A survey of ground-level ozone levels in reforested parts of Africa will support the UK Centre for Ecology & Hydrology’s research into the impacts of the pollutant on restoration activities.

In the stratosphere, ozone performs a protective role against harmful ultraviolet radiation from the sun, but increased concentrations of the chemical at lower levels of the atmosphere pose a threat to human and animal health, restrict plant growth and contribute to climate change.

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 better decisions over which type of trees to plant and where.

The UK Centre for Ecology & Hydrology (UKCEH) has teamed up WeForest – an international non-profit organisation that conserves and restores forests – to collect ozone data.

Staff at WeForest are placing ozone diffusion tubes, which collect traces of the chemical from the atmosphere in absorbent material, at its project sites in Katanino, Zambia, and Mulanje, Malawi. Each tube will be left for around four weeks in the field and then sent back to the UK for analysis.

Dr Felicity Hayes of UKCEH says: “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.”

WeForest research officer Rachel Cohen explains this is a new area for Restoration Science, adding: “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.” 

Ground-level ozone 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.  

For information on UKCEH’s research into ozone pollution, see our project page.