Ozone Level Assessment on the Boukornine National Park (Tunisia) using Plant Biomonitoring: Influence of Altitudinal Parameter and Meteorological Conditions

Abstract

The variations of tropospheric ozone levels was assessed for the first time in the Boukornine National Park (N.E. Tunisia) by detection of leaf injury development on Nicotiana tabacum "Bel-W3" exposed to environmental conditions during summer 2004. Two cultivars of tobacco (Nicotiana tabacum), Bel-W3 (sensitive) and Bel-B (resistant to ozone), were used for this biomonitoring study. These cultivars were dispersed in 24 different biostations, according to a square grid mesh, every 2 weeks. Four successive cultures were utilized to follow the ozone levels inside the park during the summer exposure period. Levels of ozone may vary in time and space depending on the local environmental and meteorological conditions. The results showed a positive correlation between ozone concentration and foliar injury index (FII; r=0.958; p<0.05). A significant positive correlation was observed between the FII of Bel-W3 tobacco plant and AOT40 (accumulated over the threshold of 40 ppb). The altitude appeared to be the most important variable explaining the variation of ozone pollution with the highest correlation coefficient (r=0.964; p<0.0001). The altitude was followed by topography for the prediction of ozone concentration levels. Maximal temperature was also an important factor in addition to the others in determining the FII and was negatively correlated with the FII (r=−0.979; p<0.05). Average ambient ozone levels were positively linked to plant leaf damage. The ozone profile characterizing the study area was primarily influenced by wind direction and speed in relation to intercontinental transport, in addition to the local influence of motor vehicles traffic flow in the Tunis region.

Climate-environment interactions under global warming

“…Using meteorological data from the period of June 2004 to July 2004 from the national park of the Tunisian coast, it is found that O 3 concentration variation in summer is closely related to weather elements such as air temperature, rainfall, and wind over the coastal region. Their experimental study suggested that the local environment and meteorological conditions significantly influence temporal and spatial variations in O 3 distribution (Mechergui et al, 2009). Alghamdi et al investigated the effects of relevant meteorological variables on frequently high NO 2 and O 3 concentrations in the coastal cities of Saudi Arabia in 2012-2013. They discussed the influence of seasonal variations under meteorological conditions on the O 3 concentration and indicated that O 3 concentration values peak in the summer and drop in the winter (Andreas and Jochen 2004).…”

Changes in the height of the pollution boundary layer and their meteorological effects on the distribution of surface ozone concentrations

“…Using meteorological data from the period of June 2004 to July 2004 from the national park of the Tunisian coast, it is found that O 3 concentration variation in summer is closely related to weather elements such as air temperature, rainfall, and wind over the coastal region. Their experimental study suggested that the local environment and meteorological conditions significantly influence temporal and spatial variations in O 3 distribution (Mechergui et al, 2009). Alghamdi et al investigated the effects of relevant meteorological variables on frequently high NO 2 and O 3 concentrations in the coastal cities of Saudi Arabia in 2012-2013.…”