Why do we need to swale?
Heathland is one of the rarest habitats in Europe. The Quantock Hills heathland is designated by Natural England as a mix of ‘lowland' and ‘upland’ heath as the majority is below 300metres in altitude. For this reason the heathland is designated a Site of Special Scientific Interest (SSSI).
If left unmanaged heathland would quickly become overgrown, with scrub species such as mountain ash (rowan) and silver birch that have self-sown amongst the heather. Gorse may also out compete the heather, therefore changing the wildlife value and landscape appearance of this rare habitat.
Swaling (burning) in conjunction with grazing, is the most efficient way to control this growth and it enables vegetation to quickly re-grow, starting in the spring immediately following the burn. Other benefits of swaling are:
A good burning rotation creates a mosaic of different habitats that maximises benefits for a wide range of heathland wildlife.
Reduces the possibility of larger uncontrolled summer fires with serious impacts on the fragile wildlife
Reveals hidden archaeology
Swaling is never carried out without the landowner's permission. Although it may help, swaling is not carried out to destroy tick larva as these are buried in bracken mulch and can survive the above ground vegetation burning of a swale.
When do we carry out swaling?
Quantock Common has a management plan, called a Moorland Implementation Plan, which sets out all the management options for the common. This includes the grazing, control of invasive species, bracken as well as swaling.
Areas are swaled on an approximate 15-year rotation. On the Quantock Common swaling is carried out between November and the end of March to avoid breeding wildlife and the damp and cold protects the valuable root and seed stock. Swaling beyond the end of March could impact on nesting birds like the skylark, dartford warbler, whitethroat, meadow pipit, stonechat and yellowhammer. Many ground nesting birds actually prefer the shorter fresh vegetation which grows back after swaling.
Though we are allowed to start swaling in November, the Hills are very exposed to wet south westerly winds so swaling before Christmas is rare. We usually wait for a cold dry, but relatively calm high pressure weather from the east in January, February and March. Too strong a breeze can make fires too intense and more difficult to manage, possible even jumping fire breaks if not watched very closely.
What about the wildlife, is it in danger from swaling and what benefit is it to them?
The swaled area does not immediately provide a valuable habitat but vegetation is quick to re-grow in the spring and also provides lots of young fresh shoots for wildlife and livestock to eat. The edge of the swaled area can be a particular favourite of the adder on warm days but you'll be unlikely to spot an adder in the heart of the burned area - too exposed to a hungry bird of prey! The National Landscape team in partnership with the Reptile and Amphibian Group for Somerset (R.A.G.S) have been carrying out detailed surveys of adder populations and hibernation sites, allowing us to avoid them when swaling. The most important benefit however, is that swaling perpetuates the habitat the heathland wildlife depend upon.
But isn't burning releasing carbon into the atmosphere, contributing to climate change and having an adverse effect on the environment?
This is an understandable reaction, but, in short, the answer is ‘no'. Swaling is generally regarded as ‘carbon neutral' when carried out at the right time of year and in the right way. The positive impacts from swaling include:
It's neutral because the heather starts regrowing as soon as it's burnt, taking back carbon equivalent to that released into the atmosphere.
The emissions from very small controlled burns between November and March are substantially less than the large damaging burns in summer.
The whole objective of swaling as a form of land management, is to create the best possible living conditions for plant life and animals, so, indirectly, it actually contributes to maintaining and increasing wildlife populations;
The vibrant more lush, new growth following a burn - in the years until the next swale - can make a more positive contribution to the atmosphere than the vegetation there before the burn.
Who carries out swaling?
The areas that are burned are agreed between landowners, commoners (farmers), the National Landscape team, National Trust and Natural England. On the day of a burn once the landowners and emergency services are informed, the burn is undertaken by the Commoners, National Landscape National Trust team and specially trained volunteers.