Ground-level ozone (O₃) is created by the chemical reactions between pollutants such as nitrogen oxides and volatile organic compounds in the presence of sunlight. For humans, it can aggravate respiratory diseases, causing premature deaths. For sensitive plants and trees, higher concentrations of ozone in the atmosphere can reduce photosynthesis, growth and resilience to drought, resulting in lower yields of important crops such as wheat. It also restricts the growth of forests – which in turn reduces their potential to sequester carbon from the atmosphere. 

Rising temperatures associated with climate change, as well as land-use changes and industrial development, will increase ozone production. However, there are few actual measurements of ground-level ozone, and its potential effects on tropical forests are not well understood. More research will inform restoration activities, including decisions over which types of trees to grow and where.

To address this, the UK Centre for Ecology & Hydrology (UKCEH) has launched a campaign to collect some of the first ever data on ground-level ozone concentrations in restoration forests in Africa, and WeForest staff are taking part. To collect the data, we’re placing ozone diffusion tubes (pictured) at our Katanino and Mulanje project sites, into which ozone from the atmosphere is collected in absorbent material. Each tube is left for 3-4 weeks in the field and then sent back to the UK for analysis.

“This work marks the start of a new research collaboration with UKCEH, and we hope that the data collected will support the case for more research into ozone and forest restoration,” says WeForest’s Research Officer, Rachel Cohen.  

Dr. Felicity Hayes of UKCEH adds: “We are delighted to work with WeForest in this project. Understanding the ozone concentrations in forests in Africa is an important first step in assessing the risks of ozone pollution to forest restoration efforts and the implications for the wider benefits that these projects deliver.”