possible future using of relatively new methods (visible symptoms and stomatal O3 flux modelling) used for O3 impact assessment on native vegetation in the field; that means physiologically relevant methods for the determination of O3 influence. During 2006 and 2007, O3-like visible symptoms were assessed on the leaves of seven species at four sites. Symptoms on only two species (Fagus sylvatica L. and Rubus idaeus L.) have been determined as O3-induced. To our knowledge, it is the first study in the Czech Republic in which the O3-like symptoms on native plants have been verified by the Ozone Validation Centre for Central Europe. Our results based on O3-induced symptoms indicate that ambient O3 is likely to have a much lower impact than expected, considering the measured O3 concentrations (measured with passive samplers) and...
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Prediction of mean hourly values of surface ozone concentrations from passive sampler measurements
Sinkulová, Michaela ; Hůnová, Iva (advisor) ; Zíková, Naděžda (referee)
In terms of air pollution, ground-level ozone is according to current knowledge, contributes the most to damage to ecosystems. To calculate the key indicators of potential damage to ecosystems, such as the exposure index AOT40 and stomatal flux, it is important to know the hourly ozone concentrations, which are the input data for both calculations. For the measurement of O3 air pollution concentrations for the purposes of environmental studies, continuous measurement is not used, but measurement by passive (diffusion) dosimeters, which are exposed for a longer period (usually 1 week-1 month) and thus indicate the average concentration for the relevant longer period. The aim of this diploma thesis is the prediction of hourly concentrations of ground-level ozone from measurements by diffusive samplers, which took place in the period 2006-2010 in Jizerské hory mountains. Monitoring always took place for 2 weeks during the vegetation seasons (April-October) at localities and at various altitudes (714 m above sea level - 1,000 m above sea level). Ogawa diffusive samplers were used. From these average and meteorological concentrations, hourly values of ground-level ozone concentrations were calculated according to the model from professional study and these were compared with measurements from an...
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Surface ozone influence on native vegetation: results based on ozone visible symptoms and stomatal flux
Matoušková, Leona ; Hůnová, Iva (advisor) ; Albrechtová, Jana (referee) ; Hovorka, Jan (referee)
Regarding the vegetation, the most affected areas by high levels of surface ozone (O3) are the mountain ridges. Our study has been carried out in the Jizerske hory Mts. High O3 levels together with the convenient environmental conditions for stomatal conductance could be a threat for the health of recovering ecosystems in this area. The aims of this study was both to assess the influence of O3 on vegetation in the Czech mountains and to provide recommendations and outlooks for possible future using of relatively new methods (visible symptoms and stomatal O3 flux modelling) used for O3 impact assessment on native vegetation in the field; that means physiologically relevant methods for the determination of O3 influence. During 2006 and 2007, O3-like visible symptoms were assessed on the leaves of seven species at four sites. Symptoms on only two species (Fagus sylvatica L. and Rubus idaeus L.) have been determined as O3-induced. To our knowledge, it is the first study in the Czech Republic in which the O3-like symptoms on native plants have been verified by the Ozone Validation Centre for Central Europe. Our results based on O3-induced symptoms indicate that ambient O3 is likely to have a much lower impact than expected, considering the measured O3 concentrations (measured with passive samplers) and...
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Estimation of exposure index for surface ozone AOT40 from diffusive sampler measurements
Pavlíková, Monika ; Hůnová, Iva (advisor) ; Matoušková, Leona (referee)
The study summerizes methods of ozone AOT40 index estimation from time intergarated passive sampler measurements in forests. Ground-level ozone is a highly phytotoxic atmospheric pollutant. In recent years negative impacts of elevated concentrations of ground-level ozone on vegetation and ecosystems have been studied and atmospheric levels of ozone have been measured. There is a noticeable negative impact of elevated concentrations of ground-level ozone on forests in the Czech Republic, mainly in rural areas that are far away from the emission sources. The AOT40F exposure index is a tool to assess the geographical areas with vegetation potentially at risk due to elevated ground-level ozone concentrations. The AOT40 index is the accumulated hourly exposure during daytime hours above cut-off concentration of 40 ppb, during the growing season. Passive samplers are used for measuring ground-level ozone in high spatial resolution. Passive samplers are easy to use. However this metod provides time intergrated values of pollutant concentrations (1-2 weeks). It is not possible to estimate AOT40 index by using just data of mean ozone concentrations over the sampling period. Three methods were used to estimate the exposure index AOT40F for forests by mean ozone concentrations measured in the Jizerské Hory...
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