Blackmill Woodlands

Also within

Mid Glamorgan County

Habitats

Bracken scrub

Description

Description Blackmill Woodlands is of special interest for the size and geographical position of its semi-natural woodland being the largest known stand of this Annex 1 habitat in the Mid and South Glamorgan Area of Search. The site comprises two woodland blocks on opposing slopes of the Afon Ogwr valley, 6 kilometres north of Bridgend. The woodlands lie between 80 and 210 metres on shallow, sandy, mineral soils over Pennant Sandstones of the Coal Measures. Both woodlands are situated on Common Land and have been managed subject to common rights since the Middle Ages. Allt y Rhiw has a north-westerly aspect and is dominated by a uniform stand of sessile oak Quercus petraea. The field layer is characterised by bilberry Vaccinium myrtillus and wavy hair-grass Deschampsia flexuosa, with bryophytes such as Polytrichum formosum and Mnium hornum. Craig Tal-y-fan is situated on the opposite valley side, with a south-easterly aspect. Sessile oak also dominates on this slope, with the field layer characterised by common bent grass Agrostis capillaris, sweet vernal-grass Anthoxanthum odoratum, sheep’s fescue Festuca ovina and wood sorrel Oxalis acetosella. Bracken Pteridium aquilinum is also present and forms dense stands in more open areas. Typical bryophytes of the ground layer include the mosses Polytrichum formosum, Mnium hornum, Dicranum majus and Leucobryum glaucum. Remarks: The site supports woodland vegetation assignable to the habitat type ‘Old sessile oak woods with Ilex and Blechnum in the British Isles’, listed on Annex I of the EC Habitats and Species Directive (Directive 92/43/EEC on the Conservation of Natural Habitats and Wild Flora and Fauna).

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