‘The girth is three point eight metres.’

‘Wow, that’s the biggest so far!’

This is Avon Wildlife Trust’s (AWT) monitoring team, and they are looking for Ancient and Veteran Trees.

Why? you might ask – indeed, several puzzled dog-walkers already have. The answer is that ancient trees are special – and very important.

Why are ancient trees important?

All trees are a vital habitat, providing shelter and food for all kinds of creatures. As they mature and change, the wildlife they can host changes too.  Old bark develops crevices and holes, that might be used by woodpeckers, bats or dormice. Eventually, the tree’s heartwood begins to die, and it hollows out from the inside. Not only does this provide valuable nesting space, but the decaying wood hosts unique species of fungi and insects that can live nowhere else. These include the oak polypore fungus, which only grows on ancient oaks, and the violet click beetle whose grubs feed on the wood.  A tree that has reached this ‘ancient’ stage, therefore, is very precious.

In the UK, we have a particular responsibility to look after this unique resource; an astonishing 90% of all the ancient trees in Europe are here in our little island. The reason for this is surprising – the survival of British aristocracy! In countries where uprisings and revolution ousted the nobility, their estates were opened up to common use, with the result that trees were used for timber and firewood. Here in the UK, estates survived behind enclosing walls, and most of our ancient trees are in forests that were once a gentleman’s property. Undemocratic perhaps, but good news for the trees and the wildlife within them, which thrived under this aristocratic protection.

Old trees can also tell us how land was used in the past. A suspiciously straight line of gnarled hawthorn and field maple may reveal an ancient boundary. A tree with wide, spreading branches growing in the middle of a wood shows that it once grew in an open field, with room to stretch. Trees are part of our history, as much as castles and cathedrals, and ought to be cherished and preserved in the same way.

Sadly, ancient trees have no legal protection in the UK and as more land is sold to developers, many are being lost. So Avon Wildlife Trust is on a mission to find as many as it can on its own reserves – and that’s where the monitoring team comes in.

What do ‘ancient’ and ‘veteran’ mean?

The age at which a tree is judged ‘ancient’ depends on species. Short-lived trees such as birch or field maple would be considered ancient at 150-200 years old. At the other end of the scale, oaks, yews and sweet chestnuts wouldn’t be considered ancient until they reach 400 – and a few are known to have lived to a thousand years.

However, unless you have documented evidence, you can’t tell how old a tree is without cutting it down to count tree rings – which obviously AWT doesn’t want to do! So, how else can you determine a tree’s age?

One key aspect is size – hence the tape measure. The longer a tree lives and grows, the bigger its girth, or circumference. Again, this depends on species. A field maple or apple would be huge at 2 metres round. Some truly ancient oaks can exceed 10 metres – AWT haven’t yet found one over 4, but there’s always hope!  Size isn’t everything though. A tree in a hedgerow, competing with close neighbours for space and nutrients, is unlikely to get really big. So the monitoring team look for other signs of long life. These might include fungi, an indication of decaying wood; branches dying back in the crown of the tree, giving it a typical ‘stag’s head’ appearance; or hollowing in the trunk and larger branches.

AWT also looks for ‘veterans’. These trees may not be as old, but have been in the wars – perhaps due to disease, or being exposed on a woodland edge. These may have some of the same valuable attributes as truly ancient trees. The Wildlife Trust also adds an extra category; ‘notable’. These are trees worth keeping an eye on – perhaps because they are the only example of their species in the area, or they’ve just got something a bit special about them.

Caring for ancient and veteran trees

Once found, Ancient and Veteran trees are measured, mapped and photographed. They can then be included in a site’s management plan to make sure they are cared for. This might mean clearing the area around them to make sure they aren’t choked, or trimming the crown back so it is less susceptible to wind damage. With a bit of care they should have an even longer life and a dignified decline.

So next time you’re in a woodland, keep an eye out for trees which are large, or obviously charismatic, or just a bit battered-looking. They’re worthy of respect.

This blog was written by Emma Creasey. Emma has been a member of the AWT monitoring team since 2014. She has lost a lot of arguments with holly bushes.

Further information

Learn more about our Willder Woodlands project in North Somerset 

For more information on ancient trees see https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/ancient-trees/

Want to find an ancient tree near you? Or perhaps you think you know of one and want to record it? Peruse the Woodland Trust’s Ancient Tree Inventory - https://ati.woodlandtrust.org.uk/

The Woodland Trust have a petition to get legal protection on ancient trees - www.woodlandtrust.org.uk/LivingLegends

The Ancient Tree Forum champions the conservation of ancient trees - https://www.ancienttreeforum.org.uk/