Ranwell, D.S.

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   Chapter (non-refereed)    Ranwell, D.S.. 1977 Extensive survey of dune vegetation in Scotland. In: Ranwell, D.S., (ed.) Sand Dune Machair 2. Colney, NERC/ITE, 12-13.   Copyright © 1977 NERC  This version available at http://nora.nerc.ac.uk/7145/   NERC has developed NORA to enable users to access research outputs wholly or partially funded by NERC. Copyright and other rights for material on this site are retained by the authors and/or other rights owners. Users should read the terms and conditions of use of this material at http://nora.nerc.ac.uk/policies.html#access    This document is extracted from the publisher’s version of the volume. If you wish to cite this item please use the reference above or cite the NORA entry                       Contact CEH NORA team at  nora@ceh.ac.uk The speculative step in the calculation concerns the relation-ship between tractive stress and sand transport rate in azone where both are changing spatially. Uniform flowrelationships cannot be relied on in such a zone, since oneimplication of Bagnold's two-stage model is a dislocatedgrain transport response to a change of wind condition. Anattempt is being made to establish this relationship withsufficient accuracy to make predictions of dune growthreliable.Were the attempt to be successful, there would be severaluseful consequences in terms of machair. Most obviously,the predictive.capacity developed would help in deploymentD. S. RanwellOver the past ten years, regular visits have been made toScotland to iMprove botanical knowledge of coastal sites inanticipation of inevitable changes. These reconnaissancevisits provided lists of vascular plant species, informationon the range of habitat and vegetation types, and on hUmanimpacts on the environment, for the Nature Conservancy.Within the past five years, with more assistance available, amore quantative approach was developed . to sample therange of habitats in representative examples of our biggerdune systems such as St. Ouens Bay, Jersey, ChannelIslands (Ranwell 1975. 1976). Strathbeg, Aberdeenshireand Dunnet Links, Caithness. Data have been subjected toreciprocal averaging analysis (Hill, 1973) and indicatorspecies analysis (Hill, Bunce & Shaw, 1975), but resultsof these exploratory analyses have not been published.Recently, these studies have been transformed by the needsof the Nature Conservancy Council for objective informationon a large scale urgently in relation to oil and other develop-rnents on the Scottish coast. The Institute of TerrestrialEcology has been asked to take responsibility for biologicalsurvey of 94 sites (mainly sand dune) all round the coast ofScotland, covering a total area of some 32,500 ha. Thestudy was started in April 1975 and is expected to run for3 years.The objectives are to determine the nature and extent ofhabitats and composition of vegetation so that objectivecomparisons can be made between stes. Also the surveyaims to record the vascular plants, terrestrial bryophytesand lichens on each site. and to estimate so far as possible,population sizes and distributions of rare species. Estimatesof the effects of human activities on the site are also to begiven.of fences used to control sand drifting. Perhaps this wouldbe less useful, however, than the consequent ability to pre-dict sand behaviour in areas where tractive stress varies forunintentional reasons in no way connected with fencesSuch circumstances occur, for instance, on any topograph-ical feature, wherever patches of bare sand occur in agenerally vegetated area, or where there are dry areas ina generally wet sand surface.REFERENCESBAGNOLD, R. A. (1941). The physics of blown sand anddesert dunes. London: Methuen,Extensive Survey of Dune Vegetation in ScotlandThe method for objective botanical and habitat survey hasbeen adapted from Bunce and Shaw (1973). Samplingpoints were pre-located objectively on 6 inch to the milemaps and located in the field by direction and distancefrom fixed features on the map. Each sampling point wasthe centre of a uniformly orientated nest of six quadratsincreasing in size from 1m2 to 200m2. The nest of quadratsgives information on habitat variability around the samplingpoint. Vascular plants are recorded in an additive way sothat only new species are recorded in quadrats successivelylarger than the 25m2 quadrat. Cover and height measure-ments of the vegetation are made for the 25m 2 quadrat, anda collection of bryophytes and lichens from this sin alsomade. Environmental data and a sketch map are recorded onthe 200m2 quadrat. Soil and water table data are collectedfrom a small pit and augur borings to 2rn at the samplingpoint, the centre of the nest of quadrats.In 1975, 1,117 sampling points were recorded at 28 sites by4 teams of two people working from May to September.Data are coded. punched onto tape and stored in acomputer. Analyses will provide objective site to site com-parisons and explore correlations between a wide range ofenvironmental factors and vegetation.Further information on the progress of the survey is givenin Institute of Terrestrial Ecology: Annual Reports for1975 and 1976.REFERENCESBUNCE, R G. H. & SHAW, M. W. (1973) A standardisedprocedure for ecological survey. J. environ. Manage. 1,239-258.HILL, M. 0. (1973). Reciprocal averaging: an eigenvectormethod of ordination J. Ecol.  61, 237-249HILL, M. 0., BUNCE, R. G. H & SHAW, M. W. (1975).Indicator species analysis, a divisive polythetic method ofclassification, and its application to a survey of nativepinewoods in Scotland. J. Ecol.  63, 597-613.RANWELL, D. S. (1975). The dunes of St. Ouen's Bay,Jersey. an ecological survey, Pt. I. History and plant com-Birds and MachairI. R. HepburnINTRODUCTIONSand dunes and machair systems have attracted a largenumber of workers from a variety of disciplines within thegeneral field of 'environmental sciences'. These includeplant and animal ecologists, geomorphologists and palaeo-. ecologists. It appears, however, that little attention hasbeen paid to the bird-life of these systems. A search of themore recent ornithological literature uncovered only onepaper on the "bird populations of a Welsh sand dunesystem", and nothing at all relating to machair birds.This dearth of information is particularly apparent whenconsidering breeding birds. Many sand dune systems (suchas Blakeney Point, Norfolk and Minsrnere, Suf folk) are verywell known to ornithologists for their regular attraction ofPasserine migrants. Such birds are normally not associatedwith the dune systems, but with the scrub or tree coverwhich is invading the dunes either through natural successionor with aid from man. Less is known (or at least little ispublished) about the breeding birds of these same systems.This paper, while not pretending to rectify the presentsituation, may be regarded as an initial statement summariz-ing the ornithological status and significance of one partic-ular sand dune and machair area in the Outer Herides —the Monach Isles.The work reported here was carried out during the summerof 1973. and concentrates on the distribution of breedingbird populations within different habitats.HABITATSThe plant communities of the Monach Isles (Photos 4 and5) were described by Dr. Randall during the first meeting ofthe Machair Working Group. As a brief summary, the 5islands situated 10 km south-west of North_ Uist are com-prised of 8 basic vegetation habitats:munities least modified by man. Bull. a. Soc. jersiase  21,381-391.RANWELL, D. S. (1976). The dunes of St. Ouen's Bay,Jersey: an ecological survey. Pt. II. Plant communitiesstrongly modified by man, the whole flOra and managementirnplications. Bull. a Soc. jersiase 21, 505 -516.WILLIAMS, W. T & LAMBERT, J. M. (1959). Multi-variate methods in plant ecology. I. Association-analysisin plant corrununities. J. Ecol.  47, 83-101.1. Unstable dunes, dominated by Arnmophila arenaria2 Flat dunes, dominated by Ammophila and Be Ills perennis3. Stable dunes, dominated by Ammophila and Carexarenaria4. Machair pasture, dominated by Bellis perennis5. Carex arenaria pasture6. Maritime cliffs and coastlands, dominated by Armeriamaritime7. Peat lands, dominated by Carex nigra8 A 'residue' of strandline and cobble-beach habitatsThe habitats relevant to the following discussion are firstly,stable dunes (which includes flat dunes), and secondly,machair pasture. These two habitats cover about 75% ofCeann Ear, the island on which most of the bird distributionsurvey work was carried out.BREEDING BIRDS13Nine species were recorded as breeding in either or both ofthe stable sand dune and machair habitats. This recordaccounted for 25% of the total number of species foundbreeding on the Monachs. Two species were foun.c1 nestingon stable sand dunes but not machair eiders, which requirethe extra cover provided by rnarram compared with theshorter, grazed machair turf, and starlings which useddeserted rabbit burrows in the dunes. Three species nestedin both machair and stable dunes- fulmars, skylarks aridmeadow pipits. The last two are commonly associated withdune and grazed pasture habitats, but the fulmar's use ofsand dune and machair habitats is of particular interest.The nest site distribution of this species was the subject of adetailed investigation, and it was found that 57% of thetotal fulmar population of 176 nests on four islands wasusing sand dune/machair nest sites. Most of these nestswere located in stable sand dune areas adjacent to the sea.Others were inland on the machair, often where rabbit

Extensive survey of dune vegetation in Scotland

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Extensive survey of dune vegetation in Scotland

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