Trees and wildlife
Mature trees support a huge range of species, many of them rare or in decline. Our native broadleaved trees are a particularly rich wildlife resource; they are large, long-lived, and decay slowly, creating splits and hollows for invertebrates, fungi, bats and birds.
Woodland cover in East Devon is around 6% of the area, which is below the national average of 8.4%. However it has a high proportion of broadleaved woodland. Our fantastic hedgerows are of course a feature of the East Devon landscape and vital to wildlife, including bullfinches, dormice, small eggar moths and brown hairstreak butterflies, all of which are in decline through hedgerow loss and too much flailing.
We also have a number of old parklands with ancient trees standing in open grassland such as the grounds of Bicton College or Killerton House. Parkland and Wood Pasture are particularly important because they provide a variety of niches that suit species that cannot live in a dense and more shaded woodland habitat. They are often very ancient habitats and this continuity makes them particularly diverse. Isolated trees standing in fields in farmland are also a haven to wildlife although many have been removed in the past.
You can help trees in East Devon by:
- Giving your trees space to live and die naturally
- Planting new broadleaved trees in appropriate places, preferably using local seed. Characteristic species are Oak, Ash, Field Maple and Hazel.
- If you have a native hedgerow, don’t flail it but lay it. Also don't interplant with conifers or laurel, since their heavy shade and acid leaves will kill off your Devon flowers and ferns.
- Finding out more about them and the wildlife they support
We have specific information on looking after ancient trees, hedgerows and orchards.
Bats
All bat species use trees for foraging or roosting. Trees are particularly important for noctules, barbastelles and Bechstein’s bats who rely on suitable hollows and splits in trees for their summer and winter roosts. Pipistrelles and long-eared bats often hibernate in trees in winter. All bats rely on the high numbers of flying insects that are supported by trees; a pipistrelle can get through three thousand insects in a single night.
Bats use hedgerows and landmark trees to find their way around the countryside; hedgerows form a “bat highway” which is most valuable when it is unbroken.
Tree species that are particularly valuable to bats are Oak, Ash, Beech and Scots Pine. East Devon has 14 of the 16 species of British bats. We have significant populations of both Horseshoe Bat species and two of the country’s rarest bats are found here - Bechstein’s and grey long eared bat - and both require good quality woodland habitat. A male Bechstein's bat has recently been discovered in Holyford Woods, an East Devon District Council Local Nature Reserve. All species of bats are protected by law and it is illegal to deliberately kill, injure or capture bats, to deliberately disturb them or to damage bat roosts.
To find out more about bats, visit the Bat Conservation Trust at www.bats.org.uk or Devon Bat Group at www.dbg.me.uk
Invertebrates
The commonest trees, such as oak and willow, are the most important for invertebrates. Interesting features, like dead branches, hollows, splits and sap runs, support completely different groups of invertebrates. Trees with all kinds of different features are often known as “veteran trees” and support a very wide range of species. If trees are “tidied up” very thoroughly, many of these micro-habitats are lost, reducing the range of invertebrates the tree can support.
East Devon's woodland support many rare invertebrates, such as the purple emperor butterfly, the waved carpet moth and the white-line snout moth. Coastal woodlands and scrub are a particularly important habitat for invertebrates, as are some of our wet woodlands.
Lichens
Lichens provide homes for other species, such as spiders and mites. They are sensitive to pollution and can tell us if the air is clean. Old pollarded trees often support a lot of lichens. Since pollarding is no longer done for commercial reasons, lichens of the future may lose their homes unless we re-pollard trees now.
In East Devon, we have some very rare lichens dependent on trees, particularly on Ash. Five species are identified in the Biodiversity Action Plan as needing special conservation measures. They benefit from our clean air but are at risk from roadside pollution and accidental spraying during farming operations.
Fungi
Fungi are essential to the health of trees and particularly important in sustaining ancient trees. All trees form associations with mycorrhizal (thread) fungi which grow around their roots and pass substances between each other. The trees pass carbohydrates from their roots to the fungi while the fungi take up phosphorus and nitrogen which benefit the trees. However too much nitrogen or too little oxygen can easily kill these fungi, so fertilising grassland close to trees or compacting their roots through livestock pressure or surfacing really weakens the tree.
80% of rare fungi (listed in what is known as the Red Data Book) are dependent on ancient or veteran trees. They are under threat because so many old and rotting trees are removed. Fungi are fascinating and diverse and an important part of the food chain. In East Devon we have just one record of a beetle Dorcatoma flavicornis which can only survive in the hollows of Oak trees where dead wood has been colonised by the Chicken of the Woods fungus Laetiporus sulphureus.
Hollow trees do not necessarily fall down; they are often stronger than ones that have not been hollowed. Many species of fungi have evolved to feed on the dead wood in the centre of a tree but leave the living wood on the outside of the tree untouched. It is essential to get an expert to look at your tree if you have concerns about a fungus growing on it. You can look at our Tree Officers' page Trees in East Devon for more information.
For further information about looking after trees and encouraging the range of species that trees can support, visit www.english-nature.org.uk or www.woodland-trust.org.uk/ancient-tree-forum/
