South-central England Research Articles

Phosphorus in soils and field drainage water in the Thame catchment, UK

Field drains were sampled at five farms in a catchment in south-central England. The farms were selected to include the main soil types present in the catchment, stagnogleys and pelosols. The phosphorus content of field drainage water was measured on several occasions from 1999 to 2000, under varying flow conditions. The components measured were soluble reactive phosphorus (SRP), total dissolved phosphorus (TDP) and total phosphorus (TP). SRP concentrations in drainage water were lower than in streams in the catchment which had no apparent point source. This indicated that many streams were receiving unidentified point sources of SRP. Measurements of P in field drainage water samples under high flow conditions showed concentrations of particulate phosphorus and SRP up to 1300 and 300 μg l −1, respectively, these being associated with high suspended sediment concentrations. Comparison of field drain and soil phosphorus contents at the locations sampled did not provide evidence of an inter-relationship. The equilibrium phosphorus content (EPC 0) of surface soil was generally higher than the SRP content of drainage water, at one farm by 1 order of magnitude. The variability in measurements suggested a larger-scale and more focussed survey would be required to characterise catchment-scale phosphorus losses from commercial farms by land use and soil type.

Chaffinch Fringilla coelebs foraging patterns, nestling survival and territory distribution on lowland farmland

Numbers of many bird species which breed on farmland, and are reliant on cropped land for feeding or nesting, declined between the 1960s and 1990s. In contrast, Chaffinch Fringilla coelebs numbers increased on farmland over the same period. This study investigates the influence of both cropped and non-cropped land on Chaffinches foraging for nestlings, nestling survival and territory density. The study was carried out on nine mixed lowland farms in south central England in 1996 and 1997. Chaffinches made little use of cropped areas when foraging for young (less than 9% of foraging visits, despite cropped areas covering 93% of study areas). Instead, trees and bushes influenced foraging patterns and breeding success. Extensive use was made of trees and bushes by adults searching for food for nestlings (75% of foraging visits were to hedges and trees within boundaries or fields, despite these areas covering <3% of study areas). Oaks (69% of visits) and Willows (15% of visits) were found to be the most favoured species of tree for foraging. In one year of the study, chick starvation was less frequent in nests located on field boundaries with Oak trees than in nests on boundaries without Oaks. Successful nests also tended to be closer to Oak or Willow trees than those where nestlings starved. Territory density was not related to hedgerow structure, presence or absence of Oaks and Willows in field boundaries, or adjacent cropping. Our findings on nest survival were supported by analysis of British Trust for Ornithology nest record data which revealed that nests associated with trees had better brood survival rates than sites not located close to trees. The use of trees and shrubs for feeding and nesting in the farming landscape and the ability to utilize unkempt hedgerows may have contributed to the ability of Chaffinches to persist on farmland despite wide-scale agricultural change in recent decades.

Discussion on lithospheric flexure, uplift, and landscape evolution in south-central England

Scientific editing by Alex Maltman. J. C. W. Cope writes: The paper by Watts et al. contains interesting ideas on landscape evolution, but by concentrating their observations locally, and by overestimating post-Anglian erosion, they may have lost sight of more widespread effects that could have been major contributors to the features they describe, and thus their causative mechanisms may need re-examination. ⇓Cope (1994) suggested that uplift centred in the Irish Sea explained the loss of >2 km of Mesozoic cover there, explaining apatite fission track analyses from the eastern Irish Sea and northwestern England. The southeasterly regional dip of the Mesozoic outcrop of the English Midlands could be attributed to this uplift; although a mantle plume was suggested as the cause, the same effect could be attributed to mantle underplating. Substantial igneous activity is known around the Irish Sea region before the earliest Antrim basalts. The Fleetwood dyke, in the Eastern Irish Sea is dated at 65.5 Ma (⇓Arter & Fagin 1993) and similar ages are known from dykes in North Wales (⇓Evans et al. 1973). Pre-basalt dykes exist in Northern Ireland whence ⇓Simms (2000) records dykes cutting Chalk and truncated by the basal Palaeogene lavas. ⇓Cope’s (1994) reconstruction of the missing Mesozoic cover of the area from the Cheshire Basin southwards led him to suggest that the resultant average gradient imparted over the Midlands from the Cheshire Basin to the Chiltern scarp was 1: 87.5. What was incorrectly calculated from this figure by ⇓Cope (1994) was the angle of dip represented by that figure, which is 0.7° and not 2°. The former is close to that recorded by Watts et al. for the area of Oxfordshire they considered and this suggests that they may have overestimated the uplift caused by lithospheric flexuring. There may be …

Lithospheric flexure, uplift, and landscape evolution in south-central England

The high level river gravels in Oxfordshire (the Northern Drift Group), which range in age from Early Pleistocene to around 450 ka, contain pebbles that were derived from a source area to the north near Birmingham. The pebbles could not have been transported across the Upper Triassic and Lower Jurassic clay outcrops of the Midlands unless the region was at or close to sea level. The present day Cotswold escarpment ranges from 70 to 215 m: this uplift must therefore have occurred after deposition of the Northern Drift Group, when the drainage of the Midlands appears to have shifted from towards the Thames basin to the Bristol Channel area. It is concluded that lithospheric flexure due to the removal of &gt;500 km 3 of soft Late Triassic and Early Jurassic clays and marls from large areas of the Midlands and their re-deposition in the Celtic Deep might account for this Late Pleistocene uplift. Uplift in the Midlands is the likely explanation for both the tilted (approximately 0.3°) plateau surface in north Oxfordshire and the change in strike of the Jurassic beds SW of Northamptonshire. Although some uplift occurred in SE England during the Early Cenozoic and Miocene, we demonstrate here that there has been significant uplift of the region in the Late Pleistocene. The tilted plateau surface in north Oxfordshire may therefore be a relatively young (i.e. post-450 ka) feature related to tectonic uplift in the Midlands.

Assessing the potential impacts of various climate change scenarios on the hydrological regime of the River Kennet at Theale, Berkshire, south-central England, UK: an application and evaluation of the new semi-distributed model, INCA

A new semi-distributed integrated nitrogen in catchments (INCA) model was used to attempt to assess the potential impacts of several recent Hadley Centre climate change scenarios on the hydrological flow regime of the entire River Kennet catchment to Theale, south-central England, UK. The climatically and hydrologically anomalous period 1985–1995 was used for baseline data in an attempt to: (1) represent any possible future climatic or hydrological variability not available from scenario use alone; and (2) attain maximum possible model calibration validity under future climates by simulating extremes of within-year hydrological variability. Substantial reductions in total annual runoff occurred, with an average reduction of 18.97%. Summer and late autumn soil moisture deficits (SMDs) increased in intensity, and were also found to persist for longer periods into autumn and (occasionally) winter. A generally enhanced hydrological regime of the River Kennet was simulated, with increased seasonality overall. A greater percentage of flow was observed to occur in spring and (occasionally) winter. Month-to-month variability of flow was discovered to be greater than annual changes. An average reduction in minimum annual flows of 46.03% occurred. Implications for catchment ecology and water resource requirements are briefly discussed. An evaluation of the new INCA model’s performance as a tool for climate change impacts assessment is made.

End-Carboniferous fold-thrust structures, Oxfordshire, UK: implications for the structural evolution of the late Variscan foreland of south-central England

Interpretation of commercial seismic reflection data from the west of Banbury, south-central England, has provided information on the late Carboniferous structural evolution of the Oxfordshire Syncline. End-Carboniferous structures are preserved in the footwall of the main basin-bounding faults of the Permo-Triassic Worcester Graben. Restoration of major pre-Triassic normal faults has allowed reconstruction of earlier compressional structures. In contrast to the WNW-ESE trend of structures to the south, in the Variscan foreland fold-thrust belt, major faults and folds in Oxfordshire are approximately N-S trending. The structures seen to deform Westphalian D-Stephanian-aged sequences on the seismic profiles are a combination of steep (30-40° dip) fault-bounded uplifts and less dominant thin-skinned tectonics, apparently showing transport to the east. In the south, some thin-skinned structures are present, and in the north cover sequences are uplifted in a narrow zone of deformation on reactivated basement faults. The amount of shortening also changes along strike, from c. 1600 m in the south to c. 950 m in the north. Reactivation of major basement faults with differential basement shortening accounts for the main structures. Localized detachment in the young and weak sediments close to the palaeo-land surface explains the thin-skinned structures seen on some of the seismic lines. These end-Carboniferous structures in Oxfordshire and structures in the Malvern-Abberley Hills represent the structural limits of a large N-S-striking intra-Stephanian uplift in the late Variscan foreland. It is suggested that the structures formed during a discrete phase of intra-Stephanian E-W-directed regional shortening prior to the final phase of movement in the Variscan belt.

Gender and Heresy: Women and Men in Lollard Communities, 1420-1530 by Shannon McSheffrey

BOOK REVIEWS797 Accurate transcriptions and meticulous scholarly attention to detaU are saUent features of this work.The explanatory preliminary chapters and exhaustive indices render it an invaluable source for scholars of medievalValencia, and one which should find a place on the shelves of aU major research Ubraries. Jill R.Webster St. Michael's College University ofToronto Gender and Heresy: Women and Men in Lollard Communities, 1420-1530. By Shannon McSheffrey. [Middle Ages Series.] (PhUadelphia: University of Pennsylvania Press. 1995. Pp. xui, 253. $38.95 cloth; $18.95 paperback.) Shannon McSheffrey's detailed study of eight Lollard communities in southeast and south central England (1420-1530) examines the interplay of gender, social status, familial linkages, and literacy to counter the idea that medieval heretical communities were more attractive to women than was orthodox reUgiosity . In arguing that Lollardy was not notably attractive to or supportive of women, McSheffrey keeps an eye on comparative findings relating to early modern and modern religious groups and on recent debates regarding literacy levels and patriarchy. The evidence is drawn from bishops' registers, court books, and wiUs, with a judicious use of Foxe where original records are missing. Only occasionaUy does this study draw support from the Uterature of LoUardy The narrative analysis rests on a matrix of names of persecuted LoUards listed in the appendix, which McSheffrey has sorted by gender, relationship to other LoUards, and literacy (defined as reading in English). McSheffrey's primary finding is that women composed a relatively smaU percentage of recorded LoUards (28%), that they did not assume public teaching roles, were not in leadership positions, were more likely than men to have famUy connections with other LoUards, and were therefore more likely to have been attracted to LoUardy for famiUal rather than ideological reasons.They also had far lower literacy rates than men (3% as opposed to 19%). McSheffrey details one significant exception to this picture—a group of female LoUards in Coventry who met together and looked to the leadership of one Alice Rowley, a woman of higher social status who seems to have been able, uniquely, to cross gender Lines and provide leadership to the male LoUards from more modest social levels. Despite the strengths ofthis study, McSheffrey's work raises questions. She argues that men controlled the movement at the pubUc, conventicle level, and that women listened, learned, and sometimes taught only in informal, private circumstances. Considering the privy nature of conventicles, however, the distinction is problematic, and court documents, more routinized after 1428, often 798BOOK REVIEWS use the same language for men as women (e.g.,"counseling or defending heretical doctrines in privy conventicles or assembUes"). A few stronger women in the movement (AUce Harding, Hawisse Mone, Margery Baxter) are quite possibly not given theU due in McSheffrey's emphasis on the private nature of their actions. McSheffrey argues that LoUard literacy rates support assessments of a low level of literacy in late medieval England, but what low and high Uteracy means she does not say. In my work, which she cites as arguing for high Uteracy her figures and mine (an estimated 25% male Uteracy rate) converge nicely. Some of her conclusions—husbands had greater influence on wives than the reverse (p. 92), neighbors were particular targets of proselytizing (p. 75), and her larger conclusion (p. 136) that women could stretch their gender roles only when their social status gave them some precedence over men—require more evidence than the sources presently aUow. The evidence for women is more suggestive than conclusive (partly because, as McSheffrey notes, authorities were less interested in them); what evidence there is represents only a proportion of the actual cases, and the information provided by legal documents is often spare. More evidence from LoUard writings might strengthen her conclusions . Her effort to close with comparative conclusions regarding orthodox devotional practices and their attractiveness to female piety needs further fleshing out. Overall, this is an intriguing but inconclusive study that provides important support to an argument offered by others studying continental heresies, viz., that medieval heresies,upon close examination, do not appear to have provided women with greater leadership roles or outlets for their reUgiosity than did orthodox religious practices...

Soil erosion and flooding as a result of a summer thunderstorm in Oxfordshire and Berkshire, May 1993

A summer thunderstorm of exceptional severity struck parts of south central England on 26 May 1993; some locations were affected by amounts of precipitation with return periods in excess of 1000 years. Little agricultural land was bare at the time but considerable erosion occurred on fields planted with maize and linseed. In Berkshire and Oxfordshire several villages were flooded. Severe rill and gully erosion in maize fields near Faringdon is described in detail. Rates of erosion exceeded 30 and in some areas 100 m 3 ha −1, with mean rates estimated at 66 m 3 ha −1 on 18 ha of maize fields. Runoff from the fields caused flooding in the town and the costs of damage were over £100000. The risk of erosion and off-site damage will increase should the area planted to maize and linseed increase in the future.

The geomorphological context of the Brimpton Late Pleistocene succession (south central England)

Mapping of the area surrounding the site of the important Brimpton succession shows that it aggraded in a c . 10 m deep depression beneath the low 2 m (Beenham Grange) terrace of the river Kennet system. This is contrary to the previously published account by Bryant et al . (1983) which claimed that the depression underlay the 8 m terrace of the Kennet. The latter situation implied a large magnitude aggradation and incision cycle during the Late Devensian (post 25 ka bp ) and this factor had led to doubts as to whether the 2 superposed interstadials in the lower part of the depression were of early Devensian age. Geomorphological reaffirmation of a Devensian age plus new data makes the Brimpton-Woolhampton Gravel Pit sequence one of the most complete onshore Devensian records yet identified in Britain.

Hexanchid shark teeth (Chondrichthyes, Vertebrata) from the Lower Cretaceous Albian sediments of Leighton Buzzard, South-central England

Hexanchid sharks (Family Hexanchidae) are extremely rare in Lower Cretaceous deposits and are known only from isolated teeth. Two species are recorded from the British Lower Cretaceous: Notidanodon lanceolatus (Woodward. 1886), two teeth being known, and Notorynchus aptiensis (Pictet, 1865), represented by three British teeth. Until recently only nine isolated teeth of this latter species, Notorynchus aptiensis , were known including the holotype from Apt, France, and other specimens from France and Germany. This paper describes an assemblage of fifteen additional teeth of N. aptiensis discovered as isolated specimens from three localities in the Albian sediments of the Leighton Buzzard area.

The release of phosphorus from oxygenated estuarine sediments

Grab samples were collected at the oxygenated sediment-water interface during August 1987 from eight stations along the longitudinal salinity gradient of the Beaulieu River Estuary, south-central England. The bulk sediment composition and phosphorus associations in the sediments were determined to identify the factors causing phosphorus concentrations and associations to vary in the sediments. Bulk sediment elemental composition and organic matter content were unrelated to sedimentary total P, although there was a correlation with percentage silt and clay. Sediment fractionation studies indicated that the majority of bound sedimentary P was associated with the Fe-Al-sesquioxide phases which were in turn closely related to extractable Fe and Mn. Experiments were performed to determine the effect of salinity, agitation, biological activity, addition of a carbon source and degree of water oxygenation on P exchange between the estuarine sediments and the overlying water column. Phosphorus adsorption was decreased in deoxygenated sediments, and those supplemented with a secondary carbon source or a mixture of biocides, indicating that both release from iron oxides in reducing conditions at low Eh and microbiological conditions can influence P exchange. P release, however, did not deplete a specific P-containing fraction, but led instead to a redistribution of P between various sedimentary phases after extended experimental incubation. Sedimentary oxygen demand produced by carbon sources must be considered for proper management of eutrophication problems.

The Perception of Riverscape Aesthetics: an Example from Two Hampshire Rivers

Although the public perception of landscape aesthetics should be considered in environmental management, previous studies of riverscapes have given insufficient attention to rivers in woodland areas. In such woodland areas it is desirable to know how the unmanaged river channels are regarded aesthetically, and whether the presence of coarse woody debris affects the perception of riverscape aesthetics. This study used carefully selected photographs of type sites representing different types of woodland channel, together with some channels affected by urbanization, all in south-central England. After an initial pilot study, a data set was obtained from a total of 199 largely student responses to a set of 20 photographic slides in three groups of geography undergraduates, psychology undergraduates and research students and staff. In addition to analysis of these responses, the slides were rated by two independent operators according to their natural character, and the content of each of the 20 photographs was analysed quantitatively so that a regression analysis could relate the quantitative variables established for each photograph to the reaction of the respondents. The most natural woodland channels containing debris are not the most highly rated, and, according to the regression equations, the assessment of channel colour, reflecting water quality and the percentage of channelized bank are the two best single predictors of overall scenic aesthetic preference. In woodland areas, the general preference is for channels which do not have in-channel debris, but the advantages of retaining such debris should be considered in channel management strategies and an improvement in the public appreciation of the significance of such debris in woodland river channels could preferably be made.

A possible basaltic deep source of the south-central England magnetic anomaly

The group of large, positive, magnetic anomalies in south-central England is shown to originate from two sources at different depths. The shallow source originates from Silesian basic igneous rocks. The anomaly of the deeper source has been isolated by upward continuation and inverted via pseudofield transformation. The magnetic model is interpreted as a large body of basaltic rocks intruding the middle crust. It is proposed that the body was emplaced by buoyant ascent and may be the cause of the stability of the London Platform during Mesozoic times. It is speculated that the basalt was intruded in a back-arc environment during the period preceding the Variscan orogeny.

Dartford warblers Sylvia undata, their habitat and conservation in the New Forest, Hampshire, England in 1988

The breeding range of the Dartford warbler Sylvia undata extends over much of maritime western Europe as far north as southern England, where it is more or less confined to lowland heaths. It is vulnerable to extended winter snowlie and periodically its numbers and range have contracted to the distribution centre in Hampshire and Dorset in south-central England. In a census of the species in the New Forest, Hampshire, in 1988, 454 occupied territories were found, 123% more than in a 1984 survey and the largest number recorded since surveys began in 1960. The increase was attributable mainly to four mild winters. In 1988 the New Forest may have held nearly 75% of the national population of Dartford warblers compared with 48% in 1984. In 1984 most pairs were in the south and east but in 1988 there was a more even distribution, reflecting adjustments in the management of the heaths by burning. In 1988, 402 pairs (89%) were in mature dry heath, humid heath, or thickets of gorse Ulex europaeus These vegetation types covered 1830·6 ha, comprising 22% of the ericoid heathland in the New Forest, and had remained unburnt for at least 15 years. We consider that it is probably not possible to increase the amount of Dartford warbler habitat by changing the burning rotation. However, there may be opportunities to restore heathland on some areas planted with conifers. In this event, attempts should be made to create Dartford warbler habitat on the restored heathland.

New adherent foraminiferans from the Lower Cretaceous (Aptian) of south-central England

Abstract. Three new species and one new genus of adherent foraminiferans have been found within bivalve borings in cobbles from the Faringdon Sponge-gravel (Upper Aptian) of south-central England. The new genus and species, Lapillincola faringdonensis is a uniserial textulariine with an initial planispiral coil and a multiple aperture. Lapillincola gen. nov. is a remarkable homeomorph of Arenonina Barnard, which was originally described as an agglutinated form. Arenonina is shown here to actually be calcareous and perforate, and thus a junior synonym of Rectocibicides Cushman &amp;amp; Ponton. Acruliammina parvispira sp. nov. is another uniserial textulariine with an initial coil. Bullopora ramosa sp. nov. is an adherent polymorphinid with a branching, irregular series of adherent chambers. These foraminiferans may have used the bivalve borings as spatial refuges from the abrasive, high energy environment of the Sponge-gravel.

A Tectonic Model for the Late Paleozoic of Southeastern New England

Hornblende and biotite /sup 40/Ar//sup 39/Ar age spectra from rocks in south-central Connecticut help define a Permian-Triassic cooling curve for the area. Together with petrologic and structural information, a time-temperature-pressure-strain path is established. Similar data for the Narragansett basin in Rhode Island and Massachusetts allow correlation of the late Paleozoic histories of the two areas. Together, these data suggest that in the late Paleozoic, south-central New England was part of a fold-thrust belt, and the Narragansett basin was a retroarc foreland basin. NW-SE compression during the final assembly of Pangaea resulted in SE directed thrusting, causing the development of clastic wedges in adjacent Rhode Island and Massachusetts in the Late Carboniferous-Early Permian. A clockwise rotation of this deformation from NW to NNE led to northward underthrusting and concomitant uplift of both eastern Connecticut and Rhode Island in the Permian and Triassic.

Lateglacial/Early Flandrian Vegetation Change on Northern Dartmoor, South-West England

Pollen analysis and radiocarbon dating of a 2.12 m blanket peat profile from Black Ridge Brook, northern Dartmoor, reveals the presence of deposits of Lateglacial/early Flandrian age. Sites of this period are not only rare on Dartmoor but there are relatively few in the South West and central southern England as a whole. Pollen assemblages show the persistence of open ground plant communities into the Flandrian and the radiocarbon dating implies a significant delay in woodland development. It is suggested that this delay was caused by a combination of edaphic and climatic factors, although there is also evidence in the section for the early influence of fire. Birch-hazel woodland did eventually spread onto the higher areas of Dartmoor by c. 8000 BP but treelines began to fall by c. 7700-7600 BP. From this time charcoal is continually present in the profile and it is suggested that woodland recession and blanket peat development were, at least in part, due to the activities of Mesolithic communities.

Response of aquatic vegetation to sedimentation downstream from river channelisation works in England and Wales

Measurements of aquatic vegetation at four sites of river channelisation works in south-central England are described and analysed. Physical factors determine the nature and extent of downstream deposition of sediment arising during construction. Depending on the depth of sediment, individual plant species may respond either by varying their rooting levels or by becoming smothered. Suspended sediment released was silt and did not abrade plant parts. Post-construction deposits were a short-term phenomenon, being washed out during flood events, thereby facilitating recovery of vegetation.

Hydrogeomorphology downstream from bridges

Although recent studies have quantified effects upon river channel morphology downstream of reservoirs, urban areas and channelization schemes, consideration has not been given to effects upon channels downstream of road bridges. Engineering literature focuses upon hydrologic considerations involving estimation of peak flow at the bridge site, and upon hydraulic aspects including backwater effects and scour around the bridge and piers. A reconnaissance survey at 19 bridges in the New Forest shows that channel shape changes below many bridges with width-depth ratios increasing substantially to double their value; that apparent channel capacities may increase below the bridge to twice their above-bridge value, due to incision and scour; and that such effects can be evident for distances downstream of the bridge of the order of 10 times channel width. Reference to large-scale topographic maps for one site, and to maps and large-scale aerial photographs for 15 sites in south central England, shows how these sources can be used to provide measurements of channel width above and below bridges and this indicates that the average downstream width is 1.99 times the upstream width. Such channel adjustments should be considered when measuring morphological and ecological characteristics of river channels and when explaining reaches of rapid channel adjustment.

THE ORIGINS OF WARWICK

The evidence of the Mercian Register of the Anglo-Saxon Chronicle, which records that in the early autumn of A.D. 914 Aethelflaeda, Lady of the Mercians, went with all the Mercians to Warwick and built the burh there, is the basis of the accepted dogma on the urban origins of Warwick. Warwick was the sixth of nine burhs built by the Mercian queen between 912 and 915 as part of a strategy to secure and expand English territory at the expense of the Danes. This strategy was pursued in conjunction with a similar policy being put into effect in south-central England by King Edward of Wessex, Aethelflaeda's brother. There are no earlier accepted documentary references to Warwick and it has therefore been considered that the burh was new-founded upon a greenfield site.