Recovery from Muirburn, Assynt
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Muirburn in Assynt A project by the Assynt Field Club, 2004-2006 Grant-aided by Scottish Natural Heritage Project directed and report edited by Ian Evans Research and mapping by Robin Noble Site research by Viv Halcrow Other contributions by: Dr Malcolm Bangor-Jones, Reay Clarke, Dr Althea Davies, Dr Tony Fletcher and Gordon Rothero !1 Contents Page 1. Introduction (IME) …………………………………………………………… 3 2. Summary (IME) ………………………………………………………………... 4 3. Information gathering Objective 1 Mapping/quantification (RN/IME) ………………………… 6 Objective 2 1990s study by Hamilton et al. (RN/IME) ………………… 8 Objective 3 Remote sensing …………………………………………….. 10 Objective 4 History of muirburn (RN/AD/MB-J/RC/IME) …………… 11 Objective 5 G.I.S. ………………………………………………………... 16 Objective 6 Effects of muirburn (RN/GPR/AF/IME) General/vegetation …………………………………………. 17 Juniper ……………………………………………………… 19 Bryophytes ………………………………………………….. 21 Lichens ……………………………………………………… 22 Mammals …………………………………………………… 23 Birds ………………………………………………………… 24 Reptiles and amphibians …………………………………... 25 Invertebrates ……………………………………………….. 25 Objective 7 Views on muirburn ………………………………………… 28 4. Field Survey and monitoring Objective 1 Relocation of 1990s study site ……………………………... 30 Objective 2 Monitoring plots surveyed in 2005 (VH) …………………. 31 Objective 3 Future monitoring of local fauna (IME) ………………….. 33 5. Future practice (RN/IME) ……………………………………………………… 34 6. References ………………………………………………………………………. 35 7. Acknowledgements ……………………………………………………………… 37 8. Appendices 1. Grant Application !2 2. Map showing extent of recent burns 3. Photographs of recent burns 4. Notes by Dr Anthea Davies 5. Notes by Dr Malcolm Bangor-Jones 6. Notes by Reay Clarke 7. Survey report by Viv Halcrow !3 1. Introduction 1. In late February 2003 uncontrolled muirburn, on a scale unprecented in recent years, occurred in the west of Assynt. The main burn ran for nearly 10 km in a dog-leg from north of Lochinver (NC0924), north-east to the edge of Loch Beannach (NC1326), and then north- west to the edge of Loch Poll (NC0930), but there were others. 2. In December 2003, the Assynt Field Club asked Scottish Natural Heritage to grant-aid a project to investigate the impact of muirburn on the vegetation and wildlife of the parish (see Appendix 1). The proposed project had three main elements: a. Information gathering b. Field survey and monitoring c. Future practice 3. In January 2004, Scottish Natural Heritage made an offer to the Field Club of £4000 towards the costs of the project. Contributions in kind have been made by members of the Field Club and other interested parties. 4. Fieldwork on the project commenced early in 2004. Robin Noble undertook most of the information gathering, including detailed mapping of the boundaries of all identifiable areas of recent muirburn. Viv Halcrow undertook vegetation surveys in summer 2005 of six sites straddling burn boundaries, together with a further one of an unburned juniper-rich area. 5. Other significant contributions were made by Dr Althea Davies and Dr Malcolm Bangor- Jones on the history of muirburn, Reay Clarke on the practice of muirburn, Dr Tony Fletcher on lichens and Gordon Rothero on bryophytes. 6. The project was supervised and the report edited by Ian Evans. The report has been divided into sections corresponding to the Objectives stated in the Grant Application (Appendix 1). !4 2. Summary. 1. Uncontrolled muirburn in 2003 affected some 18 sq.km. of hill ground in Assynt, compared with about 9 sq.km. in the previous 12 years. Most of the 18 sq.km. burned was on or adjacent to the common grazings of the crofting townships from Inverkirkaig round to Nedd and it included the sites of two crofter forestry schemes. No precise information was available as to the precise extent of these burns, so both they and all other identifiable burns that have occurred since 1990 have been mapped. 2. A detailed study had been made in 1996-1999 of the effects of muirburn on the vegetation of a site near Loch Poll, but changes in the land-use of this site meant that the study could not usefully be repeated. 3. Aerial imagery did not prove useful in mapping past burn sites and satellite imagery was not therefore investigated. 4. There is palynological evidence of burning in the Assynt area going back some 5500 years, and recent detailed information from sites in Gleann Leireag dating back to the 16th century. Documentary evidence confirms that burning was a common practice from the 18th century, but that it was closely regulated by the landowners until at least the beginning of the 20th century. Anecdotal evidence suggests that inadequately controlled burning became more frequent in the second half of the 20th century, and some of the burns affected large areas. 5. No useful information could be located on the effects of muirburn on nutrient levels and run-off in Assynt or landscapes in the North-West Highlands with comparable climate, soils or topography. 6. General observations on the effects of muirburn on the vegetation of Assynt reveal that they are complex and that, so far as higher plants are concerned, to some degree contra- dictory. However, there is strong evidence, based on extensive fieldwork in the parish since 1990, of the destructive effect of muirburn on the distribution and abundance of one important vegetation type, juniper-rich dwarf-shrub heath, which may once have been much more widespread. The parish has one of very few good remaining examples of this community in West Sutherland. 7. Detailed study of internationally important bryophyte communities in those parts of Assynt affected by muirburn suggests that their present distribution is largely a relict one. Significant elements of these communities have very limited powers of dispersal and are now confined to crags, screes, woodlands and mires that have escaped burning. 8. Similarly, the lichen flora of rocks, whether isolated boulders, outcrops or crags, in open habitats, is now mainly dominated by fast-growing species with good powers of dispersal; other species that may have occurred more widely in the past are now very limited in their distribution. 9. Research on the impact of muirburn on the animal life of moorland is curiously sparse, !5 even at a national level, especially any that relates directly to the climate, geology, soils and topography of Assynt. Evidence from Assynt is largely anecdotal, but mammals, birds, reptiles and amphibians all appear to be adversely affected. 10. The views of local individuals on muirburn tend, predictably, to be polarised, between a small number of practitioners and advocates, and a much larger number of critics. The Assynt Crofters’ Trust, as landowner of much of the ground on which the 2003 burns occurred, advocates adherence to the Muirburn Code, but control is vested in individual grazings committees. For whatever reasons, muirburn is frequently carried out without adequate control, when weather conditions are manifestly unsuitable, with scant regard for either the Code or the Law. 11. As a contribution to the future study of the effects of muirburn on the vegetation of Assynt, six monitoring plots have been set up on the boundaries of the 2003 and earlier burns, and surveyed in detail, together with one in juniper-rich dwarf-shrub heath. 12. Elements of the invertebrate fauna are suggested for detailed future study. 13. In view of the huge areas burned in 2003, the resultant devastating local effects on wildlife, the continuing shortage of skilled manpower to control burns and the large areas recently fenced and planted with trees, it is recommended that, within areas of the parish under crofting tenure, there should be a complete moratorium on burning for ten years, followed by a review of the policy township by township. 14. In view of the widespread evidence for burning, some of it recent, elsewhere in Assynt, it is recommended that there should be a similar moratorium on burning for ten years on the land that has recently passed into the ownership of the Assynt Foundation and the John Muir Trust, followed by a similar review of policy. !6 3. Information gathering Objective 1: to map/quantify the extent and severity of recent muirburn…, using information from the emergency services, grazings committees and other local sources. Upon investigation, it was found that there existed no accurate records of the boundaries of even the most serious burns during 2003, or any earlier ones, and that the only way to obtain even an adequate impression of the scale of the burns was to walk the hill. The appended copy of the 1:50,000 O.S. map (Appendix 2) shows the extent of these and other identifiable episodes of burning since 1990. The mapping exercise concentrated on the area bounded by Quinag to the east, and Loch Assynt and the River Inver to the south. Within this area, some 18 square kilometres of hill were burnt in 2003, against an approximate total of 9 square kilometres in the preceding 12 years. Nearly all the identifiable burns were located on the common grazings of the crofting townships stretching from Achmelvich round to Nedd, most of which fall within the North Assynt Estate (Assynt Crofters’ Trust). Elsewhere in this area, there were three burns on the Ardvar Estate (the largest in 1996, and two smaller), and two much smaller burns in 2003 on the western flanks of Quinag. Elsewhere in the parish, there were large burns during 2003 and 2004 (on ground also burned in part in 2001-2) in an area south-east of Lochinver. They covered an area of about 8 sq.km, running from Cnocnaneach (NC1121) south-east to the shore of Fionn Loch (NC1317). The area was on Assynt Estate ground, but the burns were not initiated by Estate staff; they are believed to have started on the adjacent Strathan or Inverkirkaig common grazings. There was also in 2003 a small burn behind Inverkirkaig (NC0819).