Beacon Hill bryophytes

Beacon Hill, part of the Aston Rowant National Nature Reserve, was the latest destination for the bryophilic element of the Oxfordshire Botany Group (28/01/2018). Three members assembled for a bryological recording session around the chalk grassland and woods of the hill (SU7296 & SU7297), a location that has not been thoroughly surveyed for bryophytes since Ron Porley's study of Chiltern chalk grasslands in the mid-1990s. We admittedly had a fairly easy-going recording session, and so I don't think we would claim that we surveyed the site anywhere near as intensively as Ron, but we recorded 53 species (67 records) across two monads, and refound a few of the characteristic species noted by Porley, as well as some species which appear to be new for the Hill.

Looking across to Aston Rowant from Beacon Hill.

Fissidens dubius

Focusing first on the west-facing slope around SU728968, we quickly picked up a slew of typical chalk grassland species, including Homalothecium lutescens, Fissidens dubius, Plagiomnium affine, and Weissia longifolia. Here we also found our first plants of Rhodobryum roseum, a particularly large and handsome moss that tends to be indicative of habitats that are of importance for nature conservation (due to its requirement for an open, low nutrient sward), and was unfortunately one of the species included in the "decreasing generally" category of Mark Hill & Chris Preston in their analysis of change in the recent Atlas of British and Irish Bryophytes.

Rhodobryum roseum

Rhodobryum in a typical anthill setting

Later on, in a "hollow way" lane cutting down the west-facing escarpment we recorded a good number of epiphytes, most new for the site, including two attractive Neckera species, N. complanata (pictured) and N. crispa. Here we also found a number of more weedy species existing on the risers and treads of wooden stairs installed for easier access, including Orthotrichum anomalum, Campylopus introflexus, Barbula sardoa, B. unguiculata, and Homalothecium sericium.

Neckera complanata

After lunch, we were back on higher-quality ground, inspecting the open expanses of grassland on the plateau of the hill, around SU727971. Here, after some patient hound dog style searching, we were rewarded with a cluster of rarer chalk grassland pleurocarps. These included Campylium protensum, Entodon cocinnus, and Hypnum cupressiforme var. lacunosum. The first of these has apparently not been reported for Beacon Hill, and is rare in chalk grassland in Oxfordshire; E. cocinnus is known from Beacon Hill, but has not been reported recently, at least according to records available from the British Bryological Society and the NBN.

Campylium protensum

Entodon cocinnus

The full list of species for the day is given below. Another visit will certainly be in order, as there are a number of nationally scarce bryophytes found by Porley that we didn't manage to rediscover.

Liverworts	Fissidens dubius	Zygodon conoideus var. conoideus	Plagiomnium undulatum	Brachythecium rutabulum	Entodon concinnus
Metzgeria furcata	Fissidens adianthoides	Orthotrichum affine	Campylium protensum	Brachythecium salebrosum	Cryphaea heteromalla
Radula complanata	Dicranum scoparium	Orthotrichum anomalum	Amblystegium serpens	Homalothecium sericeum	Neckera crispa
Frullania dilatata	Campylopus introflexus	Orthotrichum diaphanum	Thuidium tamariscinum	Homalothecium lutescens	Neckera complanata
Lophocolea bidentata	Weissia longifolia	Bryum pallens	Pseudoscleropodium purum	Calliergonella cuspidata
Mosses	Barbula convoluta var. sardoa	Bryum capillare	Eurhynchium striatum	Hypnum cupressiforme var. cupressiforme
Seligeria calycina	Barbula unguiculata	Bryum pseudotriquetrum	Rhynchostegium confertum	Hypnum cupressiforme var. lacunosum
Fissidens viridulus	Didymodon vinealis	Bryum dichotomum	Oxyrrhynchium hians	Hypnum cupressiforme var. resupinatum
Fissidens incurvus	Syntrichia ruralis var. ruralis	Rhodobryum roseum	Oxyrrhynchium schleicheri	Ctenidium molluscum
Fissidens taxifolius	Zygodon viridissimus var. viridissimus	Plagiomnium affine	Kindbergia praelonga	Rhytidiadelphus squarrosus