- REVERSING SPONTANEOUS SUCCESSION TO PROTECT HIGH-VALUE VEGETATION - 103 Applied Vegetation Science 4: 103-110, 2001 © IAVS; Opulus Press Uppsala. Printed in Sweden Abstract. Despite existing management agreements, signifi- cant change has occurred on Carnwath Moss and Coladoir Bog, two mire complexes in central and western Scotland. Spontaneous succession has accelerated, resulting in exten- sive degradation of the mire vegetation on both sites and, in particular, widespread expansion of Calluna vulgaris- and Molinia caerulea-dominated vegetation types. Vegetation surveys across strong gradients of change were conducted with the aim of quantifying the extent of early (desirable) and late (undesirable) successional vegetation on both sites. For each site multivariate analyses of the vegetation data were carried out using TWINSPAN, which clearly differ- entiated higher quality and degraded surfaces. In manage- ment terms percentage Sphagnum cover can act as a useful proxy measure of water level and shrub layer height can also serve as a useful indicator of the degree of degradation. A broad-based, five class condition continuum was devel- oped for the Carnwath Moss site. While such an assessment scheme is a somewhat arbitrary means of allocating mesotope areas to specific condition classes, it is rapid to apply and simple enough to be applied by a range of users. A drawback is that the methodology is data-light in tempo- ral terms and is not a long-term substitute for properly- funded monitoring programmes for important sites. For both mires, recommendations are made for management with the main emphasis being on maintaining water tables at appropriate levels to maximise the floristic diversity of active mires. Keywords: Bog complex; Degraded mire; Restoration man- agement; TWINSPAN. Nomenclature: Tutin et al. (1992). Abbreviations: SAC = Special Area of Conservation; SNH = Scottish Natural Heritage; SSSI = Site of Special Scientific Interest. Reversing spontaneous succession to protect high-value vegetation: Assessment of two Scottish mires using rapid survey techniques Large, Andrew R.G. Department of Geography, Daysh Building, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK; Fax: +44 191 222 5421; E-mail a.r.g.large@ncl.ac.uk Introduction Vegetation surveys comprise a continuum from base- line survey to long-term monitoring and permanent plot analysis, with increasing commitment of time and resources. Relatively undemanding (resource-wise) short-term community analyses can play a valuable role in site management as they can identify appropri- ate methods and techniques to achieve specific restora- tion objectives. They can also help ensure that restora- tion practices and objectives for specific sites are well phased and integrated with one another. This paper evaluates short-term survey results and presents resto- ration management recommendations for two bog com- plexes in Scotland: Carnwath Moss, Clydesdale Dis- trict (55° 43'N, 3°22'W) and Coladoir Bog, Isle of Mull (56° 30'N, 6°0'W) (Fig. 1). Efforts are made to develop a methodology suitable for the rapid survey of bog sites which is important from a nature conservation perspective as, while repeat monitoring is necessary to monitor degradation and/or habitat restoration efforts, the costs involved often mitigate against this type of activity. Few sites in Britain can be defined as ‘macrotopes’ sensu McTeague & Watson (1989), where they form an undisturbed hydrological system comprising of sev- eral inter-linked mire units. Carnwath Moss and Coladoir Bog are no different: both bog sites are indi- vidual, but fragmented, mire mesotopes (or mire sub- units). In bogs, disturbance effectively accelerates suc- cession from wet-mire vegetation into shrub-domi- nated vegetation communities more often associated with bog margins or with drying areas. Lindsey (1995) has stated that it is only through positive conservation management of such damaged areas that expansion of the amount of active bog surface in Britain can be achieved. From a conservation perspective, spontane- ous succession is undesirable for mires in general, and management is targeted towards inhibiting the proc- ess. It is not, however, possible to return a site to its original condition following damage (Wheeler & Shaw 1995), although restoration approaches may still add value to damaged landscapes.