Ambient Ozone Levels in the Eastern Mediterranean Region and Assessment of Its Effect on the Forested Mountain Areas of Southern Turkey

Ambient ozone measurements were conducted from the beginning of May 2003 to the end of October 2004 in the forested areas of west Mediterranean mountains of Turkey. The ozone concentrations were estimated using a passive sampling method from the bottom of the valley (altitude 10 m) to the top of the mountain (1950 m) over 20 sites distributed all over the study area. Active continuous measurements of ozone were done at one of the monitoring site and helped to calibrate the concentrations of ozone obtained by passive method. The results indicated that ozone concentrations were in the range of 19−410 μg m⁻³, the yearly average of ozone was 89.37±71.25 μg m⁻³. Generally, maximum ozone concentrations were measured at high altitude stations (1950 amsl) during the spring and summer season, and minimum concentrations were measured at the locations near to the road traffic. The sypmtoms of probable ozone injury in the vicinity of passive ozone samplers were examined by collecting needle and leaf samples from the main native plants. According to the visual inspection of leaves and measurement of photosentetic pigments of control and symptomatic leaves, out of 41 species of native plants, 11 species were identified as potential bioindicators of ozone. Ozone concentrations in the west Mediterranean part of Turkey appear to be high enough and of sufficient duration to cause foliar injury on a wide variety of native plants.