Coed Dolgarrog

Also within

Clwyd County Eryri / Snowdonia National Park

Habitats

Bracken scrub

Geology & landscape

Geological Period: Ordovician · Rock Type: Rhyolite

Landscape processes: Glacial, Volcanic / Igneous

Birds & fish recorded

Birds

Description

Description Coed Dolgarrog is selected for its biological interest as an example of a Wood Sage/Oak/Birch Teucrium scorodonia/Quercus/Betula woodland type and for its invertabrate interest and breeding bird community. The site is geologically complex with acidic Ordovician rhyolites, rhyolite tuffs and slates but with basic pumice tuff buttresses. Underlying rocks are often masked by glacial drift but more basic soils have a ground flora dominated by species such as dog's mercury Mercurialis perennis, Enchanter's Nightshade Circaea lutetiana and Ramsons Allium ursinum. The ground flora of the more acidic areas is dominated by Bracken Pteridium aquilinum, common bent Agrostis capillaris, red fescue Festuca rubra and Bilberry Vaccinium myrtillus with a range of bryophytes. The dominant tree throughout is sessile oak Quercus petraea but with other species including downy birch Betula pubescens, Wych elm Ulmus glabra, Ash Fraxinus excelsior, Holly Ilex aquifolium and crab apple Malus sylvestris. Non-native tree species include Beech Fagus sylvatica, sycamore Acer pseudoplatanus and Scots Pine Pinus sylvestris. The shrub layer consisting of hazel Corylus avellana with some Holly Ilex aquifolium, rowan Sorbus aucuparia and a few spindle Euonymus europaeus -is well developed in some parts of the wood but absent from others. The Ardda alderwood on the north bank of the Afon Ddu represents a type of woodland previously more common at this altitude but now very rare in Wales.Coed Dolgarrog is of invertebrate interest for its Lepidoptera (butterflies and moths) and Coleoptera (beetles); the rare spider Saloca diceros also occurs. Breeding birds include typical species of western Oakwoods such as redstart, wood warbler and Buzzard. A large badger population occurs. Remarks: The site was declared as a National Nature Reserve in 1959. Partly within the Snowdonia National Park.

Species mentioned

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities