Meirionydd Oak Woods & Bat Sites SAC, North Wales

Fay Brotherhood
2 days ago
4 min read

Back in June 2024 I visited the Meirionydd oak woods of north Wales, which is a Special Area of Conservation due to being important for the lesser horseshoe bat Rhinolopus hipposideros and containing Annex 1 Habitat 91A0 Old Sessile Woods with Ilex and Blechnum in the British Isles, which is noted for its outstanding Atlantic bryophyte and lichen flora.

They extend along interconnected valleys with diverse slopes and aspects, which contain many narrow gorges and ravines and a thousand associated micro habitats and microclimates.

It occura as an intimate mosaic with various other Annex 1 wet woodland, western limewood, wet heath and bog woodland types but in the main, 91A0 is based around NVC Community W17 Quercus petraea-Betula pubescens-Dicranum majus (Sessile oak-Downy birch-Greater fork moss) woodland.

More specifically, W17a....the Isothecium myosuroides-Diplophyllum albicans sub-community.

This is one of the Atlantic woodland subtypes of the westerlands which qualify as Temperate Rainforest.

A strongly acidic, hyperoceanic community of the northwest upland fringe, it requires consistently wet soils and high humidity. It is famed for an incredible and internationally important abundance and diversity of mosses, ferns and lichens.

Ground flora

The fleld layer is basically an acid grassland inside a wood and contains a diverse range of acid indicating forbs, grasses and dwarf shrubs. Bilberry Vaccinium myrtillus and wavy hair grass Deschampsia flexuosa forms constant components and the likes of heath bedstraw Galium saxatile, tormentil Potentilla erecta, common cow wheat Melempynum pratense, wood sage Teucrium scorpdonia, devils bit scabious Succisia pratensis, European goldenrod Solidago virgaurea, pill sedge Carex pilulifera and various wood rushes Luzula spp are all characteristic

The only ones of this assemblage I didn't see were goldenrod and devil's bit scabious but I photographed the rest.

Catching the vibe

In learning to recognise NVC communoties you do need to get out of the floristic table and learn with your eyes to catch "the vibes" that define each community. That's a simple case of learning to appreciate what you see and notice how one wood differs from another. Practice describing what you see with your own eyes. And your feelings. Different visuals evoke different feelings and that's why I call it "the vibe".

Here, the cow wheat, which in places formed extensive carpets really stuck out. Combined with the tormentil and in places buttercups, this duo of yellow flowers combined with a distinctly warm light gives this woodland a distinct "gold studded" warmth that differs from south eastern continental woodlands.

Ferns

Hard fern (Blechnum spicant) forms another distinct element with its high frequency helping separate it out from W17's other upland companion W16. Here it can attain both great abundance and impressive size. This species looks really Carboniferous and in abundance imparts a real primeval vibe!

A wide range of other ferns are present but tend to reach maximum diversity and luxuriance in gorges. Amongst others, you might find lemon scented fern Oreoptis limbosperma and some really snazzy rarities like Wilson's and Tunbridge filmy fern Hymenophyllum spp.

But the absolute defining element is its bryophytes, which often exceed the vascular plants in both abundance and diversity, creating the visual that gives the wood its distinctly faery vibe.

In W17, moss blankets all as far as the eye can see!

Six species of bryophyte contribute to the constants of the community and in this sub-community there are several rarities and a lot of Sphagnum, creating a real moss mosaic.

Here, this photo also shows another frequent herbaceous component of the field layer, wood sorrel Oxalis acetosella which often forms an important component of wetter woodland communities.

I think that this tamarisc moss may not be the usual Thuidium tamaricum but T. delicatum because it seems a lot more less regularly branched, less rigid and more...well....delicate.

Certainty here requires a microscope and it is advised that all "irregular" forms of tamarisc moss get scoped.

Flushes

Many woodlands contain interesting hydrological features, with pockets of wet woodland associated with flushes. When reading through Rodwell, I was excited to realise that even the vegetation of the flushes matched what I found, with species like yellow pimpernell Lysimachia nemorum.

I found and photographed pretty much everything Rodwell listed except for the Solidago and Succisa. The pill sedge Carex pillulifefa was one of the coolest sedges I have seen!

When I spotted this in the W17 Meirionnydd Oak Woods in June 24 I was drawn to it by it's unusual presentation.

Pill sedge Carex pillulifera — Pill sedge *Carex pillulifera*

Most sedges go up. This one goes down.

It sat atop its little moss mound, gracefully arching its stems down around the mound,like a fishing rod, which made me think there's got to be an adaptive seed dispersal based function to this.