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New Research Highlights Threat of Pests and Diseases to UK Trees
Emerging plant pests and diseases pose a significant risk to the future of UK trees and woodlands, according to new findings from scientists at the University of Exeter.
The urgency of this study arises from the ash dieback epidemic, which compelled the UK government to evaluate potential external threats to its trees and agricultural crops.
In their research, published in the journal Plants People Planet, the team analyzed 636 tree pests and diseases to assess their likelihood of invasion and potential impact on tree growth. The report, titled “Potential impacts of plant pests and diseases on trees and forests in the UK,” predicts that by 2050, the UK could see a loss of over 50% of tree growth if new pests and diseases continue to arrive at current rates.
Addressing these invasions is challenging in an era of global trade and travel. However, implementing strict biological control measures may mitigate the influx, and proactive tree-planting initiatives could enhance resilience.
“The key to defending against unknown risks is diversity,” said Professor Dan Bebber. “The UK currently has low tree diversity, both in terms of species variety and genetic variation within these species.”
“The ash dieback crisis demonstrated the devastating impact a single tree disease can have, highlighting the urgent need to understand these threats and safeguard our biodiversity,” Bebber emphasized.
Additionally, he urged consideration of societal and cultural factors in forestry management, questioning which tree species should be prioritized for planting in light of potential threats from pests, diseases, and climate change.
The research identifies several species at risk, including pine, cherry, spruce, larch, and oak. Historically, the UK has seen about one new tree pest or disease establish annually, and the increasing number of potential invaders suggests this trend will likely continue.
Tree cover in the UK fell below 5% at the start of the 20th century but rebounded to approximately 13% by 2018, contrasting sharply with the European average of 39% forest area.
The majority of UK reforestation has utilized fast-growing exotic conifers, which now account for around half of the total forest area. Ancient woodlands, defined as areas continuously tree-covered since 1600, represent merely 2.5% of the UK’s coverage.
Current government initiatives aim to increase tree cover to 16.5% in England by 2050, 21% in Scotland by 2032, and an addition of 2,000 hectares annually in Wales.
Professor Bebber cautioned, “Our findings underscore the importance of ensuring these reforestation projects are resilient to future pests, diseases, and climate changes.”
This research serves as a critical reminder of the imminent threats posed by emerging plant pests and diseases to UK forests, along with the biodiversity and ecosystem services they support.
More information:
Potential impacts of plant pests and diseases on trees and forests in the UK, Plants People Planet (2025). DOI: 10.1002/ppp3.70023
Source
phys.org