Like all wooded sites that were hit by the recent storms, we saw numerous trees and large limbs fall across the Common. Although we don’t have any ancient trees, it was still good to see all of our veteran and notable trees still standing. It can be sad to see old and important trees felled by the weather, especially where they provide crucial habitat for rare species and are enjoyed by the local community. However, it’s worth remembering that trees and woodlands have co-evolved with storm events and for sites with predominantly young trees and woodland, (such as Barnes Common and Leg o’ Mutton) these events can provide opportunities for further habitat creation and continuation between older and younger trees, writes our Conservation Manager, Will Dartnell.
Decaying wood plays a key role in ecosystem functioning, providing habitat for many species of bryophytes, lichens, fungi, invertebrates, amphibians, reptiles, birds and mammals. Unfortunately, decades of ‘tidying’ up of deadwood has meant that most wooded sites across the UK are severely lacking in the amount of dead wood and it is estimated that an absence of decaying wood habitat could deprive an area of woodland of over 20% of its fauna. This is no surprise given that when looking at invertebrates alone, in the UK, more than 2000 species are dependent upon decaying wood for part of their life cycles, and a recent study highlighted that over 320 of these invertebrates also pollinate flowers.
And so as the storms felled trees and tore out limbs, important habitats were created. Where whole trees or canopies have collapsed more light can reach the woodland floor, allowing previously suppressed seeds to germinate, and increasing the structural diversity of the woodland. The upturned root plates can provide water filled hollows, and where the soils are south facing, various solitary bees and wasps will use them to nest. Large trunks provide long-term habitat for decay fungi as they break down the wood for the thousands of saproxylic (deadwood dependant) insects. Torn out limbs can go on to create cavities which are used by hole nesting birds, bats and insects. Only last summer a small survey on the Common, carried out by one of our volunteers, Charlotte Tracey, found several previously unrecorded Nationally Scarce insects using an old storm damaged dead limb that had developed several cavities.
We can safely say that the term ‘deadwood’ does this type of crucial habitat a complete disservice, as it is in fact thriving with life! It is for these reasons that, unless there is a safety risk or fallen trees or limbs are blocking paths, we aim to leave trees and limbs where they lie.