Heathland is often described as open, sunlit and windswept: swathes of purple heather, golden gorse and scattered birch. What that picture misses is the quiet importance of deadwood. Fallen branches, standing dead trees, old stumps and rotting logs are not untidy leftovers. They are some of the richest microhabitats on a heath, and many invertebrates simply cannot survive without them.
On a warm day, a sun-exposed log can be several degrees warmer than the surrounding ground. That matters for beetles, flies and wasps that need heat to move, mate and develop. In shade, damp deadwood offers the opposite: a cool, humid refuge during dry spells. Both are valuable, and a heath with a mix of the two is far better for wildlife than a tidy one.
Deadwood is not a single habitat. It changes as it decays, and different invertebrates specialise at each stage. Freshly fallen birch or pine has tight bark and sapwood. Bark beetles and their larvae tunnel just beneath the surface, leaving winding galleries. As fungi move in, the wood softens. Longhorn beetle larvae bore deeper, while click beetles and their larvae thrive in crumbly red-rot.
Later, the log hollows out. That cavity becomes a nursery for solitary bees and wasps, a shelter for overwintering adults, and a humid retreat for woodlice, millipedes and pseudoscorpions. A single oak or birch log can support dozens of species over ten to twenty years. Remove it, and that entire succession disappears.
Standing dead trees, often called snags, add another dimension. They stay drier and warmer at the top, especially when exposed to the sun. Loose bark, rot holes and fungal brackets create homes at different heights. On heathland, where such trees are often scarce, each one is disproportionately important.
Fungi do the heavy lifting in deadwood. Their thread-like mycelium spreads through the wood, breaking down lignin and cellulose and releasing nutrients back into the sandy heathland soil. Without fungi, deadwood would simply pile up and nutrients would stay locked away. Fungi also soften the wood, making it accessible to invertebrates that cannot chew sound timber.
Look for bracket fungi such as birch polypore, beefsteak fungus and cramp balls. These fruiting bodies are food for beetles, slugs, flies and fungus gnats. The mycelium itself is grazed by springtails and beetle larvae. Some invertebrates live only in the fruiting bodies of a particular fungus. Leave the brackets where they are. Kicking them off or picking them for a photograph removes a whole micro-community.
You do not need a microscope to see deadwood working. On a mild day after rain, turn a loose piece of bark and look for oval or round exit holes, fine wood dust called frass, and the winding galleries of bark beetles. You may find woodlice, centipedes, spiders or a pseudoscorpion no bigger than a pinhead. Longhorn beetles, click beetles and hairy fungus beetles are all possible on a good heath.
Check fungal brackets for small beetles and flies. Look for solitary bee holes in old stumps and for the tell-tale tunnels of wood-boring larvae. Always replace bark and logs as you found them, and keep handling to a minimum. Deadwood is alive, and it is easily damaged by good intentions.
Heathland management often focuses on grazing, cutting and scrub control. Deadwood can seem like a low priority, or even a fire risk. But leaving some is one of the cheapest and most effective things we can do for invertebrates. A single log pile in a sunny corner, a retained birch snag, a stump left in the ground: these small decisions add up.
If you garden with heather or manage a patch of heath, resist the urge to tidy every fallen branch. Leave a scruffy corner. Let fungi work. Let beetles bore. Let the wood rot slowly back into the soil. A heath with deadwood is not neglected; it is complete.
The Tawny Heath shares practical, down-to-earth guidance on british heathland and wildlife for readers across the UK.
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