Ozone (O3) as mentioned in our previous blog post is one of the more prevalent air pollutants in our atmosphere. It is formed when Nitrogen oxides and volatile organic compounds (VOCs) from industrial sources or vehicle exhausts enters the atmosphere, and are transformed under photochemical reactions (through heat and sunlight).

Ozone is a strong oxidizing agent, and it can react with the plant’s macromolecules such as lipids, proteins, nucleic acids and carbohydrates. These macromolecules affect how plants carry out their normal biochemical and physiological functions. For example, nucleic acids form the backbone of a plants DNA, and oxidation changes its structure, leading to a modification of its function thus causing the plant system to collapse (Iriti and Faoro, 2009).

In a study conducted on plants native to Southern Switzerland, it was found that ozone causes implications to plant species, as it affects their foliar (leaf) sensitivity. This results in lower photosynthesis rates, hence affecting the plant’s physiological function. Plants that were affected by ozone exhibited symptoms like discolouration (reddening, yellowing or bronzing) and stippling on their upper leaves. Symptoms were also found to have increased during peak ozone episodes, and have also led to leaf abscission (shedding away of leaves) (Novak et al., 2003).

Sustained damage from ozone will affect forest health as a whole, posing a threat of extinction to native species. As mentioned in earlier posts, the extinction of such native species will be detrimental to those reliant on them, furthermore, it will also close off many of the important ecosystem services.

 

References

Iriti, M., & Faoro, F. (2009). Chemical diversity and defence metabolism: how plants cope with pathogens and ozone pollution. International journal of molecular sciences, 10(8), 3371-3399.

Novak, K., Skelly, J. M., Schaub, M., Kräuchi, N., Hug, C., Landolt, W., & Bleuler, P. (2003). Ozone air pollution and foliar injury development on native plants of Switzerland. Environmental Pollution, 125(1), 41-52.