Managing gorse for wildlife
Gorse scrub occurs wherever soils are light and free draining, in areas that are relatively free from severe frosts. It's very important for birds and for invertebrates but can encroach on to otherwise variable land.
Gorse is relatively short-lived (up to 25 years) but, with careful management, its vigour and value for wildlife can be maintained.
There are three species of gorse in Britain. Common gorse Ulex europaeus is the most familiar and widespread, and has the most robust growth character. Western gorse Ulex gallii is frequent in the western half of Britain and occurs along the East Anglian coast. It is relatively low growing yet robust.
Dwarf gorse Ulex minor is a low growing, sprawling shrub that is a relatively uncommon component of the heathland shrub layer in central southern and eastern Britain.
These pages discuss the first two species together, whereas dwarf gorse is best treated as part of the heathland dwarf shrub community.
Benefits for wildlife
Compact gorse is ideal for a range of nesting heathland, downland and farmland birds, including the Dartford warbler, stonechat, linnet and yellowhammer. The dense structure also provides important refuge for these birds in harsh weather, and is essential for the survival of Dartford warblers in winter.
Gorse is important for invertebrates. It is in flower for long periods, so is an important nectar source in early spring and early winter, when little else is in flower. A number of scarce invertebrates are dependent on it.
Gorse management techniques
Gorse should not be difficult to establish if a few straightforward principles are adhered to.
- Prepare a fine loose seedbed of dry, low fertility soil, free from competing vegetation by using, for example, a rotovator.
- Dead ground, for example former bracken beds or cleared scrub, is an ideal location. Avoid areas of important vegetation such as heather.
- Collect seeds from under existing gorse during management (see below). Broadcast and tread in.
- Drought is usually the main cause of mortality. Water in dry weather until the seedlings are growing strongly.
- Translocate young plants as an alternative to seeding. Seedlings that germinate within management plots are shaded out by growth from coppiced stools. Dig these out, avoiding damage to the roots, and plant into areas free of competition.
- For small clumps of gorse, plant seedlings in clusters of 10–15 plants, so sufficient survive. If survival is good, relocate surplus plants.
- For larger stands, plant well spaced clusters, say 1–1.5m apart. Bushes can then grow together rather than compete with each other.
Restoring old and degenerate stands
- Old and degenerate gorse is relatively poor for wildlife. Meanwhile, the accumulation of plant debris increases soil fertility, aiding colonisation by, for example, bracken. The accumulated dead material also presents an increased fire risk.
- Very old, leggy gorse rarely regenerates when cut.
- A large bank of seeds usually survives in the soil surface beneath the stand. Clearing the gorse and removing the loose organic litter exposes the seeds to germinate.
- Burning in situ can be dangerous, because of the high volume of very combustible material. Where it is safe, the fire will expose the seeds and heat them, which encourages germination.
- Otherwise, cut the old gorse and burn the arisings and litter in a series of fires across the restoration to encourage seed germination.
Management is essential to keep the gorse healthy and robust. Bushes and stands of gorse start to lose their compactness after approximately 10 years and they then degenerate with time, losing their value for wildlife, increasing the fire risk and reducing their ability to regenerate.
- Adopt a planned approach to ensure a continuity of gorse in good condition across the site at all times. Break up large stands into several parcels and manage these on rotation, and apply a rotation to scattered gorse across the site.
- Aim to manage the most mature stands first.
- Cut gorse to ground level and remove or burn the arisings. Also remove the accumulated litter of dead plant material as it is highly flammable and adds to the nutrient load in the soil – bracken could take over the area and surrounding habitats. Most cut stumps will regenerate within a year.
- Small patches and individual bushes are usually best cut by chainsaw or clearing saw, but it is more economical to flail large stands, although removing the large volume of shredded gorse is likely to be a problem unless a cut and collect machine is used.
- Where discrete patches can be completely isolated from other habitats, they could be burnt in situ, although extreme caution is required as gorse is very flammable. Burning removes most of the accumulated litter, so significantly offsets the accumulation of nutrients. Regeneration is from both the rootstock and from seed.
- High rabbit populations often suppress regeneration, so recently cut stands may need protecting with appropriate fencing.
- Control bracken – otherwise it will grow up quickly and shade developing gorse.
- Gorse hedges can be maintained by regular trimming.
Gorse can be restricted or removed relatively easily using a number of techniques depending on local conditions.
- Cutting the gorse to ground level and treating the cut stumps with an approved herbicide is likely to have the least impact on surrounding vegetation or any archaeological features.
- Cutting to ground level and letting livestock, deer or rabbits browse the regeneration is often effective where the surrounding vegetation has low palatability. High numbers of livestock can, however, compromise sensitive vegetation and vegetation structure.
- Repeated cutting will eventually kill gorse but may take several years and so be expensive.
- Grubbing out whole bushes with the rootstock is effective but can create conditions for gorse to recolonise. It is also not appropriate for archaeological features.