Shingle Beaches Research Articles

Nest building by birds

What is a bird nest like? Bird nests vary enormously among species in their form, size and composition. The nest of a long-tailed tit (Aegithalos caudatus) is a flexible bag composed of small-leaved mosses entangled in myriad loops of fluffy spider egg cocoon silk - a 'Velcro' fabric. For insulation, this bag is lined with as many as 2,000 small feathers. For camouflage, the outside of the nest is covered with a few thousand small lichen flakes. At the other extreme of nest complexity is the nest of the Arctic tern (Sterna paradisea), which is often no more than a shallow depression scraped in a shingle beach. The size of nests is equally variable. An Antillean crested hummingbird (Orthorhyncus cristatus), at ∼2.4 grams, may be more than twice the weight of the tiny nest cup on which it sits, while the massive platform nest of the bald eagle (Haliaeetus leucocephalus) can be three metres in width and weigh up to three metric tons, about 600 times the weight of the bird itself. The composition of nesting material varies from grasses and twigs to those used by the common tailorbird (Orthotomus sutorius), which stitches together a folded-over living leaf with threads of spider silk.

The Intellectual Bully of Baltimore

The Intelectual Bully of Baltimore Richard O'Mara Marion Elizabeth Rodgers , Mencken: The American Iconoclast: The Life and Times of the Bad Boy of Baltimore. Oxford University Press, 2005. 662 pages. $35; Terry Teachout , The Skeptic: A Life of H. L. Mencken. HarperCollins, 2002. xviii + 396 pages. Illustrated. $29.95, $15.95 pb. I've been walked through H. L. Mencken's life before, each time convinced the claim has been overworked. Yet each time more is brought forth about the man—how he lived, worked, and related to people; successive biographers, critics, idolaters bore in closer in ten or more works since 1925, much to the reader's interest and the subject's disparagement. William Manchester (Disturber of the Peace) wrote an affectionate tribute. Carl Bode (Mencken) was correct, objectively academic. Terry Teachout (The Skeptic, now available in paperback) may have seized the essence of the man: it was all in the writing. Mencken proved that extraordinary style, when animated by a specific skeptical disposition, could trump substance, even want of it. I have just emerged from Marion Elizabeth Rodgers's long book, jammed with more facts about the man than stones on a shingle beach, but the mystery, to me at least, remains: I don't know for certain why H. L. Mencken was so famous, though I am ready to admit he was, still is. A single fact related by Vincent Fitzpatrick, the scholar and Mencken biographer who keeps the Mencken Room on the third floor in the Enoch Pratt Central Library in downtown Baltimore, persuaded me. According to the sharp-eyed minions of the clipping service Dr. Fitzpatrick employs, Mencken remains the most frequently quoted American author, even today. (Well, it's either he or Mark Twain.) Every year Fitzpatrick fills hundreds of pages of a scrapbook with articles about Mencken or with quotations from his work. In fact, a few years back, while living in Mexico, I sent Fitzpatrick a copy of Mencken's posthumous advice to those who might want to honor his spirit, urging them to "forgive some sinner and wink your eye at some homely girl." That's what I call staying power. That's what I call global reach. Marion Rodgers worked hard on this book; she seems to have tracked down and talked to every living person who had some kind of connection with Mencken. She read millions of words in libraries and private collections, his dossier in the fbi. Her book, says the blurb on its cover, is "the full portrait of one of America's most colorful and influential men." Why do I think Oscar Wilde? Why do I think The Picture of Dorian Gray? Yet I am grateful to her. Anyone with even the faintest interest in the "Sage of Baltimore," the "Glare of the Sunpapers," or, her preferred epithet, the "Bad Boy of Baltimore," should be as well. Owing to all that industry [End Page 146] she's gotten to things few people knew about before, and she treats more thoroughly incidents only touched upon by other biographers—such as her account of Mencken's brief tenure as editor of the editorial page of the Evening Sun. I never met the man; he died nine years before I landed at the Sunpapers. (This is the way Baltimoreans referred to the two papers published here; they still do, though only the morning paper remains.) My only connection, tenuous indeed, is that I worked for six years on the editorial page whose staff Mencken terrorized during the three months he served as its editor. I have met three, and briefly knew two, of the victims of that horrific tenure: Robin Harriss and Gerald Johnson, a noted Maryland historian whose bust is positioned in the Pratt's soaring Central Hall. Mencken was put in charge by the publisher, Paul Patterson, and told to rattle the Ivory Tower. This he did—and in the process revealed himself as a raging ideologue and vicious propagandist. He thought the staff a pack of second-raters, harried them, rejected their ideas, rewrote their copy, nudged aside those whose opinions, especially on FDR and the New Deal, collided with his. He ordered two of...

Number of tracers required for the measurement of longshore transport distance on a shingle beach

The aim of this study was to identify a method for determining the number of tracer particles required to define the mean longshore transport distance of indigenous littoral shingle with a particular level of precision. A method is presented which can be applied to existing tracer data to determine both the precision of the measurements collected and the number of tracers required to achieve a particular level of precision. The method, which utilises well established statistical relationships, is demonstrated by applying it to archive tracer data. The study demonstrates the sensitivity of the number of tracers to the variance of the transport distances of indigenous particles at the site and the precision with which the investigator wishes to define the mean. It is anticipated that application of the method by other practitioners, in the future, will allow a dataset to develop which can be used alongside the method presented here to allow the number of tracers required for a study to be estimated prior to entering the field. Results are presented to initiate the development of this dataset and a “look-up chart” derived using the method is given to aid its application.

Habitat dynamics at the catchment – coast interface: contributions from ELOISE

This paper summarises contributions made by the ELOISE cluster of research projects to our understanding of European coastal habitat dynamics. ‘Habitat’ is used as the key concept defining Europe's coastal ecosystems following the European Community, which uses ‘habitat’ as formal currency in its directives on water and nature use, management and conservation. Eight aggregate habitat categories are identified: cliffs, shingle beaches, and associated kelp beds; dune complexes with freshwater wetlands; salt marsh; sandbanks and mudflats; seagrass beds, lagoons; subtidal sediments, and open sea pelagic. We distinguish between dynamics ‘within’ and ‘between’ habitats. The former tend to be coupled to physical forcing. The latter concern transitions from one habitat to another. Both types have been charted for the eight habitat categories. The Drivers – Pressures – State – Impact – Response framework is used to review the possible impact on habitat of foreseen future changes in key drivers and pressures, which would lead to major changes in the state of European coastal ecosystems. Drivers comprise climate change, the increase in built-up area, expansion and intensification of trade, ports and related industry, as well as of fishing, aquaculture and agriculture. Together these would lead to sea level rise and coastal erosion, contamination, eutrophication, and loss of biodiversity, but to different extents in Europe's regional seas. This report concludes with specific recommendations for future European coastal research.

Rosa rugosa Thunb. ex Murray

Rosaceae, Rosoideae, Rosa L.; subgenus Eurosa Focke; section Cinnamomeae (DC.) Rehder. Japanese Rose. Rhizomatous multi-stemmed erect deciduous shrub, strongly suckering, mature clones forming impenetrable thickets. Rhizomes woody, with orange-brown cortex and triangulate scale leaves. Rhizome branches and suckers emerge from axillary buds subtended by scale leaves. In addition, suckers may arise from buds on the roots. Stems erect, sometimes arching, to 1.5( − 2) m, often much branched, tomentose when young, densely prickly. Cortex light yellowish brown. Prickles subulate, slender and straight, of all sizes down to acicles. Larger prickles tomentose, at least near the base, and usually glabrous in the apical part. Leaves alternate with (5–)7–9 leaflets contiguous on the rachis. Leaflets nearly equally sized, 2–5 × 1.5–3 cm, leathery and robust, widely elliptical, acute, with broadly cuneate or rounded base. Adaxial side dark green, conspicuously bullate or rugose, rather shiny. Abaxial side green-grey, tomentose to pubescent, with sessile pale glands, and with reticulate nervation. Leaf margin bluntly and simply crenate-serrate, involute, edge of teeth often deflexed. Petiole and rachis densely pubescent, and with many unequal subulate prickles. Stipules pale green, densely pubescent, 2.5 × 1–1.5 cm, divergent, the free part broadly ovate or deltoid. Flowers usually solitary or few together, 6–9 cm across, fragrant, nectarless. Sepals 2–3 cm, entire, with a broad, expanded tip, appressedly pubescent, aciculate and glandular (sometimes with stipitate glands), erect on the hip, persistent. Petals five, bright purplish-pink, sometimes white ( R. rugosa f. alba (Ware) Rehder). Stamens 200– 250 per flower, and styles often more than hundred. Styles pilose; stigmas in a large, domed head, sunk in the narrow, concave disc; disc 2.5–4 mm across; orifice large, at least half the diameter of the disc. A hypanthium (hip) encloses the achenes. It is depressed globose, 1.5–2 cm long and 2–2.5 cm wide, with a distinct neck below the sepals, dull green to orange when unripe, becoming glossy and brilliant red when ripe, most often smooth. Pedicel of the same length as the hip, tomentose, often with gland-tipped acicles, erect in flower, curved in fruit so that the hip points downwards. Achenes with a woody-bony pericarp enclosing the seed. Achenes broadly ovoid, obtusely angular, 4.0–6.0 mm long and 2.0–2.6 mm wide and 1.8–2.2 mm thick, with a distinct suture on both ventral and dorsal sides, hilum basal. Achene surface more or less lustrous, orange-brown. Mean seed (achene) mass is 6.6 mg. The albumen is oily. No subspecies of R. rugosa have been recognized in the British Isles. Despite the many cultivated varieties of the species, mainly forms close to the wild type are seen naturalized. However, naturalized clones may be confused with R. × hollandica (syn. R. × kamtchatica ). This taxon differs morphologically from R. rugosa by having soft-textured, dull leaflets, without prominent veins, less prickly stems, conspicuously glandular sepals, and smaller flowers and hips (Rutherford 1990). Taxonomic position: Rosa L., subgenus Eurosa Focke (syn. subgen. Rosa ), section Cinnamomeae (DC) Rehder (syn. sect. Rosa ; sect. Cassiorhodon Dumort.). Section Cinnamomeae is central in the subgenus Eurosa , which contains all but four of the approximately 150 Rosa species in the world. The diploid species of this section, including R. rugosa , are probably basal in the reticulate evolutionary series from diploid species to irregular polyploid species within this genus (Erlanson 1938; Grossi et al . 1998). Originally introduced as a garden and landscape ornamental, and widely used as rootstock for other cultivated roses, R. rugosa can be found in many different cultivated settings. Now a well-established naturalized alien occurring scattered throughout Britain and invasive in fixed dunes and other coastal habitats.

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Laboratory abrasion tests on beach flint shingle

Abstract Laboratory tumbling experiments demonstrate that rounded flint beach shingle is less durable than commonly supposed. The mean rate of abrasion for dark grey Sussex flints (Senonian) in the first few hours of tumbling increases with weight whereas that of white Normandy flints (Turonian and Coniacian) does not. Depending on pebble weight, the Sussex flints abrade at up to six times the rate of the Normandy flints. Abrasion rates also vary according to tumbler load, the water:shingle ratio, and tumbling period. The abrasion rate of Sussex flints decreases with time at a much greater rate than could be expected from the reduction in size. The abrasion debris is mostly silt sized, but small quantities of sand are produced from samples containing larger pebbles. In situ abrasion of flint shingle is estimated to be significant, reducing the protection shingle beaches afford to cliffs thus exacerbating Chalk cliff instability.

Results of a Three Year Monitoring Programme on the Natural Recovery of Vegetation after the Erika Oil Spill: Lessons for Adapting Response Techniques

ABSTRACT The Erika oil spill and the attendant cleaning operations it required have impacted almost every type of Breton shoreline, habitats and plant communities on shingle and sandy beaches, rocky cliffs, marshlands and dunes. The French Ministry of the Environment (Ministère de l'écologie et du développement durable) launched an impact assessment in 2000 on oil spill clean-up operations and the recovery of impacted vegetation via the «Réseau de suivi des conséquences écologiques et écotoxicologiques de la marée noire résultant du naufrage de l'Erika» (Monitoring network of the ecological and ecotoxicological consequences of the Erika oil spill). The Cedre and the Conservatoire Botanique National de Brest are dealing with the terrestrial vegetation program. Vegetation was surveyed in sixty locations where one hundred quadrates were recorded covering all vegetation types including all the degrees of oiling and the varying amounts of damage resulting from the removal of the HFO. A few examples of the oiled areas are discussed. The three year monitoring program shows a high degree of persistence of the HFO in uncleaned quadrates of a number of habitats. The FO 6 did no really serious damage in terms of mortality, vegetation cover and species composition. The survey illustrates how gentle manual oil removal techniques can enhance vegetation recovery within the space of a few years. It also exemplifies how some techniques have a very negative impact such as HWHP washing which only serves to delay recovery.

Excavation of two burials at Galson, Isle of Lewis, 1993 and 1996

Two burials of Iron Age date were recorded at Galson during rescue excavations in 1993 and 1996, as a result of erosion of the steep, north-facing sand-dune face, which rises over 6 m between the shingle beach and a field wall. This erosion face is the site of a well-known cemetery and settlement extending in date at least from the Iron Age to the Norse period. The burials are placed in the context of past discoveries at Galson and a brief consideration of the evidence for long cist cemeteries in the Western Isles is presented. The excavations were funded by Historic Scotland.

Tidal effects on cross-shore sediment transport on a shingle beach

This paper presents a model study of the sediment transport processes of a shingle beach under the combined action of waves and tides. Parallel experiments were carried out with a constant water depth corresponding to the high water level of the tidal experiments, thus allowing a direct comparison between the two cases. It was found that the presence of the tide affected the beach behaviour differently depending on the wave climate. Under storm conditions, a rolling bar was clearly seen moving below the Mean Water Level (MWL) with both the flood and ebb tides. Under swell conditions on the flood, sediment was eroded once a critical depth had been reached but was moved onshore in the uprush to form the berm. The presence of the tide was shown to increase the size of the berm in a summer profile, and push the offshore bar further seaward in the winter profiles. The overall beach slope did not change when subjected to the wave attack without the tide but altered significantly under the combined action of the wave and the tide.

Life expectancy of shingle beaches: measuring in situ abrasion

In situ abrasion of shingle beach material is a neglected area of study in coastal geomorphology, with reduction in beach volumes normally attributed to longshore and offshore drift. Results from field abrasion experiments conducted on flint shingle beaches on the East Sussex coast, southern England, show that in situ reductions in volume of beach material may be more significant than has been thought. Two beaches composed almost entirely of flint shingle were seeded with hard quartzite from a Devon beach and less resistant limestone from a South Wales beach that are readily distinguishable from the flint.The seeding commenced in January 2001. The pebbles, similar in size and shape to the natural flint shingle, were left in the surf zone at two sites. Prior to exposure the pebbles were engraved with a code number and weighed. At regular intervals those that could be re-found were re-weighed and returned to the beach. Abrasion rates were calculated for each pebble as percentage weight loss per tide. By the end of October 2001, more than 700 measurements of abrasion rates had been made from a total of 431 pebbles.Average limestone abrasion rates (0.0266% loss of weight per tide) were three times greater than those of quartzite (0.0082% per tide). Measurable abrasion rates were recorded over just a few tidal cycles, not only in severe wave conditions but also in much calmer weather. The maximum abrasion rates recorded exceeded 1% per tide for limestone.

Diaspore ecology ofMertensia maritima: effects of physical treatments and their relative timing on dispersal and germination

This paper reports an experimental study of water dispersal potential and germination of the shingle beach plantMertensia maritimain which we consider the effects of physical factors (cold treatment, mechanical wear of the pericarp and salt‐water exposure) on the diaspores. Our approach also includes testing effects of different orders of the treatments, in contrast to most earlier studies of diaspore ecology. A cold period was necessary to break seed dormancy, and prolonged cold treatment (stratification at 2°C) enhanced germination. Mechanical wear of the pericarp before cold treatment did not affect germination, whereas mechanical wear after cold treatment increased germination significantly. Seeds exposed to 6 weeks of cold treatment before floating in salt water for 6 weeks did not germinate. In contrast, for seeds given the same cold treatment after floating, the germination was more than 50%. Most undamaged and slightly damaged nutlets stayed afloat throughout the dispersal experiment (9 weeks) in 3% salt water, whereas seeds that fell out of damaged nutlets sunk immediately. Thus, the results suggest that the potential for long‐distance dispersal is high unless the diaspores (nutlets) are severely damaged, but the order of cold treatment and water dispersal seems to be of great importance for germination: seeds dispersed in autumn (before cold periods) have a much higher probability of germinating than seeds dispersed in winter or early spring (after a cold period). Similar effects of the relative timing of physical processes have hitherto only been reported for two other water‐dispersed beach plants. Future studies in diaspore ecology should consider such timing effects as they may be important determinants of the distribution and abundance of plants.

A review and assessment of longshore sediment transport equations for coarse-grained beaches

Previous assessments of analytical longshore sediment transport formulae have been heavily biased towards sand-sized sediment. All have noted the shortage of high quality field data from coarse-grained beaches against which to test predictions of longshore transport rates. In this paper, 12 existing formulae were identified as being potentially applicable for coarse-grained sediments and predictions from these formulae are compared using a measured annual transport rate from a shingle beach and a concurrent hindcast wave climate. Two new empirical equations are also derived, one from a numerical model calibrated against the same data set, the other derived from field experiments on coarse grained beaches. Energetics-based equations are found to give reasonable predictions of the shingle transport, despite being derived for sand beaches. In contrast, those dimensional analysis type equations which had been validated using laboratory data, grossly over-predicted the measured transport rates. The most accurate predictions were from formulae previously validated at sites similar to that used for this comparison and therefore require further testing against field data from dissimilar sites.

The Mackerel Skies, the Salmon-Crowded Seas

The Mackerel Skies, the Salmon-Crowded Seas William Greenway I've always wanted to catch a fish in Britain. Not necessarily one of those huge trout they always catch in movies in Scodand whüe wearing a tweed cap and waders, just a fish. Fish are not very far from sight since every vülage and High Street has its own fish store, the windows fuU ofwhite metal trays on snow holding cockles—soft, wet tiger claws of translucent pearl, orange rooted—red smoky kippers, shiny as sheUacked boards, bones woodburned black, Uke fern shadows, fossüs. In another tray wül be a chevron of rainbow trout, sulking. Through the ice between the trays twine conger eels thick as fire hoses. We've never quite understood how fish get into the stores, because for aU the time we've spent on the harbors of the coast, the only boats we've seen are wrecked, sticking out ofthe sand like sugar scoops, or decorative, brightly painted and covered in nets, full of lobster traps, lying on picturesque shingle beaches, puUed up next to thatched cottages. Their names seem either ironic—Uke Success, Victory, Providence, Industry, Diligence, Perseverance, or appropriate , like Blind Fortune, Happy Return, or Marie Antoinette. Only twice have my wife and I seen anybody come in with any fish. In CornwaU we saw them unload some skate onto the stone cob of the harbor , their white undersides like clown faces with the giUs like sad, downturned eyes. On the docks in Portree, Isle ofSkye, we finaUy caught a fuU fishing boat. GuUs swirled, watching the men as they worked on a board cleaning their catch, hovered, eyeing particular bits, tiU the yeUow mackintoshed, watchcapped fishermen raised one end oftheir board and slid the remains offinto the bay, the way a body is buried. When we asked them questions, they wouldn't answer direcdy "What have you caught?" we asked, and they just looked quickly, shyly at us and smüed. But when we asked, "Are those prawns?" they said "Oh, aye."To everything we asked they'd say "Oh, aye," 79 80Fourth Genre never stopping tearing heads off, separating into buckets. A local restaurant owner came out of his shop on the dock and bought the prawns, and for the next week we saw prawn salad advertised on his chalk board, a direct lesson in simple economy. Although I have always been a salt-water fisherman, what I had seen of salt-water fishing in Britain hadn't been encouraging. Someone once said you're never more than forty mues from the coast in Britain, so I guess it's not unusual to have so many kinds of fishing cheek by jowl. On the pier along the coast, they fish with huge rods they cast with both hands, flipping the heavy weights a country mile. The weights sit on the bottom whüe the treble hook, a mass of bloodworms, catches the dab, sole, flounder, cod, whatever. There's a little beU on the rod tip to teU them when they have a bite. The wind seems to be blowing every day, and they huddle in oüskins waiting for a bite. I never saw anyone catch anything, though the chalk boards at the entrances to the piers always listed as the catch of the month something I never recognized, Uke a five pound cocUing, which must be a cross between a ling and a cod. The fish they catch in these northern waters seem strange to me, more prehistoric than the fish of the Gulf of Mexico where I have always fished. No swordfish, pompano, tuna, or red snapper for them; the salt-water fishermen hold up for the camera things coelacanthine , pelagic, bony, Uke shark, skate, tope, plaice, dab, and sole, their eyes goggled or on one side of their body, ice-water fish. Scottish salmon or Welsh sewin (sea trout) aside, they seem aU bones and scales, and when I eat them I feel Uke I'm grappUng with them—they don't go down smoothly like the sauced seafood of New Orleans. So I was after freshwater fishing in the beautiful ponds, lakes, and...

Galium aparine L.

Galiun L., Section KOLGYDA Dumort. (Section Aparine Koch). An annual herb with prostrate or, more usually, scrambling-ascending diffusely branched stems 15-300cm, stout and hairy at the nodes, the four angles very rough with downwardly directed prickles. Leaves 12-60 x 3-8 mm, in whorls of 6-9, narrowly to widely oblanceolate or elliptical, mucronate, 1-veined, glabrous or with hooked bristles above, margins rough with backward-pointing prickles. Flowers 1.5 mm diameter in 2-5-flowered axillary cymes, their peduncles topped by a whorl of 4-8 bracts; hermaphrodite, sometimes male (andromonoecious). Calyx a minute annular ridge; corolla 1.5-1.7 mm in diameter, whitish, with four acute lobes. Stamens 4, exserted; styles 2, short, connate below; stigmas capitate. Two-seeded fruits with length of longest axis 3-5 mm (excluding setae), wider than the corolla, olive or purplish, covered with white hooked setae with tuberculate bases, their stalks divaricate. Mature fruit a dry mericarp with length of longest axis 2-3 mm, and a mean airdry mass of 9.65 mg ? 0.33 (10 samples of 100 from a hedgerow population). Salisbury (1974) reports the average mass of seed from shade-tolerant woodland and hedgerow plants as 3.7 mg, and Grime et al. (1988) record a mean seed mass of 7.25mg for a hedgerow population. Galiumn iparine is a highly variable species owing to a combination of phenotypic plasticity and genecological variation. The species has different responses to the environment corresponding to different environmentally conditioned life cycles [see VI (e)]; plasticity in the timing of seed germination, productivity, growth form, freezing tolerance, and the light and temperature dependence of photosynthesis enable G. apa7ine to establish itself in a wide variety of habitats. Potential variability concealed in the higher polyploid conditions, especially in the widespread hexaploids [see VI (d)], enabling them to respond to changing environmental conditions, is probably also the basis of their success. Among plants of G. apariine raised from seed collected from various sites in continental Europe, B6cher etal. (1955) distinguished at least five different climatic ecotypes or races that either may be discrete or more probably ranges of a large clinal variation: mediterranean, summer-annual (seed germinates in the spring) with accelerated development from Portugal; mediterranean, biennial from Spain; southern, winterto summer-annual from France; northern, rather late flowering winterto summerannual from Denmark and Poland; and northern, very late flowering winter-annual (seed germinates in autumn) from Denmark and Sweden. Ecotypes of G. aparine have been demonstrated by Berkefeld (1988), differing in shape of cotyledons, hairiness of stems, colour of stem edges and length of fruit spines in plants grown under uniform garden conditions from seed collected in several different habitats. In Britain, two discrete ecotypes of G. apa7i71e exist, one found in arable fields or open situations and the other growing in hedgerows (FroudWilliams 1985); the two ecotypes are very similar morphologically but differ markedly in seed dormancy and germination requirements [see VIII (d)]. Bain & Attridge (1988) provide evidence of genotypic differences in shade strategies between hedgerow and field populations [see VI (e)]. Two forms have been recognized, the rarer G. aparine f. interimediwan Bonnet, with smooth or tuberculate fruits without spiny hairs, and the common form G. apar-ine f. apari71e with spiny fruits (Moore 1975). Variants of G. spur-ium with setose fruits, apart from the flower characters and the diploid chromosome number, are often not easy to distinguish from G. caparine and have been described as G. spuritini ssp. infestlin (Hanf 1983). Galiuiml apariine is native on maritime shingle beaches, in primary tall-herb fen communities, and in primary alderwood in natural hydrarch successions, but is also a very variable cosmopolitan weed found in hedges, waste places, drained fen peat, on limestone scree, roadside verges, river and stream banks, and is a major arable weed, especially of cereal crops. *Abbreviated references are used for standard works, see Jolurnal of Ecology (1975), 63, 335-344. Nomenclature of vascular plants follows Florca Euri0opaea and Stace (1997) for British species.

The motion of a rigid body impelled by sea-wave impact

A wave breaking against a sea wall causes high pressure gradients to act along the sea bed, pushing objects away from the wall. This situation is modelled using pressure impulse theory to show that, for a large object near a sea wall, the impulsive force due to the wave will move the object. This force can be found, given knowledge of the added mass and volume of an object. In particular, if the wall is thought of as a plane, gently sloping beach, then this theory may explain how shingle beaches are graded according to the size of the shingle, with larger boulders being moved farthest by the impact of a wave. In order to obtain estimates for the distances moved up, or down, the beach, a single boulder is treated as a spherical body which is free to move.

Vulpia ciliata Dumort. ssp. ambigua (Le Gall) Stace & Auquier (Vulpia ambigua (Le Gall) More, Festuca ambigua Le Gall)

<i>Vulpia ciliata</i> Dumort. ssp. <i>ambigua</i> (Le Gall) Stace &amp; Auquier (<i>Vulpia ambigua</i> (Le Gall) More, <i>Festuca ambigua</i> Le Gall)

Evidence for Late Pleistocene and Holocene sea-level, neotectonic and climate control in the coastal zone of northwest Portugal

The coastal zone of northwest Portugal can be subdivided into two geomorphological sectors: Sector 1, between the Minho River and the town of Espinho, where the coastal segments consist of estuaries, sandy and shingle beaches with rocky outcrops, and Holocene dune systems (foredunes and some migrating dunes with blow-outs). The estuaries and the foredunes in particular are very degraded by human activities. Sector 2, between Espinho and the Mondego Cape, where coastal lagoons and Holocene dune systems (foredunes, parabolic and transverse dunes) occur. This study deals with the macroscale, i.e. 100–1000 years, forcing by sea-level changes and neotectonic activity on the one hand, and mesoscale, i.e. 1–100 years, forcing by climate fluctuations on the other hand, on these (palaeo-)environments. It is shown in particular that sea-level changes and neotectonic activity play a dominant role in the evolution of the coastal zone since the Late Pleistocene. Sediment starvation on the shoreface is postulated to be one of the major causes for coastal erosion since at least the 15th century. The mesoscale role of climate is difficult to assess at the present stage of knowledge, mainly because of overprinting by the macroscale evolution of the coast. However, data on estuarine saltmarsh evolution in sector 1 point towards discrete changes in storminess, while the development of Medieval dune systems in sectors 1 and 2 are attributed to the Little Ice Age or, alternatively, to human occupation of the dune areas.

Sources of sand and gravel on the Northern European Continental Shelf

Abstract The extraction of marine sand and gravel has taken place in a number of countries around the North Sea, the Baltic Sea and English Channel for several centuries, but large-scale dredging for aggregates only began in earnest in the 1960s. Today, marine sands and gravels have an increasing role to play in maintaining European supplies of concreting aggregates as well as material for beach nourishment and constructional fill. The distribution of sand and gravel resources offshore is uneven. They vary in their thickness, their composition and grading, and their proximity to the shore. Many deposits lie in places that are currently inaccessible to the dredging industry. This paper outlines the production of marine sand and gravel in northern Europe and describes the distribution, composition and Quaternary origins of the most important marine sand and gravel resources in northern Europe. Examples are given for the UK, the Netherlands and Denmark, and in summary form for France, Belgium, Norway, Sweden, Ireland and Germany. Most marine sand and gravel deposits are of fluvial or glacial origin and have been reworked to varying degrees by marine and coastal hydrodynamic processes. They represent a range of former depositional environments, including fluvial channel-fill or terrace deposits, glacial meltwater plain deposits, seabed lag gravels and degraded shingle beach or spit deposits, as well as modern marine tidal sandbanks and sandwave deposits.

The Restoration of Coastal Shingle Vegetation: Effects of Substrate on the Establishment of Container Grown Plants

1. The use of container-grown plants in restoring shingle beach vegetation was investigated at Sizewell, Suffolk, UK, where the vegetation had been destroyed by the construction of a power station. Six species, Crambe maritima, Eryngium maritimum, Giaucium flavum, Honckenya peploides, Lathyrus japonicus and Rumex crispus, were selected to counter erosion and assist the development of a more complex and natural community. Plants were raised from stored seed, indigenous to the site, by horticultural techniques. 2. Shingle substrates are dry, nutrient-poor and heterogeneous in their physical composition. Field experiments investigated the efficacy of organic matter and fertilizer treatments as ameliorants, and examined the influence of position on the beach profile and substrate composition on the establishment of container-grown plants. 3. Neither organic matter nor fertilizer additions had any significant effect on mean plant size in any species after one field season. Planting location on the beach profile was the most important factor influencing establishment. Crambe maritima, G. flavum, H. peploides and R. crispus plants all grew significantly larger in the seaward plots, with more coarse shingle. Only G. flavum produced many reproductive plants during the first year, and these were more frequent and more fecund in the seaward plots. 4. The establishment of container-grown plants of four of the species was also compared at two sites at similar distances from the sea, but with sandy or shingle-dominated substrates, respectively. Again, greater growth on the coarser shingle substrate by three of the most characteristic shingle beach species reflected an apparent selective advantage. Thus, substrate physical composition was probably the primary determinant of differences in performance across the beach profile. 5. The use of container-grown plants to establish shingle vegetation resulted in low mortality, with rapid plant growth and establishment. Fertilizer and organic matter treatments were not generally cost-effective in establishing shingle beach vegetation from container-grown plants. The use of resources to recreate an appropriate substrate composition is of far greater importance.