Discovery and History

The elm (Ulmus spp.) has been under attack, mostly on the Northern Hemisphere (Brasier and Buck 2001) for more than a century (Santini and Faccoli 2013; Smith and Hulcr 2015; Wingfield et al. 2016; Martín et al. 2019) due to Dutch elm disease (DED).

Dutch elm disease was first noticed in continental Europe in 1910 and spread slowly and eventually extended to all other countries except Greece and Finland (Clouston and Stansfield 1979). Barendina Gerarda Spierenburg (1921) compiled records of trees displaying symptoms from 1900 - 1905 onwards in the Netherlands and her publication of this information in 1921 was one part of the start of extensive research and practical measures to try to halt the disease. In addition the fungus that caused the disease was isolated in 1921 in The Netherlands by Bea Schwarz, a pioneering Dutch phytopathologist, and this discovery would lend the disease its name (Holmes and Heybroek 1990). Following this, in the 1920s and 30s Christine Buisman, working in the Netherlands and USA, identified the sexual stage of the fungal pathogen and also developed methods for experimental infections of elm seedlings that led to selection of resistant trees (Clinton and McCormick 1936, Heybroek and Nijboer 2013).

The geographical origin of first agent of DED Ophiostoma ulmi is unclear.

Elms have experienced two pandemics of DED – the first at the beginning of the 20th century when 10-40% of elms were killed (Peace 1960, Gibbs 1978, Brasier 1996, Brasier 2000) and the second since the second half of the 20th century (Brasier and Buck 2001) when also billions of elms were killed (Phillips and Burdekin 1992, Herald 2019).

By the beginning of the 21st century (Brasier and Buck 2001, Kirisits 2013) approximately 80-90% (28 million) of mature elms had died in the UK (Brasier 2001, Brasier and Buck 2001).