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Meetings of the BBS - 1989

 

Spring Field Meeting 1989

Salisbury, 6 - 11 April

Wiltshire is one of those counties that bryologists travel through. It contains no famous bryological localities; no new species have been described from its soil. Its moss flora has not been interesting enough to stimulate any of its native sons or daughters to study it in detail. Mention Wiltshire to the average British bryologist and he will immediately think of Salisbury Plain and conjure up a vision of rolling chalk grassland, chewed up by military vehicles and quite inaccessible to the civilian public. Nevertheless on the evening of 5 April a goodly gathering of BBS members assembled in Salisbury to see what they could find in South Wiltshire (vice-county 8).

On the morning of Thursday 6 April we had our first excursion, to Prescombe Down National Nature Reserve, an area of chalk grassland and scrub. To start with we wondered if we had been wise to come, for the ground was snow-covered. However, it was not very deep, we paddled through it and looked first at the scrub, where we found Cryphaea heteromalla, Bryum flaccidum, Metzgeria temperata, M. fruticulosa and Tortula papillosa. In the turf, which was almost clear of snow when we left, were Brachythecium glareosum, B. mildeanum, Dicranum bonjeanii, Neckera crispa, Fissidens cristatus, Weissia microstoma and Rhodobryum roseum.

In the afternoon we visited Little Langford Down, a Wiltshire Trust for Nature Conservation reserve, again consisting of chalk grassland with some scrub. The moss flora was rather similar to that of Prescombe Down but included Bryum pallens (or at least what passes for this on southern English chalk), Encalypta streptocarpa, Fissidens adianthoides, Seligeria paucifolia, Weissia longifolia and also Bryum torquescens, new to v.-c. 8, found by Nick Hodgetts. The surrounding Grovely Wood (Forestry Commission) proved disappointing. Lejeunea ulicina was plentiful there and Rhytidiadelphus triquetrus particularly abundant and luxuriant.

7 April was spent on the Upper Greensand. The morning visit was to Wardover Wood (Forestry Commission), which includes a large area of old semi-natural broad-leaved woodland with a rich bryophyte flora. The many epiphytes seen included Cryphaea heteromalla, Orthotrichum pulchellum, O. lyellii, Metzgeria fruticulosa, M. temperata and also a scrap of Ulota phyllantha on a poplar "new" to v.c. 8 though previously seen there but not collected by Rod Stern.

After lunch the party went on to Oysters Coppice (a Wiltshire Trust for Nature Conservation reserve). The Upper Greensand does not outcrop in the wood and the bryophyte flora is limited but species included Dichodontium pellucidum, Rhytidiadelphus loreus and the "woodland taxon" of Ctenidium molluscum. Racomitrium heterostichum, new to v.c. 8, was found on a nearby cottage roof by Howard Matcham. Gutch Common (SSSI) was within walking distance. Most of the species found there had been seen earlier in the day, but it had five species of Sphagnum including S. recurvum var. amblyphyllum, new to v.c. 8. Most members took the opportunity to pay a visit to Brachythecium appleyardiae in its only known Wiltshire site at Middle Coombe, where it was found to be flourishing and in fair quantity.

8 April was spent in the grounds of the Chemicals Defence Establishment at Porton Down. This straddles the Wiltshire-Hampshire boundary, and our field of study was the Hampshire portion, an SSSI and one of the last remaining areas of chalk grassland in southern England, visited by Francis Rose and Ted Wallace in 1974 but otherwise unknown bryologically. We were ably conducted by three local guides. Their main function, no doubt, was to see that we did not stray where we should not, but we found them helpful and informative. It was a warm sunny day, by far the best of the week and the chalk grassland was most rewarding. New to North Hampshire were Pottia caespitosa and Bryum torquescens. Other species of interest were Aloina aloides, Brachythecium glareosum, Bryum pallens, Encalypta streptocarpa, E. vulgaris, Entodon orthocarpus, Phascum curvicolle, Pottia lanceolata, P. recta, Thuidium hystricosum, Tortella tortuosa, Trichostomum crispulum, Weissia longifolia and Leiocolea turbinata; but not Frullania tamarisci or Scapania aspera previously recorded by Rose and Wallace. At the end of the day we were taken to the excellent little Museum illustrating previous bryological work on the area and we came away impressed with its quality and very grateful for the warm welcome we had received.

9 April (Sunday) was a "free day" and splinter groups went off to different places. The main body spent the morning at Britford Water Meadows where the banks of the watercourses and the trees by them yielded Amblystegium varium, Cinclidotus mucronatus, Fissidens crassipes, Leskea polycarpa and Tortula latifolia, also Ulota phyllantha on a willow, the second record for v.c 8. The afternoon was spent on the Clarendon Park Estate where George Bloom found Fissidens limbatus, and Dicranum montanum was abundant on a couple of logs. The day ended at Clarendon Palace where Ray Harding gave an interesting account of excavations there. This former royal palace is now just ruins among scrub. Porella platyphylla and Tortula marginata were abundant there. Also found on the chalk were Cirriphyllum crassinervium, Gyroweisia tenuis and Seligeria paucifolia.

On 10 April we went a few miles east of Salisbury to Blackmore Copse and Bentley Wood, two areas of mixed and broad-leaved woodland and plantations on Reading Beds and London Clay. Blackmore Copse produced the longest list, but without much of interest apart from Hylocomium brevirostre, Hypnum lindbergii and Polytrichum longisetum. From Bentley Wood we had also Brachythecium mildeanum, Cryphaea heteromalla, Dicranum bonjeanii and Orthotrichum lyellii.

On 11 April, the last day, a reduced party spent a morning of torrential rain in a bog and on wet heathland in the south-east of the county. On Landford Bog none of the ten previously recorded Sphagna were found. Among the hepatics were Cladopodiella fluitans, Riccardia latifrons, Kurzia paucifolia and (new to v.c 8) Cephaloziella elachista. Plaitford Common, now in Hampshire although within v.c 8, is part of the New Forest. It was difficult to do much there in the rain, but eight Sphagna were seen, also Hypnum imponens and fruiting Gymnocolea inflata.

It cleared up at lunch time and a very pleasant afternoon was spent on Whiteparish Common which was found to be quite rich bryologically, species seen there including Neckera pumila, Rhytidiadelphus loreus, Zygodon baumgartneri, Frullania tamarisci, Eurhynchium schleicheri and Ctenidium molluscum "woodland taxon".

Those of us who attended this meeting found the bryophyte flora of Wiltshire a little more interesting than we had expected. We are all most grateful to Vanessa Williams and Rod Stern for organising it extremely well and I must thank Rod Stern for supplying me with some of the information used in writing this account.

A.C. CRUNDWELL


Summer Meeting 1989

Aberystwyth, 2-9 August

The meeting was based at the Penbryn Hall of Residence of the University of Wales. Seventeen people attended the meeting for at least some of the time, varying from 14 on Saturday to 7 on the final day. We were pleased to welcome Theo and Marie-Yvonne Arts from Belgium on their first BBS meeting. All the localities mentioned below are in V.C. 46 unless stated.

On the first evening, as we walked through the college campus to examine our laboratory, Jean Paton pointed out Marchantia alpestris* in cracks between paving stones. After this encouraging start the laboratory was found to be locked, and after a steep climb to the bar at the highest point of the campus, any hopes of a good chat about bryophytes were shattered by a loud jukebox. The misunderstanding over the laboratory, was sorted out on later evenings, but the problem of finding a quiet drinking-place was never fully resolved.

[* = new vice-county record]

3 August. The group assembled at Devil's Bridge to meet the Nature Conservancy Council warden Mr John Davies, who had kindly agreed to show us the 'easy way' into the oak-clad gorge of the River Rheidol. Lepidozia pearsonii was locally abundant on banks, and Plagiochila punctata and Mylia taylori were seen in small quantity. Other species seen in the woodland included Plagiochila spinulosa, Scapania gracilis, Trichocolea tomentella, Bazzania trilobata, Cephaloziella hampeana and Sphagnum girgensohnii. Metzgeria leptoneura was found in a small wet ravine. The rocky outcrops proved to be basic in places, with Marchesinia mackaii, Amphidium mougeotii, Homalothecium sericeum, Neckera crispa and Tortella tortuosa. A brief misty rain was a welcome sight after such a hot dry summer. Sliding down a surprisingly damp scree to the river, some may have been grateful that this was not the 'difficult way' into the site. Lunch was eaten on level, well-illuminated rocks by the river. Jungermannia hyalina was abundant here, and Hygrobiella laxifolia was also detected on wet rocks. Old records for species such as Radula aquilegia and Lepidozia cupressina were not confirmed. It is probable that these were restricted to the less accessible and more humid areas of the gorge downstream but the difficulties of thoroughly searching such a large area of woodland, and the value of having accurately localised records, were evident.

In the afternoon two people visited the accessible part of the Mynach river above the point where it plunges into a steep gorge to join the Rheidol. Cololejeunea calcarea* was collected by Ray Woods on a vertical rock face where Neckera crispa was a conspicuous indicator of the presence of basic conditions

The remainder of the group visited Cwmystwyth mine. Despite the extensive spoil heaps of this old lead mine, little of interest was found. Leptodontium flexifolium was recorded amongst thin grass, and Pohlia muyldermansii and Philonotis arnellii were found by the nearby river and roadside. Nearby, at the confluence of the Diluw and Ystwyth members refound Bryum riparium. Large tufts of Atrichum crispum, a common species in upland Mid-Wales, occurred by the stream, and Plagiochila killarniensis* was found by Jeff Bates on a slightly basic outcrop.

In the evening a very civilised bar was discovered, and Harold Whitehouse was able to show us his impressive stereoscopic photographs of bryophytes.

4 August. The north-facing corrie overlooking the small lake of Llyn Llygad Rheidol which lies at 510 m on Plynlimon, was visited on a warm clear day. Species found included Anthelia julacea, Mylia taylori, Gymnomitrion crenulatum, G. obtusum (in small quantity), Lophozia incisa, Rhabdoweisia crispata, R. crenulata and Andreaea alpina (including one very large patch). Rod Stern and Michael Fletcher recorded Plagiothecium denticulatum var. obtusifolium* below a cliff overhang. Preissia quadrata and Rhizomnium pseudopunctatum were recorded in flushes.

Later, several people went separately to the site of the old Eaglebrook copper mine. This is a valuable site for metal-tolerant lichens, but no bryophytes confined to metal-rich substrata were detected. Dicranella varia, Jungermannia gracillima and Weissia controversa were abundant on the spoil heaps; other species recorded at the site included Cephaloziella stellulifera*, Gymnostomum aeruginosum*, Bryum pallescens*, Tetraplodon mnioides and Ditrichum lineare.

5 August. The shadeless expanse of the north-east bog of Cors Caron NNR (Tregaron Bog) was visited on a hot sunny day. The bog surface, old peat cuttings and a small area of sallow carr yielded Cephalozia macrostachya, C. loitlesbergeri*, Kurzia trichoclados*, K. sylvatica, K. pauciflora, Riccardia latifrons, Calypogeia sphagnicola and 11 taxa of Sphagnum, including S. recurvum var. tenue*. The steep eroded silty banks of the Afon Teifi that flows through the bog had Fissidens curnovii, Pohlia annotina, P. camptotrachela, Fossombronia wondraczekii and Atrichum tenellum*. Some people seemed unimpressed by the latter, but this was the first Welsh record.

6 August. Sunday was left open as a free day. Most participants moved north in a group, stopping first to examine the dunes and slacks of Ynyslas NNR. Despite the existence of several interesting old records from this site, little of interest was found during the present visit. Rhynchostegium megapolitanum was the most notable species found. The group moved on to Esgairgeiliog one mile south of Corris (V.C. 47) where Rod Stern demonstrated a colony of Fissidens polyphyllus by a roadside streamlet. Further up the Afon Dulas at Aberllefenni (V.C. 47 and 48), Isothecium holtii, Bazzania trilobata, Plagiochila spinulosa and Tritomaria exsectiformis* (new to V.C. 47) were found in a sessile oakwood.

A very small contingent spent the day in Cwm Einion, searching the streamsides and fragments of sessile oakwood. Isothecium holtii, Polytrichum alpinum, Bazzania trilobata, Jubula hutchinsiae, Lejeunea patens and Plagiochila spinulosa were recorded. Lepidozia pearsonii and Scapania umbrosa (on wood) were restricted to a small area on the south bank of the river, probably the same place referred to in previous records. Plagiochila atlantica was recorded on the north bank earlier this summer, but the small colony could not be refound, though doubtless still present

Back at our base, the group was charmed to hear of the quaint local custom forbidding the public sale of alcohol on a Sunday (sadly discontinued as recently as November 1989). Luckily Peter Goodman was kind enough to sign us into the staff bar.

7 August. The north side of Cadair ldris (V.C. 48) was visited, primarily to examine the base-rich slopes near Llyn y Gafr. Species recorded included Anastrepta orcadensis, Bazzania tricrenata, Grimmia torquata, Herbertus aduncus subsp. hutchinsiae, Encalypta ciliata, Eremonotus myriocarpus, Funaria obtusa, Hygrobiella laxifolia, Jungermannia sphaerocarpa, Leiocolea bantriensis, Lejeunea patens, Lophozia sudetica, Marsupella sprucei, Plagiobryum zieri, Preissia quadrata, Pohlia cruda, Porella arboris-vitae and Scapania scandica. The perfect walking weather tempted some people to the summit, and Marsupella stableri was found above Llyn y Gadair.

8 August. Several sites were on offer for today, but people were attracted to the small bay at Cwmtudu near Newquay by the promise of swimming. In practice, only 3 people swam, while the remainder recorded Schistidium maritimum on seashore rocks, and Cephaloziella hampeana, Amblystegium fluviatile and Bartramia pomiformis on the roadside and streamside nearby. In the afternoon the wooded lowland valley of the Afon Arth was visited. Plagiochila killarniensis* and Marchesinia mackaii grew on a slightly basic outcrop, on wet rocks by the stream Jubula hutchinsiae, Jungermannia pumila, Amblystegium fluviatile, A. tenax, Cinclidotus fontinaloides, Porella pinnata and confusingly robust Fissidens pusillus were recorded. Basic flushes were marked by Cratoneuron commutatum and Pellia endiviifolia. Fissidens celticus was locally abundant on the banks of small side streams, and tubers were later found on material from this site by Theo Arts. Metzgeria fruticulosa* was collected on elder.

During the week various people confirmed the continued presence of Coscinodon cribrosus on shale outcrops on Constitution Hill in Aberystwyth, after some discussion about species of Grimmia.

Cardiganshire lacks the variety of geology and altitude to make it really exciting bryologically, and I was both disappointed and relieved that BBS expertise did not manage to shower me with too many rarities that I had overlooked. Many people contributed to what I hope was a successful meeting. The local help of Peter Goodman and John Savage was much appreciated. Members of the Nature Conservancy Council, particularly John Davies, gave invaluable help, and the owners of the sites we visited willingly gave permission for access. Participants bravely ate the Hall food with the minimum of complaint.

ALAN ORANGE

 

AGM & Symposium Meeting 1989


Lincoln, 22-24 September

The hard work and unfailing organisation of the local secretary, Dr Mark Seaward, was rewarded by a well-attended and memorable meeting. The Society was accommodated in great style in the heart of Lincoln, one of the finest cathedral cities, in the comfortable and ancient Edward King Hall, only yards from the cathedral itself. The weather on both Saturday and Sunday was also remarkably pleasant, setting off the fine surroundings to best advantage.

The papers read on Saturday 23 September included three on the subject of 'bryology and bryologists of lowland England'. These were varied, including ecological, historical and distributional approaches. The other presentations ranged from the bryology of continental Antarctica and New Zealand to the ultrastructure of the bryophyte placenta and problems and progress in bryophyte conservation. The following are summaries of the papers presented, written by their authors.


Dr R.D. SEPPELT (Antarctic Division, Tasmania): "Taxonomy and Biology of Antarctic Mosses."

1. Origins:

Most Antarctic bryophytes are thought to be post-glacial immigrants while many of the lichens, particularly endemic species, may have survived in Antarctica through the Pleistocene on high- altitude nunataks. There is a growing body of evidence from glacial geomorphological studies that ice-free refugia, some of which may now be submerged offshore, have persisted throughout the Quaternary period and may have been important centres for persistence and, later, dispersal of plants in Antarctica.

2. Taxonomy:

The moss flora of continental Antarctica consists of relatively few widespread species. Most do not produce, or have not yet been found with, sporophytes. In the severe climate of Antarctica environmental modification can be extreme, compounding taxonomic difficulties in what are often taxonomically difficult genera. Few genera have been reported from continental Antarctica. They include Bryum, Grimmia (including Schistidium), Ceratodon, Sarconeurum, Pottia, Bryoerythrophyllum and, perhaps doubtfully, Pohlia, Desmatodon and Plagiothecium. Recent recoveries from fumarolic areas include Tortula and Campylopus, and Dicranella has been discovered in some lakes.

Bryum and Grimmia are the most widespread and both present considerable taxonomic difficulties. A variey of methodologies, including field morphological comparisons, morphology of cultured material, biochemical analysis of enzyme systems, and cytological studies have been used to provide a rational basis for determination of Bryum species. Consequently, only two species - B. argenteum and the highly polymorphic B. pseudotriquetrum (found at a few localities with capsules) - are represented on continental Antarctica.

Grimmia and Schistidium are represented by a number of species but the taxonomy of all - both hair-pointed and non-hair-pointed species - needs careful revision. Continental species having hair-points include the endemic G. lawiana, G. trichophylla (with capsules) and possibly G. donniana and G. nordenskioldii (synonymised with G. immerso- leucophaea.) A variety of species is found on the Antarctic peninsula but the taxonomy is anything but straightforward. Confusion exists between specimens identifiable as G. donniana and similar plants with leaves lacking a hair-point. Some fruiting material is clearly identifiable as Schistidium, some as Grimmia but just where Grimmia (Schistidium) antarctici fits into this confusion remains to be elucidated.

Several species of Ceratodon have been included in the Antarctic flora but the name now applied to most material is C. purpureus. There are, however, consistent morphological differences between Antarctic Ceratodon and Australian C. purpureus both in field populations and in culture experiments. No capsules have been found in Antarctic collections. There is some additional biochemical evidence, from enzyme analysis, to support possible separation of the Antarctic material from C. purpureus.

3. Photosynthetic Physiology:

Field and laboratory studies of photosynthetic physiology on Antarctic Grimmia, Ceratodon and Bryum have been recently carried out. The slow growth of Antarctic terrestrial plants is commonly attributed to the short summer growing season and low temperatures. Water stress and nutrient deficiencies are cited as additional factors. Long hours of summer daylight are frequently believed to compensate for the short growing season. The very bright light intensities commonly experienced at high latitudes have until recently only rarely been considered as stressful, despite the comparatively low light intensities required to produce maximum photosynthesis in mosses and lichens.

Observations of quantum yields, light saturated photosynthetic rates, and variable fluorescence of bryophytes suggested that photoinhibition was a major factor limiting productivity of Antarctic ecosystems.

A reduction in photosynthetic capacity in the presence of high light levels reflects damage to the photosynthetic apparatus caused by light in excess of that which can be used in the pathways of photosynthesis. The light intensity required to produce damage varies, depending on the light- harvesting capacity of the plant and the rate of photosynthetic pathway reactions that convert atmospheric carbon dioxide to carbohydrate. Circumstances which slow down these reactions, such as low temperature, drought stress and nutrient deficiencies, lower the level of light required for photosynthesis and, therefore, substantially increase the sensitivity to photoinhibition. These conditions are the norm in Antarctic ecosystems.

Photoinhibition has been observed at very low light levels using Grimmia antarctici. Maximum inhibition of photosynthesis by light was observed at 500 Eµm-²s-1. (microEinsteins per meter squared per second), while half the maximum inhibition of the fluorescence ratio occurred at only 100 Eµm-²s-1. Above 500 Eµm-²s-1. photosynthetic capacity is reduced by about 40%.

Studies carried out continually over a number of days indicated that photoinhibition is experienced daily throughout the summer growing season and must significantly reduce the potential growth of the moss.

Further experiments have indicated that photosynthesis in Grimmia antarctici is also limited by atmospheric carbon dioxide concentrations. The low rates of photosynthesis (22-29µmol CO2/gm dry wt/hour) are typical for bryophytes at the normal atmospheric carbon dioxide concentrations of about 340 parts per million. By experimentally increasing carbon dioxide levels photosynthetic rates nearly three times higher have been observed. Maximum rates of oxygen evolution in G. antarctici were obtained at carbon dioxide levels ten times higher than present atmospheric levels.

Bryophytes are magnificent tools for physiological research. Perhaps one way to foster an awareness of bryophytes is by encouraging their use in this way, through applied research, rather than from the traditional taxonomic standpoint.


Dr R. LIGRONE (Institute of Botany, University of Naples): "The Evolution of the Placenta in Bryophyta."

The embryophytes are characterized by a distinctive life cycle in which the sporophyte develops within the gametophyte and depends on it for nutrition. This is a very transient condition in tracheophytes (pteridophytes and phanerogams), but persists for the duration of the life cycle in mosses, liverworts and anthocerotes. In these groups the sporophyte produces a basal organ, the foot or haustorium, that establishes a close morpho-functional relationship with the parental gametophyte.

Several studies have shown that, in all three major bryophyte groups, the sporophyte is able to carry on photosynthesis but needs organic nutrients supplied by the gametophyte for sustained growth (see Ligrone & Gambardella, 1988 for review). Moreover, despite the paucity of experimental evidence, it is widely maintained that the sporophyte does not absorb water and mineral ions effectively.

The site of nutrient translocation is the placenta, a specialized region that develops at the junction between the two generations. In general, the placenta consists of the epidermal cells of the foot, the adjoining cells of the gametophyte, and an intervening apoplastic space containing mucilage and cellular remnants of gametophytic origin. The cells of the placenta play an active role in the transport of nutrients towards the sporophyte, and generally exhibit a specialized structure that makes them clearly distinct from the adjoining parenchyma cells of the respective generation. For example, they have dense cytoplasm rich in ribosomes and mitochondria and an extensive endomembrane system. Most frequently, they exhibit protuberances of irregular shape forming a complex labyrinth on tangential walls. The wall labyrinth is closely outlined by the plasmalemma, which thus has a greatly amplified surface area. Cells with a wall labyrinth are widespread in embryophytes and are t hought to be specialized in short distance transport of solutes from the apoplast to the symplast and vice versa. For this reason they have been called the "transfer cells". In higher embryophytes transfer cells have been found in many different tissues but are unknown in algae except around the zygote of Coleochaete (Graham & Wilcox, 1983). It may be that this cell type first evolved in the placenta of primitive embryophytes associated with improved nutrition of the sporophyte.

The structure of the placenta varies significantly in the different bryophyte groups. These differences mainly concern the presence and distribution of transfer cells.

Within the mosses, transfer cells are restricted to the sporophytic side of the placenta in the Andreaeopsida and Polytrichidae, whereas they occur on both sides of the placenta in the Eubryiidae and Buxbaumiidae, as well as in Tetraphis. Transfer cells are absent from the placenta of Sphagnum. Considering that transfer cells are of common occurrence in the placenta of other embryophyte groups (i.e. liverworts, anthocerotes, pteridophytes, etc.), it would seem likely that the condition found in the Andreaeopsida and Polytrichidae is primitive, with the absence of transfer cells in Sphagnum being due to reduction. Starting from the primitive condition, a more advanced type of placenta might have evolved in the Eubryidae and Buxbaumiidae with the appearance of transfer cells in the gametophyte. The presence of an "advanced" type of placenta in Tetraphis indicates that this genus, often regarded as being "primitive", is more closely rela ted to the Eubryidae-Buxbaumiidae clade than to the nematodontous group Polytrichidae, as also supported by studies of sperm ultrastructure (Duckett, Carothers & Miller, 1982).

In the liverworts the structure of the placenta appears to be far more diverse than in mosses. The Marchantiidae present transfer cells on both sides of the placenta, often arranged in several layers in the gametophyte. The only known exception is Riccia which lacks transfer cells. In the Metzgeriales Fossombronia has a placental structure very similar to that typical of Marchantiidae, whereas Pellia lacks transfer cells. In the Jungermanniales, two species have so far been examined; in both Marsupella funckii and Jungermannia gracillima, transfer cells are restricted to the sporophyte. Too few species of liverworts have been studied for any wide-ranging conclusions. However, it is interesting to note that the two jungermannialean species, belonging to a group that many authors consider to be primitive among liverworts, exhibit a placental structure similar to that suggested as primitive in mosses. This, if confirmed by further observations, may support the notion of a common ancestry for liverworts and mosses.

The placenta in the anthocerotes is much more uniform than in mosses and liverworts. In all genera (Phaeoceros, Notothylas, Anthoceros, Folioceros, Megaceros and Dendroceros), transfer cells are present in the gametophyte only, whereas the sporophyte forms long and branched haustorial cells that penetrate the gametophyte tissue. As a consequence, the cells of the two generations are so closely intermingled that, with the partial exception of Anthoceros, they can hardly be distinguished with the light microscope. The placental spaces between cells of the two generations contain abundant protein crystals of gametophytic origin in Phaeoceros and Notothylas. This is indicative of a close relationship between these two genera, crystals being lacking or very rare in the other genera. Overall, the placental structure of the anthocerotes appears to be quite distinct from that of mosses and liverworts, thus providing a strong additional criterion for separating the anthocerotes from other bryophytes.

References

Duckett, J.G., Carothers, A.B. & Miller, C.C.J. (1982). Comparative spermatology and bryophyte phylogeny. J. Hattori bot. Lab. 53, 107-125.

Graham, L.E. & Wilcox, L.W. (1983). The occurrence and Phylogenetic significance of putative transfer cells in the green alga Coleochaete. Am. J. Bot. 70, 113-120.

Ligrone, R. & Gambardella, R. (1988). The sporophyte-gametophyte junction in bryophytes. Adv. Bryol. 3, 225-274.


Mr N. HODGETTS (Nature Conservancy Council, Peterborough): "Progress and Problems in Bryophyte Conservation."

At the BBS Leeds meeting (1986) Peter Pitkin suggested that bryophytes were the poor relations in nature conservation and 6 measures could be taken to further their conservation. Many of his points are now being addressed:

  1. Appointment of a lower plant ecologist in NCC. This has now taken place, though the continuation of the post is somewhat doubtful.
  2. Establishment of criteria for selecting bryological SSSIs. Now being done.
  3. Mentioning bryophytes in SSSI citations. Being encouraged.
  4. Review of representation of bryophyte flora in SSSIs. Although many communities are well represented, those that are under-represented include Atlantic woodlands and ravines and highland communities.
  5. Appreciation among bryologists for site-based records. This is improving.
  6. Bryologists communicating site records to NCC. This still needs to be emphasised.

There remain many problems in addition to the well-known ones of pollution and habitat-destruction:

  1. The "credibility barrier". Even among conservationists bryophytes are often ignored or not taken seriously, because of their small size, long Latin names and lack of common names. To overcome this it is necessary to explain the philosophy behind bryophyte conservation, and the international importance of the British flora. The former can be explained in terms of (a) the value of bryophytes in scientific research and education, (b) their potential use to man (e.g. alkaloid extracts, etc.), and (c) man's responsibility to protect them for heritage/aesthetic/spiritual reasons. Their international importance can be emphasised by noting that while only about 18% of the European Vascular flora is represented in Britain, the figure for bryophytes is about 70%.
  2. Lack of survey information in many areas.
  3. Lack of information on the practical conservation of bryophytes, and management of habitats for bryophytes.
  4. Bryophytes of ephemeral habitats, or otherwise dull localities, are difficult to conserve using the existing available measures.
  5. Collecting. Probably not so much of a problem as formerly, but still to be considered. Indiscriminate collection of Sphagnum for horticultural purposes is, however, a problem.
  6. Climatic change. The onset of the greenhouse effect may have dramatic consequences for the British flora.

Additional ways in which bryophyte conservation is being furthered:

  1. More surveys are being made, particularly in Scotland.
  2. A BBS initiative for local recorders has been proposed.
  3. Management advice is being given to NCC Regional staff, as well as SSSI selection/boundary advice.
  4. The Red Data Book for cryptogams is well under way.
  5. International initiatives, e.g. the European list of threatened species; bryological representation at IUCN; recognition of the international importance of British bryophytes.
  6. The Bryophyte Atlas is well under way.
  7. Species will be added to Schedule 8 of the Wildlife and Countryside Act in 1991.
  8. Translocation trials for rarities is proposed.
  9. Training of NCC staff in bryophyte recognition and in recognition of good habitats.

Dr J. BEEVER (DSIR, Auckland, New Zealand): "'Bryology down under' - Current Research in New Zealand."

New Zealand numbers amongst its three and a quarter million people seven members of the BBS, and in addition five institutions take the Journal of Bryology. Thus our links with the Society are strong.

The basis of modern knowledge of New Zealand bryophytes is a series of papers entitled 'Studies in the Bryology of New Zealand' published between 1913 and 1929 by H.N. Dixon, who worked on collections sent to him in England. Subsequently he corresponded extensively with G.O.K. Sainsbury, who produced in 1955 A Handbook of New Zealand Mosses which is still our moss bible today. More recently K.W. Allison and John Child produced a popular book on mosses, published in 1971, The Mosses of New Zealand, and a companion volume The Liverworts of New Zealand. The hepatics are much less well known than the mosses, the literature is widely scattered, and there is no equivalent to Sainsbury's Handbook. Prof Rudy Schuster and Dr John Engel have taken a keen interest in the New Zealand hepatics, and it is hoped that they may produce a Flora for this region. A new Moss Flora for New Zealand is being prepared by Dr Allan Fife at Botany Division of the Department of Scientific and Industrial Research. My own projects are:

  1. Preparation of a revision of Allison & Child's Mosses of New Zealand. This is a more extensive treatment than the first edition. In addition to 75 spp. treated in detail, distinguishing features are given for a further 376 spp. A new key and drawings have been prepared, and colour photos are included.
  2. Studies of mosses on the northern offshore islands of New Zealand. Many of the islands off the east coast of the northern part of the North Island are reserves, and some have areas of relatively undisturbed vegetation which makes them particularly valuable. Their climate is very mild. Several mosses of tropical affinity have recently been found on the offshore islands, e.g. Thuidium cymbifolium and Syrropodon armatus. Both are also known from a very few localities on the North Island mainland.
  3. A revision of the genus Fissidens in New Zealand. There are approximately 20 species known in New Zealand, several of which may be undescribed. Fissidens oblongifolius Hook.f. & Wils. provides an example of the complexities to be unravelled. In this case three species, two of them previously unrecognized in New Zealand, have been confused.
  4. Collaboration with Professor Zen Iwatsuki of Hiroshima University and Professor Janice Glime of Michigan Technological University in their world-wide study of bryophytes of thermal regions. Permanent quadrats set up on ejecta from a recent hydrothermal eruption have shown that the primary colonisers are mainly exotic vascular plants and cosmopolitan mosses.

Other bryological projects at present under way, or recently completed, include:

  1. An account of Fossombronia species in New Zealand, and the description of a new genus in the Calobryales, Steereomitrium, by Dr Ella Campbell of Massey University.
  2. A taxonomic revision of the genus Camptochaete (Lembophyllaceae), by Ray Tangney, as a PhD study at the University of Otago.
  3. A revision of the genus Riccardia in New Zealand, by Elizabeth Brown. Her PhD thesis, supervised by Dr John Braggins at the University of Auckland, is to be published this year in the Journal of the Hattori Botanical Laboratory.
  4. A revision of the genus Hookeria in New Zealand, by Dr Allan Fife.

DR J.M. LOCKE (Milton, Cambridge): "Calcifuge Bryophytes at Wicken Fen - normal succession or temporary aberration?".

Wicken Fen Nature Reserve is one of the earliest sites acquired by the National Trust; the first portion was donated in 1899. It is an undrained, but not undisturbed, relic of the original fenland, and supports a complex of open water, reed beds, sedge fields (cut every four years), litter fields (cut annually) and carr (scrub dominated by Frangula alnus). Most of the carr developed after the National Trust took over the Fen. Habitat diversity is maintained by cutting and other management, and the Fen has recently become wetter as a result of the sealing of the northern bank.

The earliest moss records are those of Richards (1930) who recorded 17 mosses and 3 liverworts. Proctor (1956), in his bryophyte flora of Cambridgeshire, remarked on the general poverty of the flora, pointing out that it was more typical of wet meadow and woodland than of the Norfolk valley fens. He made no mention of any calcifuge species.

In 1963 Sphagnum fimbriatum, Polytrichum commune, Hookeria lucens and Tetraphis pellucida were found, and in subsequent years many more calcifuge species were added to the list, so that of the 89 mosses and 18 hepatics now known, about 35 can be regarded as calcifuge. Species such as Campylopus brevipilus, Plagiothecium undulatum, Rhytidiadelphus loreus and Hylocomium brevirostre have been found. In the 1980s the area occupied by calcifuge bryophytes has declined and some species have not been seen recently (Hookeria - last record 1975; Leucobryum glaucum - 1979; Sphagnum recurvum - 1975; Plagiothecium undulatum - 1975).

Calcifuges occur within the carr on dead Molinia tussocks, and on the ridges left by peat digging, both sites of local leaching. In places they also occur on the general surface of the peat beneath the carr. They have presumably arrived by wind dispersal of spores or fragments. The recent decline can be attributed to high winter water tables and, more especially, to increased competition from higher plants, particularly Calamagrostis, following the death of much of the Frangula canopy following a fungal infection, probably identical to an outbreak in the late 1920s. In the long term the shrub canopy will re-establish and bryophytes may then become more widespread again.

References.

Richards, P.W. (1930). The Bryophyta of Wicken Fen. In: J. S. Gardiner (ed), The Natural History of Wicken Fen.

Proctor, M.C.F. (1956). A bryophyte flora of Cambridgeshire. Trans. Brit. Bryol. Soc. 3, 1-49.

Discussion:

Dr Jones wondered if the failure of earlier collectors to find calcifuge bryophytes was due to the parts of the Fen where they grow being closed to visitors in the 1930's. He also pointed out that Hylocomium brevirostre, although a western woodland species, was not a calcifuge. Dr Lock replied that calcifuges had first been found in an area quite close to the Fen entrance, and in other areas which had always been open.

Mr Perry suggested that Scandinavia was a more likely source of spores than western Britain, as some of the species concerned fruited much more frequently there. Dr Hill suggested that fragments, rather than spores, were a more likely mode of spread for many species. In response to a query from Dr Lock, it was said that extremely small moss fragments are capable of giving rise to new plants, and that in Japan mosses are introduced to new sites by grinding plants in a domestic blender and spreading the resulting suspension.


Dr M.R.D. SEAWARD (University of Bradford): "Lincolnshire Bryology and Bryologists. "

Historical research into bryology of Lincolnshire reveals that although many leading botanists of the day visited the county, their bryological contribution was minimal. The work of F.A. Lees was the exception: his discoveries, mainly in the Market Rasen area, during his residence there from 1877 to 1879, give a clear indication of the once rich bryophyte flora, much of which had declined by the end of the 19th century, mainly as a result of extensive land drainage and other agricultural practices. The work of G.H. Allison during the 1930s deserves special mention; many of his discoveries, particularly the rare Bryum spp. on the N.E. Lincolnshire coast, have not been found since. From 1959 onwards, M.R.D. Seaward and many other bryologists making short-term visits to the county have regularly added VC records and, more recently, re-discovered several rarities not seen for 50 or more years. The Lincolnshire bryophyte flora can currently be summarized as follows: of the 388 t axa recorded, 265 (223 mosses, 42 hepatics) are known to be extant, 97 have not been seen for 50+ years and 13 have not been seen for 100+ years, 8 possibly occur but are not supported by herbarium material, and 5 are doubtful in the absence of herbarium material. An overview of Lincolnshire bryophyte habitats past and present was provided and lines of enquiry likely to prove fruitful suggested.


Dr K.J. ADAMS (Polytechnic of East London): "Proposals for a 5 km² Mapping scheme for Eastern England".

Publication of the three volumes of the Bryophyte Atlas should serve as a stimulus to further recording as the patterns of blank squares are revealed, but because recorders are unlikely to see their post-Atlas records appear on updated maps in published form for a long time to come, some other carrot is needed to ensure that mapping of distribution patterns is continued.

The importance of detailed mapping on a regional basis is being spectacularly underlined by the rapid recovery of SO2-sensitive bryophytes and lichens in London and eastern England as SO2 levels decline. In south-west Essex species such as Rhytidiadelphus loreus, R. triquetrus, Hylocomium splendens, Bartramia pomiformis, Tortula intermedia and Tortula ruralis, in addition to the more familiar sensitive epiphytes such as Cryphaea, the Ulotas, Frullanias and Orthotricha (other than O. diaphanum), had been wiped out by 1950, reappearing further out in concentric zones centred on London, depending on their sensitivity to this deadly gas.

Despite a continued rise in nitrogen oxide and ozone levels certain bryophytes are making a remarkable comeback. On Hampstead Heath the author has found Orthotrichum striatum bristling with capsules on one Crack Willow, Ulota bruchii on three willows, again in fruit, and 4cm wide patches of Frullania dilatata on two others. The presence of lichens such as Usnea inflata and Parmelia perlata tell the same story. Bryophytes and lichens would appear to be far more sensitive to SO2 than other pollutants in the south of England. Monitoring the recovery will be particularly interesting, as rather than a sequential reversal of the pattern of extinction, the species reappearing are those most effective at innoculating the now 'safe' substrates with their propagules, irrespective of their degree of sensitivity to SO2 . To pick up such rapid distribution changes, detailed base-line surveys are required on a regional basis. The bryophyte SO2 zones for example can only be adequately defined by mapping out from central London in a wide arc to the Norfolk coast.

A few counties have been or are being mapped on a 5 km², or 2 km² and even a l km² basis, but bryologists are so thin on the ground that only a few counties are likely to be mapped in this detail for the forseeable future, and adequate coverage on a tetrad or monad basis is likely to be impossible except in a small county such as Rutland. Furthermore individuals vary somewhat in their success in locating all the species in their area; some for example tend to avoid arable field species with rhizoidal gemmae, others those of urban habitats. Marchantia alpestris and Bryum gemmiferum for example are common pavement gap species in London, and Trichostomopsis has been found growing as a 'turf' on soil between the paving slabs of a station platform, whereas most people would only look for it at the base of a wall. Similarly Tortula brevis is generally found on river banks or at least not far from water, but acting on a suggestion by Harold Whitehouse that it might be spread around by badgers, the author succeeded in locating it on fresh spoil, outside a badger hole, half way up a cliff in Grays Chalk Quarry. What better proof than that!


Tortula brevis (in cultivation!)

Thus apart from the obvious advantages of reasonably detailed mapping on a regional basis the whole exercise can be made that much more enjoyable and informative by passing on the snippets of information gleaned from one county to recorders in adjoining counties. In Essex for example. Cricket Bat Willows form an ideal substrate for epiphytic lichens and bryophytes, and since they grow to maturity in about 14 years can be used to detect recent colonists.

To show up distribution patterns on a regional as opposed to a national basis the 10 km² is too coarse a grid. A tetrad or monad would be ideal but probably impractical. However, a 5 km² grid superimposed over a map of the vice-counties of eastern England suggests a suitable compromise.

Species check-lists for Vice-counties 18-21 and 25-31 have been prepared, a compendium of vice- county records is being compiled on disc, and a set of provisional maps is being produced for circulation to interested participants. Several BBS members are already collecting data for county floras within the region. A 10 km square Atlas of the Bryophytes and Lichens of Essex is in the final stages of preparation for example. This will include maps of more interesting species on a 1 km² basis; and the data collection for a later 5 km² Atlas of bryophytes is well advanced.

The proposed 5 km² Atlas of Bryophytes of Eastern England is not intended to take the place of such county Floras. By co-operating, bryologists working on vice-counties in the region can, however, produce a more even coverage of the area, concentrate on more detailed investigation of pollution-sensitive species, and tackle some of the adjoining areas which are not currently being mapped. It is proposed that a working party be set up to co-ordinate mapping in Vice-counties 18-21 and 25-31 in March 1990. Anyone interested in participating in the scheme is invited to contact Ken Adams for a copy of the check list and further details.

After the Annual General Meeting the evening continued with a book sale - becoming rather a tradition during the autumn meetings - with Mark Seaward as auctioneer. As is customary, a conversazione followed with several notable exhibits.

PHILIP LIGHTOWLERS


 

Field Meeting, Lincolnshire, 24 September 1989

Sunday was devoted to fieldwork, most of those attending the Saturday functions staying on for the morning visit to Swanholme Lakes (43/9468), a complex of flooded sand and gravel pits within the SW boundary of Lincoln. The site was notified as an SSSI in October 1985, only ten weeks after coming to the attention of the NCC through a routine consultation on a planning application for housing, hotel and leisure facilities. Not surprisingly, the NCC objected to the proposed development (see Urban Wildlife News 6(3): 1, 1989): as well as an interesting fauna and aquatic plants such as Littorella uniflora, Pilularia globulifera, Stratiotes aloides and Callitriche hermaphroditica, the site supports a locally important bryophyte flora, particularly in respect of Sphagna and other acidic wetland species. Of 80 bryophyte taxa recorded from grid square 43/96 over the past 30 years, more than 60 were observed on this occasion, together with 13 new ones, including Dicranella rufescens. Sphagnum auriculatum var. auriculatum, Aneura pinguis, Pellia neesiana, Riccardia cf. incurvata and R. chamaedryfolia. It is hoped that this area can be properly managed and protected to safeguard its wildlife.

In the afternoon, localities to the south of Lincoln were visited, including Ancaster churchyard (43/983435), site of Armeria maritima ssp. elongata (see Watson ia 4, 125 & 136, 1958), but the bryophyte flora here, and at the neighbouring Ancaster Valley (43/9842), proved disappointing, particularly when compared with the species lists compiled by G.H. Allison hereabouts in the 1930s. The current poor bryophyte flora in Ancaster Valley is almost certainly the result of poor grazing management.

The number of BBS members had by now dwindled, the few stalwarts remaining moving on to Rauceby Warren (53/034439), a calcareous heathland over sand and clay with a limited but interesting bryophyte flora of about 44 taxa, including Riccia cavernosa, Pottia starkeana ssp. minutula and Physcomitrella patens, and unusually Fontinalis antipyretica surviving here as a plant of seasonal ponds.

Several BBS members furnished useful bryophyte lists from other Lincolnshire sites they visited on their homeward-bound journeys, for which I am most appreciative. I am also grateful to the Lincolnshire & South Humberside Trust for Nature Conservation for permission to visit their nature reserves at Ancaster and Rauceby, and to the numerous members of the BBS, NCC and Lincolnshire Naturalists' Union who actively participated to make this an enjoyable conclusion to an eventful weekend.

MARK R.D. SEAWARD


 

Autumn Workshop 1989

Whitelands College, Roehampton, 24-26 November

The workshop was intended to cater particularly for the needs of beginners and attracted 14 participants, 7 of whom were members of the Society.

On Friday evening there was a session on basic bryology for those who felt they needed it. Saturday and Sunday each began with an expedition to Wimbledon Common to collect specimens, which participants identified using microscopes and equipment kindly made available by Whitelands College. No rarities were found, but a useful list of 28 mosses and 6 hepatics is being sent to the Common Conservators. Polaroid spectacles were donned to view some exciting 3-D colour slides of bryophytes, most kindly presented by Dr Harold Whitehouse.

The advice and help given during the weekend will make a real contribution to many attendees' identification skills. Of particular value, at least for me, were the practical hints and tips on dissection and slide preparation, whilst the clarification of difficult points in the keys may help to reduce future frustration.

The success of the workshop owed much to the presence of Drs Alan Eddy and Philip Lightowlers, who gave generously of their time and expertise; and especially to Jennifer Ide whose organisation was ideal. Finally, the contacts made during the Workshop will help to assuage the 'loneliness of the long-distance bryologist' which afflicts most amateurs who take up the art.

ROY HURR

 
 
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