Chernobyl - a radioactive ecosystem on fire (CHAR)

Starting in early April 2020, wildfires have, to date, burnt about 500 square km of land in the Ukrainian Chernobyl Exclusion Zone (CEZ). Formed as a result of evacuation following the 1986 accident at the Chernobyl nuclear power plant, the CEZ (2600 square km) and the adjoining similar sized area of Belarus now constitute the third largest nature reserve in mainland Europe. Although levels of radioactivity remain high in some areas of the CEZ and it includes the world's most radiologically contaminated ecosystems, the CEZ is internationally recognised as an iconic example of rewilding (ecosystem recovery/restoration). The current fires are the worst in the 34 y history of the CEZ and have decimated large areas of forest and former meadow land, including in the most contaminated areas. These fires have the potential to remobilise contamination, modify ecosystem services and result in long-term habitat change. Given the importance of the CEZ as a natural laboratory, research into the impacts of the fires needs to start as soon as possible. This urgent research activity must capitalise on the opportunity to learn how fire affects radiologically contaminated landscapes whilst also establishing post-fire baseline data to underpin future CEZ research.

CHAR brings together an interdisciplinary network (from hydrology to social science) of three UK organisations with key European and Ukrainian collaborators (both researchers and practitioners). The CHAR team's UK and international partners have collaborated for >20 years, including successfully coordinating extensive field research in the CEZ since 1993. The CHAR team is in a unique position to conduct the proposed research because of baseline data from our previous NERC-funded projects, including one which investigated the impacts of a fire in the small (<6 square km) but highly contaminated Red Forest area in 2016, and long-term data holdings for the CEZ held by Ukrainian collaborators.

CHAR will address four key research questions: (i) What is the influence of the fires on birds and mammals in the CEZ?; (ii) Have the fires increased the mobility of radionuclides for uptake into plants and/or transfer to aquatic systems?; (iii) Do repeated fires and radiation stress impact soil function in the Red Forest?; and (iv) Does contaminated smoke present a significant risk to fire fighters and the wider public?

CHAR's results will benefit any users of the CEZ natural laboratory, including radioecologists studying the effects of radiation on wildlife, environmental modellers and those undertaking broader ecological research on rewilding. The findings of CHAR will also be used to inform future management of the CEZ and other contaminated regions (such as the large forest areas in Fukushima). Fires in radiologically contaminated regions give rise to concerns from both those responding to the fires (e.g. fire fighters) and the wider public; CHAR's independent risk assessments will be useful in addressing these concerns.

Recognising that CHAR research will mainly take place during a period of international travel restrictions due to the coronavirus pandemic, the work programme has been specifically designed to ensure that all aspects can still be completed successfully. The longstanding collaborations between the UK and Ukrainian scientists and a proven track record of delivering NERC research in the CEZ during a previous period of travel restrictions (due to the armed conflict on the eastern Ukraine border) provide a high degree of confidence in the ability of the CHAR team to deliver all aspects of the proposed research. The Ukrainian collaborators have the support of the relevant Government Agency and already have permissions to work in the CEZ during the coronavirus pandemic. Additionally, the Ukrainian collaborators have the equipment and consumables required to begin the CHAR research activities as soon as CHAR is approved.