Why study the impacts of O3?
In the lower atmosphere (troposphere) ozone (O3) is considered a major atmospheric pollutant posing a risk to both human health and plant growth around the world. On average, tropospheric O3 has doubled since 1850 due to emissions from vehicles, industrial processes, and the burning of forests, and is now considered responsible for substantial losses in primary productivity around the globe.
At the same time, across much of the tropics we are continuing to see increases in the emission of O3 precursors as a result of population growth, urbanization and land conversion for agriculture. When coupled to high temperatures and generally high levels of volatile organic carbon (VOC’s) emitted by tropical vegetation it is likely that O3 responsiveness will emerge as a significant factor in limiting tropical forests and agronomic productivity in the coming decades.
O3 reduces plant productivity by entering leaves, generating reactive oxygen species and causing oxidative stress. This in turn increases respiration and decreases photosynthesis, with consequences on plant growth and the overall terrestrial carbon sink. Tropical forests were highlighted in Sitch et al. (2007) as potentially the most vulnerable system to future O3 scenarios given their high productivity, generally high stomatal conductance and environmental conditions conducive to O3 uptake. However, little is known about how changing air quality in the tropics impacts both natural and agricultural landscapes nor how this may impact land-atmosphere feedbacks.
TropOz 