Cresponea premnea

On dry, rough, usually well-lit bark and sometimes lignum of old Oak, Holly, Yew and rarely other species including Beech, Hornbeam, Rowan and Lime; intolerant of nutrient enrichment. The dominant species of the Ancient Dry Bark Communities (Lecanactidetum premneae) on dry bark on old trees, often with Lecanographa lyncea, but spreads on to communities in wetter bark in woods with very high populations, as in the New Forest. It occurs primarily in ancient, usually open, parklands or forests, sometimes in hedges and roadsides, more rarely on hard, acid rocks under dry overhangs.

The Ancient Dry Bark Community (Lecanactidetum premneae) needs a generally humid oceanic climate, but not a very wet one where frequent stem flows and hence bryophyte growth extends into overhanging bark. It is therefore very rare or absent in temperate rainforest habitats but can be abundant in southern oceanic woods. Sanderson (1996 & 2010) found that, in the New Forest, Cresponea premnea was rare in developing old growth stands that were clear felled in the early 18th century, even when the lichen was frequent in adjacent ancient old growth pasture woodland. It had however, fully recolonised pasture woodland developed over farmland abandoned after the Black Death. Cresponea premnea was a somewhat earlier colonist than Lecanographa lyncea, which was wholly absent from early 18th century stands, but still needs over over 300 years to fully colonise new woodlands.