Trees play a vital role in our environment and our economy, they are important to our health and wellbeing – but they are in grave danger. The nature and extent of the virulent non-native tree diseases now present in the UK promises a grim future for our forests, woodlands, parks, gardens and urban trees. The extent and cost of the damage is becoming increasingly evident as Chalara fraxinea has infected the whole of the UK and failure to intervene will, according to Oxford University, cost the UK up to £18 billion in the next 25 years. Millions of Japanese larch are being felled due to Phytophthora ramorum, a disease which spread from Cornwall to Argyll is less than two years – despite the extensive felling designed to contain it. The number of diseases and pests affecting our trees has grown alarmingly in the last ten years and more are moving closer from continental Europe.
The future threats include Xylella fastidiosa– potentially the most destructive of all – and we cannot depend on biosecurity in the modern world to keep it out. We have to be ready to deal with the attack it when it arrives.
Arriving non-native pathogens which began as local outbreaks have become national epidemics because they have not been contained. Felling as a containment measure is too little, too late.
We are now in a position in which decisive action must be taken because these pathogens cannot and will not be controlled without direct intervention. Some ‘experts’ are saying that there is nothing we can do and that the ash and other tree species are doomed and that we are facing the uncontested loss of millions of mature trees. The environmental consequences of such losses are significant.
We have to face facts. The bacteria and fungi attacking our trees are intelligent and adaptable. Many have become increasingly resistant to conventional chemical treatments and Defra and Forest Research websites insist ‘there is no broken treatment’. As a result local councils, private landowners and public bodies like British Rail are cutting down thousands of healthy trees.