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Meetings of the BBS - 1991

 

Spring Field Meeting 1991

Clevedon, North Somerset, 3 - 9 April

This meeting was based in the area of North Somerset (v.-c. 6), which the society last visited for a field meeting over 30 years ago. It was attended by a total of 36 people, with a maximum of 25 people on Saturday. The headquarters hotel was the Walton Park which proved an excellent last minute substitute for the previous selection which became bankrupt only weeks before the meeting.

3 April. The morning was spent at Draycott Sleights, situated on a steep south-west facing slope of the Mendip Hills. The geology consists of various strata of the Carboniferous Limestone and a significant part of the soils is made up of windblown silt (loess). The weather was pleasantly sunny with views of heavy showers passing below. Plentiful Gymnostomum viridulum was found along with Phascum curvicolle, Pottia recta, Weissia longifolia var. angustifolia, and the hepatics included Reboulia hemisphaerica and Riccia sorocarpa. Cliff Townsend found a short leaved form of Tortella tortuosa and Alan Crundwell found Bryum caespiticium var. imbricatum. Other species included Orthotrichum cupulatum and Scorpiurium circinatum.

In the afternoon we were sown around the Somerset Trust for Nature Conservation reserve at Ubley Warren by the warden and BBS member Valerie Cornell. The ground here is dissected by old workings providing rock faces and boulders. The rock faces supported Scapania aspera, Gymnostomum aeruginosum and Gyroweisia tenuis. Climacium dendroides was plentiful on the tops of boulders, and in the turf Rhytidium rugosum was found. Cliff Townsend found Acaulon muticum. The nearby old lead workings at Charterhouse proved disappointing though the locally uncommon Grimmia donniana and Racomitrium lanuginosum were seen.

A brief visit to Cheddar church en route back to Clevedon produced Barbula revoluta, Gyroweisia tenuis and Orthotrichum cupulatum on the church walls. On the chippings around the church it was interesting to find Scorpiurium circinatum thriving.

In the evening Harold Whitehouse showed some excellent stereo photographs of New Zealand bryophytes.

4 April. The Stockhill forestry commission plantation near Priddy was visited in the morning but we failed to find Ditrichum plumbicola previously recorded here. Old Elders in the rides of the plantation provided good epiphytes, and on them Rod Stern found Orthotrichum pulchellum and O. striatum. Also seen were Cryphaea heteromalla, Metzgeria fruticulosa and Zygodon conoideus c.fr.

In the afternoon Harridge wood near Shepton Mallet was visited. The bryophytes were luxuriant and near the entrance to the wood Cliff Townsend and Mark Hill found Pylaisia polyantha on Ash. The epiphytes proved interesting, due perhaps to the influence of dust carried from the adjacent quarry. The following epiphytes were seen: Tortula subulata var. graeffii, Barbula rigidula, Encalypta streptocarpa, Leskea polycarpa and Tortula latifolia - the last two far from water. Rock faces had Cirriphyllum crassinervium, Seligeria pusilla, Marchesinia mackaii, Porella arboris-vitae var. arboris-vitae and Zygodon viridissimus var. stirtonii. Further species seen include Orthotrichum pulchellum, Neckera pumila, Metzgeria temperata and fine fruiting Thamnobryum alopecurum.

5 April. In the morning we visited Westhay Moor reserve, where the Somerset Trust for Nature Conservation are trying to preserve a raised bog from drying out. Drying is caused by adjacent peat extraction mainly by the company Fisons. Eight species of Sphagnum were recorded but in poor quantity. Other species seen included Calliergon cordifolium, Aulacomnium androgynum, A. palustre, Ulota phyllantha, Cephalozia connivens and Cephaloziella hampeana.

In the afternoon we visited Withial Coombe near Glastonbury. This steep sided wooded valley which lies over the Lower and Middle Lias made access difficult in places. Epipterygium tozeri and Fissidens incurvus grew on the steep clay banks. Alan Crundwell found Eurhynchium schleicheri, and epiphytes included Neckera pumila, Orthotrichum pulchellum, Metzgeria fruticulosa and M. temperata.

Finally, Harold Whitehouse took us to a bridge near Butcombe where Leptobarbula berica had been recorded. Fruiting Gyroweisia tenuis caused us some confusion but turned out not to be the second British record for fruiting Leptobarbula.

6 April. The morning was spent on the old Iron Age fort site of Dolebury Warren. In this steep sided hill in the Mendips 25 members saw a fine range of species on the Carboniferous Limestone. Nine species of Barbula were seen including B. vinealis which is uncommon in N. Somerset. Vanessa Stern found Acaulon muticum on an anthill where Ephemerum serratum var. serratum was also recorded. Grimmia orbicularis was detected amongst large quantities of G. pulvinata. On the thin soiled slopes Eurhynchium swartzii var. rigidum and 5 species of Pottia were seen including P. bryoides by Alan Crundwell and P. intermedia by Eustace Jones. Chris Preston found Platydictya confervoides on a rock face, and George Bloom found Bryum radiculosum. Other species seen included Brachythecium glareosum, Funaria muhlenbergii, Zygodon baumgartneri, Rhodobryum roseum and Tortella nitida. David Long found Tritomaria quinquedentata in the third locality for N. Somerset.

The afternoon in Cheddar wood was in fairly heavy rain which dulled the enthusiasm, though a few interesting records included Eurhynchium schleicheri, Taxiphyllum wissgrillii, Porella arboris-vitae var. arboris-vitae, Cirriphyllum crassinervium and Isothecium striatulum c.fr. Ron Porley found Orthotrichum stramineum.

In the evening a council meeting was held in the Walton Park Hotel, Clevedon.

7 April. A fine but windy morning was spent on the slopes of Crook Peak in the southern edge of the Mendips. Harold Whitehouse found and photographed Barbula hornschuchiana c.fr. Bryum caespiticium var. imbricatum was again found, this time by David Long who also found Campylopus fragilis and Rhodobryum roseum. The south facing slopes support Pleurochaete squarrosa, Phascum curvicolle, Pottia lanceolata and P. recta and Mark Hill found Pottia starkeana ssp. starkeana var. brachyodus. Nick Hodgetts found Metzgeria conjugata and Eustace Jones found Cephaloziella stellulifera which he also recorded in Burrington Coombe and Ebbor Gorge in the 1959 BBS meeting. Other species seen included Bryum canariense c.fr., Entodon concinnus, Lophozia excisa and Tritomaria quinquedentata c.gemmae. The best find of the day was Porella obtusata by Nick Hodgetts which was new to v.-c . 6.

In the afternoon the Avon Wildlife Trust reserve at Goblin Coombe was visited. The site consists of mixed woodland with short turf in open areas below cliffs. Marchesinia mackaii was found growing over the rock face and extending onto the trunk of a Yew tree which was growing out of a crack in the cliff face. Bryum canariense and Dicranum bonjeanii were found in the openings on the cliffs and in the woodland Fissidens exilis and F. incurvus were found. Small amounts of Hylocomium brevirostre were seen and David Long found Orthotrichum tenellum and Phascum curvicolle. Other species seem were Isothecium striatulum, Plagiothecium latebricola and a mixed patch of Lejeunea cavifolia and L. lamacerina.

8 April. The Black rock area of the Cheddar Gorge showed a range of habitats - rock faces. quarry floor, walls, woodland and grassy slopes. Boulders in the woodland had Platydictya confervoides, Hylocomium brevirostre, Isothecium striatulum, Scapania aspera and Neckera crispa c.fr. Hygrohypnum luridum was found growing on a wall. On the quarry floor David Long found Barbula reflexa and Entodon concinnus. On the slopes leading up to the top of the gorge were Bryum caespiticium var. imbricatum and Funaria muhlenbergii. Alan Crundwell found Riccia subbifurca here growing with R. sorocarpa.

In the afternoon Kings Castle wood near Wells was visited. It proved a little dry and the most interesting plants we found were Platydictya confervoides, Hylocomium brevirostre, Taxiphyllum wissgrillii and Porella arboris-vitae var. arboris-vitae.

Michael Fletcher failed to find us after visiting Wells en route from Cheddar Gorge but did manage to see extensive Tortula papillosa on lime trees in the city.

9 April. In the morning Berrow dunes was disappointing in that the few wet areas in the dunes did not have the Riccia cavernosa and Petalophyllum ralfsii we tried to refind. In the dunes Tortula ruraliformis and Rhynchostegium megapolitanum were found. Frank Lammiman found Tortella flavovirens and Nick Hodgetts found Cololejeunea minutissima epiphytic in scrub in the dunes in only the second record for N. Somerset.

A pleasant final sunny afternoon was spent on Brean Down where no great surprises were seen on this well worked site. Amongst the bryophytes were Grimmia trichophylla, Pleurochaete squarrosa, Pottia starkeana ssp. conica, Scleropodium tourettii, Reboulia hemisphaerica, Trichostomum brachydontium, Funaria pulchella and Weissia levieri.

During the week more than 200 species of moss and 40 species of liverwort were seen and hopefully everyone enjoyed the North Somerset countryside. We managed to find only one new v.-c. record, though perhaps not unexpectedly, in a well-worked area. This is largely due to the previous thorough field work of the late Joan Appleyard.

I am grateful to the various bodies who gave permission to visit the sites and to participants in forwarding records to me.

PETER MARTIN


 

International Symposium on the Biology of Sphagnum


Exeter, 17-18 July (+ Field Meeting 12-16 July)

The first International Symposium on the Biology of Sphagnum was sponsored jointly by the BBS and the International Association of Bryologists (IAB) and was held at the University of Exeter on 17-18 July, 1991. It was preceded by a field excursion starting in Glasgow on 12 July.

The field excursion, with 36 participants, visited a number of sites where different habitat conditions and species of Sphagnum were seen. After an inauspicious start which meant that a planned visit to the Silver Flowe NNR could not be undertaken because the Cooran Lane was in spate and could not be crossed to reach the site, an alternative site was found on the Cairnsmore of Fleet. Standing high above Loch Grannoch, this provided an exhilarating, if fleeting, glimpse of Scotland before the journey south. Late afternoon provided a contrast at the lowland raised bog, Glasson Moss.

The following day provided an opportunity to see rarities in the British Sphagnum flora, with visits to Muckle Moss and Moor House, again two contrasting sites. A measure of the interest in these peatlands and their Sphagna can be gauged by th fact that we were too late for our evening meal in Lancaster. We were undeterred, and the following day saw equally intensive visits to the fen at Malham Tarn and degraded blanket bog on Featherbed top.

Chartley Moss was the main attraction of the following day before we pressed southwards ready to take in the valley mires of the New Forest and Dorset on the final day. This part of the meeting produced interesting finds to add to the Sphagnum flora of Britain (including the North American S. bartlettianum and S. andersonianum) and showed the value of bringing together in the field bryologists with different taxonomic cultures and with different experiences and conceptions of the same species.

The two days of papers in Exeter were attended by some 75 people. The intention was that the meeting should be wide-ranging and provide an up-to-date picture of current work on this important genus, but forcing eight crowded sessions into two days was something of a test of stamina. The participants stood up very well. Sessions covered were: taxonomy, biogeography, population genetics, physiology, physiological ecology, ecology, peat-forming systems and the interactions between Sphagnum and man. An opening survey on the history of Sphagnum studies by Hugo Sjörs and a closing session of crystal ball gazing by Dicky Clymo were especially appreciated.

The most gratifying thing about the meeting was that the high attendance brought together not only workers from different geographical areas, but also from different disciplines to provide a stimulating atmosphere for exchange of ideas and information. I look forward to the second Sphagnum symposium.

R.E.DANIELS


 

IAB Biennial Meeting: Experimental Bryology

Exeter, 19-24 July

A joint IAB/BBS meeting on this topic was held in the Hatherly Laboratories, University of Exeter from 19-24 July 1991, immediately following that on the Biology of Sphagnum. The programme was organised by Dr M.C.F. Proctor in consultation with Dr R.E. Longton, and Dr Proctor was also responsible for the excellent local arrangements. These included a most enjoyable Symposium dinner attended by all participants at both the Experimental Bryology and Sphagnum meeting, an exhibition of morris dancing, and field excursions to Wistman's wood and Fingle Bridge (21 July), and to Bicton Common and the Axmouth-Lyme Regis landslip (24 July). Approximately 50 bryologists attended the meeting. Invited and contributed papers were presented on three days and posters were on display throughout the meeting. The papers were arranged under six themes:

1. Physiology and metabolism. J.A. Lee (Manchester) gave the keynote address on the effects of airborne pollutants on growth and nitrate metabolism in Racomitrium lanuginosum. He was supported by S. Morgan (Manchester) who discussed responses of bryophytes to desiccation. The session also included papers by the home team on physiological and ecological implications arising from measurement of stable carbon isotope discrimination (M.C.F Proctor), and on biochemical aspects of desiccation tolerance (N. Smirnoff), and by S. Gagnon (Houghton, Michigan) on effects of ozone on photosynthesis and growth in Sphagnum.

2. Cell biology and fine structure. Rather surprisingly there were only two papers under this heading, by J.G. Duckett et al. (London) on protonemal morphogenesis in Sphagnum and by N.W. Ashton (Regina, Canada) on applications of polymerase chain reactions in bryophyte research.

3. Reproduction and control of development. After a stimulating review on the action of place-dependent growth suppression in liverwort morphogenesis (D. Basile, New York) papers were presented on experimental studies of variation in life-history traits in Polytrichum species (T.A. Hedderson and R.E. Longton, Reading) and on the life-history ofArchidium alternifolium at a reservoir in northern England (C.J. Miles and R.E. Longton, Reading).

4. Ecophysiology and experimental ecology. Studies on boreal and polar bryophytes figured prominently in this session, which included papers by D.H. Vitt and L.D. Gignac (Edmonton, Canada) on the response of bryophyte species and their potential in simulating the response of vegetation to climatic change, by R.I.L. Smith (British Antarctic Survey, Cambridge) on bryophyte colonisation of a recently deglaciated site in the Antarctic, and by H. Adamson el al. (Australia) on in situ levels of CO2 in colonies of Grimmia antarctici. Other papers were by J.W. Bates (Imperial College) on nutrient uptake and retention, and by J. Glime (Houghton. Michigan) on stresses of bryophytes at geothermal sites.

5. Biosystematics and population ecology. Martha Newton opened this session by gazing into her crystal ball and attempting to predict the state of bryophyte cytology in the year 2001. She was followed by three papers discussing variation in specific bryophytes, i.e. the polyploid, dioecious hepatic Marchantia globosa (H. Bischler-Causse, Paris), Meesia triquetra along a gradient from boreal to arctic regions of Canada (D. H. Vitt and J. Montagnes, Edmonton), and Sphagnum centrale in Poland (M. Krzakowa and I. Melasik, Poznan). Finally H. J. During et al. (Utrecht, Netherlands) described an experimental approach to the study of chalk grassland bryophytes.

6. Pollution and conservation. The final session began with a review by D.H. Brown and M. Sidhu (Bristol) on the effects of heavy metals on bryophytes. This was followed by papers by H. Adamson et al. (Australia) on the effects of cement-dust on the bryophytes at Casey Station, Antarctica, and by K. Satake (Tsukuba, Japan) on the ecology of the copper moss Scopelophila cataractae in Japan. The meeting was closed on an optimistic note by P. J. Beckett (Sudbury, Canada) who described the recovery of some bryophytes following a reduction in air-pollution around Sudbury.

A selection of the papers delivered at the meeting will be published in the Journal of Bryology.

R.E.LONGTON

 

AGM & Symposium Meeting 1991

Sheffield, 13-15 September

The Sheffield meeting was a return to our traditional format of AGM weekend meetings - with no special anniversaries or topics to consider in the symposium session. For all that it was a very successful meeting, due in no small part to the impeccable arrangements made by Tom Blockeel. The venue, Tapton Hall, was pleasant enough and - as one member noted - offered no nonsense service at no nonsense Yorkshire prices.

There are many interesting bryological sites of interest within striking distance of the city. Tom's local expertise and superb field knowledge showed through here. Surprisingly he took the meeting not west towards the Peak District but east, towards intensively farmed land. What initially appeared to be an unpromising and disturbed woodland turned out to be a marvellous site, holding many rarities.

I am also grateful to the speakers who provided an interesting day of talks covering tropical, temperate and laboratory bryophytes. As usual, accounts of the lectures follow, written by the speakers.

PHILIP LIGHTOWLERS


Mr J. GOODE (Royal Holloway and Bedford New College, Egham, Surrey): 'Caulonema, chloronema, rhizoids and plates in the moss protonema.'

Moss protonemata represent an ideal model system with which to answer fundamental questions in plant cell biology. They are small, grow rapidly, are relatively simple and can be easily cultivated under axenic conditions in the laboratory.

The moss protonema is the juvenile stage of growth of mosses, from spore germination until the production of the mature gametophyte shoot. Protonema are also produced by regeneration of either specialised vegetative reproductive propagules (gemmae), or of virtually any part of the moss plant. In the majority of protonemata, the spore germinates to produce a tip-growing filament which divides and branches, and eventually produces a gametophore shoot as a modified side-branch. This progression can be summarised as 1-D to 3-D.

Tetraphis pellucida and Sphagnum fimbriatum are different in that the protonema has an intermediary two-dimensional plate phase, produced from the filamentous phase and from which the shoot is formed; a 1-D to 2-D to 3-D progression. These mosses differ from each other in the mechanism of plate formation: in Sphagnum plates are formed at the tips of chlorophyllose filaments, and in Tetraphis they are formed as modified side branches.

There is a wide array of types of filaments in the protonema. Although in some cases the distinction between different types is clear-cut, absolute distinctions between filamentous types is ill-advised owing to the developmental plasticity shown by the protonema.

Although widely regarded as a simple phase of growth, some protonema exhibit quite complex structures. Dicranoweisia cirrata produces specialised protonemal gemmae by means of an abscission cell, and Bryum tenuisetum produces abscission cells which produce gemmae by fragmenting the chloronemal filaments. Other protonema, including Rhytidiadelphus loreus and Bryum flaccidum produce unspecialised gemmae by sub-apical cell divisions and the subsequent rounding off of cells to form short fragments of 'brood cells'. If these are then transplanted to fresh media they regenerate in a manner similar to the regeneration of gemmae.


Dr T.A. HEDDERSON (University of Reading): Influences of size, phylogeny and water relations on life history variation in mosses.'

Life histories (the combination of age-specific fecundities and survival probabilities which organisms display in some particular environmental context) are of great interest to evolutionists since they define the operation of the joint processes of natural selection and adaptation. Physiological and energetic realities mean that life history traits will be involved in trade-offs (e.g. Schaffer, 1974; Stearns, 1976) and should thus co-evolve to yield adaptive 'tactics' in specific ecological contexts (e.g. Stearns, 1976; Brown, 1983).

Comparative approaches have been widely used to identify such tactics, generally emphasising the importance of age-specific mortality or spatio-temporal patterns of resource availability to selection on life histories (Harper, 1967; Southwood, 1977; Stearns, 1976). However, other ecological factors may be important, and traits may be constrained allometrically, or by peculiarities of physiology or development in some organisms (see review in Stearns. 1980). Furthermore, phylogenetic effects seem to be pervasive, suggesting that microevolutionary forces acting on life-histories are constrained within larger phylogenetic lines.

The existence of such a suite of interacting factors has important implications for comparative approaches to the study of life histories, and raises a number of questions relating to the existence of life history tactics and our perception of them. This analysis addresses five of these questions for a group of mosses: 1) Does taxonomic level significantly affect life history variation? 2) Does covariation of life history traits depend on taxonomic level or phylogenetic affinity? 3) What are the relationships of life history traits and their patterns of covariation with gametophyte size? 4) Is there a relationship between life history variation and morphological variation associated with water relations? 5) Are phylogenetic effects mediated by difference in size or water relations among taxonomic groups?

The analysis included a total of 336 species from the Pottiales, Funariales and Polytrichales, representing nine families and 52 genera, for which data were available on five life history traits (i. sexuality, ii. presence or absence of specialised asexual reproductive diaspores, iii. longevity, iv. median spore diameter, v. number of spores per capsule (estimated as the ratio of capsule volume to spore volume minus 35% for interspore space)), size (the only readily available measure is maximum length of the female gametophyte), and five water relations traits (i. growth form, ii. stem structure, iii. leaf papillosity, iv. nature of the leaf margin, v. nature of the leaf apex).

Univariate and Multivariate Nested Analysis of Variance revealed strong taxonomic effects on individual life history traits and the ways in which traits covary. Principal Components Analyses within orders and families also show that the ways in which life history traits covary differs among higher taxonomic levels. Size has only a small effect on variation in individual life history traits, and regression analyses yielded either non-significant or low R² values.

A Canonical Correlations Analysis was used to examine joint variation among life history and water relations traits. This analysis revealed a clear relationship between life history variation and variation in morphological design associated with differing water relations. The first Canonical Variate from the water relations set ranks species from those with poorly developed water uptake and/or retention mechanisms. The life history Variate associated with it ranks species from those that are small, short lived, and produce few large spores to those with the opposite suite of traits. Variation on the water relations Variate accounted for 70% of variation on the life history Variate. Plots of species on the first pair of Canonical Variates revealed again the influence of phylogeny, with each family occupying a unique region of the reduced space. The relationship between water relations and life history seen across all species is sometimes weakened when examined across species within families.

After statistically removing the effects of size and water relations by Analyses of Covariance and Regression procedures, all phylogenetic effects noted earlier still persist.

Patterns of life history variation seen across species may result from a number of co-acting factors including phylogenetic inertia, ecological forces and allometrically forced relations with size. The influence of phylogeny is particularly great and phylogenetic information needs to be included explicitly as part of comparative analyses.

References

Brown, K.M. (1983). Do life history tactics exist at the intraspecific level? Data from freshwater snails. Am. Nat. 121: 871-879.

Harper, J.L. (1967). A Darwinian approach to plant ecology. J. Ecol. 55: 242-270.

Schaffer, W.M. (1974). Optimal reproductive effort in fluctuating environments. Am. Nat. 108: 783-790.

Southwood, T.R.E. (1977). Habitat, the templet for ecological strategies? J. Animal. Ecol. 46: 337-365.

Stearns, S.C. (1976). Life history tactics; a review of the ideas. Quart. Rev. Biol. 51: 3-47.

Stearns, S.C. (1980). A new view of life history evolution. Oikos 35: 266-281.


Dr S. RUSSELL (British Antarctic Survey, Cambridge): 'Bryofloristic relationships within southern African forests.'

The degree of uniformity shown by the vascular flora of the inland forests of southern and eastern Africa has led to the inclusion of this vegetation in a single 'Afromontane' phytochorion. Recent improvements in knowledge of the bryoflora of the region - particularly in Tanzania and South Africa - permit a more detailed understanding of biogeographic relationships among the 'islands' of forest vegetation that occur in the Afromontane 'archipelago', viz.:

  1. A far larger proportion of southern Africa's bryoflora occurs in the forest biome than is the case for the vascular flora.
  2. The drop in forest species numbers from the Equator to the Cape is not as evident among bryophytes as it is for vascular plants.
  3. Many bryological examples can be cited to support the diminution in numbers of tropical species southwards, and temperate species northwards along the Afromontane chain. However, the trend is not as marked among mosses and liverworts as it is with the vascular plants.
  4. Adjacent forest regions show an average 50% greater similarity when compared on the basis of their bryofloras rather than the flowering plants alone. Concomitant lower levels of endemicity are displayed by the forest regions, when their total flora is considered.

A low apparent degree of affinity between the forests of Malawi and those of neighbouring Zimbabwe and Tanzania may at present be explained by the poor knowledge of the Malawian bryoflora. This situation will be remedied as results become available from several collecting expeditions to the Malawi-Zimbabwe region that are taking place during the early 1990s.


Mr B.J. O'SHEA (London): 'Beginner's guide to tropical bryology - the BBS Tropical Bryology Group trip to Mount Mulanje, Malawi.'

The BBS TBG stated some time ago its wish to organise a tropical collecting trip, and the activity on Bryologia Africana (the new African flora) and the current gap in our knowledge of African bryophytes - the 'Malawi gap'- served to make Mount Mulanje in Malawi the target.

The expedition numbered nine botanists - three academics, two herbarium staff, three conservationists and one amateur. Three of the party were from Africa, and the leader, Shaun Russell, moved from Africa to England during the course of organising the trip.

The trip took place from 12 June to 4 July 1991, and was based at the National Herbarium and Botanic Garden, Zomba, which also provided logistic help. We were on the mountain for 12 days, with 3 more days around the base.

The base of Mount Mulanje is at about 800 m, and at this height it is about 26 x 22 km in size. The plateau area of rolling grassy uplands, intersected by deep forested ravines and gullies, is at about 1800 m to 2100 m. Above the plateau are deeply fissured boulder-strewn rock slabs and walls, and there are 20 peaks that exceed 2500 m. The highest peak is Sapitwa at 3002 m.

It is a popular walking area and there are well-marked paths, and huts to stay in (the paths and huts being maintained by forestry staff). The rock is largely granitic, giving landscapes reminiscent of Scotland, but particularly to the south of the mountain there are areas of rain forest in the ravines and on the south-facing cliffs.

Bryophyte collecting in Malawi was until recently very limited, and Mount Mulanje is probably the richest area. Before the expedition, there were only 205 mosses and 97 hepatics recorded from Malawi, of which 98 and 59 respectively were from Mount Mulanje.

The expedition covered a large area of the mountain, and collected about 4500 packets from a wide variety of habitats. Some of the areas of the mountain damaged by agriculture and forestry were visited, with the aim of providing evidence of the reduction in bryophyte numbers in such areas. The disturbed areas were clearly less rich, and this underlined the concern of the authorities about deforestation on the mountain - several hundreds of lives were lost earlier this year on the NE of the mountain owing to landslides, widely blamed on deforestation, and the water supply of much of southern Malawi depends on water captured by Mount Mulanje.

Our collections are now being catalogued at Reading University Herbarium, and the task of identification is now about to begin. We hope that out results will add to the pressure for making Mount Mulanje a National Park and a Biosphere Reserve.


Ms A.J. RUSSELL and Prof D.J. COVE (University of Leeds): 'Studying protonemal development using time-lapse video recording. '

Physcomitrella patens is being used for studies of development in Leeds because, as in other Funariales, the pattern of development from newly regenerated protonema to the formation of gametophores is marked by clearly defined transitions from one cell type to another. The apical protonemal cells respond to environmental stimuli in a similar manner to higher plants. The techniques of genetic analysis, including the isolation of developmental and physiological mutants, are being used to study the role of plant hormones in development and the molecular basis of tropic responses.

Time-lapse microscopy has previously been used to study the gravitropic response of moss filaments grown in the dark. We have now developed a method of filming protonema in the light to enable more detailed observation of light-mediated steps in development and to obtain data on their timing. To avoid the problems of unnatural growth of filaments caused by their confinement on a microscope slide and/or the continual perfusion of liquid medium, cultures are grown on a thin layer of agar surrounded by deep agar, and filmed using an inverted microscope.

Using this technique we have been able to obtain data on the comparative growth rates and cell cycle times of chloronema and caulonema and film the transition from one cell type to another. The hypothesis that the timing of the cell cycle is related to cell volume can be tested.

Spore germination and the regenerative effect of light on dark-grown filaments have been compared. The increase in mitotic activity and lack of a polar direction of side-branch initiation has lead to the hypothesis that spore germination and cell regeneration represent a preferred starting point for development.

The plant hormone cytokinin, which at certain concentrations causes a massive increase in budding in the moss, is known to have a promotive effect on cell division. It has been possible, using time- lapse, to compare the first cell divisions of natural buds with those of cytokinin-induced buds. We found no increase in the timing of cell division in response to cytokinin. While the initial steps in bud formation such as the movement of chloroplasts into the apex of an initial and the formation of the vacuole in the stalk area appear to be the same in both cases, the subsequent pattern of cell division in natural bud formation is disrupted by the addition of cytokinin. Particularly noticeable is the inhibition of the early development of rhizoids.

We are planning to use this technique to film the effects of specific inhibitors on growth. From observations of these and normal cellular events we hope to gain more insight into developmental mechanisms.

Reference

Knight, C.D. and Cove, D.J. (1988). Time-lapse microscopy of gravitropism in the moss Physcomitrella patens. In J.M.GIime(ed.), Methods in Bryology, pp. 127-129. Hattori Botanical Laboratory, Nichinan, Japan.


Mr G. ROTHERO (Dunoon, Argyll): 'The bryophyte dominated snow-beds of the Scottish Highlands.'

As a result of ideas mooted by the conservation committee of the BBS and taken up (and paid for!) by the NCC in Scotland, I spent the summers of 1989 and 1990 visiting a substantial proportion of the hills in the Highlands where the snow lies into mid-summer or later. The first year concentrated on the Cairngorm area and the second covered as much as was possible of the rest. A bryophyte species list with an assessment of relative abundance was compiled for each site and a series of quadrat samples recorded for community analysis.

Broadly speaking, the major division of sites is between the deep coire sites with a high amplitude of relief, crags and block scree and the 'nivation hollow' type of site with rounded features, low relief and large areas of fine substrate. The former occurs widely but the latter is concentrated on the Cairngorm plateau with outliers in the Ben Alder Forest and on Creag Meagaidh. The 'coire type' site, with its great variety of habitat, often has the most impressive species lists, but the best examples of the snow-bed bryophyte communities come from the finer, more uniform substrates of the 'nivation hollow' sites.

Where the substrate is fine and is subject to frost-heave then the vegetation is likely to be some form of Marsupella brevissima - Anthelia juratzkana snow-bed, often in the form of a wrinkled crust of small hepatics. Within forms of this community some very rare plants occur. Marsupella condensata can be abundant on some Cairngorm sites, and on Creag Meagaidh and Ben Lawers both male plants and sporophytes occur occasionally. Other rarities which seem to have a more sporadic occurrence are Marsupella arctica, M. sparsifolia and Gymnomitrion apiculatum - though the last two are exceedingly difficult to pick out in the field.

Where the substrate is more stable but still relatively fine, large stands of the Polytrichum sexangulare - Kiaeria starkei snow-bed occur, particularly in melt-water channels. These may be dominated by one or the other of the mosses, the largest pure stands being of Kiaeria starkei, sometimes covering over 100 m². Often associated with this community are stands of Moerckia blyttii and Pleurocladula albescens, as well as large cushions of more cosmopolitan species like Cephalozia bicuspidata, Nardia scalaris and Barbilophozia floerkei. Where the substrate is permanently irrigated there can be large areas dominated by Pohlia ludwigii snow-bed, visible from a distance as a bright green carpet, often bordering burns.

In spring communities associated with melt-water, spectacular and very visible stands of Pohlia wahlenbergii var. glacialis may occur, often at some distance from the snow-beds themselves. Scapania paludosa occurs as cushions in springs at the base of block scree (where it may grow with Rhizomnium magnifolium). Rather more remote from the late snow but irrigated by melt-water, a small number of mires contain substantial populations of Sphagnum lindbergii.

On rocks associated with the areas of late snow-lie a number of interesting Andreaea species occur. Andreaea nivalis can be abundant on rocks in burns, on crags with permanent irrigation and on irrigated gravel. This level of abundance is limited to the Cairngorms and the Ben Nevis- Aonachs massif. In one or two of the larger melt-water burns in the Cairngorms Andreaea frigida is common, occurring with Andreaea nivalis. On flat rock surfaces in the areas of latest snow-lie, Andreaea blyttii can be abundant and is certainly widespread. This species is easily picked out and it is a puzzle as to how it has been overlooked in the past.

On the crags and screes in the coires a few more interesting species occur. Marsupella boeckei var. boeckei forms green wefts on irrigated steep rock faces and bears little resemblance to the var. stableri which is common. Brachythecium glaciale, B. reflexum and, more rarely, Lescuraea patens can be found, usually associated with the litter of the fern Athyrium distentifolium in the block scree. Irrigated rocks in one or two coires have Hygrohypnum molle, H. smithii and in one case Hygrohypnum styriacum, a surprising addition to the British flora.

All of these sites are wonderful places, most are remote and, in their snowy garb for most of the year, seem inviolate. The tiny total area involved (some 160 to 200 hectares seems a reasonable estimate) makes the snow beds vulnerable. The major threat is amply demonstrated by a visit to the Cairngorm plateau on a good day in the summer; today it is possible to count hundreds of walkers where only ten years ago there would only have been a handful. A similar situation has already arisen on Aonach Mor and Aonach Beag in the Nevis range. The increase is due to the ease of access provided by the skiing facilities which depend on summer income for their existence. A pro-active management policy for the high hills is an urgent issue.


Mr N. HODGETTS (Joint Nature Conservancy Council, Peterborough): 'Bryophytes in the new conservation agencies.'

In the Environmental Protection Act 1990, the Nature Conservancy Council was reorganised into four separate bodies; English Nature, the Nature Conservancy Council for Scotland (soon to become Scottish Natural Heritage), the Countryside Council for Wales and the Joint Nature Conservation Committee (JNCC). The lower plant specialist post went to the Species Conservation Branch of the JNCC. The JNCC was set up to deal with Great Britain-wide issues that could not be dealt with effectively on a country-by-country basis. For example, legislative matters, setting standards for survey, monitoring and site selection, advice to government, liaison with national voluntary organisations (such as the BBS), coordinating conservation initiatives and international matters.

Within the JNCC, the Species Conservation Branch has special responsibility for legally protected species, reviewing the schedules of the Wildlife and Countryside Act 1981, Red Data Books, the National Vegetation Classification, the Invertebrate Site Register and lower plant conservation.

Current bryophyte work in the JNCC includes selection of rare species to recommend for addition to the schedule of fully protected species in the Wildlife and Countryside Act: 31 species have been submitted. The Red Data Book (RDB) project is well under way, and a RDB for bryophytes should be produced in 1993-4. Other proposed publications currently being worked on include SSSI selection guidelines for lower plants (in use but not yet published), field guides to selected groups, popular pamphlets to promote lower plants and management guidelines. Monitoring rare and threatened species is another aspect of the JNCC's work. International groups with JNCC involvement such as the IUCN bryophyte specialist group and the European Committee for the Conservation of Bryophytes also have a number of initiatives under way.

The JNCC research programme has yet to be finalized but proposals include grazing experiments, climate change monitoring, ecological studies on oceanic bryophytes, the development of work on lower plant community types and ensuring adequate representation for bryophytes in the Nature Conservation Review.

Recent work in the country agencies has included bryophyte surveys in western oceanic woodlands and snow patch vegetation in Scotland. Proposed work includes further woodland surveys, monitoring projects and pollution studies. Initiatives such as the BBS Recorders Scheme and the activities of Plantlife are also likely to give bryophyte conservation a boost.

In conclusion, bryophyte conservation does not seem to have suffered significantly from the reorganisation of the NCC, and may actually benefit in the long run. In particular, the international scene is developing well, sites are being afforded protection specifically for their bryophytes and professional conservationists are coming to terms with the idea of conserving bryophytes, even embracing it enthusiastically.


Field Excursion, 15 September 1991

The meeting visited two sites on the Magnesian Limestone east of Sheffield. Although the countryside here is less attractive than in the Peak District to the west, the limestone is relatively little known to bryologists and it supports some very interesting communities. The naturally dry climate was exacerbated on this occasion by two months of almost unbroken drought, and conditions were not good for field work.

The first site was at Anston Stones Wood between South Anston and Worksop. This important wood occupies a small steep-sided valley along the busy A57 road, and it is traversed by a railway line and a rather polluted stream! Nevertheless, the wooded banks, with low crags and limestone boulders, continue to support rich bryophyte communities.

Some species which are more characteristic of the wetter uplands manage to survive here, though not very luxuriantly. These include Scapania aspera, Apometzgeria pubescens, Distichium capillaceum, Tortella tortuosa and Neckera crispa. On the other hand there are also species present which have a broadly Mediterranean or Mediterranean-Atlantic distribution. Tortula marginata is one of these: it is a rarity in northern England, but it is a characteristic species of Magnesian Limestone woods. More surprising is the occurrence of Marchesinia mackaii. The station here is one of four recently discovered in the area where Yorkshire, Derbyshire and Nottinghamshire meet. The known population was seen and a new one located on the northern side of the wood. In both places it is accompanied by Cololejeunea rossettiana. Perhaps even more remarkable, in view of its great rarity in Britain, is the occurrence of Anomodon longifolius. This was relocated on the boulder where it was found a few years ago. There is just a single patch of it, associated with A.viticulosus, but it appears to be holding its ground.

Other locally rare species which were seen in the wood included Leiocolea badensis, Fissidens cristatus, Eucladium verticillatum, Gymnostomum calcareum, Homalia trichomanoides and Isothecium myurum. Amblystegium compactum, growing as it so often does on dark damp ledges at the bottom of an overhanging crag, attracted a lot of attention. A new record for the wood was Ephemerum serratum var. minutissimum, collected by Jeff Duckett on a damp path by the stream. Some members commented on the species which were not present. There was no Lejeunea (though this is known in small quantity on Magnesian Limestone over the Derbyshire border) and there was no Porella platyphylla. Epiphytes, in this dry and polluted district, were almost non- existent.

In the mid afternoon, a reduced party moved on to the Don valley at Sprotborough near Doncaster, to pay respects to Desmatodon cernuus at its best (and perhaps the only reliable) British site. A large quantity of the species was demonstrated on a railway embankment, the setae so dense in some of the patches as to colour the ground. Many of the capsules, however, had been lost, presumably grazed by invertebrates. This population is restricted to a small area covered with highly calcareous matter, about which there was much speculation. Further plants occur a little distance away on the bank of the riverside track. The locality is in a derelict area of old quarries, which are soon to be used for tipping, but the site on the railway embankment is presumably safe from destruction. Other species seen included Leiocolea badensis and Aloina aloides.

T.L. BLOCKEEL


Autumn Workshop 1991

Rogate, 11-13 October

 

 

A taxonomic workshop - bryophytes for beginners and intermediates - was held at the Rogate Study Centre over the weekend of 11-13 October, and led by June Chatfield, Alan Crundwell, Francis Rose and Rod Stern and attended by 22 participants.

The first morning, led by Francis Rose, was spent at Rondle Wood, north east of Rogate, investigating a sweet chestnut coppice, oak wood and sunken lane on acid sandy soil. The usual common mosses of acid woodland were found - Atrichum undulatum, Dicranella heteromalla, Dicranum scoparium, D. majus, Hypnum cupressiforme, H. jutlandicum, Mnium hornum, Orthodontium lineare, Pleurozium schreberi, Polytrichum formosum and Tetraphis pellucida. One of the more unusual finds was Leucobryum juniperoideum, occurring with the more common and somewhat larger L. glaucum on and around chestnut stools of the coppice. On more open ground by the path near the top of the scarp, heathland species occurred -Campylopus introflexus, Ceratodon purpureus, Pohlia nutans and Polytrichum juniperinum. The north grassy bank of the track running west had much Barbilophozia attenuata, Cephalozia connivens and C. lunulifolia.

A sandy sunken lane under beeches through Common Wood to the road at Harting Combe (41/815257) proved particularly rich in liverworts - Calypogeia muelleriana, Cephalozia bicuspidata, Diplophyllum albicans, Lepidozia reptans, Lophocolea bidentata and L. heterophylla. Francis Rose showed us an extensive patch of Bazzania trilobata, a liverwort rarely found in lowland England. It often associates with the moss Dicranum majus, and such was the case at Combe Wood. Plagiothecium undulatum was also found on this bank.

A late afternoon foray into the churchyard at Rogate yielded a different range of species including many of the smaller calcicole acrocarps - Barbula convoluta, B. revoluta, B. tophacea, B. trifaria, B. unguiculata, B. vinealis, Grimmia pulvinata and Tortula muralis. Hypnobryales on walls and in turf were: Brachythecium rutabulum. Eurhynchium praelongum, Homalothecium sericeum, Rhytidiadelphus squarrosus and Lunularia cruciata. The pteridophyte Selaginella kraussiana, a non-native species which looks like a moss, was present in turf.

On the sandy bank at the entrance gate to the Rogate Study Centre were some patches of the local Reboulia hemisphaerica, indicating a less acid soil here.

Sunday morning, led by Rod Stern, was spent on Iping Common seen in a mist, scenic with webs of spiders. The heathland had been severely affected by fire in 1976 and its bryophyte flora was still limited, but a rich flora remained intact in the bog in the valley below (41/850218). Sphagnum was particularly well represented at this site with eight species of different colour and growth form - S. compactum, S. papillosum, S. magellanicum, S. tenellum, S. recurvum var. mucronatum, S. cuspidatum, S. auriculatum and S. capillifolium with two other typical bog mosses - Aulacomnium palustre and Polytrichum commune. The Sphagnum cushions in the bog provided a good habitat for leafy liverworts - Kurzia pauciflora, Cladopodiella fluitans, Cephalozia macrostachya and Mylia anomala.

A final visit was made to Tullecombe Wood descending to wet woodland in Harting Combe. Woodland species of Sphagnum were found in an alder swamp - S. palustre, S. auriculatum and S. recurvum var. amblyphyllum. There were also lush growths of Plagiomnium undulatum and of the horsetail Equisetum sylvaticum in this habitat.

Within a short distance of the Study Centre, a good range of bryophyte habitats was found which kept up the variety in the species at each site. The Centre is owned by Kings College, London, and provides residence and excellent laboratory facilities: it is available for hire by parties and also runs its own programme of weekend field courses. For details contact The Rogate Study Centre, The Red House, Rogate, Nr Petersfield, GU31 5HN.

JUNE CHATFIELD

 
 
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