TECHNICAL
Of all 454 tree species native to the European region, 168 are considered threatened, with 34 of those native to the UK
Phytophtora ramorum shows how devastating pests and diseases can be to our local flora. Since its discovery in the UK, in 2002, it led to the mass destruction of larch trees.
Plant health more on the agenda than ever
W
ith climate change, the advent of Brexit and changing biosecurity protocols, plant health is in the spotlight more than ever before. Over 500,000 jobs in the ornamental horticulture industry rely on good plant health, and an estimated £9bn value to the economy is provided through our plants and trees. With all that at stake, it is important the sector stays vigilant to the threats posed by non-native plants, diseases and plant pests.
Xylella fastidiosa is a disease-causing bacterium that is the main concern for future infections
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LANDSCAPE NEWS SUMMER 2021
Of all 454 tree species native to the European region, 168 are considered threatened, with 34 of those native to the UK. Invasive and problematic species have been identified as the highest threat to the UK’s trees – higher than deforestation, wood harvesting, and urban development.
There are 127 plant pests and diseases that are considered high risk to the UK, with several presenting serious danger to our native plant life.
Phytophtora ramorum shows how devastating pests and diseases can be to our local flora. After being first discovered in the UK in 2002, it led to the mass destruction of larch trees. Before its discovery there were approximately 154,000 hectares of larch planted in Great Britain, or 5% of the total area – most of this has now been lost because of the disease, and the timber industry has been affected by no longer being able to use larch as a species.
Ash dieback is a fungal disease, originally from Asia, that is thought to have been brought to the UK on infected, imported trees. It is currently
Written by Emily Magdij Marketing and Communications Officer ravaging our ash trees and is expected to kill between 95% and 99% of all ash in Britain. The total cost of the disease to the UK is estimated to be £15bn – a third more than the reported cost of the foot-and-mouth disease outbreak in 2001. Xylella fastidiosa is a diseasecausing bacterium that can affect many woody plants including broadleaved trees and is the main concern for future infections. Though not currently found in the UK, an outbreak is likely to result in the destruction of host plants within 100m and a 5km movement ban for ‘specified’ plants for five years. With plant health so important to the industry and to the UK’s flora, horticulturists and importers are urged to take extra care to familiarise themselves with the UK’s new biosecurity protocols. These new, post-Brexit systems are covered in more detail in this issue of Landscape News on pages 28 and 29. Visit bali.org.uk/help-and-advice/ plant-health for more information.
