Imperial College London


Faculty of Natural SciencesCentre for Environmental Policy

Visiting Researcher



+44 (0)7714 051 468david.slawson




Weeks BuildingSouth Kensington Campus





Dr David Slawson is an honorary visiting researcher at Imperial College London and coordinator of the UK Tree Health Citizen Science Network. He is a trustee of the National Biodiversity Network and a member of the Royal Horticultural Society’s Science Committee.  From 2014 – 2019, David was the Director of Open Air Laboratories (OPAL), a citizen science partnership based in the Centre for Environmental Policy, Imperial College London.

Research Interests:

Citizen science, plant health, tree health, biosecurity, plant pathology

The OPAL Project:

The OPAL network, led by Imperial College London, was a UK-wide partnership initiative that inspires communities to discover, enjoy and protect their local environments through citizen science-based activities. OPAL began in 2007, operating across England and funded by a Big Lottery Fund – Changing Spaces grant. Since January 2014, the programme has expanded to Scotland, Wales and Northern Ireland thanks to a further award from the Big Lottery Fund. OPAL closed at the end of September 2019, although resources and data remain accessible on the OPAL website In addition, plans are in progress to transfer the OPAL brand and resources to the British Ecological Society.

Biographical Details:

David Slawson graduated with a BSc Hons in Applied Plant Biology from the University College of Wales, Aberystwyth in 1980.  In 1985, he was awarded his PhD “Foliar diseases of barley with particular reference to effects on green leaf area and yield” from the University of Wales.

Before joining OPAL Imperial College in March 2014, David spent 30 years in Defra (previously MAFF) and its agencies, including the following roles: advisory plant pathologist (ADAS; 1984 -1989), principal fungicides expert (Pesticides Safety Directorate; 1989-1999), Principal Plant Health & Seeds Inspector (Plant Health & Seeds Inspectorate; 1999 – 2009), Head of Plant Protection Programme (Food and Environment Research Agency; 2009 – 2011) and Head of Plant Health Public Engagement (Food and Environment Research Agency; 2011- 2014).

David has a wide experience of managing surveillance and eradication campaigns against plant pest and diseases, most notably Phytophthora ramorum.  He is familiar with advising policy-makers and Ministers and negotiating in various European fora.  He chaired both the EU legislation working group on Phytophthora ramorum and Defra’s 5-year £24m Phytophthora Disease Management Programme.  In 2012 and 2013, he was actively involved in the Government’s response to the Chalara crisis, which included acting as an official adviser to the Secretary of State’s Tree Health and Plant Biosecurity Expert Taskforce.

In recent years, David has focussed his interests on engaging with industry and the public to raise their awareness and to help them to adopt practices to reduce the risk of plant pests and pathogens damaging our cultivated plants and the wider landscape.  This has included production of eye-catching ‘biosecurity’ posters, films, best practice protocols and an award-winning show garden at the Centenary RHS Chelsea Flower Show, the first in 100 years to feature dead trees, and which was estimated to reach an audience of 50.2m people.  He has also made numerous appearances on national television and radio.