Flora of Northern Ireland

Moorland and upland heath

Upland heath at CushendunThe term ‘moor’ is not one that figures in Irish vernacular terms, but is in general use by ecologists and botanists. It grades imperceptibly into blanket bog and upland heath, but tends to be used to describe the large tracts of acidic, peaty, but relatively drier ground dominated by Nardus stricta, Agrostis spp., Erica spp., Calluna vulgaris, Vaccinium myrtillus, Salix repens etc. Diphasiastrum alpinum is a rare but locally dominant member of the vegetation. The only Irish site for Rubus chamaemorus consists of this sort of habitat.


Blanket bog at CushendunUlex europaeus and U. gallii frequently occcur amongst heather-dominated upland areas, and this type of vegetation is usually termed a heath, as is that dominated by Myrica gale.


Flushes

GlenshaneSprings, usually on a hillside slope, have a local effect on the vegetation and flora. In acid, species-poor, areas like the Mourne Mountains, the spring water carries dissolved minerals which have an enriching effect on both the vascular plant and bryophyte floras, allowing more demanding species like Schoenus nigricans to grow. In basaltic and limestone districts the wet ground develops a fen-like vegetation with such species as Ranunculus flammula, Carex panicea and Hydrocotyle vulgaris. The wet or marshy areas around a spring, which may itself be quite invisible, are called flushes and are often clearly visible from some distance on a hillside because of the light green coloration of their vegetation. This contrast is particularly strong on slopes dominated by dark-coloured heath species. The rare and local Saxifraga hirculus is associated with flushes on the basaltic Garron Plateau in Co Antrim. The impact of a spring or flush on the flora is closely linked to the underlying geology of the site.

At some sites base-rich ground water collects or wells upwards into natural hollows or basins. In areas of blanket bog this leads to local species-rich sites where the acidity and base-poor nature of the bog is ameliorated.