ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00131.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

RANDALL, R. E., 1989.Shingle habitats in the British Isles. Shingle is the term applied to sediments larger in diameter than sand but smaller than boulders. Around Great Britain there are almost 900 km of pure shingle and vast stretches of rock/shingle, sand/shingle and mud/shingle mixtures. Outside Japan, New Zealand and north‐west Europe, shingle is an uncommon coastal sediment. Shingle may form fringing beaches, spits, bars, cuspate forelands and offshore barrier islands, depending upon available supply of sedimentary material and coastal topography.Species composition on shingle features is partly determined by climate which affects the geographic range of certain species. The other major factors are beach stability and beach composition. Climate results in distinctive patterns in the flora but within the each climate zone beach movement will affect the quantity of annuals, short‐lived or long‐lived perennials present. The presence or absence and nature of the fine material within the shingle will cause different combinations of species ecologically related to those of sand dunes, salt‐marsh or cliff. Coastal shingle vegetation has a distinctive flora which contains several rare or declining species as well as some common coastal and ruderal plants.At the largest shingle sites a successional sequence can be recorded which initiates with halophytic forbs near the foreshore and moves through neutral to acid grassland species with shrubs and prostrate scrub in the more inlan

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00132.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

FERRY, B. W., BARLOW, S. L.&WATERS, S. J. P., 1989.The shingle ridge succession at Dungeness. The range of plant communities which have colonized both intact shingle ridges and areas of disturbed shingle on Denge Beach, Dungeness, are described. An attempt is made to place these communities into categories of the National Vegetation Classification scheme, and further to relate them to physical and chemical gradients and variations in the shingle substrate.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00133.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

WILLIAMS, P. H., 1989.Why are there so many species of bumble bees at Dungeness?Dungeness is unique in the British Isles in that it has more species of bumble bees than any other locality. Three ideas about what governs the number of species at a locality are examined by locking at patterns of flower visits at Dungeness in comparison with those at Shoreham, a species‐poor locality also in Kent. The species of bumble bees that are present at Dungeness but absent from Shoreham show no association in their distributions among 2 km grid‐squares in Kent with the species of food‐plants that they prefer at Dungeness, nor is there any correlation between the diversity of bees and diversity of food‐plants at Dungeness and Shoreham. From the information available, Dungeness is most likely to have more species of bumble bees because it has a particularly high density of the more nectar‐rich flowers that bumble bees can use. Bumble bees feed most profitably from deep flowers because these contain more nectar than shallow flowers, although direct access to deeper flowers is ultimately limited by the length of each bee's proboscis. The distribution of worker proboscis lengths among species in the species‐pool in Kent is clumped about a median of 7.9 mm. The best foraging conditions for the maximum number of species should be provided when flowers of similar depths are present in sufficiently large numbers for all foragers to make near‐optimal flower choices. Although there is no difference in median between the distributions of the bees' proboscis lengths and the depths of the flowers they use at Dungeness, at Shoreham the flower depths used are shorter than the proboscis lengths. Among the food‐plants at Dungeness, high densities ofTeucrium scorodoniaandEchium vulgareare likely to be espec

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00134.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

WILKIN, P. J., 1989.The medicinal leech, Hirudo medicinalis (L.) (Hirudinea: Gnathobdellae), at Dungeness, Kent. An account of the ecology and conservation of the medicinal leech (Hirudo medicinalis(L.)) at Dungeness, Kent, is presented.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00135.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

WATERS, S. J. P.&FERRY, B. W., 1989.Shingle‐based wetlands at Dungeness. At Dungeness, a unique development of open water and natural wetland has occurred on the shingle beaches. Over 700–1000 years, low‐lying areas have changed from saline lagoons into freshwater lakes which are now largely infilled by reedswamp and sallow carr. Since about 1970, the water‐table has been lowered, by a combination of water abstraction and hydrological changes associated with gravel extraction. Water‐table lowering has accelerated colonization by reedswamp and sallow carr, and has caused loss of sedge‐rich marshland. Possible methods are suggested for promoting development of such marshland in artificial

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00136.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

STERLING, P. H.&SPEIGHT, M. R., 1989.Comparative mortalities of the brown‐tail moth,Euproctis chrysorrhoea(L.) (Lepidoptera: Lymantriidae), in south‐east England. The mortalities within natural infestations of the brown‐tail moth were investigated from 1982–1984 in four sites in south‐east England. Mortality agents were quantified from field and laboratory assessments. Microsporidial disease was the most important factor, causing 91.9% mortality in large larvae in one population; cytoplasmic and nuclear polyhedrosis viruses were present, but not significant. Many species of parasitoid were recorded, particularly at the end of the larval and in the pupal stages; however, combined parasitoid mortality was low. Predators were also of little importance, although cuckoos were found to take up to 19.3% of pupae at one site. Changes in density of larvae in the spring were more strongly influenced by dispersal following defoliation than by any particular mortality agent in most cases. In terms of biological control, diseases offer the greatest potential for de

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00137.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

McMINN, S., 1989.Migration studies at Dungeness Bird Observatory. The part played in the study of bird migration by the Dungeness Bird Observatory is outlined. Information concerning blackbird (Tardus merula) and robin (Erithacus rubecula) migration is presented as well as notes on migration over the sea.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00138.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

FULLER, R. M., 1989.Orfordness and Dungeness: a comparative study. Dungeness originally developed as a shingle spit from Winchelsea, across the bay which now forms the Romney Marshes and, 700–800 years ago, probably had its distal end between New Romney and Hythe. The structure seems to have been very similar to present‐day Orfordness. Then a breach at the spit's origin produced an abrupt change in accretion and erosion patterns with the eventual development of the present‐day cuspate foreland. It would seem that Orfordness is on the verge of such a breach, which is prevented by coastal defence works. Much can be learned by comparing physiographic and ecological processes at Orfordness with those at Dungeness, using Orfordness as an historical model for early Dungeness. This paper considers some of the evidence for these conclusions, examines the structures which survive to the present‐day and discusses the ecological significance of the features, especially in terms of plant successional devel

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00139.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

LAUNDON, J. R., 1989.Lichens at Dungeness. The lichen vegetation at Dungeness is reviewed. The most important lichen communities are of three types. Firstly, there are the crustose lichens which colonize the bare pebbles. Secondly, the tracts of richCladoniaturf which form the lichen heath and which play a major role in the vegetation cycle. Thirdly, there are the epiphytes onPrunusscrub. In addition, lichens on artificial substrates, especially wooden fences, are noteworthy. About 150 species occur, amongst the most interesting beingCladonia mitis, Lecanora helicopis, Lecidea insidiosa, Parmelia soredians, Rinodina aspersaandUmea glabrata.A new combination is made in the genusPorpidia.The term ‘bird farming’ is published. The fragmentation of the vegetation by building and gravel extraction receives critical comm

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1989.tb00140.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY