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Aljezur, Portugal

Preston C.D.,UK Center for Ecology and Hydrology | Hill M.O.,UK Center for Ecology and Hydrology | Porley R.D.,Cerca Dos Pomares | Bosanquet S.D.S.,Countryside Council for Wales
Journal of Bryology | Year: 2010

Knowledge of the distribution of arable bryophytes lags behind that of bryophytes of many other habitats, and we have almost no information on their occurrence in relation to crop type and agricultural management regime. A survey of arable fields in Britain and Ireland carried out by members of the British Bryological Society in 2001-05 was designed to provide such baseline data. We surveyed a stratified random sample of 200 fields in the main areas of arable agriculture and a further 620 fields in these areas and in areas where arable fields are less frequent. The species present in each field were listed and their frequency within the field assessed. Data on the crop, the cover of vascular plants, bryophytes, trash and bare soil, and the pH and texture of the soil were recorded for each field. Six species assemblages are described on the basis of a classification of the species recorded in each field and their frequency values. The Tortula truncata-Anthoceros and Dicranella staphylina-Riccia glauca assemblages are the most species-rich and are concentrated on acidic soils in northern and western Britain and in Ireland. By contrast, the Barbula unguiculata-Bryum klinggraeffii and Phascum cuspidatum-Microbryum davallianum assemblages are mainly found on calcareous soils in southern and eastern England. The Bryum dichotomum-Marchantia polymorpha assemblage is characterised by widespread, weedy generalist species and is concentrated in East Anglia. The final assemblage, Brachythecium rutabulum-Fissidens taxifolius, characteristically occurs in late-successional fields and was scattered throughout the area sampled. A comparison of the results from Kent with those of a survey of Kentish fields (using a different methodology) by A.G. Side in 1973-74 suggests that the Bryum dichotomum-Marchantia polymorpha assemblage may possibly have replaced the Dicranella staphylina-Riccia glauca assemblage on acidic soils in the last 30 years. The considerable geographical variation within the arable flora of Britain and Ireland revealed by the survey should be taken into account when assessing the meagre evidence for historic changes in the arable bryophyte flora. © 2010 British Bryological Society.

Porley R.D.,Cerca Dos Pomares | Pressel S.,Natural History Museum in London
Polish Botanical Journal | Year: 2012

Gemmae are reported for the first time in Grimmia fuscolutea Hook. The morphology, development and abscission mechanisms are described and contrasted with other gemmiferous Grimmia species in the Rhabdogrimmia clade. Light microscopy and cryo-scanning electron microscopy were used to make observations, the latter a novel technique that allows detection of any water soluble surface ornamentation and to distinguish between hydrophilic and hydrophobic surfaces. Smooth walled highly hydrophilic gemmae in G. fuscolutea occur on the dorsal and ventral laminal and costal cells usually medially but sometimes distally. Gemma ontogeny follows a similar pattern in all propaguliferous Grimmia with cells of either the lamina or costa or both giving rise to uniseriate or branched multicellular filaments which differentiate into gemmae. The parent filament never re-differentiates into a new initial from which further gemmae arise. Detachment of gemmae from the parent filament is usually by formation of specialized abscission cells whilst separation of individual gemmae is by the breakdown of the middle lamellae and either or both mechanisms may occur in one species. Similarly to G. fuscolutea, the position of gemmae in G. trichophylla Grev. is variable. Uppermost leaves that support distal gemmae result in highly modified leaves consisting of almost exclusively smooth-walled elongate cells. In all other gemmiferous Grimmia species, including G. austrofunalis Müll. Hal, the position of gemmae is much more stable; in G. austrofunalis gemmae occur almost exclusively proximally on the dorsal costa.

Ah-Peng C.,University of Cape Town | Ah-Peng C.,University of Reunion Island | Bardat J.,French Natural History Museum | Ellis L.T.,Natural History Museum in London | And 9 more authors.
Journal of Bryology | Year: 2010

This contribution is a result of collaborative work based on the fieldwork organized during a workshop of the Tropical Bryology Group on Mascarene bryophytes in September 2008, and also from previous unpublished records of the authors. We add 35 new taxon records (17 mosses and 18 liverworts) as well as five other interesting records for Réunion Island (Mascarene Archipelago). Grimmia austrofunalis Müll. Hal., Sphagnum magellanicum Brid. subsp. magellanicum, Didymodon tectorum (Müll. Hal.) K. Saito, Anastrophyllum revolutum Steph. and Lejeunea exilis (Reinw. et al.) Grolle are reported for the first time for Africa. Syrrhopodon vardei L. T. Ellis, Ceratolejeunea papuliflora Steph. and Xylolejeunea grolleana (Pócs) X.-L. He & Grolle, previously known as endemic from Madagascar, are here recorded for Réunion. The latter species is also illustrated with SEM pictures. © British Bryological Society 2010.

Porley R.D.,Cerca Dos Pomares | Edwards S.,Vine Cottage
Journal of Bryology | Year: 2010

The southern hemisphere and neotropical moss Leptodontium proliferum Herzog is reported new to Europe and the English material is described and illustrated with photomicrographs. It occurs in open turf on disturbed margins of a recreational bowling green. It is concluded that L. proliferum is an unintentional introduction and probably arrived in Britain by a migrating bird, or as a contaminant of imported lawn-sand or seed mix. © 2010 British Bryological Society.

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