Ben Alder SSSI
Total Page:16
File Type:pdf, Size:1020Kb
Scottish Natural Heritage Archive Report No. 054 Site dossier for bryological interest – Ben Alder SSSI ARCHIVE REPORT Archive Report No. 054 Site dossier for bryological interest – Ben Alder SSSI For further information on this report please contact: David Genney Scottish Natural Heritage Great Glen House Leachkin Road INVERNESS IV3 8NW Telephone: 01463 725253 E-mail: [email protected] This report should be quoted as: Rothero, G.P. 2004. Site dossier for bryological interest – Ben Alder SSSI. Scottish Natural Heritage Archive Report No. 054. This report, or any part of it, should not be reproduced without the permission of Scottish Natural Heritage. This permission will not be withheld unreasonably. The views expressed by the author(s) of this report should not be taken as the views and policies of Scottish Natural Heritage. © Scottish Natural Heritage 2019. Archive Reports Scottish Natural Heritage is committed to making the findings of all of its research publicly available whenever possible. In the past, a number of reports from staff and contractors were produced as paper documents and lodged in the SNH library or file systems. Some related to Site Condition Monitoring, others covered a range of subjects. These were not published as Research Reports for a number of reasons. In order to make these reports more available, we have decided to publish them online under the series title of Archive Reports. These will be numbered consecutively in the order that they are prepared for web publication. Their publication date, authors and title will be recorded as presented in the original report. The Archive Reports will be published as scanned PDF files of the original reports. They have not been subject to any new editing, formatting or other changes, other than the cover, title page and this page. Many of the reports published as Archive Reports were produced by contractors and were originally intended as internal documents to inform our policy and advice. As a result they may contain historical information that is no longer current or accurate, and may contain views of contractors or staff which do not represent the current views and policy of SNH. Many of the reports published as Archive Reports were produced by contractors and were originally intended as internal documents to inform our policy and advice. As a result they may contain historical information that is no longer current or accurate, and may contain views of contractors or staff which do not represent the current views and policy of SNH. This report was commissioned by SNH as part of the Site Condition Monitoring (SCM) programme to assess the condition of special features (habitats, species populations or earth science interests) on protected areas in Scotland (Sites of Special Scientific Interest, Special Areas of Conservation, Special Protection Areas and Ramsar). Site Condition Monitoring is SNH’s rolling programme to monitor the condition of special features on protected areas, their management and wider environmental factors which contribute to their condition. The views expressed in the report are those of the contractor concerned and have been used by SNH staff to inform the condition assessment for the individual special features. Where the report recommends a particular condition for an individual feature, this is taken into account in the assessment process, but may not be the final condition assessment of the feature. Wider factors, which would not necessarily be known to the contractor at the time of the monitoring, are taken into consideration by SNH staff in making final condition assessments. Access permission was obtained from all those owning and managing the site. Site dossier for bryological interest Ben Alder SSSI Introduction Sites of Special Scientific Interest (SSSI) are designated on the basis of notified features of interest. These include habitats, species or geological features. Site Condition Monitoring (SCM) is a six year programme of assessment of the state of all notified features of interest on designated sites. Reporting is based on feature types and will be to common standards across the four UK country conservation agencies. This project addresses bryophyte monitoring on sites in Scotland, and covers all Scottish SSSIs where bryophytes are a notified feature. Site name: Ben Alder SSSI SNH area: East Highland, Aviemore Office Site notification: The citation mentions the extent of Racomitrium lanuginosum heath on the summits of the hills on the SSSI and picks out two communities for specific mention: “Some Northern Atlantic liverworts have their Eastern outposts in the Ben Alder range and include Scapania nimbosa and Herbertus aduncus ssp hutchinsiae.” and “Mosses, lichens and liverworts associated with long snow-cover in the snowbeds are well represented…..”. Surveyor: Gordon Rothero Date of survey: 2004 Site description and limits of survey: This is a very large and mountainous site with a number of hills over 1000m on which there are deep coires and large areas of crag and scree. Ben Alder itself has the largest contiguous area of ground above 1000m outside of the Cairngorms and there is also a large plateau area on Geal- charn and consequently, both have large areas of snowbed vegetation. Ben Alder itself is rather acidic but does have large areas of block scree with a N or NE aspect which have significant bryophyte interest. Aonach Beag and its eastern outlier, Geal- charn have bands of limestone at high altitude and these outcrops and the associated scree, flushes and grassland are very important for bryophytes. The site is so remote that camping or staying in a bothy is almost essential so that sufficient time can be spent in the field. The limited time available for survey meant that the survey had to be limited to those areas known to contain the bryophyte features of interest. The sites visited over three days were the crags and screes in Garbh Choire on Ben Alder, the snow beds and meltwater flushes on the Ben Alder plateau, the crags screes and snow beds on the eastern slopes of Geal-charn above Loch an Sgoir and the crags, scree and grassland associated with the limestone outcrops in Coire Cheap. It is clear from this that a large part of the site was not visited and, although it is probable that the areas surveyed do contain the major bryophyte interest of the site, much of importance will have been missed. Previous surveys The richness of the bryophyte flora here, particularly that on the limestone of Geal- charn was first recognised by Derek Ratcliffe in the 1960s. In the last 25 years there have been 4 visits paid to the site by bryologists and all concentrated on the areas that I visited on in 2004: 1 Bryophyte site dossier-Ben Alder SSSI 1979 David Long (RBGE) private visit 1987 Martin Corley, David Long, Peter Pitkin (NCC), Gordon Rothero private visit. 1990 Gordon Rothero – bryophyte survey of areas of late snow-lie for NCC 2003 Gordon Rothero – SCM vascular plants Bryophyte communities: On such a large site, a number of different types of plant community important for bryophytes are represented but there is only good information on a limited number of these. Grassland and heaths: Much of the grassland on the site is rather acidic with a rather limited bryophyte interest. Where there are limestone outcrops, the calcareous grassland below them has considerable interest and this is particularly true of Coire Cheap. Nationally rare and nationally scarce species that occur in here are Ptychodium plicatum, Hylocomium pyrenaicum, Thuidium recognitum, Hypnum bambergeri and Racomitrium canescens. These species are usually sparse in a bryophyte-rich turf where the dominant bryophytes are species like Hylocomium splendens, Rhytidiadelphus triquetrus, Racomitrium lanuginosum and Sanionia uncinata. There is a large extent of U10 (Carex bigelowii - Racomitrium lanuginosum heath) on the high level plateau areas of the site with Racomitrium lanuginosum particularly abundant in the more rocky sections. Dwarf shrub heaths lower down also have an abundance of bryophytes and on those slopes with an east or north- east aspect may have some oceanic-montane hepatics like Scapania ornithopodioides and Plagiochila carringtonii and in one place Anastrophyllum joergensenii, but this community is better developed in the screes. Acidic crags and scree: Outside of those areas with late snow lie which are dealt with separately, the acid crags, which dominate on Ben Alder itself, have an abundant but not particularly diverse bryophyte flora. The most frequent species is probably Racomitrium lanuginosum but Hylocomium splendens, Rhytidiadelphus loreus and Pleurozium schreberi can all be frequent. A few nationally scarce species have stan ds here including an excellent population of Oedipodium griffithianum on Ben Alder and smaller amounts of species like Isopterygiopsis muelleriana. Lophozia obtusa and the oceanic-montane liverwort Plagiochila carringtonii. The large areas of acidic scree on Ben Alder are of more importance for bryophytes, particularly where they are subject to moderately late snow lie as in Garbh Choire or on the slopes above Bealach Dubh. It is here that the oceanic-montane hepatics like Scapania ornithopodioides, Scapania nimbosa, Plagiochila carringtonii and Anastrophyllum donianum have their best stands Calcareous crags: The calcareous crags in Coire Cheap and to a lesser extent above Loch an Sgoir have a very diverse flora with numerous nationally scarce and some nationally rare and RDB speci es (see Table 1 below). Of particular importance here are the populations of Blindia caespiticia and Campylophyllum halleri, two ‘Lawers specialities”, which probably have better populations here than on Ben Lawers. Blindia caespiticia is only known elsewhere from Ben Lawers and Campylophyllum halleri only from Lawers and Caenlochan Glen. In addition, the abundance of other species like Hypnum bambergeri, Ptychodium plicatum and Timmia norvegica is remarkable. The calcareous scree is also an excellent habitat with some of the same species occurring as on the crags and, in addition, Heterocladium dimorphum, Mnium spinosum and Pseudoleskea incurvata.