Deadwood is the dead and decaying wood that lies in our woodlands - fallen branches, rotting stumps and dead trees which still stand, also known as snags. There is even deadwood in living trees, called rotting heartwood. Dr. Orton explores the importance of deadwood for Britain’s forests.
The first thing to say about deadwood is that it is, in some ways, alive – while the wood itself may be dead, it is a habitat for a myriad of species, and a cornerstone of woodland wildlife.
In unmanaged European broadleaf forests, deadwood cam make up 5-30 percent of the total timber. The Game and Wildlife Conservation Trust says that that 40% of the forest ecosystem is dependent on dead wood and 5,000 British species have life cycles that are dependent on it.
Rotting heartwood is found in veteran and ancient trees in their trunk hollows. Some trees can live for hundreds of years while decaying in parts, with living wood continuing to support the tree towards the outside of its trunk. The Woodland Trust says that around 30% of Europe’s forest-dwelling birds nest or roost in tree cavities.
Deadwood is important in nutrient recycling so that other trees and plants can use the unlocked nutrients.
In our rivers, deadwood provides habitats for fish, supports invertebrate life cycles, and offers shelter and perches for mammals, birds, invertebrates, amphibians, and reptiles. It also creates microhabitats by adding complexity to the waterway in the form of pools, riffles, and chutes. It helps to stabilise waterway banks and beds and improves water quality through the removal and oxygenation of fine silts.
Deadwood and the Diversity of Forest Life
Deadwood is also important for biodiversity, creating microhabitats for plants, fungi and animals, who use these for food, nesting, shelter and nurseries.
Some species are deadwood specialists. For instance, oak-stump bonnet cap fungus is found exclusively on decaying wood. Many beetles (known as saprolyxic beetles) rely on deadwood for the development of their larvae. Around 650 UK beetle species are thought to require deadwood at some point in their lifecycle. The stage beetle is a good example.
Some woodland birds have evolved to feed on the invertebrates found in deadwood. Woodpeckers in particular prefer standing deadwood in which to excavate nest holes - and these may be taken over by bats and other cavity nesting birds.
Some of our bat species use crevices in standing deadwood for roosting, hibernating and even breeding – the noctule bat is a good example.
The WWF points out that, even before a tree dies completely, it attracts specialised species: 115 species of hoverfly are found almost exclusively in dying rather than dead timber. Newly dead trees attract specialised organisms like fungi that break down the wood and make it usable by other life forms. Plant and animal species move in, including herbivores and their predators.
Woodpeckers are dependent on deadwood, particularly in winter. Willow tits, nuthatches and treecreepers also use tree holes.
Forest deadwood is important in maintaining an abundance of bryophyte (mosses and liverworts) and lichen species. These are important for biodiversity. They also shelter invertebrates like woodlice and molluscs that are food for birds and small mammals.
Some studies have found that bryophytes are the predominant group of plants inhabiting deadwood. One German study found one-third of epiphyte vegetation (plants that grow on other plants) only on deadwood.
Our Habitat Piles
Deadwood has declined in Britain, partly due to humans overlooking the value of fallen branches and dying trees and wanting to “tidy up” our woodlands. It’s understandable that people want to keep paths clear so that everyone – elderly or disabled people and children – can enjoy the forest, but it’s important to make sure we leave enough deadwood to support the ecosystem, too!
We’ve started planting a native woodland from scratch in the last few years, but we also maintain a historic Victorian spinney. We want to make sure that both of these enjoy the benefits of deadwood.
As well as leaving some fallen trees and some standing deadwood, we’ve added a number of “habitat piles” to our woodland: piles of logs and branches that can provide habitat for woodland creatures.
Some of these are over ten years old and already decomposing – others were created within the last few weeks.
Buglife recommends that log piles should be created in shaded, open, wet and dry areas to provide a habitat suitable for a variety of different species. Deadwood will rot more quickly in the shade, encouraging mosses and fungi, whereas deadwood in the sun will turn dry and hard, attracting solitary bees and wasps.
The Heart of England Forest create “dead hedgerows” by piling or weaving rows of branches and twigs between vertical branches.
It’s also a good idea to balance the use of resources with the need to keep some deadwood in the forest. We recently had a fallen tree across one of our paths, much of which will be used for firewood, but we used a lot of the upper branches to make a new habitat pile.
For those who would like to take action to preserve our wild spaces, there’s plenty you can do. If you do have some land, think about leaving deadwood on the ground, or creating a “habitat pile” by laying branches and logs on top of one another. Even if you don’t have a big garden, there are plenty of things you can do to help biodiversity in your area. Why not put up a solitary bee nesting box or insect home, create a woodpile as a habitat for small creatures or leave small areas of your garden to go wild?
Find Out More
If you’re interested in conservation and wildlife, we have a blog series on British wildlife and a series on the people and wildlife of South Asia, from the altitudes of the Himalayas to the dense mangrove forests of Bangladesh!
We also offer online private tuition in our interdisciplinary course, Culture and Conservation, in which you can explore the links between our natural and cultural heritage and study wildlife and cultures from across the world! This is a template of a possible study route and can be combined, adapted, or designed from scratch to suit your interests and goals.
Dr. Orton will work with you to design a course of private tutorials tailored to your needs, ability and schedule. Click the link to find out what it’s like to work with her and contact us to find out more!
Do More
Think about your own area and how you can protect vulnerable but important parts of your own environment. You might even want to start your own project investigating the cultural importance of wildlife in your area. Dr. Orton works with independent scholars undertaking their own research for an independent project, people writing a book or simply those who have a personal interest. Click the link to find out what it’s like to work with her and contact us to get started!
Reach Out
We’d love to see what you’re doing to help wildlife in your area. Follow the Conservation highlight reel on the Orton Academy Instagram to see what we’re getting up to and tag us in to any snaps you put up!
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