Banagher Glen

Also within

Londonderry County Sperrin Scenic Area

Habitats

Fast flowing river and stream

Geology & landscape

Geological Feature: Geological Fault · Rock Type: Limestone, Schist

Landscape processes: Glacial, Volcanic / Igneous

Birds & fish recorded

Birds

Description

Banagher Glen Invertebrate assemblage, Breeding bird assemblage Mixed ashwoods, oakwood Dalradian The area is of special scientific interest because it is the largest surviving intact block of semi-natural woodland in Northern Ireland, in addition to being the finest example of a calcifuge oak woodland found. It is also of geological and physiographical importance because of the valley structure and exposure of Upper Dalradian rocks. The site has a history of continuous woodland cover, with the present woodland being over 200 years old, having once been extensively cleared during the 1770s. Since this clearance the wood has again developed a well-defined structure with associated features such as a distinct stratification, the presence of mature and over-mature trees, and an abundant epiphytic component all being well represented. The site consists of a complex system of river valleys, with woodland flanking the main Owenrigh River valley and its three tributary valleys, formed by the Altnaheglish River and the Glenedra and Cushcapal Waters, all to the south. The combined length of the wood is around Skm and is over 0.2Skm in width at its broadest point. The glen contains outcrops of the Upper Dalradian orthotectonic series. These include the Dungiven Limestones, limited extrusive epidiorite and the Dart schistose grits, including feldspathic units. Intrusive epidiorite sill-like bodies are also present. The major Sperrin Fault passes through the site. This has particularly dislocated the limestone beds, both laterally and vertically. Although the lower glen is related to a northern extension of the Sperrin Fault, the entire valley acted as a meltwater channel during late glacial times, leading to overdeepening. Local variation in topography, hydrology, aspect and soil condition as well as the dramatic change from the predominant underlying schist type rock to limestone along a fault line at the northern end, have resulted in a wide range of growing conditions. This has lead to the notable diversity of plant community types which form the wood. The woodland communities present range from strongly calcifuge types characterised by a sessile oak Ouercus petraea canopy over a ground cover dominated by calcifuge bryophytes and grasses or occasionally the dwarf-shrub bilberry Vaccinium myrtillus; through moderately calcifuge types characterised by a sessile oak Quercus petraea and downy birch Betula pubescens canopy, a hazel Corylus avellana understorey and either an impoverished greater wood rush Luzula sylvatica or bluebell Hyacinthoides non-scripta ground carpet; to flushed or calcicolous woodland types both characterised by the predominance of ash Fraxinus excelsior in the canopy, a field layer of ferns and brambles and a lush ground cover composed of wood anemone Anemone nemorosa, opposite-leaved golden-saxifrage Chrysosplenium oppositifolium, lesser celandine Ranunculus ficaria and bluebell H. non-scriptus. In addition to the community diversity, the wood has one of the richest variety of plants recorded for a woodland site in Northern Ireland, including a number of notable bryophyte and lichen species. Overall the wood has a high degree of naturalness and purity with the exotic species present being local and sporadic in occurrence, while disturbance is mostly confined to a few marginal locations. The woodland also supports some faunal interest, which includes a diverse moth community, notable breeding birds such as peregrine Falco peregrinus, wood warbler Phylloscopus sibilatrix and redstart Phoenicurus phoenicurus as well as badger Meles meles and red squirrel Sciurus vulgaris. https://www.daera-ni.gov.uk/publications/banagher-glen-assi

Species mentioned

Plant communities