National Tree Week (27 November – 5 December) started in 1973 as a result of Dutch Elm Disease – a tree disease that saw the decimation of the UK elm population. The idea was to get communities to do more to help the trees in their area. Now National Tree Week aims to spread awareness about the vital role trees play in our environment.
It’s widely understood that trees are central to our ecosystem, not only because they absorb carbon dioxide from the atmosphere, helping to limit global warming, but also because of the nutrients they release into the soil, allowing other plants to grow. Many species depend on them. For example, oak trees support 2,300 species – 326 of which are entirely dependent on oak for their survival.
They have other super-powers, too. They are often long-lived, with some yews surviving for over 4,000 years. Old trees are particularly rich in wildlife: one ancient oak has more diversity of life than a thousand 100-year-old oaks. Ancient trees are notably special for their fungi, invertebrates and lichen. They’re not only important when they’re alive: deadwood has important ecological benefits, providing habitats for bugs and beetles, which is why our reserves teams try to leave fallen trees on the ground wherever possible.
Nearly 50 years on from the Dutch Elm Disease crisis, our trees are facing another deadly threat. Confirmed in the UK in 2012, ash dieback is a fungal disease affecting ash trees. With the spores causing the infection moving large distances on the wind, it is likely that most of Avon’s ash trees have now been exposed. The disease makes it likely that deadwood will fall out of the canopy – or the tree may even fall altogether.
For Avon Wildlife Trust, this is a significant public safety issue. Trees posing a threat to safety will have to be felled. Reserve visitors are likely to see increasing evidence of tree-felling, especially when visiting sites with a high proportion of both ash trees and public access, such as Browne’s Folly. For news about these impacts, or to learn more about the challenge we are facing in dealing with ash dieback, head to the Trust’s website.