Information on the distribution of British lichens lies scattered in many publications, manuscripts and databases. D. L. Hawksworth and M. R. D. Seaward (1977) Lichenology in the British Isles 1568-1975 Richmond Publishing Company, review a large section of the published literature and manuscripts lodged in the major institutions up to 1975. This information can be accessed alphabetically by authors or by vice-county lists. This is the single most useful summary of published information on lichen distribution. Section 8 below lists more recently published papers in the Lichenologist, the journal of the British Lichen Society, which may be of some interest to Welsh lichenologists, if only for comparison purposes.
Census Catalogues etc.
Census Catalogues list all those species ever recorded from one or more of the Vice-Counties created by H. C. Watson in 1859 to provide stable, roughly equal sized recording units throughout the British Isles. The Welsh Watsonian Vice-Counties roughly follow the old Welsh counties prior to local government reorganisation in the 1970’s. W. Watson (1953) produced a Census Catalogue of British Lichens, Cambridge University Press. Though historically interesting it is now very out of date. The author of this account and Mr A. Orange of the National Museum of Wales have produced an updated version for Wales. It was published by NMW in 1999 and is entitled A Census Catalogue of Welsh Lichens. Over 1500 lichens and lichenicolous fungi recorded from Wales are assigned to one or more of the 13 Welsh Vice-Counties. Attempts have been made to update this document by the authors and copies can be obtained from the authors. There is some debate as to the value of such listings and I would welcome comment as to the value you place on such information. Smith et al (2009)(see section 2 below) provide a brief summary of the British and World distribution of all British species, together with habitat requirements. M. R. D. Seaward has produced a Vice-County Distribution of Irish Lichens in Biology and Environment: Proceedings of the Royal Irish Academy 94B No.2 177-194 (1994).
Dobson (2005) (see section 2 below) provides distribution maps at a 10km square level for the common species. (Earlier edition distribution maps should be used with caution). These maps were obtained from British Lichen Society records. In 1963 the Society set up a mapping scheme, for which Prof. M. R. D. Seaward at Bradford University has been its Secretary since its inception.
In 1982 Vol.1 of an Atlas of Lichens of the British Isles was edited by M. R. D. Seaward and C. J. B. Hitch and published by the Natural Environment Research Council. This volume provides 10km square distribution maps of 176 species, split into pre and post 1960 records. Each map is accompanied by a description of the habitat requirements of the species. In 1984 a further 120 species maps were issued to a small number of lichenologists by Prof . Seaward.
In 1995 the first fascicle of the Lichen Atlas of the British Isles, edited by M. R. D. Seaward, was published by the British Lichen Society. It deals entirely with the genus Parmelia, but also includes a list of references to maps published up to the end of 1994 for other species, compiled by M. R. D. Seaward. (A sample page is provided as appendix 3). This Atlas provides detailed information on species, including substrate ecology, conservation information, world distribution, in addition to 10km square dot maps of the British Isles, and advice on identification. A CD Rom of this data, together with colour illustrations was produced by The British Lichen Society in 1997. Further Atlas fascicles have now been produced including Cladonia species, Anaptychia, Physcia and allies, Lepraria and allies, Pannariaceae (and key to genera), Lobaria, Sticta, Pseudocyphellaria and aquatic lichens.
The above remain almost the only readily available printed maps, though it is hoped new fascicles of the Atlas will appear regularly. A summary map showing the coverage achieved by this scheme has been produced from time to time in the Lichenologist. Anyone requiring 10km distribution data should contact the author who will access the BLS database. In addition the author maintains maps at 5 x 5km level for Brecknock, E. Carmarthenshire, Radnorshire and Montgomeryshire. S. P. Chambers has a database of Ceredigion lichens.
The only readily accessible set of BLS distribution maps for all British lichen species is provided by F.S. Dobson in his CD Lichen Identifier Version 3 (2007)(see appendix 1).They are easily accessed via “My Computer” or “Windows Explorer”, opening the maps folder. Caution should be exercised in their use as some maps require re-evaluation.
The British Lichen Society has also now set up a separate database linking records of lichens to sites initially using the programme “Biobase” but now “Recorder”. This data will become available via the National Biodiversity Network. The Society has also produced country databases of sites for lichens of conservation concern. The Welsh data base is currently being checked and will be made available via the NBN. Much data from Wales is being incorporated into the local record centres recently established throughout Wales. (See http://www.nbn-nfbr.org.uk/nbn.php for details). This data is being shared with the BLS who are currently checking its accuracy.
The following local floras have been published and contain information on Welsh lichens.
- Flora of Glamorgan .Wade, A.E., Kay, Q. O. N., and Ellis, R. G, British Museum, London.
- Flora of Radnorshire (1993) Woods, R. G. National Museum of Wales, Cardiff
- The Lichen Flora of Gwynedd (1987) Pentecost, A. (1987), Lichenologist 19: 97- 166.
- Lichen Flora of Brecknock (2003). Woods, R.G.. Privately published by the author.
The only recently published local flora of a vice-county adjacent to Wales is that of Fox, B.W. & Guest, J. (2003). The Lichen Flora of Cheshire and the Wirrel. Nepa Books, Frodsham.