摘要:

AbstractAttention is drawn to reports of gemmae inPleuroclada albescensandP. islandica, and to the evidence from which Krzakowa (1972) deduces thatP. islandicashould be restored to specific status. A study of British and non-British material reveals that the criteria for distinguishing two species are untenable, and supports the view that var.islandicais merely a habitat form ofP. albescens. The development of gemmae inPleuracladais discussed since their origin was inaccurately described by Krzakowa.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.1

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractA moss of non-calcareous arable fields, recognized by its yellowish brown pear-shaped tubers, has been identified asDitdchum pusillum(Hedw.) Britt.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.7

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.13

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractPhilonotis hastata(Dub.) Wijk et Marg., a pantropical species, is reported for the first time from Europe, where it has been found in the Sierra Nevada, South Spain.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.17

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractA new genus and family are proposed for a unique moss which is so greatly reduced that it is difficult to assess its affinities.Viridivellus pulchellum(Viridivelleraceae) which has the appearance of a tiny green fleece was found on earth banks in tropical forests in Queensland, Australia. Vegetative leaves are absent, their function taken over by the photosynthetic branching system of the protonema as inEphemeropsis, which is not considered to be closely related. The tiny bud-like, synoecious inflorescence has a few short, nerved bracts; there is a short seta with a central strand and a cleistocarpic capsule with a long rostrum and cucullate calyptra.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.21

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.33

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractCalypogeia afrocaernleaE. W. Jones, sp. nov. is described (type, from Kilimanjaro, in BM). Critical notes are provided onCylindrocolea chevalieri(Steph.) Schuster,SimiaS. Arnell,Syzygiella ruwenzorensisSteph., andTaxilejeunea pulchrifloraPearson. The following are new combinations:Cheilolejeunea surrepens(Mitt.) (basionymLejeunea surrepens),Stictolejeunea balfourii(Mitt.) (basionymLejeunea balfouri).Calypogeia fusca(Lehm.) Steph. is recorded from Cameroun and Ruanda;C. longifoliaSteph. from Sierra Leone.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.43

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractDuring a preliminary limnological survey of a number of high altitude lochs in the Scottish Highlands a rich benthic bryophyte flora was noted in four of these with exceptionally clear water. Eight species of moss and seven species of liverwort were collected at depths ranging from 1 to 20 m. Some of these deep-water bryophyte communities were dense with luxurious growth covering many square metres. Although bryophytes have been collected from considerably greater depths in other parts of the world, the previous maximum depth from which they had been recorded in a British lake appears to bec. 12 m. Since a few of the mosses were detached and entangled in shoots of other species they had almost certainly been washed or blown into the lochs. However, the remainder were firmly attached to their rock or mud substratum and, although several are not typically aquatic and had almost certainly originated from terrestrial habitats, they had obviously adapted to the relatively stable deep-water environment. The lochs in which these bryophytes occur are covered by about 1 m of ice and varying depths of snow for up to 7 months of the year, thereby considerably reducing the amount of light penetrating the water. Ice scour and wave action have a marked influence in preventing widespread colonization of the littoral zone down toc. 1 m.We should like to thank Dr M. E. Newton and Mr M. O. Hill for confirming the identification of the mosses, and Mrs J. A. Paton for determining the liverworts.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.55

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractTwo types of fires were distinguished, rapid fires and bonfires, the amount of ash deposited and the intensity of heating both being greater during a bonfire. Rapid-fire sites are recolonized largely by the pre-burn species, but on bonfire sites, after an initial delay period, in which both angiosperm and bryophyte growth is inhibited, a characteristic bonfire community is formed in whichFunaria hygrometricais the most conspicuous species. Field experiments and soil analyses confirmed that edaphic conditions were of primary importance in determining the establishment of the bonfire community and showed that a major difference between the two sorts of fire lay in their effect on the surface soil.After a bonfire, high concentrations of soluble organic matter and inorganic nutrients were found. With the exception of the calcium concentrations, these decreased with time, the levels of potassium, magnesium and phosphorus approaching or even reaching those of the unburnt soil after 18 months. It seems very likely that after an initial increase in the levels of both ammonium- and nitrate-nitrogen, the rate of nitrification would be stimulated and remain high for a considerable length of time. Rapid fires, as expected, appeared to have relatively little effect on the surface soil, levels of calcium and phosphorus in particular were never as high as in bonfire soils and it is most unlikely that there was any stimulation of nitrification.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.63

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor

摘要:

AbstractLiterature dealing with the use of bryophytes for water quality assessment is briefly reviewed. Reasons for selection of the two bryophyte species,Eurhynchium riparioidesandFontinalis antipyretica, used in transplantation experiments, are discussed.Results are presented showing that the breakdown of the two bryophyte species, exposed at six stations in the river Ebbw Fawr in the winters of 1970 and 1973, reflects improvements in water quality both downstream of the main source of pollution as a result of dilution and precipitation of pollutants, and over a period of 4 years as a result of improved effluent treatments.Modifications of the technique to deal with various types of pollution are discussed.

ISSN:0373-6687    

DOI:10.1179/jbr.1976.9.1.81

出版商:Taylor&Francis    

年代:1976

数据来源: Taylor