The distribution and reproduction of Pterosiphonia complanata

The geographical distribution of the red alga Pterosiphonia complanata (Clem.) Falkenb. is described. New records confirm that it is restricted to the warmer waters of the North Atlantic and extend its known distribution in the British Isles where it is at the northern limits of its range. The apparent scarcity and restricted distribution of the species in the British Isles and the absence of sexual plants throughout its range are discussed in relation to the habitat and possible life history of the species.     

Distribution and ecology of small cow-wheat (Melampyrum sylvaticum L.; Scrophulariaceae) in the British Isles

Summary

Melampyrum sylvaticum L. is an annual, hemiparasitic herb which mainly grows in light woodland and on upland ledges in northern Britain and Ireland. Its distribution is poorly known due to confusion with the variable M. pratense. A review of its ecology and distribution has been carried out and it has now been recorded from 83 10-km squares in the British Isles, including three in England and two in Wales; an updated distribution map is given. It is probably declining slowly in the lowlands at the margins of its range due to afforestation, development of dense shade, over-grazing and intensive agriculture.     

The geographical relationships of British and Irish vascular plants

Classifications of British and Irish vascular plants into floristic elements are reviewed. Only H.C. Watson and J.R. Matthews have attempted to devise a more or less comprehensive classification, based on the British range of the species (Watson) or the European distribution (Matthews). A new classification of 1481 native species is presented, based on their range in the Northern Hemisphere. Species are classified by their occurrence in one or more major biomes (Arctic, Boreal, Temperate, Southern) and their longitudinal distribution (Oceanic, Suboceanic, European, Eurosiberian, Eurasian, Circumpolar). The distribution of species in the floristic elements is illustrated by coincidence maps for the British Isles and Europe. The British and Irish flora is dominated by Boreo-temperate, Temperate and Southern-temperate species, with the Temperate species being the most numerous. Species with continental distributions (i.e. species which are rarer than expected in western Europe) are listed; most of these are in the Boreo-temperate and Temperate elements. The floristic elements are discussed in relation to the life-form spectra, habitat preferences and altitudinal limits of the component species, and analysed in terms ol˜ Ellenberg indicator values for temperature and continentality. The new classification is compared with that of Matthews. An additional 48 species which are endemic to the British Isles are listed. The scope for extending this method of classification to other organisms and for adapting it for use outside the British Isles is discussed.     

Athalamia hyalina (Sommerf.) S.Hatt. in Scotland,new to the British Isles

Abstract

The liverwort Athalamia hyalina (Sommerf.) S.Hatt. and the family Cleveaceae are reported as new to the British Isles from the eastern Scottish Highlands. The Scottish plants are described and illustrated and the significance of the discovery is assessed. In Scotland, Athalamia hyalina occurs on thin soil on eroding limestone ledges in a montane habitat with a continental climate. It is in active growth in the winter months, producing spores in spring. Its range is restricted but it occurs within a protected area and is not threatened at present. The species is widespread in the northern hemisphere.     

AN ATLANTIC POPULATION OF PIKEA CALIFORNICA (DUMONTIACEAE,RHODOPHYTA)1

The marine red alga Pikea californica Harvey, previously known only from the east coast of Japan and the west coast of North America, was found in 1983 to be abundant in the surge zone throughout the Isles of Scilly archipelago, off SW England. Examination of herbarium material showed that the population was present in 1967. All plants observed in July 1983 and September 1984 were sterile, but reproductive male and female plants were collected in November 1983. The habitat and phenology of P. californica in the Isles of Scilly closely resemble those of Pacific populations. English plants are vegetatively and reproductively identical to the type and other California specimens. They can easily be distinguished from Sphaerococcus coronopifolius Stackhouse (Sphaerococcaceae, Gigartinales), the most similar species in the flora of the British Isles, by the presence in transverse sections of several lacunae, representing axial and whorl-branchlet filaments, in contrast to the single axial filament of S. coronopifolius. It is possible that the Isles of Scilly population of P. californica is a relict of a species once more widespread, but it seems more likely that it is another example of the well-established pattern of marine introductions into the British Isles from the North Pacific. The range of temperature regimes occupied by P. Californica in the Pacific suggests that the species could become more widespread in Europe, but at present it appears to be confined to the Isles of Scilly.     

The larva of Tinodes maculicornis (Trichoptera: Psychomyiidae), with notes on the species' distribution and habitat in Ireland

SUMMARY. A key is given for the identification of the larva of Tinodes maculicornis which is the only undescribed psychomyiid in the British Isles. The Irish distribution and habitat of the species are outlined.     

DERMATOCARPON LEPTOPHYLLODESAND RELATED SPECIES IN THE BRITISH ISLES

The species ofDermatocarponoccurring in the British Isles are reviewed, with special reference to the hydrophilous species; a number of related species not yet recorded for the British Isles are also briefly treated.Dermatocarpon deminuensandD. leptophyllodesare confirmed as British; the nameD. leptophyllumshould be deleted from the British list. The nameD. meiophyllumis shown to be based on discordant elements. A key is provided to the British and Irish species.     

A comparison of distribution patterns in British and Irish mosses and liverworts

Abstract

We classified 747 species of British and Irish mosses into 10 clusters, based on their recorded distribution in 10×10 km grid squares (hectads). We generated the clusters in a two-stage process using the CLUSTASPEC program, the method that we had earlier used for British and Irish liverworts and hornworts. The clusters are named after the species with distributions which are most similar to those of the clusters as a whole. Clusters of widespread species (Bryum capillare), southern, lowland species (Rhynchostegium confertum), widespread calcifuges (Pleurozium schreberi), upland species (Blindia acuta), and montane calcifuges (Kiaeria falcata) closely match clusters recognised in the liverworts. The remaining clusters (Tortella flavovirens, Weissia longifolia, Mnium stellare, Encalypta alpina, Mnium lycopodioides) are less similar. The classification of mosses into 15 and 20 clusters generates additional clusters of hyperoceanic and montane mosses which also resemble liverwort clusters. The influence of calcareous bedrock has a more marked effect in determining moss distributions and, unlike the liverworts, the 10 moss clusters include one which is predominantly coastal. Mosses tend to be a less upland group than liverworts; a smaller proportion of their species have northern and western distributions and the lowland clusters are characterised by more extreme environmental conditions. As with the liverworts, geographically restricted clusters of species with predominantly Mediterranean-Atlantic, Arctic-montane and Boreo-arctic Montane world ranges include marked concentrations of threatened species, and species which are not recorded as fruiting in the British Isles.     

Genetic signatures of population change in the British golden eagle (<Emphasis Type="Italic">Aquila chrysaetos</Emphasis>)

The golden eagle (Aquila chrysaetos) was once widely distributed in the uplands of the British Isles, but is now extinct in Ireland, and largely confined to the highlands and islands of Scotland. As the precise extent and severity of the reduction in population size are unclear, it is important to understand how the population was affected by the decline. We therefore genotyped 13 polymorphic microsatellite loci in 172 individuals from the contemporary British population and compared their genetic diversity to 70 British and 9 Irish museum specimens. Despite the recent population decline, there is only slight evidence for a concomitant loss of genetic variation. Instead, two likelihood-based Bayesian methods provided evidence for a severe ancient genetic bottleneck, possibly caused by the fragmentation of a large mainland European population and/or the founding effects of colonising the British Isles. As the population persisted despite this ancient bottleneck, our conclusion is that there is limited need for intervention to augment the present-day genetic diversity. The main short-term objective of conservation measures should be to increase population sizes by continuous safeguarding of individuals and habitat management. Finally, we also confirmed that, for management purposes, the species should be considered a single population unit and that the extinct Irish population was not differentiated from the British one.     

Cystocarpic plants of Gigartina teedii—A new record for the British Isles

Cystocarps are recorded for the first time on plants of Gigartina teedii (Roth) Lamour., collected in the British Isles.     

Notes on British Boleti: III.

Summary

A key to the British species of the genera Aureoboletus, Boletinus, Gyroporus, Phylloporus, Porphyrellus, Pulveroboletus, Strobilomyces and Uloporus based on habitat, microscopic and macroscopic features is discussed. Four species as yet unrecorded from the British Isles, Boletinus asiaticus, Xerocomus amarellus, Boletus vaccinus, Boletus badiorufus and seven species which could possibly be sought in one of these genera are included in the discussion for completeness; the latter are also included in the key.     

Arctoa anderssonii Wich. (Dicranaceae), new to the British Isles

Abstract

Arctoa anderssonii Wich. is described as a species new to the British Isles with an account of its habitat on Ben Hope, a mountain in Sutherland, north-west Scotland. The differences between this species and Arctoa fulvella and A. hyperborea are specified.     

Notes on some British Barbulas

Abstract

The moss Hypnum cupressiforme var. heseleri is reported new to the British Isles and its status is discussed. Line drawings and a photographic illustration are provided. It was found growing on an apple tree on the Royal Estate, at Flitcham in West Norfolk. It differs from other species of Hypnum in its distinctive rounded-concave leaf form and julaceous branches. The habitat and ecology are broadly similar to those in the other European sites from which this moss has been reported.     

Metzgeria temperata Kuwah. in the British Isles,and M. frnticulosa (Picks.) Evans with sporophytes

Abstract

Kuwahara separated Metzgeria fruticulosa, which is European and develops a blue pigment in long-dried material, from Japanese and North American plants which lack the pigment, and to which he gave the name M. temperata. About one third of British specimens previously determined as M. fruticulosa have proved to be M. temperata. It is distinct from M. fruticulosa in many characters including the absence of brood-bodies on the costa. Sporophytes of M. fruticulosa arc described for the first time. M. temperata favours more base-deficient substrata than M. fruticulosa, and has a I1l0re southern distribution in the British Isles.     

New national and regional bryophyte records, 47

Abstract

The moss Timmia megapolitana is reported new to the British Isles. It occurs in an area of freshwater tidal Salix carr in the Norfolk Broads and differs from the other two species of Timmia in Britain and Ireland in leaf form and anatomy, sexuality and habitat. In the field Timmia megapolitana is most likely to be passed over as Atrichum undulatum, and since access to the area is difficult there is the possibility that it has been present for many years. The habitat and ecology shows a remarkable similarity to that in the Netherlands, the nearest European locality. Rare in Europe, the plant also occurs in Finland, northern Russia and Siberia, regions that provide staging posts and breeding grounds for migratory birds that over-winter in Norfolk.     

Notes on British Boleti: IV

Summary

A key to the British species of the genus Suillus based on habitat, microscopic and macroscopic characters is discussed. Some species as yet unrecorded for the British Isles are included for completeness. Also included in the key are the only W. European member of Fuscoboletinus, the single British species of Bolentis, and two Xerocomus spp., X. badius and X. rubinus, both of which are superficially similar (in some characters) to members of the genus Suillus. The genera Chalciporus and Fuscoboletinus are reviewed and the taxonomic status of Boletus grevillei is discussed in detail.     

Breeding bird populations of Irish peatlands

Capsule Peatlands are very important habitats for birds despite low species diversity.

Aims To describe the variation in breeding bird populations that occur on different types of Irish peatlands and their associated habitat characteristics.

Methods Bird abundance and diversity were compared between four peatland habitat types (fens, raised bogs, Atlantic blanket bogs and montane blanket bogs) at 12 study sites using transects. Various measures of habitat quality were also taken at each location.

Results Only 21 species were recorded during the study, with Meadow Pipit Anthus pratensis and Sky Lark Alauda arvensis accounting for over 80% of all birds recorded. Fens had greater bird species diversity and densities than the other three peatland types. Raised bogs, Atlantic blanket bogs and montane blanket bogs were very similar in terms of their avian diversity. Each of the recorded bird species was associated with different aspects of the peatland habitat.

Conclusion This study shows that despite the relatively low avian species diversity of Irish peatlands, they are of enormous conservation value due to the presence of species of high conservation concern such as Willow Ptarmigan (Red Grouse) Lagopus lagopus and Eurasian Curlew Numenius arquata.     

Marginal range expansion in a host-limited butterfly species Gonepteryx rhamni

1. The British distribution of the butterfly Gonepteryx rhamni (L.) follows closely the range of its natural host plants, Rhamnus catharticus L. and Frangula alnus Miller, suggesting that it is one of the few British butterflies that has a host‐limited distribution. In North Wales, this species has its range margin, and it was recorded only occasionally in a 35‐km² area prior to the 1980s. Frangula alnus bushes were planted in the area in about 1986, allowing the hypothesis that G. rhamni would expand its range following increased host plant availability to be tested. 2. From 1996 to 1998, the distribution of the butterfly and its host plants, R. catharticus (native), Rhamnus alaternus L. (introduced), and F. alnus (introduced to the area but native to Britain), was mapped in the study area. It was found that the butterfly was more widespread than any of its host plants. Frangula alnus was the most widespread of the host plants, and received most eggs, suggesting that the carrying capacity of the habitat would have increased substantially following the planting of this species. Gonepteryx rhamni was able to complete its lifecycle on both introduced species in the study area. 3. A mark–release–recapture study showed that adult G. rhamni moved an average of 512 m, and 50% of movements were further than 400 m; these values are underestimates. The relatively high mobility of this species suggests that it probably perceives host plants and nectar sources as resource patches (patchy population) in this fragmented landscape, and this population now represents a satellite population of the butterfly's main distribution in Britain. 4. The results presented here confirm empirically the host‐limited distribution of G. rhamni, which expanded following the planting of extra host plants.     

Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta,Rhodymeniales) en Méditerranée

Abstract

Presence of Rhodymenia delicatula P.J.L. Dangeard in the Mediterranean. - The presence of Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta, Rhodymeniales) in the southern Thyrrhenian sea is reported. Both cystocarpic and tetrasporic individuals have been collected. Anatomical features of the reproductive structures, as well as the position of these on the thallus allowed the identification of this species formerly known for the Atlantic coasts of Morocco and British Isles.