A banquet in the bark 

If we were blessed with the superpower of ultrasonic hearing, then a visit to an old wood or pasture with ancient trees would be a whole new experience. We would be overwhelmed with the sounds of gnawing, nibbling and munching. But this wouldn’t be the noise of someone feasting on the crispy component of their picnic, it would be the cacophony of countless beetles and their larvae consuming rotting and dead wood, ‘the sound of the saproxyles’.  

Saproxylic beetles are defined as species dependent on dead or decaying wood, or dependent on those that are dependent on decaying wood for part of their lifecycle. These invertebrates are mostly dependent on habitats created by the processes of decay or damage in the wood and bark of trees and larger shrubs. These niche habitats include rot holes, sap runs, fungal hyphae and fruiting bodies. 

Deadwood haven in the heart of Hertfordshire 

All these rotten habitats can be found in abundance at Panshanger Park in Hertfordshire, where Herts and Middlesex Wildlife Trust has been advising the owners, Tarmac, on nature conservation since the 1980s. There are over 500 ancient trees, with the oldest specimen thought to be over 1,000 years old. Given the abundance of dead wood, we were keen to find out about the invertebrate community. In 2023, Adrian Dutton, a national expert on saproxylic beetles, was commissioned to complete a survey. The results of the survey showed that Panshanger Park is of international significance in its saproxylic beetle assemblages. 

Meet the residents of rot

Naturally rotten neighbourhoods are home to incredibly diverse wildlife communities. So, who lives where? Let’s find out! 

The larvae of the majestic stag beetle favour the basement locations of underground deadwood, whilst black and yellow longhorn beetle larvae are long-term tenants of fallen branches, taking up to three years to leave their home as adults. Fungi that thrive in decaying locations include the delicate stalks of candlesnuff fungus and the chunky chicken of the woods. 

A third of all woodland birds nest in the hollows or cavities of dead trees. Great spotted woodpeckers excavate their own holes with their powerful beaks, whilst nuthatches seek out existing cavities. 

Many of our bat species search for trees with natural ‘period features’ such as rot holes, splits and lifting bark in which to roost. Our biggest bat, the noctule, isn’t put off by a pre-loved home and is known to roost in woodpecker holes. The rare and elusive barbastelle bat, found only in woods with plenty of standing deadwood, often takes advantage of spaces behind bark which has separated from the wood.

It’s not just land-loving animals who appreciate deadwood. Fallen logs in rivers can provide the perfect refuge for fish, a sprainting spot for an otter, or a snacking spot for a water vole. Dead trees or branches fallen into chalk streams disrupt or concentrate the flow, scouring the gravelly bed, creating perfect conditions for brown trout to cut redds (nests), into which they lay their eggs. In ponds, southern hawker dragonflies seek out soft rotting wood into which they lay their eggs. 

Make space for messy nature 

Unfortunately, in our modern world, dead and rotting wood is often seen as messy, needing to be removed. In my view, nature knows best and, where safe to do so, leave dead and rotting wood in its natural state and don’t tidy it away.  

We must embrace it, conserve it, and seek to create more of it. With 13%* of all plants and animals known in the UK directly dependent on deadwood habitats, it’s a vital component of our landscapes.  

*Buglife article - Deadwood ‘Overall, it has been estimated that 13% of all species of plants and animals known in the UK are directly dependent on deadwood habitats, while many more are dependent upon the saproxylic organisms themselves, making deadwood an important focus for conservation management (Antrobus et al. 2005).’
 

Tune in to Rot Property!

The Wildlife Trusts' Tom Hibbert take a look at what's on the market for discerning deadwood specialists...