Physically, Gloucestershire can be divided into three main areas; the Forest of Dean and the Wye Valley to the west of a line between the Malvern Hills and the mouth of the River Wye, the Severn Vale running north to south through the centre of the county and the Cotswolds in the east. These landscape attributes affect the climate, such that the Wye Valley is the wettest area in the county, enabling some oceanic liverworts such as Lepidozia cupressina  to survive, whilst the Cotswolds are the driest area with Mediterranean species such as Tortella squarrosa (Pleurochaete squarrosa) on the steeper, south-facing slopes. The landscape character is accompanied by differences in land-use which exaggerate the influence of landscape, thus the Forest of Dean and the Wye Valley are heavily wooded and consequently more humid than other areas, the Severn Vale is low-lying with a number of sprawling settlements and extensive pasture, while the Cotswolds are dominated by arable with woodland and grassland along the escarpment and in valleys.

The current and historic land-use within the county, whilst related to the geology, is probably the most important factor currently influencing the distribution of bryophytes. Apart from a few particular areas such as the Wye Valley, the commons of the Cotswold escarpment, the Avon Gorge and nature reserves or other protected areas, most of the county has suffered a significant decline in bryophyte diversity at a local scale. This happened mainly through drainage and conversion of rough ground to arable or improved pasture, exacerbated by massive conversion of land to arable during the World War II.  W.R. Price (in Riddelsdell, Headley and Price 1948) notes that even up to the time of writing, the northern end of the Bristol coalfield, around towns such as Yate, Chipping Sodbury and Wickwar contained more heaths than any other area in Gloucestershire. However now, apart from species-poor rough grassland on the remaining commons such as Inglestone and Hawkesbury, these heaths have all but disappeared under improved grassland and housing. Even most nature reserves and designated sites, because they are managed with a focus on other taxa such as vascular plants, birds or butterflies, support low bryophyte diversity, the exceptions being those sites where the management has not changed for tens or hundreds of years.

It would not be an exaggeration to say that much of Gloucestershire can be considered a bryological desert. For example, most settlements support only the most widespread and abundant species such as Bryum argenteum and Tortula muralis, except where traditional materials such as sandstone or oolite roofing tiles have been used and allowed to weather and support species such as Grimmia laevigata and G. tergestina. Most pasture is now improved to the extent that it supports no bryophytes, apart from one or two more or less ubiquitous species such as Barbula unguiculata and Bryum dichotomum around gateways. Even many woods and hedges support only one or two of the more common species of such habitats, such as Orthotrichum affine and Thamnobryum alopecurum and much arable supports few or no species. This is particularly striking in comparison to sites which retain the influence of past habitat management or exploitation, such as the extensive small-scale quarrying of the inferior oolite in the Cotswolds or the carboniferous limestone in the Forest of Dean which has left many abandoned quarries that support some of the rarest bryophytes in the county. It is striking that of the 200 bryophyte species of conservation concern in Gloucestershire, only 61 species (30.5%) occur in habitats which can be described as semi-natural and not entirely anthropogenic.

Grimmia laevigata on a barn roof

The landscape and land-use are both very heavily influenced by the solid geology and it has been said that fewer counties include more geological formations and therefore a greater diversity of rocks and resultant soils than Gloucestershire (L. Richardson in Riddelsdell, Hedley and Price 1948). The solid geology is of particular importance with regard to its influence over whether the overlying soils are predominantly acid, such as the Bristol coalfield and coalfields of the Forest of Dean or calcareous, including the Carboniferous limestone of the Avon Gorge and the Wye valley, the oolitic limestone of the Cotswolds and the sandstones of the Newent and Bromsberrow areas in the north of the county. In contrast, the soils of the Severn Vale are predominantly neutral. Locally there are additional important geological influences, such as calcareous outcrops into predominantly acid areas such as at Wigpool Common and exposures of the acid Harford Sands and the Lias Clays on the Cotswold Escarpment. Aspects of natural exposures of the solid geology which are critical to the conservation of bryophytes in Gloucestershire include the limestone cliffs of the Wye Gorge and extensive boulder fields along the Wye Valley, mainly remaining within woodland, but occasionally found in fields. These boulders are of combinations of sandstone and conglomerate and each supports a slightly different bryophyte flora, including some of the rarest species in the county, such as Amblystegium confervoides,  Barbilophozia attenuata, Bazzania trilobata, Dicranum scottianum, Lepidozia cupressina, Lophozia excisa, Lophozia ventricosa and Tritomaria exectiformis.

Dicranum scottianum at Buckstone Wood

The solid geology has had a direct and very local influence over human activity and consequently the distribution and abundance of bryophytes in many parts of the county. The mining of coal in the Forest of Dean has left numerous traces and of these, the spoil heaps often provide important habitat for some rare acidophiles such as Ptilidium ciliare and Scapania compacta and at Crump Meadow, while calcareous seepage from a spoil heap supported Drepanocladus sendtneri. Similarly, quarrying has created some of the only habitat to support a range of rare bryophytes. Limestone quarrying and the resulting scowles in the Forest of Dean support species such as Cololejeunea calcarea, C. rossettiana, Gymnostomum calcareum, Metzgeria conjugata and Plagiochila spinulosa, whilst abandoned quarries in the Wye Valley support species such as Plagiomnium  cuspidatum and Seligeria campylopoda. Holland (1978) notes that excavation of sand from Bromsberrow Heath resulted in the loss of important habitat for vascular plants; this will also have affected bryophytes but in contrast, small-scale excavation of Celestine (strontium)-rich clays in the Wickwar – Yate area resulted in the creation of a large number of small ponds, from which Riccia fluitans has been recorded.

This and the following account was written by Richard Lansdown, December 2020

Bryophyte recording in Gloucestershire began in the early 19^th century with a few records mainly from the Avon Gorge. Subsequently H. Beach produced a list of species that he found in the area around Cheltenham (Knight 1914), but it was only with the establishment of the Moss Exchange Club (MEC) which eventually became the British Bryological Society (BBS) that large numbers of records started to be generated. In the early 1900s, not only were a number of eminent bryologists living in or near enough to Gloucestershire to generate numbers of records, including H.P. Reader, E. Armitage, D.A. Jones, E.J. Elliott and G. Holmes, but the Annual Report of the Moss Exchange Club was published in Stroud. However apart from some remarkable finds away from the “honeypots”, such as the discovery of Rhynchostegium rotundifolium on a lane near Bisley, most records came from The Wye Valley and the Avon Gorge, with fewer records from the wider countryside. This changed when H.H. Knight moved to Cheltenham in 1907. Knight started systematically recording in the county, covering the Cheltenham area by bicycle and parts of the Forest of Dean by train. Knight was president of the BBS from 1933; he published accounts of the mosses (Knight 1914) and the liverworts (Knight 1920) of Gloucestershire. His herbarium collections in NMW and CHM include many significant records made after these publications until his death in 1944.

Figure 1: All bryophyte records from January 1990 to October 2020

Until the national atlas project of the 1960s, there was almost no effort made in Great Britain to document the more common species, although Knight appears to have made an effort to retain at least one specimen of each of the species which he recorded in each vice county. Between the 1930s to 1980s, when G.W. Garlick started recording, mainly in the Bristol Coalfield but with a few excursions to the Forest of Dean, few bryophyte records were made. Garlick’s records are the first to be accompanied by six-figure grid references which enable many of his locations to be re-visited. Subsequently, apart from occasional visits to the county by bryologists, mainly to the Symonds Yat area, the next significant set of records was generated by Alan Orange who recorded widely in the Forest of Dean and generated a large number of well localised records of rare or new taxa for the county, as well as enabling useful documentation recording from some poorly known species such as Ptilidium pulcherrimum and Scapania compacta. Another set of useful records was generated by visits of the MEC and subsequently the BBS who recorded within the county in 1925, 1936, 1954, 1968 and 1988, although some of these records need to be treated with caution. Finally, in the 1990s, P. Martin became recorder for the two vice-counties of Gloucestershire, vc 033 and vc 034 which led to the start of systematic documentation of the bryophyte flora (Figure 2). Most of the information available on bryophytes in Gloucestershire comes from a period of only slightly over 100 years and most records have been generated since 2000.

There are two extensive areas within West Gloucestershire within which the bryophyte flora is very poorly documented, the north of the vice county around Newent and Bromsberrow and the south of the vice county between Wotton-under-Edge and Bristol have only very few records, particularly since 1990 (Figure 3). These are discussed in a little more detail below but there is an urgent need for basic documentation of the bryophyte flora.

Table 1 The number of bryophyte species recorded in Gloucestershire (vcc 33 and 34)

In 2014 the conservation status  of all bryophytes recorded from Gloucestershire (vcc 33 and 324) was reviewed and assigned a status based on the IUCN Red List Criteria (see the legend to table 3) and published as a provisional Red Data Book (Lansdown 2014). The results of this exercise (Table 2) show that there have been dramatic declines in many species of bryophyte, but particularly liverworts. Ongoing recording since publication of the Red Data Book has both found new species to the vice county and rediscovered species provisionally classed in 2014 as Regionally Extinct. However, the exercise highlighted the large number of species which appear truly to be extinct in the county. A little over half of the British bryophyte flora has been recorded Gloucestershire (vcc 33 and 34), representing slightly over one third of liverworts and more than half the moss species (Table 1). However, of these, 92 two bryophyte species recorded before 1990 have not been recorded since, in many cases in spite of extensive searches. In contrast, 30 bryophyte species have been added new to the vice county flora since 1990, some as a consequence of taxonomic changes and some are colonists but many involve the discovery of established populations which had previously been overlooked. These issues are discussed further under Conservation, below.

Table 2.  Red List bryophytes in Gloucestershire

Sphagnum

All Sphagnum records

Sphagnum species have been and in places still are particularly significant in the ecology of bryophytes in Gloucestershire. Not only did they specifically support some of the most important nationally rare species, such as Jamesoniella undulifolia, but they typically occur in inundated acid habitats which have been widely lost or degraded in the county. Historically, Sphagna would have been reasonably abundant through much of the Forest of Dean. There would also have been scattered populations to the east of the River Severn, in wet woodland in the floodplain of the Severn, as well as very locally in flushes in the Cotswolds arising from Fullers Earth or the Lias clays (L. Richardson in Riddelsdell, Hedley and Price 1948). The only Sphagnum populations recorded east of the River Severn since 2000 involve a population of S. palustre in Lords Wood, near Bristol and a population of Sphagnum denticulatum found by G.W. Garlick in Michaelwood, described as “in [a] drain in sandy clay” which still survives, although the only plants found were semi-terrestrial and etiolated in shade.

In the Forest of Dean, Sphagnum species were widespread and fairly abundant in the past, probably occurring in scattered localities throughout, but with extensive mire communities at Mitcheldean Meend, Wigpool Common, Foxes Bridge Bog, Woorgreens and Tidenham Chase/Poor’s Allotment. Mitcheldean Meend appears to have lost all its notable bryophytes and all Sphagnum except a few depauperate tufts of S. fimbriatum. Recent survey work (see below) has documented the  distribution of remnant mires which still support significant Sphagnum populations. The most important areas are in the drainage systems from Crabtree Hill through Wigpool to Foxes Bridge Bridge Bog, with an outlying perched mire on the hill to the south of Foxes Bridge Bog. Other important sites include Wigpool Common, although most of the species which formerly occurred there have been lost, Edgehills  Gloucestershire Wildlife Trust Nature Reserve which has scattered stands of many species, but little connectivity and is very scrubby and the Poors Allotment – Tidenham Chase area which has a few patchy complexes with remnant Sphagnum populations, including the only currently known population of S. compactum. Sphagnum flexuosum, S. subsecundum and S. tenellum species have not been recorded in the county since 1990, however another twelve are still present, most in good populations and in areas such as Wigpool and Foxes Bridge Bog in fairly good condition mire communities. The most significant mires support populations of Sphagnum capillifolium subsp. capillifolium and S. papillosum, with Sphagnum russowii in parts of the bog at Wigpool. S. denticulatum and S. fallax occur in many wetter areas, while species such as S. fimbriatum, S. palustre, S. squarrosum and S. subnitens var. subnitens occur at scattered locations throughout the Forest of Dean. Species which occur with or in similar habitats as Sphagnum species include Aulacomnium palustre and Calliergon cordifolium, both of which can be locally abundant, while streams and ponds support a range of wetland bryophytes such as Chiloscyphus polyanthus, Dichodontium species (mainly D. pellucidum but rarely fruiting) and Scapania undulata in streams and rivers, with Dicranella rufescens on clay banks.

Sphagnum squarrosum near the Wilderness

The Wye Valley and the Forest of Dean

The Wye Valley can be considered to be the jewel in the crown of West Gloucestershire, while the Symonds Yat area has been visited by bryologists more often than any other site in the county, mainly to see Anomodon longifolius at one of only a small number of sites in southern Britain. There is no doubt that the varied habitats, from vertical cliffs to streams, the River Wye and boulder fields, together with extensive ancient woodland and the varied geology most notably including elements of carboniferous limestone and coal measures, has enabled the development and survival of a very rich bryophyte flora. More than 200 species have been recorded  from the tetrad which includes Symonds Yat many of which are nationally or locally notable (Table 3).

Anomodon longifolius at its classic location on The Slaughter, Symonds Yat

Table 3 Notable bryophyte species recorded in the Symonds Yat area

The following codes are used here:

CR          Critically Endangered
DD          Data Deficient
EN          Endangered
NR          Nationally Rare
NS          Nationally Scarce
NT          Near Threatened
LC(NR)   Least Concern in Gloucestershire but of national conservation concern so that Gloucestershire populations are of national conservation importance
REa        Not recorded in Gloucestershire since 2000 and likely to be truly extinct in the county
REb        Not recorded in Gloucestershire since 2000 but likely to be overlooked and to still persist in the county
Sch 8     protected on Schedule 8 of the Wildlife and Countryside Act 1981 (and amendments)
VU          Vulnerable (IUCN 2001)

The Wye Valley supports most or all of the populations in the vice county of a large number of species, including Orthocaulis attenuatus (Barbilophozia attenuata), Dicranum scottianum and Lepidozia cupressina which are known only from the boulder fields of Buckstone Wood near Staunton, where Cynodontium bruntonii occurs along the dry stone wall along the top of the hill and  Bartramia pomiformis on the adjacent roadside bank. Species such as Bazzania trilobata, Jubula hutchinsiae, Lophozia excisa, Saccogyna viticulosa and Trichocolea tomentella now appear to be restricted to a few sites in woods around the Hudnalls NNR, Entosthodon pulchellus, Marchesinia mackaii, Plasteurhynchium striatulum, Scorpiurium circinnatum and Tortella nitida occur wherever the limestone outcrops, while in contrast Dicranum fuscescens, Lophozia ventricosa, Porella arboris-vitae and Scapania gracilis occur on acid rocks where boulder fields have been left undisturbed and Seligeria campylopoda is a somewhat enigmatic ephemeral plant of small stones on tracksides and in quarries, sometimes appearing in abundance but often scarce and difficult to find. Two species are of particular note along the Wye Valley in VC 34, Fissidens rivularis has been shown to be frequent in the upper reaches of small streams arising on the hillsides, as well as in a few places away from the valley and atypically, Neckera crispa is frequent on tree trunks alongside the River Wye south of Symonds Yat.

Metzgeria pubescens, Symonds Yat

Away from the Wye Valley and the remaining mires, the Forest of Dean is dominated by conifer plantations with scattered stands of semi-natural woodland which are typically dominated by oak (Quercus species) or ash (Fraxinus excelsior). The natural soil is acid except in areas where the carboniferous limestone is near the surface. As a result, throughout most of the Forest of Dean the typical bryophyte flora is characterised by species such as Polytrichtrum formosum, Pseudotaxiphyllum elegans and Dicranella heteromalla, with other typical ubiquitous woodland species such as Atrichum undulatum, Fissidens taxifolius and Thuidium tamariscinum throughout. A range of mosses are widespread on the acid soils of the Forest of Dean but scarce or absent elsewhere, such as Archidium alternifolium, Campylopus flexuosus, C. pyriformis, Campylopus introflexus which elsewhere restricted to scattered acid substrates such as decaying oak stumps, in the forest is almost ubiquitous, Dicranum majus, Grimmia trichophylla, Heterocladium heteropterum, Hypnum jutlandicum, Plagiothecium undulatum, Pleurozium schreberi, Pogonatum aloides and Rhytiadelphus loreus. There are also a number of small, specific sites which support either the only known populations in West Gloucestershire of one or two notable species such as Wimberry Slade Quarry with Tetradontium brownianum and Schistostega pennata and Barnhill Plantation with Blasia pusilla, Pogonatum nanum and Scapania compacta.

A small number of bryophyte species appears to have colonised the Forest of Dean as a consequence of forestry operations. Bryoerythophyllum ferruginascens, Didymodon ferrugineus and Nardia scalaris occur on forest rides, associated with the calcareous gravel used to strengthen the surface, while Sematophyllum substrumulosum has recently been recorded on decaying pine logs and a single small population of Ptilium crista-castrensis found near Wigpool is almost certain to have been introduced by forestry works. Species which are associated with human activities other than forestry operations include a range of Racomitrium and Grimmia species which occur on church buildings, in graveyards on slate or Cotswold stone roofs.

Liverwort records

However, it is the liverworts which set the Forest of Dean apart from the rest of the bryophyte flora of vc 34 (Figure 9), species such as Blasia pusilla, Calypogeia arguta, C. fissa, Cephalozia bicuspidata, Cephaloziella divaricata, Diplophyllum albicans, Fossombronia wondraczeckii, Lejeunea cavifolia, L. lamacerina, Lepidozia reptans, Pellia epiphylla, Ptilidium pulcherrimum, Scapania nemorea and Solenostoma gracillimum all occur in the Forest of Dean but are scarce or absent elsewhere.

The north-west, Newent and Redmarley D’Abitot

Bryologically, the northern part of the vice county around Newent is the least well documented area of West Gloucestershire both before and since 1990. The area is predominantly rural and characterised by extensive arable, with scattered woodland blocks, some of which are very extensive. Historically, the area was important for a number of species, particularly Riccia nigrella and both Sphaerocarpos species in the fields around the delightfully named Redmarley D’Abitot, as well as Tortula vahliana on roadside banks and the banks of the River Leadon where Conardia compacta was also recorded. Sphaerocarpos populations still occur in the area around Redmarley but no fertile material has been found in recent years and so it is impossible to say whether both species are still present. A spectacular population of Grimmia laevigata survives on the tiled roof of a barn south of Newent and populations of Ptilidium ciliare and Reboulia hemisphaerica survive where the extreme southern end of the Malverns extend into the vice-county, but otherwise none of the notable taxa recorded in the area has been seen in recent years. This is an area that is desperately in need of surveys to document the bryophyte flora.

The Severn floodplain

Calliergonella cuspidata, Inglestone Common

West of the River Severn, the wooded hills of the Forest of Dean slope fairly abruptly to the valley of the River Severn, while to the east the Severn floodplain dominates the vice county, rising into the Cotswolds in the east. The low-lying areas are heavily dominated by arable and improved pasture, with scattered woodland blocks such as Lower Woods and some semi-improved grassland in the commons of south-Gloucestershire. The bryophyte flora of this area has also been fairly poorly documented, with detailed information only for a few specific sites, particularly the Gloucestershire Wildlife Trust Lower Woods Reserve which supports a wide range of common species, plus a few notable mosses such including Leucobryum glaucum and Pohlia lescuriana. In spite of the extent of semi-natural habitat, these areas typically support a fairly poor bryophyte flora and certainly the grasslands are very poor, typically supporting only the typical suite of pleurocarps which are ubiquitous in southern Britain, such as Brachythecium rutabulum, Calliergonella cuspidata, Kindbergia praelonga, Oxyrrhynchium hians and Pseudoscleropodium purum. In a few areas, variation within the grassland may increase species diversity, such as on ant-hills on Inglestone Common, which provide habitat for a wider range of species including ruderals such a Bryum rubens, Tortula acaulon (Phascum cuspidatum) and Tortula truncata, while epiphytic bryophytes may be abundant in woodland blocks and hedgerows.

Recent surveys of arable fields along the west side of the River Severn have shown that they can support a quite species-rich bryophyte flora including more notable species such as Ephemerum serratum (Ephemerum minutissimum), Riccia glauca, R. sorocarpa and Sphaerocarpos sp. (again no fertile plants found) and it is likely that widespread surveys would locate more notable species in these areas on both sides of the River. There is also a group of species associated with the River Severn itself, Bryum gemmiferum, Didymodon tophaceus, Hennediella stanfordensis, Lunularia cruciata and Physcomitrium pyriforme are strongly associated with the unstable clay banks along the River Severn, while the diminutive Microbryum starckeanum (Pottia starckeana) has also been found on the banks of the Severn near Plusterwine, south of Lydney. However, it is clear that this too is an area desperately in need of bryophyte surveys as for most of the Severn floodplain in vc 34 there is simply no information on the bryophyte flora.

The Cotswolds

Although not as rich or well-known as in vc 33, some of the commons in vc 34 support a rich and varied bryophyte flora. In particularly, the abandoned quarries and steep slopes of Selsley Common support a wide range of species, with the classic Cotswold limestone grassland specialities such as Campylium chrysophyllum (Campyliadelphus chrysophyllus), Ditrichum gracile, Entodon concinnus, Fissidens dubius and Tortella squarrosa (Pleurochaete squarrosa) typically occurring on thin soil and steeper slopes, Fissidens incurvus and Scapania aspera around outcrops of the oolite, Seligeria calcarea and Tortella inflexa on the scattered oolite stones which occur throughout sloping ground and a wide range of ephemeral species such as Ephemerum recurvifolium, Microbryum curvicollum, M. rectum, Weissia longifolia var. angustifolia and Weissia sterilis on the lines of “sheepwalk” on the steep scarp slope which can best be seen when highlighted by a light fall of snow. As is the case throughout the Cotswolds, Frullania tamarisci formerly occurred in the grassland of Selsley and Rodborough Commons but has not been seen since 1990, in spite of searches. The other commons support a similar range of species but typically in smaller population and much more localised. Selsley Common grades in the south into Penn Wood, which formerly supported some of the most notable bryophytes in West Gloucestershire east of the River Severn, particularly Mesoptychia collaris (Leiocolea collaris), Metzgeria conjugata and Plagiopus oderianus, however in spite of extensive searches none of these species has been seen in Penn Wood since 1990. Another Cotswold escarpment speciality which still occurs in some abundance is Mnium marginatum var. marginatum, while abandoned quarries and the trackways which led up to them and many of which remain wet throughout the year, support a suite of species typical of this habitat on the escarpment including Jungermannia atrovirens, Seligeria calcarea and S. pusilla.

The Avon Gorge

The Carboniferous limestone of the Avon Gorge is rightly famous for its vascular flora and although much less well-studied, the bryophyte flora is also of note. In addition to the classic calcicoles which also occur on the oolitic limestone of the Cotswolds, such as Campyliadelphus chrysophyllus,  Ctenidium molluscum var. molluscum, Didymodon fallax, Flexitrichum gracile (Ditrichum gracile), Encalypta streptocarpa, Fissidens dubius, Homalothecium lutescens, Mesoptychia turbinata (Leiocolea turbinata), Trichostomum brachydontium and T. crispulum, the gorge has supported a range of rare or local species such as Didymodon ferrugineus, Entosthodon muhlenbergii, E. pulchellus, Grimmia orbicularis, Gymnostomum viridulum, Microbryum davallianum, Plasteurhynchium striatulum, Reboulia hemisphaerica, Scorpiurium circinatum and Weissia sterilis. Of these, all except Entosthodon muhlenbergii, Microbryum davallianum and Reboulia hemisphaerica still occur.

Table 4 The number of bryophyte species recorded from West Gloucestershire

More than 500 species of bryophyte have been recorded from vc 34, representing more than half of the British bryophyte flora. However, of these, more than 100 species have not been seen since 1990 whilst only 41 species have been recorded new to the vice county since 1990 (Table 4).

The most significant losses involve the hornworts, of which none of the three species recorded before 1910; Anthoceros punctatus, Antheroceros agrestis and Phaeoceros laevis have been recorded in recent years, in spite of searches in suitable habitat. Similarly, efforts to find Riccia nigrella in the arable fields around Redmarley D’Abitot, Frullania fragilifolia and Andreaea rothii subsp. falcata around Buckstone Wood, Cladopodiella francisci, Jamesoniella undulifolia, Nardia geoscyphus and Odontoschisma sphagni at Wigpool Common, Blepharostoma trichophyllum, Grimmia hartmannii,  Jamesoniella autumnalis, Orthotrichum rupestre and Plagiochila spinulosa at the Hudnalls and adjacent woods, as well as Calliergon giganteum, Climacium dendroides, Dichodontium palustre, Diplophyllum obtusifolium, Plagiopus oederianus, Pterogonium gracile, Rhodobryum roseum, Thuidium recognitum, Tortella flavovirens var. flavovirens and Tortula vahliana at a range of sites suggests that they may genuinely be extinct in the vice county. This being said, the frequency with which species are being rediscovered (de-bracketed) leaves a glimmer of hope that some may still remain. The Red Data Book provides a detailed discussion of which species should be considered genuinely extinct and those which probably remain but limited recording has so far failed to find them. The number of species which have almost certainly always been present but overlooked until recently, such as Brachythecium salebrosum, Campylopus fragilis, Dicranodontium denudatum, Lophocolea fragrans, Orthodontium gracile, Pohlia lescuriana, Sphagnum capillifolium subsp. capillifolium and Sphagnum russowii also supports the possibility that some of the species currently thought to be lost may be rediscovered as baseline surveys of the vice county progress.

Campylopus fragilis, on a conglomerate boulder in Mailscot Wood

Among the most significant factors affecting the distribution and conservation status of bryophytes in the Forest of Dean is the impact of forestry management operations. In simple terms, plantation forestry and the associated use of heavy vehicles has reduced or damaged habitat for almost all of the more sensitive species. This is most evident in boulder fields, where boulders are moved to enable access and in most cases all of the more sensitive species which the boulders support die, leaving only the resilient species such as Isothecium myosuroides. Equally, after clear-felling when brash is scraped into rows, almost all terrestrial bryophytes die off. Monitoring of the recovery of Sphagnum populations on the hill to the south of Foxes Bridge Bog suggests that some species including S. capillifolium, S. denticulatum, S. fallax, S. fimbriatum, S. palustre, S. papillosum, S. squarrosum and Sphagnum subnitens can be very resilient, not only surviving for more than forty years under planted conifers but also recover very quickly following clear-felling, as long as the ground is not too intensively drained. Drainage ditches in the area south of Foxes Bridge Bog have been blocked and although it has been planted with oak saplings, it is hoped that the former mire vegetation will recover.

Recovering Sphagnum populations on the hill south of Foxes Bridge Bog

Since 2016, work has been undertaken by Natural England and the Forestry Commission, under the Heritage Lottery Fund Forester’s Forest project, to document the current distribution of Sphagnum species toward restoration of mires throughout the Forest of Dean. The work initially involved mapping the current distribution of Sphagnum species, followed by identification of areas within which mire restoration could be feasible. The decision was taken to start with the Crabtree-Wigpool area, following felling of most of the conifer plantations. A transect-based monitoring protocol was established and implemented by volunteers from the Forestry Commission Green Team. It is hoped that the monitoring will enable measurement of changes in the distribution and extent of Sphagnum species in the area in response to re-wetting.