Why lichens are bad monitors of ozone pollution?
| Autor: | Linda Davies, Stefano Bertuzzi, Mauro Tretiach, Sally A. Power |
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| Přispěvatelé: | Bertuzzi, Stefano, Davies, L., Power, S. A., Tretiach, Mauro |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Ozone pollution
Pollutant Chlorophyll a Ozone Ecology AOT40 Chlorophyll a fluorescence Macrolichens O3 OTC Photochemical pollutants Macrolichen General Decision Sciences chemistry.chemical_compound Recovery period chemistry Environmental chemistry Chlorophyll Epiphyte Lichen Ecology Evolution Behavior and Systematics |
| Popis: | The combined effects of water availability and ozone (O 3 ) on chlorophyll a fluorescence (Chl a F) were studied in three epiphytic lichens selected for their different ecology. The samples were exposed in open top chambers (OTCs) under different watering regimes with O 3 AOT40 in the range 0–50,000 ppb. Further samples were exposed in a nearby wood, as controls. Chl a F measurements were taken before exposure, after 3- and 6-week exposure and after a subsequent 2-day recovery period to verify the long-term effects of O 3 exposure. All species tolerated the pollutant well. However, there was a strong influence associated with the mode of exposure: the Chl a F emission remained steady over time in the controls, whereas it varied significantly in chamber-exposed samples, with a strong decrease of F v / F m in non-watered and morning-watered samples, and a small decrease in evening-watered samples. Chl a F emission characteristics were also influenced by the weather conditions of the day preceding measurements, with some species-specific differences possibly related to species ecology. The ozone-tolerance of lichens is thoroughly discussed on the basis of the cellular mechanisms that allow these organisms to overcome the oxidative burst associated with the cycles of dehydration–rehydration typical of poikilohydrous organisms. |
| Databáze: | OpenAIRE |
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