| Calluna is a cool temperate,
oceanic and sub-oceanic species (Gimingham 1960). It is
native and almost ubiquitous in Britain and Ireland, very
common on heaths, moors, bogs and open woods with acid
soils, ascending to a height of c.1,000m. It attains much
greater heights in Europe. Calluna occurs in a
very wide range of plant communities (Rodwell 199 ) as
well as the various heathland associations in which it
is dominant (Gimingham 1972). In woodland it tolerates
shade unless it is very dense, but maximum development
and abundance is achieved only in the open (Gimingham
1960). It can also be abundant in some places near the
sea, although here it tends not to be as vigorous (Clapham,
et al. 1987). It can grow up to altitudes of 600m on the
western coasts of Europe, and on the exposed slopes of
Britain and Ireland's sub-oceanic and oceanic hills Calluna
dominates, but only in the absence of intensive grazing
(Tansley, 1939). Calluna vulgaris dominates upland
vegetation to a major degree, covering 25% of the uplands
(Bunce & Barr 1988). The almost total Calluna dominance
on many British moorlands is artificially maintained by
burning. Calluna is only absent from intensively
cultivated areas on highly base-rich soils and it is tolerant
of factors such as temperature range, length of growing
season and exposure. |
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