Dead Wood as a Wildlife Habitat


Organic gardeners have known for many years that their plots are important wildlife habitats, but within most gardens organic or not, is a natural substance that a huge range of garden wildlife relies upon.  Stag beetles, centipedes, fungi, woodpeckers, shrews, woodlice, hedgehogs, mosses and bats are just a small number of the animals - and plants - dependent in some way upon wood.

How we use and recycle wood in our gardens is a subject to which most responsible gardeners give a lot of thought.  Bonfires are a thing of the past to the enlightened, as the majority of ‘waste’ material produced in any garden, if not compostable, can be used in other ways.  Deadwood is now known to be a very valuable wildlife habitat both in the countryside and in our gardens, and frankly there is not enough of it around!  Trees in parks and gardens are heavily pruned to keep them safe and even in the countryside, dead and decaying trees are removed where they would cause no harm or danger if left alone as a wildlife habitat.  Yet deadwood provides food for many insects, which in turn feed birds, amphibians, reptiles and mammals. It is the substrate upon which some plants grow.  Toads and newts find the cool, damp nature of rotting wood suits their life styles.  All in all, a great deal of our native wildlife needs wood at some time and as a bonus it enriches the soil with nutrients as it breaks down.

November is a good time of year to use up wood from other sources to create a damp place for the hibernation of newts, toads and slow worms before the really cold weather sets in.  Any wood can be used for a log pile, but native hardwood rather than conifer wood (unless you have native conifers such as Scots pine around) will support a greater range of insects.  The size of the logs is not important either, but the most useful and effective pile should have a least a few of the logs buried to a depth of 10 cms or more.   Don’t build your log pile too high as the top will dry out and this is less attractive to insects.  It may be better to have several small piles than one enormous one.

After burying a few longer logs (these can be upright to create a frame to support the others if you wish) simply pile the logs, bits of bark, and untreated wood of any sort around the buried pieces.  You can add soil if you wish, to create a habitat where woodland plants will grow.  A ‘loggery’ – the log equivalent of a rockery - is a fantastic habitat for all sorts of wildlife and in a cool shady place can be used to grow ferns and other shade-loving plants such as sweet woodruff or primroses. 

Many beetles, including the magnificent stag beetle, lay their eggs in very damp and decaying wood deep in the soil, so a dry wood pile will certainly not attract as much in the way of wildlife as a nice damp, decaying one.  As far as stag beetles are concerned, the older and more rotten the wood, the better.  After the female beetle has laid her eggs in the rotting wood and they have hatched, the larvae spend up to five years chewing their way through the wood in the dark.  They have the appearance of huge white maggots or grubs, belying the beautiful insect that hatches after pupation.  Stag beetles are more common in the south east of the country and are declining as a result of lack of habitat, but many other beetles will use your log pile wherever you live.

Log piles are not the only useful wildlife habitats that can be made from waste wood.  Twig piles are immensely useful for nesting birds and can be an effective way of recycling prunings from fruit trees or shrubs if you would prefer not to shred them.  These are best left in lengths of a metre or more and if you have the room, piled up in an undisturbed corner of the garden.  In a smaller space, twig piles can also be pushed under the bottom of a hedge where they will provide a habitat for mice and shrews, a hibernation place for hedgehogs, or a nest site for small birds such as dunnocks, which are happy to build their nests close to the ground.  A large ‘twiggery’ can attract blackbirds, thrushes, wrens and even the occasional warbler used to nesting in scrub, another habitat in short supply.

Mosses, liverworts, lichens and fungi are lower plants that we sometimes forget about in our gardens, unless, like the honey fungus, they are causing us problems.  But each of these groups has an important part to play, both in the breakdown of dead wood, and in the provision of food for many types of insect.  Some lichens provide food for the caterpillars of moths which lay their eggs on one species alone, and the caterpillars will eat nothing else.  The marbled green moth is a striking example of a species that relies entirely on lichen in the early part of its life cycle.  Its mottled wing patterns provide perfect camouflage while it is laying its eggs on its lichen food plant.

There are many other things we can do to maintain a ‘deadwood habitat’ in our gardens, especially when dealing with damaged trees.  Try to leave living trees unless they are a hazard, or remove just the dead or decaying branches to create a log pile.  Pollarding a tree can extend its life and create a good wildlife habitat at the same time.  If a tree must be cut down, part of the trunk can sometimes be left in situ.  This can even become a garden feature if ivy, hops or perhaps a blackberry can be allowed to scramble over it.  

One of the most creative ways to re-use wood in the garden is to construct rustic furniture.  Allow your artistic temperament to shine through!  As long as the wood is sound it can be used in a variety of ways to make benches, seats or tables.  Its life may be short, but it is often more attractive than shop bought furniture.  A simple railway sleeper supported on two logs can make a lovely informal seat where smaller insects such as beetles and spiders can find a crevice to shelter in.  Resist the urge to treat this type of garden furniture with preservatives, and allow it to break down naturally over time.  It will soon be colonised by lichen and mosses, adding to its rustic appearance.

Wood is a very precious commodity and it also provides a huge range of wildlife with homes and food.  Think carefully about how you use it, and whenever you can, plant for the future.

 

© Text and photographs Jenny Steel 2017