Some Remarks on Blakeney Point, Author(s): F. W. Oliver Source: Journal of , Vol. 1, No. 1 (Mar., 1913), pp. 4-15 Published by: British Ecological Society Stable URL: http://www.jstor.org/stable/2255455 . Accessed: 28/06/2014 18:33

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This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions 4 Some Remarks on Blakeney Point, Norfolk

be addressed all communicationsrelating to the work of the British Ecological Society,notices of intending membership,etc. Subscriptionsfor the JOURNAL OF ECOLOGY should be addressed to the Manager, CambridgeUniversity Press, Fetter Lane, , E.C. Ecologists and Plant-geographersthroughout the world are earnestlyinvited to forwardcopies of their publications to the Editor of the JOURNAL OF ECOLOGY. By doing so they will secure early notice of their work and also help to make the Journal of Ecology a full recordof progressin the subject.

SOME REMARKS ON BLAKENEY POINT, NORFOLK BY F. W. OLIVER (With one Figure in the Text)

INTRODUCTION The present article is an attempt to place in the hands of ecologists a short general account of the Blakeney Point area calculated to convey some impression of the variety and richness of the which it affordsand of some of the more immediate problemswhich emerge fromthe preliminaryreconnaissance and surveywork of the last three seasons. The recent acquisition of Blakeney Point by the National Trust as a Nature Reserve is, we may hope, a sign of the times. Be this as it may, I should like here to express a satisfactionwhich will be widely shared by all who know it-and not least by ecologists-that so wonderfula collection of natural habitats should have been secured by the wise generosityof the donors against the possibilityof any interferencewith the operationof natural factors. Whilst the National Trust propertycomprises the distal 3-5 miles (5.6 kilo- metres)of the great shingle system termed Blakeney Point and includes the area of principal interest,all the lands, miarshes,and saltings adjoining the coast line fromWeybourne to Wells forman unrivalledfield for the attention of naturalists. As a breeding ground for wild sea fowl in summer,and as a place of call for migrantsin winter,the Point has long been famous.

I. TOPOGRAPHY We may now address ourselves to the topographical and ecological aspects of these waste lands, which consist in their entiretyof various grades of materials classifiedand thrownup by the sea on a continuousand orderlysystem. The Shingle System The outstanding topographical feature which delimits the whole is a great shinglebeach about eight miles (nearly 13 kilometres)in length which,leaving the shore at Kelling near Weybourne,runs a triflenorth of west almost parallel to the coast and ends in the sea beyond Blakeney, opposite the hamlet of . On the flank of this spit of shingle the sea continuallybeats, so that the component

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions F. W. OLIVER 5 pebbles are prevented,except for shortperiods, from passing into the restingstate. One consequenceof this enduringmobility is that the spit as a whole is encroaching on the estuary that lies between it and the mainland, but so slowly (or, more properlyspeaking, intermittently)that many years of observation are required before it will be possible to state at all confidentlythe mean rate of landward drift. But not all the shingle of this beach is active. In plan Blakeney Point some- what resembles a dilapidated comb in which the surviving teeth occur in groups near the end. The teeth representshingle spits, whieh are inserted roughlyat right angles to the main beach on its landward side, and vary in length from 100 to 500 metresor more. These laterals differfromn the main bank in that they are washed not by the open sea but by the shelteredwaters of the estuary. The mnaterialsof which they are composed are consequentlystabilised and have under- gone consolidationby lapse of time. They have arisen as successive deflectionsof the apex of the main bank during the period of growth and must be attributedin large degree to great stormswhich raged at intervals in the remote past. It is hardlypossible to study long the architectureof Blakeney Point and the incidence of presentchange withoutbeconming a convertto " catastrophism." Each time the main bank resumed its formerline of advance the last-formedlateral would be graduallyisolated fromdirect buffetingby the ocean, until,with the next inflection, it would gain perfectshelter.

i / N~a

FIG. 1. Diagramof the shingle systems of thedistal three miles of BlakeneyPoint, to showthe separatebanks and theirorder of origin. The series1 to 12 with theenclosed marshes form an aggregateknown as theMarams; Nos. 13 to 17 are coveredin largepart by a sand hill termedthe Hood; the Headland(Nos. 19 to 26) bearstwo systems of -theLong Hills overlyingNos. 19 and 20, and theBeacon Hills occupyingthe areawithin No. 26. Betweenthese two sets of sand dunesis thegreat Pelvetia marsh. All themarshes belong to thenarrow- mouthedtype with the exception of x, y,and z, whichare of the open variety.

In the numberand complexityof its laterals the Blakeney spit is most remark- able, and in this respectcertainly transcends all similar formationsin the British Isles. To the plant ecologistthe interestis of course great,as he findsto his hand a long series of homnologousstabilised laterals, the relative ages of which are determinedby their positionsin the system. Some idea of this richnessin laterals will be conveyed by the accompanying diagram (Fig. 1) which represents in simiplifiedand approximate fashion their positions and the order of their pro- duction. As regards their general distribution,the laterals are restrictedto the distal enidof the main spit; the firstof them is inserted nearly five miles fromthe base,

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions 6 Some Remarks on Blakeney Point, Norfolk whilst,in all, lnofewer than 26 are concentratedin groups on the terminalthree mile stretch. This tendency of laterals to appear only towards the close of the phase of growthin length of a spit would appear to be general to the type; it is well illustratedon a much simplerscale by the HuirstCastle bank at the mouth of the Solent. It will be noted also that the congestion of laterals is very great at the tip or " Headland," the wideningof which is really due to the lateral accretion of almost contiguous apposition beaches, a process which appears to be still in operation. No attempthas been made to represent-these latter in the diagram1. Actually they forman extensive ribbed platformof shingle which has been largely masked by the accumulation of blown sand in the form of ranges of dunes. Correlatedwith this apical transitionfrom the hooked spit to the apposition type, growthin lengthhas ceased, as is shown by the published maps of the Ordnance Survey (since 1834); actually the tip has retreated some 300 metres during this period. The source of the shingle still collectinghas not been ascertained. If the conjecture of driftedshingle from the ocean floorbe dismissedas unsupportedby evidence,the material must be derived either fromthe waste of the clifs to the east of the point of departure or, if that be inadequate, as I believe it to be, then by redistributionof existing accumulations. The last alternative-that the widening of the Headland is at the expense of the spit as a whole-does not necessarily imply any serious attenuation of the main bank either in the recent past or the near future,for a simple calculation will show that if the shingle were stripped from the sea-face throughoutthe full length of the beach to a depth of only 6 inches (15 cm.) and transportedto the tip, the supply of material thus obtained would sufficeto bring about enormous extensions. As the average diameter of the bank at low water is nearly 160 i., the anmountthus removed would be hardly perceptible. Though the laterals show great variabilityin length,breadth, and height,there is general agreementin profile. The acroscopic face is invariablyset at a steeper angle than the basiscopic. This coniditionis of course most marked in the case of the last-formedilateral, the acroscopicface of which is in contact with roughwater. This bank is highly imobileand its shoreward travel is, in consequence of its restrictedwidth, much more rapid than that of the main bank-so much so that you may findin the beach at the foot of the slope of the sea-faceof the last lateral the resurrectedremains of the bushes of Suaedafruticosa which originallygrew on its inner edge and over which the whole body of the bank must have passed. Though the contours of these laterals, as they stabilise, lose somewhat of the shapelinessof the bare and active phase, as a joint result of settling down and of colonisation by a covering of vegetation,they still preserve, even into advanced maturity,the differencein slope to which referencehas been made. There remainsone other importanttopographical feature of these laterals that demands attention, and this is the L-shaped terminal which so many of them possess. The phenomenonis particularlywell shown by the series 1 to 12 on the area termed the " Marams." The explanation camieto light in the early part of 1911, when, as a consequence of continued tempests from the west, the rather exposed tip of the Long Hills bank (No. 20), previouslyquite straight,was broken I They would come betweenbanks 25 and 26 (see Fig. 1).

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions F. W. OILIVER 7 offand turned througha riglhtangle. It is needless to say that this new terminus has been kept under close observation since that time and that all alterations of formas well as the advent of plants are being placed on record.

The Dunes

Having now attempted to convey an impression of the highly conmplicated characterof the shingle system of Blakeney Point, the relation to it of the other formnationsmust be touched on. First we may take the dunes. The Blakeney spit is almost unique among this class of formationsin that blown sand has been deposited upon it in quantities considerableenough to formnfairly extensive systems. The two largest occur respectivelyon two par'ts of the Headland, niamely,(1) overlyingbanks Nos. 19 and 20 to formthe Long Hills, and (2) the Beacon Hills, inside No. 26, along the sea front to forma series of more or less parallel ranges still in process of extensionon the seaward shingle plateau-this is the larger of the two, and has a presentarea of about 100 acres. In addition to these principal dune areas there is a third one consistingof a single horseshoe-shapedhill known as the Hood and standing on its own small complex of laterals (Nos. 13-17). The remaining six miles of the spit, including the Marams, is entirelyfree froin dunes. A feature of great ecological interestof these three dune systems is the fact of their resting on foundationsof shingle of which the historicsequence of developmentis evident. From their position on the shingle complex their order of appearance would be (1) Hood, (2) iLong Hills, (3) Beacon Hills; and that ainy one of them should have appeared out of its proper sequence is out of the question. The vegetation of the three areas, when compared, fully bears out the expectations based on the historic sequenice. It is not necessary to go furtherinto the miatterhere, however, as Mr E. J. Salisbury, who has acted as leader of the "floristic" section with our parties for three seasons, will I understanddeal with the questioni in a forthcomingpaper on the vegetation of Blakeney Point. Whilst the Hood and the Lolng Hills are in fairly advanced phases of successionl,the Beacon Hills systemis still actively growiingon its seaward edge, where embryoPsctrnact- dunes can be followedreadily throughall the earlier stages of development. Conspicuous by their absence fromithe Blakeney dunes are the freshwater dune marshes, " pannes," or " slacks," so characteristic of, for instance, the Southport area. The reason for this is doubtless to be found in the nature of the foundationon which the dunes rest. For the productionof dune marshes a water-holdinglayer is required; at Blakeney the dunes are founded upon shingle. At the sanle time our dunes are diversifiedby curious dry depressions or " lows" to which passing referencewill be made later on.

The Salt Marshes From the dunes we pass to the salt marshes which have accreted on the lee side of the spit, more especially in connectionwith the laterals. Whenever these banks are clustered together, as at the Marains and the Headlatid, the flats between have becoimmecarpeted witb limalophytesand silting-uplhas procecdedapace

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till the level of the ground has risen above the high water mark of neap tides. On the other hand, where the "teeth" of the "comb" are missing this,process is retarded. In this connectionthe presence of the L-shaped terminals must have been a factorof real importance,as by narrowingthe mouth of eaeh little bay to the channel of its creek,and thus controllingthe onrush and escape of the tides, the period of tranquillitynecessary for sedinmentationis prolonged. We have here an excellent example of a naturally produced mechanismrivalling in efficiencythe artificialbaniks which are thrown up to promote "warping" when salt marshes are earmarkedby the exploiterfor reclamation. Here and there a terminal,notably on the Marams, has actually closed its bay, effectingwith its tip a junctionlwith the bend of the next bank behind. In all these cases, however,the tide has cut a new passage and there is nothing about the characterof the vegetationor heightreached by the marsh to distinguish such freaksfrom those with a primarymouth. What has been said as to age seriationof the lateral banks holds equally of the marshesbetween, except that the open unbarrieredbays have to be eliminated fromthe series. If we take, for example, the bay between the Hood and the Marams (i.e. between banks Nos. 12 and 13), it is only within quite recent years that the pioneer halophytes have settled in any quantity and this only in the corners adjacent to the main beach. In point of fact, such bays are only just settling into the primary phase and are far behind even the youngest of the properlybanked marsheson the Headland, such as those between banks Nos. 20 and 25.

The Shingle Low This is a peculiar type of very distinctive of the Blakeney area and perhaps restrictedto shingle complexes of the present type. Whilst it would seem in all cases to be associated with stabilised shingle,it has a wide ralngeas regardsposition, height above sea level, and actual form. Typically the shingle low occurs at or near the confluenceof two juxtaposed laterals and is essentially the depression between them, the floor of which is formed of shingle. In the majority of cases (in which the low is cut off) the highest spring tides fill these lows, the water not flowingoff at once but under- g,oingpercolation or evaporation; in this way their shingly bottoms become covered with a fine dry mud. In other cases the shingle low is open to the ,being the extension of this into the angle where the two containirng laterals converge. These muddy shingle lows have much in commonwith the salt marshes,from which, however, their vegetationis very distinct. Sometimes, as on the Headland, similar lows have been isolated from tidal invasion by the movement of blown sand; if this isolation has occurred early enough the low consists of bare shingle upon which from tiine to time loose sand is deposited, but as often as not, owing to their dryness and the consequent slowness of plant invasion, the wind clears away the sanid, the low persisting for long periods as a dry shingle causeway through the dunes. In other cases isolation has been preceded by a period of tidal invasion with deposition of mud and the appearance of a characteristicvegetation. LateI when invaded by sand

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it remains,and the vegetation undergoes a characteristic succession. We may thus distinguishamong these shingle lows formswhich are bare, muddy or sandy, and others containing mud overlaid by sand. In view of the very peculiar character of their vegetation (which includes some of our choicest plants) the forinationof the shingle low will fullyrepay the labour of workingout in detail.

II. THE PLANT COMMUNITIES Apart from the dunes already mentioned, the following are the principal types of habitat: (1) the mobile shingle; (2) the stabilised shingle; (3) the narrow-mouthedsalt marshes; (4) the broad-moutlhedbays and mud-flats; (5) the shingle low. Between some of these there are of course intermediateor tran- sitional habitats, as for instance where the shingle borders on the blown sand. These may now be taken in order and their characteristic vegetations indicated. The Mobile Shingle The vegetation of this, which is unusually abundalnt at Blakeney for the type of habitat, includes two distinct elements of which the non-halophyticis represented by innumerable mats of Silene maritimnaand Arenaria peploides- both with unlimitedplexuses of subterraneanrhizomes; the great Rumex trigranu- latus and Glaucium luteum, with their long erect swollen rootstocks; and the yellow stonecrop,Sedum acre. With these are a host of other species, including several rarities,but we are mainly concernedhere with the commonthings. Most of these plants are to such an extent halophobic that if drenchedwith sea-water the foliage is apt to discolour and die, though the buds and undergroundparts survive. These plants hold their own-some by the exuberance of their vegetative methods, others by rich output of seed, and others again, like Sedunt, by a combination of both methods. The halophiyticelement is representedfirst and forernostby Suaeda fruticosa which is the halophyte of shingle par excellence. This plant fringes not only the lee side of the main bank but is even more abundant on the stabilised laterals. On the main bank it establishes itself from seed in the drift line of the lee talus and thrivesamazingly when buried, in virtue of its great capacity of strikingroot and pushing new branches. As the shingle rolls landwards this plant holds its own at higher and higher levels till in some cases specimens reach the seaward side of the crest where however the conditions generally prove too boisterous forpermanent occupation. No plants are more effectivein obstructingthe travel of the shingle thrown over the crest by the seas and tides than these bushes; a differencein height of 60 cm. or more in the shingle on the windward and leeward sides being of frequent occurrence. Should the economlicnecessity of curbing the mobilityof these shingle beaches be sufficientlyurgent, a few years' study of the peculiaritiesof this plant will, I am satisfied,provide the solution. In addition to Suaeda fruticosa, which is proper to the shingle,many of the halophytes of the adjacent salt marshes also effectan establishment. This they do by growing through the shingle as it buries them,and several of them form ioots in the new medium and may, as in the case of Artemisiamar-itinza, become

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions 10 Some Remarks on Blakeney Point, Norfolk quite independentof attachmentto the marsh soil. This probably explains why this plant is occasionally met with well above tidal limits,like Suaedcafruticosa. The horizontaldistribution of Artemnisiaon the shingle also deserves notice. This plant is not scattered everywhereon the marshesof the Marams, but is restricted to a zone where the salt marshes abut on the stable lateral banks. Consequently opportunityfor its migrationon to the advancing edge of the main shinglebank by vegetative means is localised to the points at which the Arternisiazones are intersectedby the main bank. I am informedby Mr Salisbury, who has gone into the matter,that the clumps of this plant on the shingle coincide with these intersectionsalmost without exceptioni.

On the Properties of Shingle In certain respectsshingle has outstanding physical characteristicswhich tend to differentiateit fromother media inhabited by plants. One of these is its ready permeabilityto water and gases, which depends on the wide calibre of the inter- stices and consequent relative smallness of the frictioncoefficient. No two soils contrastmore than those of a muddysalt marsh and of a shingle beach, and yet, as we have seen, many of the halophytespass readily fromone to the other. The ready circulation of air in the meati of the shingle inust be physiologicallyof no little significanceto plants growing in it. Though the problermhas not yet been attacked fromthis point of view, the cognate questionof what forconvenience may be termed the adaptive responses (both morphologicaland anatomical) of halo- phytes migrating to shingle are undergoing preliminaryinvestigation with the promise of interestingresults. To the smallness of frictionbetween the pebbles may be attributedin consider- able degree its high mobilityin the unconsolidated state. The materials of the beach are in a state of unstable equilibriumand any disturbanceleads to displace- ment and rearrangement. New supplies of shingle are shot over the crest by the action of high tides and onshoregales, and spread over the lee slope of the bank, oftenin very large quantities. In this way the surfaceof the Blakeney bank was raised over large areas during the past winter to an average of about 15 cm. In process of time this incrementwill be perceived in the form of accelerated lateral travel of the lee fringeover the marshes. These two phases are doubtless related in much the same way as increased precipitationin the high Alps to the advance of the glaciers in the valleys. Another importantfactor that works for the displacement of the stolies in sitit is doubtless the percolationlof sea-water which is a nornmalphenomenon whenever there is a high tide or great waves break on the face of the bank. By rmereobservation alone it is only possible to deter- mine the mobility relations of the surface; in the absence of proper measures directed to that end we are altogetherignorant of what these relationsmay be in the interior. We see that the bank advances laterally by the extension of pseudopodiumn-likeprocesses or fingers,but until the distributionand amount of the movementcan be analysed by the employmentof shingle gauges, such as disarticulatedrods of appropriate material with niumberedsegments which could be embedded in the beach in suitable positions,we shall remain in ignorance of its real nature. To a physicistor engineer with an interest in the dynamicsof

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the shore there could be no better field for study and experimentthan this bank, which has perfectfreedom of movementin the absence of groynesor other pro- tective constructions. These are only one or two of the problemsof the bank which affectvegetation. Others that may be mentioned are the means by which supplies of fresh water are maintained within reach of all plants during the longest periods of drought, and the building up of a soil fromthe driftand other sources.

The Stabilised Shingle of the Laterals The laterals when they become shielded fromthe open sea enter on the passive phase and their vegetation undergoes large accessions, notably on the crest where a thin turfof grasses and other plants gradually establishes itself. The vegetationof the older laterals, such as those of the Marams series, shows a well-markedlongitudinal zonation correspondingno doubt to differentiationof habitat at various levels. The slopes are occupied by a dense association of Suaeda fruticosa,which alone of the pioneers of the mobile shingle is conspicuous on the laterals. Above this is the sterile Statice binervoscazone with which is commonly associated Frrankenialaevis, whilst the summit is occupied by the rich floraof the crest where some inches of soil accumulate. As to habitat factorsit is not yet possible to say very much. The lower slopes with the Sucaeda are under the regular influenceof the spring tides and are also subject, of course,at the bottom to gradual accretion of mud as the level of the marsh rises. The formationof a soil on the crest (which is outside regular tidal invasion) is probablydue to weathering supplementedby the occasional accession of driftwhich is liable to be heaped up here on the occurrenceof spring tides of quite exceptional height. The intermediate binervosa zone is in most cases especially characteristicof that part of the bank where the slopes become less abrupt as they merge in the crest. In any case this zone is a very interestingone and the physical conditions Will probably repay investigation. The pebbles are perfectlyvisible at the surface,though well covered with crustaceous lichens of which the principal are Rhizocarpon confervoides,Buellia colludens,and Lecanora atra. The growthof Statice binervoscacoming up between the pebbles is so dense that the zone tells as a vivid streakof lilac duringthe period of flowering. It may be remarkedthat this plant is one of the best " indicators" of the whole flora of the Point and tends to recur only in this class of habitat. Of what precise pbysical charactersit is indicative,however, has not yet been elucidated. As there exist at Blakeney 26 dormantlaterals, it is needless to say that a rich fieldis offeredfor the study of the vegetationsuccessions.

The Salt Marshes A distinction has been drawn (p. 8) between the salt marshes which arise in nartow-mouthedand in open embaymentsrespectively. The formermay be touched on firstas they are an outstanding featureat Blakeney Point-indeed all the marsheswhich have yet attained to a continuouscovering of halophytesbelong to the shingle-lockedtype.

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Narrow-mouthed Salt Marshes The earliest stages available occur on the Headland and so far as I know are unique. The principialsystem lies between bank No. 20 and the series of laterals beyond it to the west, and consists essentially of a continuous field of Salicornia annua with extensions into the compartmentsbetween the laterals. Packed everywhere between the stems of the Salicornia is a carpet of non-attached vegetativePelvetia canaliculata-the forma libera already describedby Miss S. M. Baker'. Dotted about at intervalsand attaining a certain degree of dominancein the wetterregions are plants of Aster Tripolium-the usual invader of Salicornia flats. At the margin where the miud rulls up to the shingle bank the principal communitygives place to a zone with prostrateplants of Obione portulacoidesand much Suaeda maritima; this is of course where the mud overliesthe shingle. Aniotherdetached mnarshoccupies the distal part of the angle between banks Nos. 19 and 20. This is characterised by much Asterand with it frequentplants of Statice hurnilis-the only locality on the Point for this species. This nmarsh, which is at a somewhat higher level than the great Pelvetia marsh, is the next oldest in the series. Passing over the Hood, where there is a tiny Juncus maritimus marsh of as yet unascertainedrelation to the other associations,we coine to the Mararnsseries. The youngest of these (i.e. the most westerly)shows a rich complex of halophytes in the centre,including Statice Limonium, Plantago maritima, Triglochin,Aster, Glyceriamaritima, Spergularia media, etc., borderedby a rich belt of high-growing Obione. In the next oldest marshto the east the invasion of the Obione is completeand the marsh bears practically a homogeneous covering of this plant in its most luxuriant form with a relict here and there of some plant of the precedingphase. Much the same fate has overtakenthe other membersof this seriesof marshes,and in order to study the later successions in this districtit is necessaryto cross the main channel of the estuaryto a strip of saltings leading fromBlakeney to Cley where the turf is largely composed of Glyceria with Armeria maritimraand CJociklearia,the Obione being restrictedto the baniks of the creeks. A very characteristicelement of the Marams series of inarshes is the zone of Artemisia maritima which fringesthe edge where the marshyground comes into contact with stabilised lateral shingle banks. No such zone of course is presentat the edge of the main shingle bank nor is it to be expected,as the contact is differentin kind. The relations at these two junctions of mud and shilngleare fundamentallydistinct. For whilst the main shinglebank gradually overwhelmsthe marsh in its advance, the shingle resting on the marsh turf,the relationsare reversedin the case of the laterals. Here it is the marsh soil which is gradually being raised so as to overlie the shingleas the level of the formeris built up by the continueddeposition of mud. The curious libera stage of Pelvetia canaliculata occurs as a very occasional, presumablyrelict, patch on one or two of the Marams marshes. It by no meains follows as a matter of course that all of these marshes were at one time occupied

1 " 01the brownseaweeds of the salt marsh."' Joutrni.Liut. Soc. Bot., 40, 1912,pp. 275-291.

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions F. W. OLIVER 13 by the Pelvetia; for apart fromthe particularlocalities mentioned,the libera form has not been found on the borders of the Blakeney estuary nor anywhereelse so far as I know. Under these circumstancesits apparition must be a very rare phenomenon-an isolated or occasional "mutation" which, as it is sterile and as the vegetative organs do not floatabout but remain sessile among the Salicornias, has no obvious means of distributionunless carried by birds. I That it is capable of establishing itself on a Salicornia flat when introduced has been satisfactorilyproved. Last summer a cartload of it was spread and netted down on the Salicornia flat immediatelyto the east of the Hood facingthe Marams. This flat was in a very early stage of the Salicor-nia phase and was entirely free of Pelvetia. When last seen, in March, the Pelvetia had settled in comfortablyand had grown and spread just as it does in the parent locality.

The Unprotected Salt Marshes

Regarding these not much need be said. Their principal positions are outside the south face of the Marams system,in the corners between the Hood and the Marams, and between the Hood and the Long Hills. A particularlyinteresting marsh of this type occurs out in the estuaryto the east of the extremrityof lateral No. 17. For the most part these are mud flatsoccupied by Zostera nana, with quantities of green algae such as Vaucheria Thureti, Rhizoclonium,IEnteromnorpha, Chaeto- morpha,and brown algae such as FThcusvolubilis-a non-fruitingspiral foim with its basal parts embedded in the mnud. These flats are evidently undergoingthe preliminaryprefaration for settlementby higherplants and in the more sheltered places &dicornia annua and Suaeda maritima are ilow appearing in constanitly increasing quantities. The inarsh lying to the east of the much wasted lateral No. 17 has made notable progressrecently b)oth in the density of its vegetation and in its height above datum. In addition to miuchSalicornia annua mingled with the algae, a good deal of Moss's new species Salicornia dolichostachyais present,together with a thin scatteringof Aster Tripolium. A special interest attaching to this marsh depends on the fact that it has been suspected by our " floristic" section of being an eroded mlarshundergoing rejuvenation; the grounds for the suspicion being the occasional occurrenceof relict (?) halophytes,usually characteristicof a later stage of succession,such as Salicornia radicans and Glyceria maritima,com- bined with genieraldeep surfacerelief. It is named the Samphire Marsh, as it is much resortedto by the local people who collect the Salicornia for pickling, The principal features of interest of the unprotectedtype of salt marsh are then the long periods duringwhich they remain dominated by algae and Zostera nana and the lateness of appearance of the usual halophytic covering. From their surface enormous quantities of bottom drift (consisting of the plants just mentioned) are swept by the tides on to the main shingle bank and also into a large catchment area to the west of bank No. 12 where several acres of decomposingseaweeds forma slough of odoriferousblack miudwhich none crosses willingly.

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions 14 Some Remarkson BlakeneyPoint, Norfolk

On the lnarrow-mouthedmarshes the drift belongs qualitatively to a distinct type-a floating drift mainly composed of the disarticulated fragmentsof the phanerogamic halophytes. In addition to the tidal marshes there are several square mnilesof saltings occupyingthe eastern extremnityof the long stripprotected by the shingle spit that have been reclaimed for pasturage. These constitute a "hinterland" of great potential interest,on which, however, no systemnaticinvestigations have as yet been made.

The Shingle Lows The vegetationof these, nmoreparticularly in the dry mud phase, is eminently characteristicand consists of dwarfbushes of Suaeda fruticosa, the spaces between being occupied by two of the niost interestingplants on the area, which are almost peculiar to this position,namely, Statice reticulata and Frankenia laevis, both of which flower profusely. On the higher slopes of the lows Statice binervosa is commonlypresent, this part of the habitat doubtless having much in comnmonwith the ordinarybinervosa zone of the laterals. Characteristicexamples occur at both ends of the Long Hills. These habitats when modifiedby the accession of sand (as in the crescent- shaped depressionsnear the Lifeboat-houseon the Headland) show a succession which includes the disappearance of S. binervosaand probably of S. reticulataand the entranceof Glaux and of Plantago Coronopusvar. pygmaea. A special account of these attractive communitiesis under preparation at the hands of the floristic section. Faunistic Notes In closingthese notes a word or two may be said on the relationsof the animal world to the vegetation. Blakeney Point is well stocked with animals which include the wild sea-birdswhich breed anmongthe embryo dunes and the winter migrants; the rabbits and other rodents on the older dunes; a rich insect fauna on all formations; and on the flats there are crabs, worms,and shellfish-in fact everythingproper to such maritimewastes. The locality indeed has achieved no little prestige as a haunt of rare birds and has long been a Mecca for ornitho-. logists. Latterly our parties have not wanted recruitswho join primarilyfrom their interest in the animal kingdom,and if this continue,as it happily may, in fullness of time an exacter and more critical knowledge should accrue, as in the analogous case of Plankton, of the multifariousand often complex relations of the representativesof the two kingdoms. To restrictourselves to the rabbits which live on the dunes, there seems no end to the havoc they are capable of working. Their principal feeding ground is the Pelvetia marsh where they browse on the Aster,and to such a degree that hardly a plant can be found without nibbled leaves, and a floweringspike is a rarity. They also pay some attentionto the Statice Limoniurn,and bite offtwigs of Obione and Suaeda fruticosa which they leave on the ground where they fall. So inveterate is the "Suaeda habit" with them that, as the, natural production of new shoots is arrestedon the approach of winter,whole banks of these bushes are

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions F. W. OLIVER 15 mowed down to the ground. When rabbits are excluded by fenicingsmall areas, the contrastbetween the Suaedas within and without is most striking and causes surprise even to those well versed in the vices of rabbits. The drift line is a measure of the depredations of these animals, and here these twigs and branches accumulate in vast quantities brought by the higher spring tides. Nor are the operationsof the rabbits restrictedto the mnarsh.There is a sand hill on the Beacon range nearly 100 yards in length covered fromend to end with a close plexus of ConvolvulusSoldcanella. In July, when this should be a carpet of flowers,hardly a corolla is to be founid-the rabbits biting them offin the bud stage just where the funnel narrows into the tube. To see this plant in all its glory one has to walk two miles along the shingle to a spot outside the rabbit radius. One more instance mnustsuffice. There is a wet depression in the dunes with a number of sand hummocksoccupied by Glaux. Whether these are interfered with in summer by rabbits has escaped observation, but in winter when the Claux is hidden fromsight rabbits make their way to these spots with unerring instinct or knowledge, even crossing water so to do, and dig up the rhizomes which they evidently devour, as fragmentsare rarely left lying about. Indirect protection of the embryo dunes against intrusion by rabbits results from the presence of the which breed here in great niumbers. I am informedby Mr W. Rowan, who has spent weeks in ambush on the breeding ground,that whilst in winter the rabbits show every dispositionto advance their warrensamong the young Psammas, in summer when the terns are in occupation any rabbit who ventures on to the nesting area is promptlyand uinceremoniously ejected. One of the advantages of working in the field alongside the exponents of other branchesthan Botany is the opportunitythus affordedof learning something of their methods. Whilst the botanist properlypays full regard to questions of habitat and the minutiae of critical formis,the zoologist seems mnoreunreservedly to identifyhimself with the Spirit of the Field by concentratinghis attention on questions of mechanismand behaviour. Of the 120 species of floweringplants that formthe known floraof Blakeney Point it is doubtful whetherwe can truly assert that we are really familiar with the full life-histories(autecology) of more than two or three. At the same time I hasten to add that there is no reason to suppose that we are in any way singular in this respect. The truth is, of course, that the full elucidation of the life- historyof any plant whatsoeverin relation to its surroundingsis a serious under- taking demanding of the investigator greater sacrificesthan he has yet been accustomed to make. We need to cultivate closer touch with the individual plants in a way that may be comparedto the unstinted devotionof the gardener. For the attainmentof this ideal some degree of emancipation fromthe trammels of currentroutine will have to be found,nmore especially during the active season of the plant. The immediate problem, therefore,which confrontsthe ecologist attached to a Seat of Learning is how to make good-his escape fromhis urban laboratory for the six summer months.

This content downloaded from 46.243.173.128 on Sat, 28 Jun 2014 18:33:19 PM All use subject to JSTOR Terms and Conditions