Meeting report

Bryological symposium

The University of Loughborough was the venue for this year’s AGM and symposium meeting. Thanks are due to the local secretary, Dennis Ballard, who organised the weekend very ably and made sure that everything ran smoothly (or sorted it out when it didn’t!). As seems to be the norm in recent years (global warming?), the day of the field excursion was warm and sunny, and a good contingent of members were shown that even the Midlands can be bryologically interesting.

Nick Hodgetts

Mr Dennis Ballard (Leicester): Bryology in Leicestershire

The Charnwood Forest area of Leicestershire, where John Ray reported the finding of rare cryptogams in the 17th century, was described. Dr Richard Pulteney (1730-1801), an apothecary, provided the first real account of the vascular and cryptogamic flora of the Charnwood Forest, Loughborough and Leicester. The Rev. George Crabbe (1754-1832) collected and recorded in north-east Leicestershire. Their works were published in Nicol’s 1795 History of Leicestershire. Several clergymen continued the collecting and recording in the 19th century. With the formation of the Leicester Literary and Philosophical Society in 1835, botany was put on a firm base, with a few other botanists continuing to advance bryology. The publication of their work was quoted. The activities of the Society and the Leicester Museum, which opened in 1849, resulted in the production of the 1863 Flora. Separate herbaria were maintained by the two organisations. In the 20th century a new generation of botanists carried bryology forward. Floras were produced in 1909 and 1941, and several papers published. It was not until 1984 that recording was carried out in a systematic way on a tetrad basis. More work is required before a comprehensive bryophyte Flora can be produced. Records are available at present from about one third of the 617 tetrads in Leicestershire.

Dr Terry Hedderson & Dr Royce Longton (University of Reading): Morphological and genetic variation in the cosmopolitan moss Bryum argenteum Hedw.

Bryum argenteum is probably the world’s most widely distributed plant species, extending from continental Antarctica through the lowland tropics to the high Arctic. Something of the wide variation in microclimatic conditions experienced by different populations of this species was demonstrated by data showing summer moss-level temperature regimes at three polar and boreal forest sites; modal values for temperature during the day ranged from 0ºC on Ross Island, Antarctica, to 20ºC at Pinawa, Manitoba. Clones isolated from these populations nevertheless showed strikingly similar relationships between temperature and growth. All grew slowly at a day/night temperature regime of 9/1ºC, and fastest at 22/15ºC, with evidence of heat stress at 30/30ºC. This is consistent with the temperature relationships of CO₂ exchange in an Antarctic population, in which the optimum temperature for net assimilation at light saturation was 25ºC (Rastorfer, 1970). Antarctic and tropical (Hawaii) clones both survived but grew very slowly at 5/-5ºC. Similarly, North American B. argenteum from normal and metal-contaminated soils showed similar levels of tolerance to copper and cadmium, whereas in Funaria hygrometrica there was evidence of genetic adaptation in this respect (Shaw, 1991).

These physiological responses thus give the impression that B. argenteum may exist as a small range of ‘multi-purpose genotypes’. However, collateral cultivation experiments have demonstrated extensive morphological variation in features such as nerve length and shape of the leaf apex. Some of this variation is apparently random, but plants with strikingly obtuse leaf apices and abundant bulbils have been isolated from both Arctic and Antarctic sites. There is also evidence that the excurrent nerve giving many colonies in dry habitats a characteristically hoary appearance (var. lanatum) is maintained in cultivation, in isolates derived both from gametophytes and from spores, although with no discontinuity in the range of variation between these forms and var. argenteum. Moreover, a study of the nuclear-encoded rRNA internal transcribed spacer (ITS) region in B. argenteum and related species showed that much of the total variation among these taxa resides within B. argenteum. Indeed, genetic distances between some populations of this species were greater than between those of some species traditionally assigned to different genera, a finding with important implications in terms of conservation strategies (Longton & Hedderson, in press). High levels of within- and between-population variation in RAPDs has also been reported in B. argenteum from the Antarctic and Australasia (Stotnicki, Ninham & Selkirk, 1998), emphasising the complexity of genetic variation in this most familiar of moss species. Beware lest familiarity breeds contempt!

References

Longton RE, Hedderson TA. In press. What are rare species and why conserve them? Lindbergia.

Rastorfer JR. 1970. Effects of light intensity and temperature on photosynthesis and respiration in two East Antarctic mosses, Bryum argenteum and Bryum antarcticum. Bryologist 73: 544-556.

Shaw AJ. 1991. Ecological genetics, evolutionary constraints, and the systematics of bryophytes. Advances in Bryology 4: 29-74.

Stotnicki ML, Ninham JA, Selkirk PM. 1998. High levels of RAPD diversity in the moss Bryum argenteum in Australia, New Zealand and Antarctica. Bryologist 101: 412-421.

Dr David Holyoak (Camborne): Tetrad recording of bryophytes in VC 1

Recording of the distribution of bryophytes in West Cornwall and the Isles of Scilly (vice-county 1) by tetrads (2 x 2 km squares) was begun in 1993. Well over half of the tetrads have now been visited, with a total of 340 full days spent in 242 tetrads.

By means of numerous repeated visits to each of several tetrads, it was found that two hours recording effort per tetrad was sufficient to find at least 50% of the bryophyte species revealed in the same tetrads by ten hours of searching, but that a few additional species continued to be added even after 15 hours of searching. These results emphasise that field recording of bryophytes is a process of sampling, and that complete coverage of any large area is unattainable. Hence, in order to offer the prospect of increased reproducibility in any future surveys, the time (hours) spent searching in each tetrad and the range of habitats searched are being recorded. Practical considerations and the aim of achieving reasonably even coverage have led to a ‘rule’ that each tetrad is sufficiently searched when all the main bryophyte habitats have been investigated, a total of at least two hours has been spent searching, and more than 50 moss species have been found. Allowing for travel, microscopic checking of material, and input of data onto computer, this ‘rule’ allows one tetrad to be completed in a single, rather long, working day.

The Atlas of the Bryophytes of Britain and Ireland (Volume 1, 1991) described Cornwall as ‘exceptionally well covered’, but recent fieldwork has yielded 22 new and five updated vice-county records (approximately one for every 34 hours of fieldwork). These new finds emphasise that knowledge of our bryophyte flora is still much less complete than that of vascular plants. In volume 2 of the Atlas (1992), Alan Crundwell’s ‘guess’ was that the distribution maps gave two-thirds of potentially available records in 10 km squares, and this now seems approximately correct for VC 1 if we make the reasonable assumption that there must still be much more left to find. However, given that VC 1 was ‘exceptionally’ well covered it would appear that the estimate of national coverage of 10 km square records should perhaps be reduced from two-thirds to a half or less.

Mapping distributions on a tetrad scale allows patterns of occurrence in relation to environmental factors to be studied in more detail than is possible using data mapped at 10 km or 5 km grid scales. Nevertheless, many of the more detailed patterns found from tetrad studies in VC 1 were to be expected, such as Grimmia trichophylla being found mainly on hard rock outcrops (and walls and gravestones) or Syntrichia ruraliformis (Tortula ruralis ssp. ruraliformis) occurring mainly on dunes. Likewise, the occurrence of certain species (Schistidium maritimum, Tortella flavovirens) only on the coast was easily predicted, although their presence beside sheltered tidal creeks well ‘inland’ was not. More surprisingly, several species appear to avoid a zone within several kilometres of exposed coasts, among them Ditrichum cylindricum, Pseudephemerum nitidum, Orthotrichum affine, Pleurozium schreberi and Ulota bruchii (U. crispa var. norvegica), possibly because they are intolerant of excessive salt-spray. When ‘standardised’ data have been recorded for all tetrads it is intended to investigate some of these distribution patterns statistically.

Mrs Jean Paton collected detailed data on bryophytes over much of Cornwall during the 1960s that she has generously made available for comparisons with the data from the past five years. Several species show marked increases or decreases over this period of approximately 30 years. Among the most obvious increases are those of Campylopus introflexus, which has ‘filled in’ a pattern of distribution the outlines of which were already nearly complete by 1960. A more surprising increase is that of Zygodon conoideus, which has become much commoner relative to Z. viridissimus. Increase of Z. conoideus elsewhere in southern England has been attributed to a reduction in sulphur dioxide pollution, but this explanation cannot be true over much of West Cornwall where there were never high levels of SO₂. A recent increase in nitrogen deposition on bark seems a more likely explanation for the increased abundance of Z. conoideus, at least in Cornwall, since this species commonly occurs on nutrient-rich bark types such as that of Elder Sambucus nigra. Among the most conspicuous decreases since the 1960s are those of several species that grow on acidic rocks, especially Andreaea rothii, Racomitrium aquaticum and R. fasciculare. Increased nitrogen deposition on rocks may offer the most likely explanation for the decreases of these species.

Dr Angela E. Newton (Natural History Museum, London): Mosses and cladograms: floristic and phylogenetic explorations in the Americas

After a long absence from England and the British Bryological Society, twelve years of study, research and field work in the Americas were summarised, with slides of bryological habitats in different areas visited.

Duke University, in the Piedmont of North Carolina on the east coast of the United States, is situated in an area of mixed deciduous and coniferous forests. The very hot, humid summers (often over 35ºC and 95% humidity) are not conducive to bryophyte growth in the heavily-shaded forests, but in more open areas such as rocky outcrops, and in the mountains, there is more diversity. Research projects included a phylogenetic study of relationships in the tropical moss family Pterobryaceae, especially of the largely neotropical genus Pireella. Characters useful for defining the species show conflicting patterns of relationships between the species. These and additional characters were studied in depth for use in cladistic analysis, allowing the relationships between the species to be resolved (Newton, 1993 & papers in prep.) This work led to further detailed study of characters such as branching architecture in pleurocarpous mosses, and of relationships between the families of the Leucodontales.

A different group of studies involved the influence of mature plants on the germination of spores and vegetative propagules, and the evolutionary role of asexual reproduction (Mishler & Newton, 1988; Newton & Mishler, 1994). Fieldwork included long trips to the south-western states and to Costa Rica, Panama and Colombia, where many fine bryophytes were seen in a range of desert, forest and montane habitats.

A move to the National Museum of Natural History (NMNH) in Washington DC, and involvement in the Biological Diversity of the Guianas Program, led to opportunities for field work in Guyana, in northern South America. Guyana currently has very large areas of untouched lowland rainforest, but like many such areas, is threatened by logging companies. Travel to the interior involves flights on small planes to very short airstrips, where cows on the runway can be a serious hazard. Further travel is then normally by dug-out canoe or on foot, and sleeping accommodation consists of hammocks, with mosquito nets an absolute necessity. One can get very stiff after eight hours sitting on a wooden plank in a canoe, broken only by portage of equipment round a waterfall. But the continually changing riverbank, with towering forest trees, riverine birds, and numerous pale yellow butterflies following each other in long undulating lines, more than compensates. Although the recorded moss diversity is not high (ca 315 species – Boggan et al., 1997) new distributional records include species very common elsewhere in the neotropics (Hypopterygium tamariscinum and Schoenobryum gardneri), indicating that more collecting needs to be done before we can be confident that the flora is well known. Floristic studies based on political rather than biogeographic regions do not necessarily reflect biological processes, so this project also includes collating records from eastern Venezuela and northern Brazil, which together with the Guianas constitute the Guayana Highlands. An additional small project at NMNH involved studies of mosses and liverworts in amber from the Dominican Republic. The age of these collections is uncertain, but they are probably between 20 and 30 million years old. However, many of the plants found are very similar or virtually identical to extant species.

The last year was spent in Mexico, working at the Institute of Ecology in Xalapa, Veracruz. The Institute is 19º north of the equator, at 1400 m altitude (slightly higher than Ben Nevis), so all year round there is normally hot sunshine, cool nights, and frequent rain and mist, making very good conditions for mosses. The natural environment includes forests of deciduous trees, such as oaks, elms and beeches, with tropical evergreen trees and epiphytic bromeliads, and at higher altitudes forests of alders and conifers. A lot of the forests have now been replaced by coffee and citrus plantations, but nevertheless the area is rich in tropical moss families such as the Meteoriaceae, Pterobryaceae, Hookeriaceae and Calymperaceae. Research carried out here, in collaboration with Dr Efrain DeLuna, was a continuation of work on morphological characters and family relationships in the Leucodontales, started at Duke, and forms part of an international collaborative project studying the relationships of all green plants. Both morphological data and molecular sequence data from rbcL were used in cladistic analyses of the pleurocarpous mosses. Part of this work involves further studies of complex character systems, including rhizoid distribution and structure, axillary hairs, the elements of branching architecture, and the ontogeny of the foot-vaginula-calyptra complex (Newton & DeLuna, papers in revision). Field trips to collect plants for research produced several new distributional records for Mexico, Veracruz or Chiapas. The most recent field trip, to the rainforests of Chiapas in south-west Mexico, involved flights in a six-seater, single-engine Cessna, to land on airstrips that looked like rough pasture complete with tall weeds and grazing horses! But solar cells on the roofs of the field stations provide the amazing luxury of 24-hour, silent electricity, with no diesel fumes or roaring generators. The representation of moss families in the areas visited seemed quite different from the Guianas, with more species of Hypnales but relatively few species of Hookeriales and Calymperaceae.

Back in England, at the Natural History Museum, work will continue on several of these projects, with collaborators both here and abroad.

References

Boggan J, Funk V, Kelloff C, Hoff M, Cremers G, Feuillet C. 1997. Checklist of the plants of the Guianas, 2nd edition. Washington: Biological Diversity of the Guianas Program, Smithsonian Institution.

Mishler BM, Newton AE. 1988. Influences of mature plants and desiccation on germination of spores and gametophytic fragments of Tortula. Journal of Bryology 15: 327-342.

Newton AE. 1993. Phylogenetic systematics of the tropical moss genus Pireella (Pterobryaceae: Musci). PhD thesis. Department of Botany, Duke University.

Newton AE, Mishler BM. 1994. The evolutionary significance of asexual reproduction in mosses. Journal of the Hattori Botanical Laboratory 76: 127-145.

Dr Martha Newton (University of Manchester): Bonus bryophytes

This was a miscellany of the more unusual or attractive bryophytes to have been enjoyed by bryologists attending field courses I have taken. To qualify for consideration, a bryophyte had to have captured the attention of someone on the course and to have added to the pleasure of everyone. It was hoped that, in presenting these slides, some of that pleasure could be conveyed to BBS members present at Loughborough. From a wealth of qualifying species representing all nine of the major biome categories in Britain (Hill & Preston, 1998), just 57 were chosen from seven of those geographical assemblages.

It was argued that even the most experienced bryologist could not fail to admire the attractive colours and forms of many extremely common species. Ceratodon purpureus, Bryum argenteum, Lophocolea heterophylla, Dicranum majus and Thuidium tamariscinum were therefore included alongside such species as Orthothecium rufescens, Bryum weigelii, Cinclidium stygium, Dicranum bergeri (D. undulatum), Sphagnum lindbergii and Petalophyllum ralfsii.

A larger number of species, however, demanded attention for reasons of rarity, geographical distribution and factors involved in reproductive behaviour and/or genetic isolation. The rare Bryum cyclophyllum, for instance, had been discovered new to Wales, whereas the nationally scarce Anastrophyllum hellerianum had been found further east than any of its previous records in Wales. Not only was the gross morphology of Pellia borealis illustrated but also the cytological features which reveal its genetic isolation from the similar P. epiphylla. Their chromosomes differ numerically as well as structurally, there being 18 unique ones in gametophytes of the former species and nine in the latter (Newton, 1986). Both these species are monoecious and generally fertile but, in contrast, a number of dioecious bryophytes excite attention because of the rarity of sporophyte production, among them being fertile Plagiomnium undulatum, Climacium dendroides and Barbilophozia floerkei. Indeed, this was, I believe, the first illustration of sporophyte production by British B. floerkei.

References

Hill MO, Preston CD. 1998. The geographical relationships of British and Irish bryophytes. Journal of Bryology 20: 127-226.

Newton ME. 1986. Pellia borealis Lorbeer: its cytological status and discovery in Britain. Journal of Bryology 14: 215-230.

Dr David S. Rycroft (University Of Glasgow): A chemist’s view of liverworts

This paper, subtitled ‘NMR (nuclear magnetic resonance) fingerprinting and chemotype classification of British Plagiochilae’, contains some of the results obtained since the first applications of NMR fingerprinting of liverworts were presented in 1996 as a poster at the Centenary Symposium in Glasgow. Further information, including details of the chemical structures, can be found in the references cited.

This work has evolved out of the chemical studies of the secondary metabolites of liverworts that have been going on at Glasgow for over 25 years. In considering both our and other people’s work in this area, a recurring question was: are the secondary metabolites characteristic of the species or just of the particular specimen? Our efforts to answer this question for particular liverworts have involved using NMR spectroscopy to develop NMR fingerprinting (Rycroft, 1996). The novel aspect of this technique is to extract the plant material with deuterochloroform, the deuterated solvent that is normally used to measure NMR spectra; many benefits arise from the simplicity and directness of the procedure compared to more conventional methods (Rycroft, 1998a). In favourable circumstances, the amount of plant material required is only a fraction of many herbarium specimens, and the method opens up the possibility of undertaking comparative chemical studies using a wide range of fresh and/or herbarium material.

To illustrate what a NMR spectrum can tell us, we may consider the case of an extract from Calypogeia azurea. The blue compound responsible for the colour of the oil bodies was shown to be 1,4-dimethylazulene over 30 years ago (Meuche & Huneck, 1966); the signals in the NMR spectrum arise from different parts of this molecule and could be used to elucidate the structure. For the purposes of liverwort characterisation, identification of 1,4-dimethylazulene in the NMR spectrum is equivalent to seeing the blue oil bodies in the liverwort, and whatever weight is attached to the character of blue oil bodies could in principle also be attached to other compounds identified, with the advantage of course that they do not have to be coloured. An additional point to emphasise is that the case of C. azurea is one where a secondary metabolite can be demonstrated unequivocally to be localised in the oil bodies. It is commonly assumed that this is the norm, despite the fact that what are regarded as normal liverwort compounds have also been isolated from liverworts that have no oil bodies.

Inter alia, we have been using NMR fingerprinting to study all (except the most recently discovered) British species of Plagiochila. Our work on P. spinulosa started originally in 1982, and the poster at the Centenary Symposium reported that there was little chemical variation between different samples of P. spinulosa. Subsequent work (Connolly et al., 1999) has resulted in identification of more of the components: eight are 9,10-dihydrophenanthrenes (DHPs), two are methyl orsellinates, and one is a bibenzyl. In comparison with P. spinulosa, the P. punctata spectra have fewer signals; the major components have been identified, and in addition to three of the DHPs found in P. spinulosa there is a flavonoid.

One aspect of chemical interest in Plagiochila killarniensis is the characteristic smell. The proton NMR spectrum quickly revealed that the extract was dominated by methyl everninate, which is known in the perfumery world as one of the odour-impact compounds of oakmoss (the lichen Evernia prunastri). Another compound present is b-phellandrene, a monoterpenoid with a strong smell, present in essential oils from various Eucalyptus, Abies and Pinus species. b-Phellandrene is also present in Plagiochila spinulosa and P. punctata, and is responsible for the smell obtained when fresh material is crushed in the field, whereas methyl everninate is responsible for what makes P. killarniensis distinctive after it has been collected. Our isolated methyl everninate contained two minor constituents that were also methyl orsellinate derivatives, one of which we already knew from P. spinulosa. In six Scottish specimens and four from the Azores, another minor component that was always present was a more unusual type of compound, a 3-benzylphthalide that we have named ‘killarniensolide’ (Rycroft et al., 1999). The structure of killarniensolide is related to lunularic acid, the dormancy-inducing factor that seems to be ubiquitous at low levels in liverworts. There is also a structural relationship with the bibenzyl that we isolated from P. spinulosa. P. killarniensis did not contain any of the DHPs from P. spinulosa, but two of the minor components corresponded to two of the DHPs reported from a Costa Rican Plagiochila (Anton et al., 1997).

In discussions with the Saarbrücken and Göttingen bryophyte groups we learnt of the synonymy of P. killarniensis with the Neotropical species P. bifaria (Heinrichs, Grolle & Drehwald, 1998). We have now examined several Neotropical specimens, but the extract of the only sample of P. bifaria was dominated by a compound that is suspected to have arisen from fungal contamination. Until more material becomes available, the secondary metabolites of Neotropical P. bifaria remain obscure. The only work in the literature is a GC-MS study of a single Peruvian specimen that appears to differ chemically from the ten Scottish and Azores specimens studied by us. Two Madeiran samples sent from Göttingen were very similar chemically to Scottish and Azores material; however a third sample (Drehwald 960277) turned out to be very different. The NMR spectrum showed mainly a ca 1:1 mixture of two compounds, one of which was one of the DHPs in P. killarniensis and the other the bibenzyl derivative in P. spinulosa. Morphological examination of the plant then revealed that it was very different from P. killarniensis as we know it in Britain: the leaves were relatively longer, were not truncate, and the line of teeth on the postical leaf margin continued around the apex and sporadically along the antical leaf margin. An interesting development since the AGM is the discovery that the extract of a 45 year-old sample of P. sharpii (R.M. Schuster 40723 ex GL) contains a ca 1:1 mixture of the same two compounds. These observations may be placed in perspective by noting that chemically the difference between Drehwald 960277 and P. killarniensis is at least as great as that between P. spinulosa and P. punctata.

The NMR spectra of extracts of three samples of Plagiochila exigua from different sites in Glen Creran were fortuitously simple in the methoxyl region in giving one large peak. In the aromatic region, things were not so simple, but a simulated spectrum could be calculated to match the line positions of the experimental spectrum and show that the new compound 3,4-dihydroxy-3´-methoxybibenzyl was present (Rycroft, Cole & Aslam, 1998). This result differs from the only other work reported for P. exigua, from a GC-MS study of a sample from Peru: none of the compounds was identified, although two of them were subsequently recognised by Asakawa & Inoue in P. spinulosa (from Belgium), and we have since shown that they are two of the methyl orsellinate derivatives mentioned earlier. A study of a wider range of material would be necessary to discover if there is any significance in these differences.

Historically at least, it appears that Plagiochila atlantica was liable to be confused with P. spinulosa. In 1996 the chemistry of only one sample of P. atlantica, from its now classic locality of Ariundle, had been investigated. It was shown that it was very different from P. spinulosa in that P. atlantica contained plagiochiline C, a 2,3-secoaromadendrane sesquiterpenoid, rather than DHPs (Rycroft, 1996). Many 2,3-secoaromadendranes are easy to recognise in a proton NMR spectrum because they give a doublet for H-2 and a singlet for H-3 in a characteristic region of the spectrum. Subsequently we have extended the range of the study to include samples from as far as the English Lake District to the south and the Gruinard River in Wester Ross to the north, and discovered a uniform chemical pattern consistent with the idea that the population consists of one clone only, with reproduction occurring asexually.

A set of signals from a second compound was consistently present at ca 10% of plagiochiline C; the compound responsible is a new sesquiterpenoid alcohol that we have called ‘atlanticol’ (Rycroft & Cole, 1998b). It is a derivative of bicyclogermacrene, the sesquiterpenoid found most frequently in liverworts (and also present in P. atlantica); a closely-related compound has been reported by Hashimoto et al. (1993) from Japanese P. fruticosa, but without details or characterisation data.

1. P. carringtonii also contains 2,3-secoaromadendranes. The NMR spectra of five extracts are all very similar, and in this case there are two H-3 singlets, two H-2 doublets and one aldehyde and one methyl ester signal forming two sets of signals in the ratio 2:1. These signals do not correspond to any of the known plagiochilines, and the new compounds responsible were isolated using thin layer chromatography (Rycroft, Cole & Lamont, to be submitted). They are a pair of closely-related plagiochilines, T and U, that have one of the methyl groups on the cyclopropane ring of the 2,3-secoaromadendrane skeleton oxidised to either an aldehyde or a methyl ester respectively. Previously reported plagiochilines do not have these methyl groups oxidised beyond the alcohol stage, but otherwise T and U are typical plagiochilines. Therefore the Plagiochila that for a long time was placed in Jamesoniella has secondary metabolites that, although new, are of a type characteristic of other Plagiochila Lewis (1970) demonstrated a similar point by studying sugar alcohols.

Plagiochila porelloides has been recorded as new for China from Changbai Mountain, at a latitude of ca 42ºN and less than 350 km west-south-west of Vladivostok (Söderström et al., 1999). In comparison with the foregoing, the NMR spectra of this Chinese material are more complicated, but it was possible to determine that there was a major compound that did not correspond to the known plagiochilines. Again, the new compound, plagiochiline V, was isolated, and we have been able to propose a structure where one half is the same as in the known plagiochiline M, but the other half is novel. British P. porelloides also contains 2,3-secoaromadendranes, but we have still to complete our studies and confirm whether it contains plagiochiline V. Our preliminary studies of British P. asplenioides and P. britannica have also found evidence of 2,3-secoaromadendranes.

Our present knowledge, though incomplete, is sufficient to produce a provisional classification of British Plagiochilae based on the chemotypes of Asakawa (1995). In the largest group, characterised by 2,3-secoaromadendranes, we can include P. asplenioides, P. atlantica, P. britannica, P. carringtonii and P. porelloides. P. exigua can be placed in the bibenzyl group, but we need to propose a new chemotype group (Rycroft, 1998b) characterised by the presence of DHPs (with possible sub-divisions) to accommodate P. killarniensis, P. punctata and P. spinulosa. This DHP group has Neotropical connections but DHPs have not (yet) been reported from any Asiatic Plagiochila. Of particular note is the observation that, on chemical grounds, P. atlantica and P. spinulosa would be classified in different sections.

Our work has by no means been confined to Plagiochila and one example concerns Cryptothallus mirabilis (Rycroft & Cole, 1998a). A specimen from near Glasgow gave a remarkably clear NMR spectrum (Rycroft, 1998a) of a new pinguisane sesquiterpenoid derivative, a result of chemosystematic interest in view of the fact that the first pinguisane was isolated from Aneura pinguis. Investigation of a second specimen involved a return visit to the site in Glen Creran where Jeff Duckett had unearthed plants in 1996. The new pinguisane was detectable in this material but the dominant component in this case was a sesquiterpenoid with a different carbon skeleton, a cyclocuparanol that has also been found in Marchantia polymorpha (the cyclocuparanol was also detectable in the first specimen of C. mirabilis). Investigation of further specimens is a prerequisite to attributing any significance to this difference.

Application of NMR fingerprinting has enabled us to obtain detailed chemical results from a range of specimens that were unimaginable until very recently. It would be interesting to apply these methods in parallel with DNA techniques to phytogeographical problems.

Acknowledgements

Others involved in this work are cited in the references and I should like to thank them, and in particular my GC–MS colleague Dr John Cole, for their collaboration. In addition I am grateful to the many BBS members who have given much advice and encouragement to a comparatively recent recruit to the Society.

References

Anton H, Kraut L, Mues R, Morales Z MI. 1997. Phenanthrenes and bibenzyls from a Plagiochila species. Phytochemistry 46: 1069–1075.

Asakawa Y. 1995. Chemical constituents of the bryophytes. In: Herz W, Kirby GW, Moore RE, Steglich W, Tamm Ch, eds. Progress in the chemistry of organic natural products. Vol. 65. Wien: Springer, 490.

Connolly JD, Rycroft DS, Srivastava DL, Cole WJ, Ifeadike P, Kimbu SF, Singh J, Hughes MP, Thom C, Gerhard U, Organ AJ, Smith RJ, Harrison LJ. 1999. Aromatic compounds from the liverwort Plagiochila spinulosa. Phytochemistry: in press.

Hashimoto T, Asakawa Y, Nakashima K, Tori M. 1993. Chemical constituents of 25 liverworts. Journal of the Hattori Botanical Laboratory 74: 121–138.

Heinrichs J, Grolle R, Drehwald U. 1998. The conspecificity of Plagiochila killarniensis Pears. and P. bifaria (Sw.) Lindenb. Journal of Bryology 20: 495–497.

Lewis DH. 1970. Chemotaxonomic aspects of the distribution of acyclic sugar alcohols in leafy liverworts. I. Chemical evidence for the taxonomic position of Plagiochila carringtonii (Balfour) Grolle. Transactions of the British Bryological Society 6: 108–113.

Meuche D, Huneck S. 1966. Azulene aus Calypogeia trichomanis. Chemische Berichte 99: 2669–2674.

Rycroft DS. 1996. Fingerprinting of plant extracts using NMR spectroscopy: application to small samples of liverworts. Chemical Communications, 2187–2188.

Rycroft DS. 1998a. Chemical comparison of liverworts using NMR spectroscopy. Journal of the Hattori Botanical Laboratory 84: 105–111.

Rycroft DS. 1998b. Plagiochila atlantica F. Rose newly identified in England: chemotype classification. Journal of Bryology 20: 240–242.

Rycroft DS, Cole WJ. 1998a. 15-Acetoxypinguisone and a cyclocuparanol from the liverwort Cryptothallus mirabilis Malmb. Journal of Chemical Research (Synopses), 600–601.

Rycroft DS, Cole WJ. 1998b. Atlanticol, an epoxybicyclogermacrenol from the liverwort Plagiochila atlantica F. Rose. Phytochemistry 49: 1641–1644.

Rycroft DS, Cole WJ, Aslam N. 1998. 3,4-Dihydroxy-3´-methoxybibenzyl from the liverwort Plagiochila exigua from Scotland. Phytochemistry 49: 145–148.

Rycroft DS, Cole WJ, Aslam N, Lamont YM, Gabriel R. 1999. Killarniensolide, methyl orsellinates and 9,10-dihydrophenanthrenes from the liverwort Plagiochila killarniensis from Scotland and the Azores. Phytochemistry: in press.

Söderström L, Rycroft DS, Cole WJ, Wei S. 1999. Plagiochila porelloides (Torrey ex Nees) Lindenb. from Changbai Mountain, new to China, with chemical characterization and chromosome measurements. Bryobrothera: in press.

Mr Daniel Wrench (Sefton Coast Life Project): Bryophyte conservation in the management of dune systems – a case study of the Sefton coast

The Sefton Coast, north-west England, is historically a well-known stronghold for several important bryophytes. In 1995 two surveys by Dr M. Newton (JNCC Report No 239) of Red Data List bryophytes and stoneworts found only four of the seven previously recorded Red Data List bryophytes. Bryum warneum and Petalophyllum ralfsii were found to have reasonably strong populations. However, B. neodamense was sparse, and B. mamillatum (tentatively identified) was confined to a single small site – its only recent British record. B. knowltonii, B. uliginosum and B. marratii were not refound. It is probable that B. marratii is now extinct on the Sefton Coast.

Further survey work on Petalophyllum was undertaken by myself in 1997, with some incidental records also made of B. neodamense. Populations of Petalophyllum were confirmed to be strong, albeit rather localised. B. neodamense was found to be somewhat more frequent than previously thought. Detailed maps were made of all known populations using a computerised Geographic Information System (GIS). This system allows data such as species location and abundance to be entered into a database format and then displayed and analysed by their geographic attributes. Aerial photography, either displayed on screen or printed out, is a rapid and accurate means of location in an otherwise featureless landscape. Species records can be represented by a chosen symbol on enlarged aerial photos. Relocation of sparse or scattered records benefits from the high resolution of the system, providing accuracy of a metre or less.

Primarily as a guide for the land managers, a report was produced giving precise locations and photographs of Petalophyllum populations with an estimate of plant numbers (based on counts of individual thalli) plus other field notes. This report also listed possible threats and management recommendations for each population. The report also assisted in providing the information required by the Sefton Coast LIFE Project to produce a conservation strategy for Petalophyllum at Sefton.

Current management of dune slack habitat on the Sefton Coast rarely shows any consideration toward the conservation of bryophytes. This may be a consequence of the lack of recording effort and limited awareness of the conservation requirements of bryophytes, but may also reflect the level of importance given to bryophytes by conservation managers compared with other groups such as herptiles and birds. Natterjack Toad conservation is the main reason for management of many dune slacks in the frontal dunes of the Sefton Coast. This often involves heavy machinery re-profiling or excavating new dune slacks, and the use of herbicides to treat scrub re-growth. While this form of management is likely to continue in the short term, it is hoped that future management will give greater emphasis to dune geomorphological processes. Such management may include the implementation of appropriate grazing regimes and the spatial and temporal zoning of activities associated with recreation, such as beach car parking. The environmental impact of beach cleansing activities on dune processes also requires careful consideration. Most dunes in Britain are mature and in a phase of sediment recycling. Natural dune slack creation and development should therefore be encouraged as a desirable quality.

Footpath management is also an important consideration, particularly in areas of little or no grazing. Light levels of trampling can keep some dune slack areas open in structure that may otherwise become dominated by scrub and course grass species. While it is necessary to ensure heavy trampling does not destroy valuable habitat, the construction of boardwalks should only be undertaken after an adequate impact assessment and for overriding recreational management reasons. This is because boardwalks cover valuable habitat, remove trampling pressure, and encourage scrub to spread right up to the edge of the boards.

The most critical factor on the Sefton Coast for several of the Red Data Book bryophytes is water quality. The stronghold for Petalophyllum and several other bryophytes at this site is flooded regularly by eutrophic water from a nearby lake. Aside from the direct effects this may be having on these species, indirect effects include an increased vigour of vascular plants and growth of an algal mat which coats the ground when the water subsides. This algal mat then either hardens on drying or is puddled into a muddy mess.

An innovative recording approach is required for important dune bryophytes in the face of the environmental stress and rapidly changing conditions that occur in sand dune systems. This must aim to provide an adaptable and updatable system with a level of detail that can translate the information gathered in a manner that is accessible to land managers.

Field excursion to Charnwood Forest, 20 September 1998

In warm autumn sunshine, 24 of us explored the grassland and woods near Charnwood Lodge (VC 55). The way from the cars to the woods led past a dark Precambrian rock outcrop with Barbilophozia atlantica*, Ptilidium ciliare and Racomitrium heterostichum, showing at once that this was not an ordinary part of the English Midlands. Our leader, Dennis Ballard, walked us briskly for about half a mile to Burrow Wood, but we tarried by the way and found Ulota bruchii (U. crispa var. norvegica) c.fr. In the wood, we saw several plants that are often thought of as western, including Cryphaea heteromalla* on elder, Hypnum andoi (H. mammillatum) c.fr. on a stone wall, and Lejeunea lamacerina*, Scapania undulata and Heterocladium heteropterum var. heteropterum* in a small stream gully. Dicranum tauricum on dead wood, however, indicated that we were still some distance from the west coast, as did the presence of plentiful Plagiothecium curvifolium and Orthodontium lineare. In nearby Cat Hill Wood, there was a steep shaded rock outcrop with more Barbilophozia atlantica and Racomitrium heterostichum and also Barbilophozia attenuata, B. floerkei and plenty of a Cephaloziella without perianths.

Another party broke away at an early stage and visited some woodland near a reservoir south-west of Charnwood Lodge. There was some damp ground with Polytrichum commune and three species of sphagna. They also found Brachythecium plumosum and Scapania undulata. Richard Fisk and Rod Stern found Calypogeia arguta in a ditch in a nearby plantation, but did not collect it because they had no reason to suppose that the species would be bracketed in the new Census Catalogue.

Two parties went to look for Syntrichia (Tortula) amplexa. S. amplexa was duly refound in three separate places, none of which was its locus classicus, which has now become a deep hole in the ground with water at the bottom. On the advice of Dennis Ballard, one group went to look for it in an opencast mine area east of Moira (SK3215). After much searching, they eventually found it in the lower part of the site, and in the process recorded Cephaloziella divaricata, C. hampeana*, Fossombronia incurva*, Riccia sorocarpa, Aloina ambigua (A. aloides var. ambigua), Bryum dunense and a scrap of Sphaerocarpos, which was not identifiable to species. The other party found S. amplexa in small quantity near Lount (SK3819) and more plentifully in a ditch by a stone and earth dump near Boothorpe (SK3117). In the last locality, Harold Whitehouse found Ephemerum serratum var. serratum* with immature capsules on bare soil near a stream and successfully grew it on to achieve an identification.

While the cognoscenti were especially gratified to see that great speciality of the area, Syntrichia amplexa, there was pleasure for all in the beauties of Charnwood Forest, and for some in making new records for the vice-county. Some of these update old records that had been bracketed in the new Census Catalogue, but others are completely new. We are grateful to Dennis Ballard for organising an interesting meeting and for showing us that there are many good bryophytes to be found in the centre of England.

Mark Hill