Heather Management within a SAC by Burning – The First Steps

Introduction

It is widely accepted that ling heather (Calluna vulgaris) is the staple diet of Red Grouse. The carrying capacity of any upland grouse habitat is related to the nutritive value of the heather and also the cover it provides. Heather grows through four distinct age classes known as; Pioneer, Building, Mature and Degenerate. A balance of these age classes is necessary if a sizable grouse population is to become sustainable. The edible parts of heather are the green shoots and to a lesser extent the flowers and seed capsules. Young heather in the pioneer phase, one to two years after burning or cutting, has a nitrogen and phosphorous content more than twice that of 10-year old plants in the mid building phase. The food quality of heather degenerates further in the mature and degenerate phases. In general Red Grouse require tall heather for shelter or nesting (20-30cm) and prefer 10-30cm heather for foraging. Essentially, the quality and age diversity of heather will largely dictate the distribution and density of the associated Red Grouse population.

Among hill sheep farmers, gun clubs managing Red Grouse Projects and wildlife managers anxious to retain the quality of upland heath habitats, on designated and undesignated areas, there is a unifying belief that some controlled burning will be required, especially where grazing levels have been reduced.  Rank, woody and degenerating heather is of little nutritional value to sheep or Red Grouse and will gradually suppress the wider botanical and ornithological value of such sites. .  In order to maintain heather quality, burning, grazing or possibly mechanical strimming will be required if rank heather is to be avoided. But clearly there is a legal European requirement for the Irish Government to maintain the qualifying interests and habitats of many of their upland designations.  Illegal, uncontrolled burning is causing annual damage to nesting birds, loss of commercial forestry and damage to our tourism reputation.  Controlled licence burning, in liaison with the local fire service personnel has a role to play in an agreed management plan for the upland and Red Grouse management in Ireland.  Simultaneously, the statutory wildlife authorities are seriously assessing the role burning might play in upland Biodiversity plans and the farming lobbies are looking for new practical upland options to be added to the new AEOS Agri-Environment scheme.

Regeneration of heather

Heather can regenerate in three ways:

From seed: Up to 100, 000 seeds are produced per plant and in the order of one million per square metre in the season. The seeds are shed in the autumn and retain their viability in damp soil or litter for up to 10 years. Fluctuating temperatures and exposure to light, as in the area cleared by burning, stimulates germination. A fire may destroy seeds on the surface but many that lie buried survive.

From buds: With grazing or cutting which removes only part of the branch system, shoots may sprout from several levels. After burning, a dense cluster of shoots develops from dormant buds near the base of the stems.  Regeneration after burning is best when the branches have had six to ten year’s growth and declines to a minimum in the degenerate phase.

Layering: This occurs in the degenerate phase.  Adventitious roots and new shoots develop when collapsed branches lie prostrate among damp peat and moss. The heather may return to a relatively young phase, but the regeneration cycle will exceed 25 years, usually much longer than from seed or after burning.

Burning small patches of heather at regular intervals is used as a management tool to maintain heather in a phase when the biomass of young nutritious shoots is at a maximum, and to create a diversity of heather structure. Heather regenerates more successfully after autumn fires. Best practice in heather burning has been developed, particularly in Scotland. Key elements of this include:

  • When managing for sheep and red grouse, burning should be carried out in the budding phase when the heather is 20-30cm high, but patches should be allowed to grow to 40cm as nesting and roosting cover.
  • It is estimated that the interval since the last burn on a particular patch should be between 10-18 years.
  • The fire should be hot enough to consume most of the heather above ground, but not kill the basal buds and rootstock, nor destroy the seed bank.  Regeneration can therefore take place either from seed or vegetatively.
  • Burning is usually down-wind, but if a hotter fire is required to remove old woody stems, slower back-burning into the wind is practiced.  It is also best to burn across and down the slope.
  • To provide a mosaic of different aged heather for both food and cover within each grouse territory, it is desirable to have many small burns of 0.5 –1.0 ha in extent rather than extensive ones. The heather should ideally be burnt in strips no more than 30 metres wide and parallel to a previous burn, but not using its entire length.
  • Blanket bog, steep slopes and other areas unsuitable for burning should be left to encourage greater habitat diversity.

Heather regeneration can also be encouraged by cutting with brush cutter, a swipe, a flail or forage harvester.  The litter if collected in the autumn, provides a source of heather seed for reseeding areas which have lost their heather cover in a severe burn or as a result of severe grazing. Cutting can also be used to create firebreaks or to assist livestock into deeper vegetation.

What has been the experience on the Boleybrack Red Grouse Project?

Boleybrack Mountain is located north of Lough Allen and lies between the towns of Drumkeeran, Manorhamilton and Blacklion. A large portion of the northern side of the mountain overlooks the parish of Glenfarne. Boleybrack Mountain comprises an extensive upland plateau, dominated by mountain blanket bog and wet heath, with small lakes scattered throughout. There are low rocky cliffs, areas of dry heath and a variety of grass types. Most of Boleybrack Mountain is designated as a Special Area of Conservation (SAC) under the EU Habitats Directive. Much of the Boleybrack uplands lie within the club territory of Glenfarne Gun Club. In 2007, the club developed a Red Grouse Habitat Management Plan to protect and enhance the fragile Grouse population on Boleybrack. Thanks to the assistance of NPWS, The Golden Eagle Trust and the support of the commonage shareholders, this management plan is now in year 4 of its implementation with modest success.

At the outset, the Boleybrack team decided against burning in this commonage area, in order to ensure maximum support from commonage holders.  The protection of blanket bog habitat, for which Boleybrack was designated an SAC, was another consideration. It was agreed to use strimming with brush cutters as means of removing degenerate heather and stimulate regeneration of young nutritious heather. At that time, the management team agreed to review the outcome of strimming annually and whether burning will be required in the future. It is now apparent that results from heather management using strimming are much less than satisfactory. Strimmed areas from management year 1 are still struggling to produce signs of heather recovery. It was therefore agreed that with the alternatives tried with little success, it was time to try selective control burning.

Satisfying Legal Requirements

Under Section 40 of the Wildlife Act burning in Ireland is only allowed between 1 September and the end of February. Weather conditions in the uplands may permit burning on only a few days a year.   Burning within 1 mile of a wood is also restricted under section 39 of the Wildlife Act. In accordance with the requirements of this section, written notice must be given of any proposed burning, at least 7 days in advance, to the District’s Gardai Sergeant, and Coillte. In all SACs burning and cutting are a notifiable action and the National Parks and Wildlife Service must formally approve any such action beforehand. During prior consultation with the NPWS, it was agreed that the Boleybrack Red Grouse Habitat Management Project should be subject to appropriate assessment and a burn plan submitted prior to Appropriate Assessment Screening.

Notifications

Boleybrack Mountain is commonage owned, and located within an SAC. With conifer forests on all sides, the requirements for burning within 1 mile of Coillte forestry become relevant. Hence under the Wildlife Act and Habitats Regulations as well as for fire safety reasons various notifications were made and consents sought as follows:

  • NPWS– The project steering group discussed the need for controlled strip burning of heather and the benefits to the habitat. Sites suitable for burning were agreed on the ground with NPWS and a burn plan was prepared by the steering group and submitted to NPWS for approval. In addition to maps and specified locations for the burn plots, the Burn Plan contains procedures for the controlled burning of heather in accordance with the Scottish Muir Burn Code and the UK Heather and Grass Burning Code.  An Appropriate Assessment Screening was carried out and consent for the work was received by way of a notifiable action application. It was agreed that the local NPWS Ranger be present at all burning events.
  • Commonage Shareholders – Glenfarne Gun Club notified Commonage Shareholders well in advance of burning and explained the plan to control burn small parts of the mountain for the benefit of Red Grouse. The benefit to sheep farmers by improving grazing quality and also maintaining their qualifying ‘areas fit for grazing’, under farm payment requirements was highlighted.
  • Fire Service – A copy of the burn plan was emailed to the Chief Fire Officer for the county and to CAMP WEST, the emergency coordination centre in Castlebar. Follow up phone calls to the Chief Fire Officer and the CAMP WEST control room, together with a meeting with the local fire service, clarified arrangements for their notification just before burning starts.
  • Coillte – Coillte received a copy of the burn plan by email. Follow up phone calls discussed the arrangements for notification just before burning starts.
  • An Garda Siochana – The Intension to carry out controlled heather burning was discussed with the Garda Superintendent and a copy of the burn plan was supplied to the local Garda Sergeant well in advance of any burning. Arrangements were made for notification of the Gardai just before burning starts.

 

The Heather Burning Event

The weather during the last 3 weeks of February had very few days suitable for burning because conditions were often too wet or too windy. However, successful burning was carried out on the 17th of February in compliance with the approved Burn Plan. Seven areas had been selected for burning but, even with the limited weather opportunities available, 3 areas were burned successfully. An additional 2 areas were attempted but were unsuccessful. This was mainly due to wet ground conditions. Burning was instructed on the day by Jamie Little, Gamekeeper with the Grey Partridge Project at Boora and Paddy Mc Cartney of the NARGC. The burning was supervised by Fiona Farrell (NPWS Conservation Ranger). Fires were started using the Kerosene burning X500 Flame Gun. Immediately before any burning was started, the various notifications had to be made by phone as arranged earlier:

  • CAMP WEST, the fire emergency coordination centre was contacted by calling 999 and asking for the fire service. It was explained that control burning was about to start in accordance with the submitted burn plan. The senior person for the local fire service was also called and notified, as arranged.
  • Coillte’s nominated contact forester was also notified by phone.
  • The Gardai District Station was also notified by phone as arranged.

 

All the notified parties were contacted again when burning was finished to confirm that all fires were fully out.

The heather burning event was considered by all to be a great success. The damp ground conditions did mean that heather in hollows that could not be dried readily by the wind was difficult to burn. The areas that burned well were in sunny, elevated locations. The total area of heather actually burned was not as much as planned but the procedure developed got tested and it worked well. There were no mishaps and the fires were never in danger of escaping from the beaters. The preparation for the burning event allowed the project managers to develop a relationship with the various authorities and this will undoubtedly stand us in good stead when it comes to planning our next burning event in autumn.