BSBI Species Accounts ArchiveSorbus torminalis
Mon, 09/06/2010 - 12:23 | 
markd
Name: Sorbus torminalis (L. ) Crantz., Wild Service-tree.
An obsolete name for it is Chequers Tree, which often still turns up in Pub names in England.
Chromosome no.: 2n = 34 (Stace 2010).
Photography: A.J. Lockton
Widespread in England and Wales, absent from Scotland, Ireland, Man and the Channel Isles, except as an uncommon introduction. The number of records of S. torminalis in Britain has been steadily increasing for a century or so. This is thought to be largely due to better recording, because it is easily overlooked. However, it is possible that part of the apparent increase is real, either due to natural spread or deliberate planting. It is a common species throughout western Europe extending eastwards at least to Asia. Many infraspecific forms have been described.
Click on the map to view full-size on the BSBI Maps Scheme website.
It occurs in three main habitats: ancient woodland on calcareous soils; limestone and other rock outcrops; and hedges. This mirrors the distribution of other species of Sorbus. Given that these are very widespread habitats, it is perhaps surprising that it is so uncommon. Rodwell (1991-2000) gives just two vegetation communities for it: W5 Alnus glutinosa and W8 Fraxinus excelsior woodlands. W8 is the typical climax community on drier calcareous soils in England & Wales, and presumably accounts for the majority of sites. W5, however, is an acid wet woodland type and seems somewhat incongruous.
- Origin: native in Britain.
- Rarity: it is a widespread but very localised species.
- Threat: there is no obvious threat to it in Britain. Cheffings & Farrell (2005) give its status as “Least Concern” in Britain.
- Conservation: because it is widely considered an ancient woodland indicator, S. torminalis is often highly valued as a plant of conservation interest. Wherever it occurs as a native it is listed as an axiophyte.
Although this is a popular tree, most of what is written about it is folklore, and scientific studies are rare. Roper (1993) studied its distribution, focusing on its affinity with various soil types. There are many question left unanswered, though, including...
- Why is it so rare?
- What are its vegetation communities?
- What are its mechanisms for reproduction and dispersal?
- What is its natural range in Britain, and to what extent is it planted?
- Is it increasing or decreasing?
- What is its world distribution?
- Roper, P. 1993. The distribution of the Wild Service Tree, Sorbus torminalis (L.) Crantz, in the British Isles. Watsonia 19, 209-229
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