The lichens of the Scottish native pinewoods B.J. COPPINS1* and A.M. COPPINS2 1
Royal Botanic Garden Edinburgh, Edinburgh EH3 5LR, Scotland 37 High Street, East Linton, East Lothian EH40 3AA, Scotland *Corresponding author. E-mail:
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2
Summary During the last 30 years, 434 epiphytic lichen taxa have been recorded from the native pinewoods of Scotland. Of these lichens, about 219 have been recorded from the bark, lignum or stumps of pine (Pinus sylvestris) itself. Eighteen species are, in the British Isles, confined to these native pinewoods, which are themselves confined to the Scottish Highlands. A resume is presented of the habitats and niches available to lichens in the native pinewoods, using examples of the most characteristic species for each. The ‘pinewood habitat’ for epiphytic lichens is by no means restricted to pine, but also includes associated trees, shrubs and subshrubs, especially birch, rowan, holly, aspen, juniper and heather. The strong east–west variation in the composition of the lichen flora is outlined. By comparison of species lists from pinewood stands of known ancientness with those from mature plantations distant from the ‘core’ pinewoods, an additional c. 60 species can be considered as indicative of an ecological continuity of the pinewood habitat. From this pool of c. 77 species, a Native Pinewood Index of Ecological Continuity is presented as a useful tool for biodiversity assessments of pinewoods.
Introduction Prior to 1974, there were only a few scattered records of lichens from our native pinewoods, and the British Lichen Society mapping scheme had record cards with only rudimentary lists. In February 1974, accompanied by Paul Harrold, I (B.J.C) made my first visit to a native pinewood, the Black Wood of Rannoch. Our first impressions were that the lichen flora was very poor: either the trees were rather bare or where they were endowed with lichen growth, only a handful of species were responsible. This is quite different to the impression one gets on entering ancient broadleaved woodland (especially with ash (Fraxinus excelsior), hazel (Corylus avellana) or oak (Quercus)) in the Scottish Highlands. © Institute of Chartered Foresters, 2006. All rights reserved. For Permissions, please email:
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Fortunately, however, we had allowed ourselves 2 days and the weather was glorious, and after a while, we began to find small lichens in various niches, mostly those associated with deadwood. We returned home with a large collection of very unfamiliar lichens and non-lichenized microfungi. After many days work with the microscope and trawling through the foreign literature, as well consultation with some Scandinavian colleagues, several of our finds proved to be additions to the British list. This provided a catalyst to further pinewood visits, and our knowledge of pinewood lichens took a quantum leap during 1976, when Leif Tibell of Uppsala University joined me on a trip to several pinewoods, especially Glen Affric, Abernethy and Rothiemurchus. Since then, most of the major sites of Scottish native pinewood Forestry, Vol. 79, No. 3, 2006. doi:10.1093/forestry/cpl013 Advance Access publication date 25 May 2006
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have been investigated for their lichens, although most still deserve much more thorough study. There have been only three commissioned detailed lichens surveys of native pinewood: Beinn Eighe National Nature Reserve (NNR) (Coppins and Coppins, 2001), Loch Maree Islands NNR (Giavarini et al., 1999) and Forest of Mar (Street and Street, 2000). Is this because native pinewoods have not been considered important for lichens? If so, I must take a large share of the blame for not singing their praises sooner! In this paper, we present an overview of the habitats and niches available to lichens in the native pinewoods, using examples of the most characteristic species. Lichen nomenclature mainly follows Coppins (2002) and syntaxonomic nomenclature broadly follows James et al. (1977).
The resource The 30-year accumulation of data, though mostly made in an ad hoc way, has nevertheless resulted in a list of 434 lichens recorded on bark, lignum and associated soil and debris, with 219 species being recorded from the bark or lignum of pine (Pinus sylvestris) itself. Of the total list, 18 species are, in the British Isles, apparently confined to native pinewoods (Table 1), although three, Buellia sanguinolenta, Lecidella subviridis and Rinodina laevigata, are not on pine but on rowan, juniper and aspen, respectively. The inconspicuous Melaspilea lentiginosula is a supposed endemic to Scotland, but it should be looked for on the bark plates of old pines in Norway, especially.
Habitats and niches The following is a general account of what can be expected in idealized stands of mature to ‘oldgrowth’ native pinewood. There will be much variation throughout a stand, even from tree to tree or stump to stump and so on. There are also significant regional variations associated with macroclimate, which are dealt with below under ‘Regional variation’. Very rare species are mostly not referred to in this section. The native pinewood habitat is essentially one for acidophilous lichens that are able to tolerate pH levels of 2000 mm; number of wet days, >220; oceanicity, ≥20; central – annual rainfall, 1200–1800 mm; number of wet days, 180–220; oceanicity, 15–20; eastern – annual rainfall,
