bluuebunny/crossref_metadata_2025 huggingface dataset:
Birch in cultivation
Authors: Schilling A. D.
Published: March 2014

Synopsis

The authenticity of birch collections is always in doubt unless one has wild source material; even the collections of Forrest, Wilson, Rock et at. may be suspect in that labels and records have been lost or confused. Collections are best maintained from vegetative sources and clonal selection is discussed. Site tolerances, planting problems and after-care are given detailed coverage. Species, hybrids and cultivars in general cultivation are listed and a summary of representation in British arboreta is included.
Frankiasymbiosis as a source of nitrogen in forestry: a case study of symbiotic nitrogen-fixation in a mixed Alnus-Picea plantation in Scotland
Authors: Malcolm D. C. , Hooker J. E. , Wheeler C. T.
Published: March 2014

Synopsis

Alnus rubragrowing in the field in Scotland is nodulated effectively by local strains ofFrankia. Strains which have been isolated fromAlnus rubraat Lennox Forest show different growth medium requirements and colony morphology compared with isolates fromAlnus glutinosaand several different strains have been isolated from the same locality. Preliminary evidence suggests that some spore negative, northwest AmericanFrankiastrains may be more effective than local spore positive crushed nodule inoculum for nitrogen-fixation inAlnus rubra.

On the moderately fertile clay soil of Lennox Forest, a mixed plantation of alternatePicea silchensisandAlnus rubrashowed no improvement in growth of spruce compared with pure spruce plots. However, the presence of alder increased upper soil nitrogen status by 585 kg ha ' which approximates the standard 150 kg N ha 'of fertiliser nitrogen applied in practice to nitrogen deficient stands at about 5-year intervals. Although the alder had penetrated the subsoil, there was no apparent effect on spruce rooting depth in the mixed stands in this high clay soil. In addition to nitrogen content, the total phosphorus of the upper soil horizons was improved in the mixed plots by an estimated 3–6 kg ha-1y1and it is suggested that this phosphorus may be brought from the subsoil by the deeper rooting alder and deposited on the surface in its litter.

Although improved growth of spruce in mixture withAlnus rubrais only likely where pure spruce stands are stressed for nutrients, the potential benefits of symbiotic nitrogen-fixation in silvicultural practice make it desirable to investigate other species and provenances ofAlnussuited to British conditions, to achieve maximum symbiotic fixation of nitrogen by selection and inoculation with superior strains ofFrankiaand to include such plants in trials of mixtures on sites where nitrogen-availability may be critical.
Some nutritional aspects of the biology of ericaceous mycorrhizas
Authors: Read D. J. , Bajwa R.
Published: March 2014

Synopsis

Some aspects of the role of the ericoid mycorrhizal symbiosis in the ecology and physiology of ericaceous plants are described. Mycorrhizal infection leads to enhancement of plant nitrogen content and an experimental analysis of the basis of this effect is reported. In addition to improving the efficiency of ammonium absorption at low concentrations, the mycorrhizal endophyte utilises amino acids, peptides and proteins as nitrogen substrates for growth. These are the predominant nitrogen sources in organic heathland soil. It is suggested that the success of ericaceous plants in such soils may arise through the capacity of the mycorrhizal fungus to provide its host with access to this nutrient resource. A model is described in which absorption of ammonium and amino nitrogen leads to soil acidification, increased acid protease activity and improved vigour of the ericaceous plants.
A study of long-term changes in some rocky shore communities in Orkney
Authors: Baxter J. M. , Jones A. M. , Simpson J. A.
Published: March 2014

Synopsis

The distribution and relative abundance of various types of coastline are reviewed briefly. The results of a 9 year investigation of selected rocky shore communities are presented. Climatic parameters showed a marked variation during the study but were not correlated with the observed variations in flora and fauna. The main study was based on annual sampling of 8 bedrock shore transects using percentage cover or density for sessile and mobile species respectively. Seasonal fluctuations were studied in fixed areas at 2 sites over a 5 year period. Patterns of seasonal variation in various algal and faunal categories are described and discussed, canopy algae showed summer maxima while understorey species showed winter maxima. Annual studies showed species stability to be site specific: in species which showed marked, apparently cyclic, patterns of change, the changes were often asynchronous both between sites and, to a lesser degree, between stations at a site. The value of obtaining a measure of ‘patchiness’ is discussed.
The resource base—agriculture
Authors: Cunningham J. M. M. , Groves C. R. , Clark J.
Published: March 2014

Synopsis

The extent of resource use—land, capital, labour and management—in Scottish agriculture in the early 1980s is estimated, using available published data. The main developments that have occurred to create this resource base are outlined, with the likely changes that will influence its nature by the mid 1990s. Each of 3 agricultural sectors—dairying, arable and livestock—is considered in turn. The paper concludes by outlining broadly the nature of the base as it might appear by the mid 1990s from the effects of economic and market forces. The pressures on land and labour use, from limitations on production of milk and arable crops but expanded lowland stock enterprises, are highlighted. The serious consequences for agricultural land and labour use in the more remote disadvantaged areas of Scotland are recognised, as is the need to consider the social/amenity value of the retention of a sufficient agricultural base in these areas. Finally, some of the issues and questions associated with the maintenance of agriculture in the hills in the future are indicated.
The dairy industries
Authors: Banks W.
Published: March 2014

Synopsis

In 1983–84, the final year before the introduction of quotas under EEC Regulation 857/84, milk production in Scotland was some 1406 × 106 litres. The disposal of that milk can be considered under two headings, namely (i) the liquid market and (ii) manufactured products. The former category encompasses all the milk—whole, semi-skimmed and skimmed—sold directly to the public via the doorstep delivery or retail outlets. It accounts for approximately 43% of the milk produced in Scotland, but commands the highest monetary return to the producer. The remaining milk goes to manufactured products, principally butter (and anhydrous milk fat), cheese, evaporated milk and cream. The price charged for milk for each of these outlets varies, but is always less than the amount received for milk destined for the liquid market.

In all but a small area of Scotland, one of 3 Milk Marketing Boards is, by statute, the first-hand buyer of milk from the farmer. The Boards, as organisations responsible to the farmers, have a common aim, which is to maximise the price they receive for milk. Each is heavily dependent on the liquid market, but they adopt different strategies in terms of manufactured products. However, the imposition of quotas with effect from 1 April 1984, and the consequent reduction in the total volume of milk produced in Scotland, has focussed attention on the need to manufacture milk products to the most exacting standards, in order that they command a premium in the market.
Milling and baking in Scotland
Authors: Mann David L.
Published: March 2014

Synopsis

This paper is limited to the milling and baking of wheat products and, to a smaller extent, oats products. Initial analyses of the marketplace and the major manufacturers in both the United Kingdom and Scotland include references to changing consumer demands, changing market sizes, major grocery retailer power, and industrial over-capacity in both milling and baking.

The sources of wheat for baking are described, in particular the remarkable increase in the use of homegrown wheat for breadmaking. Detailed descriptions are given of the technology of flour milling, breadmaking and biscuit making, covering some of the scientific principles as well as the equipment used. Future developments are also predicted.

Scottish millers and bakers must be at the forefront of investment and new technology if they are to survive competition in declining markets and in industries that still have over-capacity.
Canning and freezing
Authors: Baxter W. G.
Published: March 2014

Synopsis

This paper gives ‘an insider's view’ of the Scottish processed food manufacturing industry, through the eyes of the Managing Director and Chairman of a distinctive family company sited midway between Aberdeen and Inverness on the banks of the River Spey.

In 1946 the company employed a mere 11 people, and manufactured only preserves and beetroot products, having an annual sales value of £40,000. Today a wide range of products is sold in over 60 countries with an annual turnover approaching £20 million and a profit of £1–5 million.

Forty years ago there were more than 20 jam making companies in Scotland; and in the United Kingdom more than 30 manufacturers of canned soups. Today there are only 5 of the former category and 5 of the latter making and selling their own brands. What has happened in these 40 years? Some answers are given to that question and an outline of the way ahead is presented.
Food service industries
Authors: Hawthorn John
Published: March 2014

Synopsis

This paper deals with a miscellaneous group of food-related industries not directly covered by the principal papers of the Symposium. Some of these serve the needs of larger processing companies for intermediates. Others produce a variety of products for retail sale. Few are large employers of labour or capital but cumulatively they make a significant contribution to the Scottish economy. The paper lists the type of manufacture in some detail, and the product range—from tripe dressing to confectionery—is too wide to permit easy classification.

These industries serve a virtually non-expanding total market, and are thus for the most part highly competitive, quality and service as much as price being the chief weapon of survival. In general, production is concentrated in small units of modest capital investment. Thus they have the advantage of flexibility and can quickly change product emphasis as circumstances demand, in contrast to the giants of the food industry, limited as they are by the inertia of their size. But these ‘service’ industries have the double disadvantage of limited access to technical and scientific resources, and the burden of complex legislation which falls proportionately more heavily on them than on their larger brethren.

The paper examines aspects of these limitations and outlines suggestions for the practical resolution of some of these disadvantages.
The geology, crustal structure and evolution of the Rockall Trough and the Faeroe-Shetland Channel
Authors: Scrutton Roger A.
Published: March 2014

Synopsis

From direct sampling, the deeper Rockall Trough and Faeroe-Shetland Channel are known to have a Tertiary-Quaternary sedimentary sequence up to 3000 m thick, which is in places, particularly in the north, underlain by early Tertiary basaltic volcanic rocks. The seamounts in the Rockall Trough are of basic volcanics of probable Upper Cretaceous age. The eastern shelf areas have a rifted basement of Precambrian-Devonian (-?Carboniferous) age, overlain by Permian + Mesozoic sedimentary rocks that reach 5000 m in thickness in rift basins. Tertiary sediments thicken rapidly from the shelf into deep water. The western shelf areas have extensive early Tertiary basalts from the Faeroe Islands to the southern part of Rockall Bank. A thin Tertiary—Quaternary cover exists and Precambrian basement lies beneath.

The pre-Tertiary geology of the deep water areas and the overall crustal structure have been inferred from geophysical investigations. In the Rockall Trough the crust is of oceanic thickness, about 6 km, but it is probably slightly thicker beneath the Faeroe-Shetland Channel. This fact, coupled with the size of the channel compared with other small ocean basins and the knowledge that fully developed oceanic crust exists just outside the mouth of the Rockall Trough, strongly suggests that at least parts of the deep water areas are floored by oceanic crust. However, seismic reflection and magnetic anomaly profiles do not yield observations characteristic of normal oceanic crust.

The age of any oceanic crust in the Rockall Trough and Faeroe-Shetland Channel is equivocal. Between 54° and 59° N a succession of largely sedimentary rocks up to 3000 m in thickness occurs between the Tertiary and the acoustic basement. To the north this succession is masked on seismic profiles by early Tertiary basalts but it is probably present; to the south it is interrupted by a series of acoustically opaque basement ridges. With slow sedimentation rates, this succession could extend back to the late Palaeozoic, but with rapid rates, only to the mid-Upper Cretaceous. An age of mid-Lower to mid-Upper Cretaceous for oceanic crust, equal to that of the ocean crust outside the mouth of the Rockall Trough, is accepted here. Although rapid subsidence and infill in Upper Cretaceous time is not characteristic of major shelf basins around Britain, it may be acceptable for the Rockall Trough and Faeroe-Shetland Channel if they are underlain by oceanic crust rather than continental crust.

A likely model for the formation of the Rockall Trough and Faeroe-Shetland Channel is of continental rifting and subsidence from late Palaeozoic or earliest Mesozoic to mid-Cretaceous time, then sea-floor spreading in Albian (c.105My)–Santonian (c.85 My) time, accompanied and immediately followed by rapid subsidence and deposition. The Tertiary was heralded by widespread basaltic igneous activity which briefly arrested subsidence, but was largely a period of subsidence without sedimentation keeping pace.
Seasonality in currents of the Rockall Channel
Authors: Dickson R. R. , Gould W. J. , Griffiths C. , Medler K. J. , Gmitrowicz E. M.
Published: March 2014

Synopsis

Though our knowledge of the circulation in this complex region is still incomplete, recent direct current measurements have identified four separate elements of the circulation which appear to undergo a seasonal variation of some sort. These are: (i) a summer-autumn maximum in the deep overflow of Norwegian Sea Deep Water across the Wyville-Thomson Ridge; (ii) an autumn minimum in the upper-ocean circulation around Rockall Bank, ascribed to Taylor Column processes; (iii) an autumn-winter maximum in the strength and breadth of the slope current along the European continental margin; (iv) a winter-spring maximum in eddy kinetic energy in the open waters of the Rockall Channel, and over the full depth range, as a function of windstress and stratification. The first three of these elements are of localised occurrence along the northern, western and eastern margins of the Channel and are described only briefly. The fourth process, encountered at a range of sites in the northeast Atlantic, is described in detail using a total data set of 68 instrument-years of direct current measurements recovered from the Rockall Channel in 1977–84. In the seasonally-varying 3–27 day (d) band of periods, eddy kinetic energies (kE) are shown to be depth-dependent in amplitude, but with little evidence of any significant phase-lag with either depth or location between the individual timeseries of kE estimates. These time-series demonstrate clearly and for the first time that the winterspring peaks in eddy kinetic energy lag the winter peaks in windstress by between 1 and 3 months. This phase-lag is explained as the cumulative result of wind forcing and eddy dissipation.
The benthic fauna of the Rockall Trough: regional distribution and bathymetric zonation
Authors: Gage J. D.
Published: March 2014

Synopsis

More than 300 bottom samples taken in the Rockall Trough and neighbouring areas (Northeast Atlantic) since 1973 provide an opportunity to study the distributions of the commoner megafaunal species. These include 131 species of echinoderms, for the most abundant of which the bathymetric and regional distributions are defined. Analysis of samples by means of the coincidence-of-range method along a bathymetric transect shows peaks-in the first and last occurrences of species at the 800–1200m and 1800 m levels. Cumulative curves of the recruitment of all echinoderm species with increasing depth show step-like increases in the rate of species recruitment with depth. These maxima in rate of faunal change are related to water–mass structure, particularly the depth of the seasonal and permanent thermoclines. A considerably broader bathymetric range is shown by post-larvae and juvenile stages compared to adults.
Continuous plankton records: the distribution and standing crop of the plankton of the shelf and ocean to the west of the British Isles
Authors: Colebrook J. M.
Published: March 2014

Synopsis

Data from the Continuous Plankton Recorder survey are used to compare the distribution and seasonal and year-to-year variations in the abundance of the plankton of the area of the Rockall Channel with both the shelf and the adjacent oceanic areas. It is argued that the distribution and size of overwintering stocks of zooplankton provide the key to understanding the dynamics of the plankton of this area.

It would appear that, due to inherent limitations to the net rate of increase of zooplankton populations, the distribution of the overwintering stocks has an influence on the distribution and abundance of most species through the rest of the year. This affects the dynamics of the seasonal cycle and also influences the form of year-to-year changes in abundance

The plankton of the area of the Rockall Channel is characterised by low overwintering stocks, coupled in spring with higher rates of population increase as compared with the adjacent shelf. There is a pronounced spring bloom of phytoplankton, which does not appear to be controlled by grazing, followed by a period of nearly five months of relative stability of stocks of both phytoplankton and zooplankton. It is suggested that during this period the zooplankton graze the daily production of phytoplankton, the growth of which is determined to a large extent by nutrients recycled from the zooplankton. The effects of this pattern of dynamics on the form of year-to-year changes in the abundance of the plankton over the last few decades is discussed.
Seasonal deposition of phytodetritus to the deep-sea floor
Authors: Rice A. L. , Billett D. S. M. , Fry J. , John A. W. G. , Lampitt R. S. , Mantoura R. F. C. , Morris R. J.
Published: March 2014

Synopsis

Evidence has accumulated over the past twenty years to suggest that the deep-sea environment is not as constant as was at one time thought, but exhibits temporal variations related to the seasonally in the overlying surface waters. Recent results from deep-moored sediment traps suggest that this coupling is mediated through the sedimentation of organic material, while observations in the Porcupine Seabight indicate that in this region, at least, there is a major and rapid seasonal deposition of aggregated phytodetritus to the sea-floor at slope and abyssal depths.

This paper summarises the results of the Porcupine Seabight studies over the past five years or so, using time-lapse sea-bed photography and microscopic, microbiological and chemical analyses of samples of phytodetritus and of the underlying sediment. The data are to some extent equivocal, but they suggest that the seasonal deposition is a regular and dramatic phenomenon and that the material undergoes relatively little degradation during its passage through the water column. The mechanisms leading to the aggregation of the phytodetritus have not been identified, and it is not yet known whether the phenomenon is geographically widespread nor whether it is of significance to the deep-living mid-water and benthic communities.
A Bibliography of the Rockall Trough
Authors: Mauchline J. , Ellett D. J. , Gage J. D. , Gordon J. D. M. , Jones E. J. W.
Published: March 2014

The deep region lying between the Scottish and Irish continental shelves and the Rockall Bank is known by two names, the Rockall Channel and the Rockall Trough. Nansen (1913) refers to the Rockall Channel as the route of the “Gulf Stream” (Krummel's Irish Current) northeastwards through the Faeroe-Shetland Channel. The name “Rockall Trough” was adopted later, principally by the geologists and is in more general use today by all disciplines. The term is given precedence in this Bibliography.
Oceanographic observations in Sullom Voe, Shetland in the period 1974–78
Authors: Dooley H. D.
Published: March 2014

Synopsis

In the five years to 1978 hydrographic surveys were conducted in Sullom Voe, Shetland and these have been supplemented since 1976 by current measurements. Conditions varied from year to year mainly due to climatic factors, the most marked changes occurring at the head of the voe where varying degrees of stagnation were encountered.

In summer the voe is weakly stratified. In winter longitudinal gradients are encountered mainly because of a slight reduction in salinity towards the head. Because of this the surface waters of the voe are more readily flushed in summer than in winter when the flushing time, calculated from the freshwater balance, is at least 15 days. The current measurements show that rapid renewal of the surface waters occurs in the summer during storms. Because the voe is open to the north, southerly winds, blowing surface waters out of the voe, drive a much stronger circulation than winds from the north and this is the main reason for the intermittent breakdown of stagnation in the upper basin. Tidal currents are very weak (<7 cm/s) but occasionally seiches, generated by sudden changes in the wind direction, with a period of about 1 hour and current amplitude of 15 cm/s are encountered. Nutrients from the adjacent tidally mixed Yell Sound are intermittently supplied to the voe by these wind-driven processes and as a result, high levels of productivity are encountered at intervals throughout the summer.
Tidal currents in Yell Sound and the outer regions of Sullom Voe
Authors: Blackman D. L. , Graff J. , Vassie J. M.
Published: March 2014

Synopsis

Currents were measured along two routes through Yell Sound to Sullom Voe in the Shetland Islands. Current meter moorings were deployed by the consulting engineers Peter Fraenkell and Partners for one month at 20 positions with three meters which measured the flow from near surface to a depth of 20 metres. The accuracy of these measurements is considered and the difficulty of making measurements in this region is illustrated.

The paper discusses the nature and variability of the currents that were measured and resolves the currents into a tidal and non-tidal component. An analysis procedure is developed for removing the tidal component and for producing tidal current vectors for each position. From this the general tidal circulation pattern is constructed and discussed. It is shown that tidal currents along the eastern route are too high at certain states of the tide for safe navigation.

Current surges of significant magnitude are shown to exist throughout the area. These are driven by the tidal motion and it is suggested that they are an effect of travelling gyres which are generated in the lee of islands and shallow banks when the tidal streams are largest.
Analysis of hydrocarbons in sediments as indicators of pollution
Authors: Douglas A. G. , Hall P. B. , Bowler B. , Williams P. F. V.
Published: March 2014

Synopsis

After a brief review of some general procedures that have been proposed for the identification of oil spills, details are given of methods that depend on hydrocarbon analyses. Hydrocarbon distributions due to a biological input are compared to those from a petroleum input, utilising hydrocarbon fingerprints obtained by gas chromatographic and combined gas chromatographic-mass spectrometric methods.

It has been shown that most of the sediment samples collected in 1976, 1977 and 1978 from sampling stations in and around Sullom Voe are substantially free from pollution by crude oil; however, three of the samples collected during 1978 do show some signs of pollution. These data will act as a baseline for future studies to be carried out during the operation of the oil terminal.
Seals in Shetland waters
Authors: Anderson Sheila S.
Published: March 2014

Synopsis

The distribution and status of grey and common seals around Shetland is reviewed. Recent surveys have produced an accurate picture of the location of breeding sites, grey seals being found at discrete localities mainly in the north and west of the islands and common seals being distributed more widely throughout the archipelago. The population of grey seals is estimated at 3,500 animals and is considered to be relatively constant. The reliability of boat surveys for estimating common seal populations is discussed. It is concluded that the population of Shetland has increased in numbers following protective legislation and it is suggested that there has also been a change in hauling out behaviour. The current population consists of at least 4000 individuals.

Grey seals do not appear to have been affected by oil developments at Sullom Voe so far, but common seal numbers in the Sullom Voe area have not increased at the same rate as elsewhere in Shetland, and the number of pups present has declined. It is suggested that these changes may have arisen as a result of the development of the oil terminal. Study methods which would enable the nature and causes of these changes to be identified are proposed.
The soft shore environment of Sullom Voe and the north mainland of Shetland
Authors: Jones A. M. , Jones Y. M.
Published: March 2014

Synopsis

The general character of soft shores in this region is considered briefly. Studies of several aspects of the biology at selected sites were instigated as part of a broader monitoring programme and the results of the baseline study are described in this paper. The structure and growth of populations of Cerastoderma edule (L.) and Macoma balthica (L.) (Mollusca: Lamellibranchiata) are described. Considerable differences in C. edule growth rates were found between sites, and recruitment and survival was sporadic at many sites. The value of C. edule populations in providing some degree of ‘retrospective monitoring’ is considered. C. edule populations were found to contain significant infections of the entocommensal nemertean Malacobdella grossa: this is a new host record for M. grossa. The distribution and abundance of the macrofauna on two sandy shores are discussed in relation to environmental conditions.
Measurement of the responses of mussels to environmental stress and pollution in Sullom Voe: a base-line study
Authors: Widdows J. , Bayne B. L. , Donkin P. , Livingstone D. R. , Lowe D. M. , Moore M. N. , Salkeld P. N.
Published: March 2014

Synopsis

The base-line study consisted of three visits to Sullom Voe before the oil terminal became operational. General stress indices were used to measure the health and condition of four native and two transplanted populations of mussels (Mytilus edulis). A mobile laboratory was used to measure the physiological responses under ambient field conditions. These were then integrated into the stress indices, scope for growth and oxygen :nitrogen ratio. The general biochemical and cytological stress indices, namely taurine: glycine ratio, gametogenic development and latency of lysosomal β-hexosaminidase were also measured for each population. All these general stress indices indicated that the mussel populations were in a relatively healthy physiological condition. However, mussels from the Houb of Scatsta showed a transient stress response, probably caused by freshwater run-off from the surrounding peat beds.

In addition to the general stress indices, specific cellular responses known to be induced by petroleum hydrocarbons were monitored. The activity of enzymes forming components of the mixed-function oxidase system (NADPH neotetrazolium reductase, G6PDH and NADP-ICDH, and aldrin epoxidation) were measured.

The rationale for measuring these general and specific stress indices as part of a Sullom Voe environmental monitoring programme is discussed in the light of experiments with petroleum hydrocarbons in the laboratory and with reference to the future operation of the oil terminal.
Water relations and xylem anatomy of ferns
Authors: Gibson A. C. , Calkin H. W. , Raphael D. O. , Nobel P. S.
Published: March 2014

Synopsis

The entire soil-plant-atmosphere continuum must be analysed to elucidate how xylem anatomy relates to water flow in plants. Measurements of water potential gradients and volume of water flow per unit time are needed to obtain values of hydraulic conductance per unit length. By comparing values of hydraulic conductance per unit length along the plant, the regions where xylem structure restricts water flow can be determined. Previous studies of fern water relations demonstrated that very large water potential gradients occurring in stipes of certain ferns were closely correlated with reduced conducting area of stipe xylem. A new study on Cyrtomium falcatum showed that the water potential gradient was relatively small and constant along the stipe and rachis; however, a much larger gradient occurred from the rachies into the pinnae. Hydraulic conductance per unit length varied with the leaf area to be supplied, leading to the fairly constant water potential gradient along the rachis.. The measured hydraulic conductance per unit length was only half the value predicted from the Hagen-Poiseuille equation. Although the Hagen-Poiseuille equation overestimated the measured value by a factor of 2, it did support the assumption that conduit number and lumen diameter are the principal determinants of water conductance in the xylem.
Distribution and ecology of early ferns
Authors: Scott Andrew C. , Galtier Jean
Published: March 2014

Synopsis

A review of current knowledge of the distribution of Palaeozoic ferns and fern-like plants is presented. Whilst numerous putative ferns occur in the Devonian, it is not until the Lower Carboniferous that ferns belonging to the Filicales appear. The Namurian represents a major gap in our knowledge. The ecology of late Palaeozoic ferns is reviewed. The association of early fern assemblages with volcanic terrains is considered particularly significant in the relationship between evolution and environment. Extinction of more specialised groups may have been caused by climatic changes.
The edible fiddlehead—Matteuccia struthiopteris (Ostrich fern)
Authors: von Aderkas P.
Published: March 2014

Synopsis

Matteuccia struthiopteris is distributed throughout most of the boreal region of the northern hemisphere. It has been variously recorded as a vermifuge and an ingredient in beer manufacture as well as a food. Young leaves, alternatively known as croziers or fiddleheads, are picked before they have unfurled and are boiled or steamed and served as a hot vegetable. The market, between Malecite indian and colonists, developed in the Fredericton area of New Brunswick 200 years ago, following a particularly severe winter. The newly arrived United Empire Loyalists, having emigrated from the United States, were so short of food that by the spring of 1784, they were reduced to eating any sort of provender nature could supply. Specific mention is made of fiddleheads, which became a traditional spring vegetable in New Brunswick. This market spread into Maine in the United States, particularly into those areas bordering the St John River. The present market is still predominantly in New Brunswick, where the wild harvest is between 150–200 t/yr, a yield which is approximately four times the harvest in neighbouring Maine. Food companies process about one third of the crop. In Maine, this is done by a single canning company in Wilton, whereas in New Brunswick, tinned fiddleheads have largely been superseded by the frozen product which is the monopoly of a company working in Florenceville. In addition, Canadian companies have recently sprung up which export the fresh spring vegetable in refrigerated lorries to larger centres west of the province. These companies account for less than a quarter of the harvest. The remainder is sold from either roadside stands, or to a wholesaler who distributes them to outlets in the region. The harvest is still predominantly done by natives. Much greater detail of both harvest, food preparation, and economic history is given by von Aderkas (1984). It has recently come to the author's attention that crowns of M. struthiopteris are sold also as a garden ornamental. Over 5000 plants/yr are sold by one Ontario distributor alone. Estimates from other nurseries in West Germany and the United States which do the same trade are presently unavailable.
Recent studies on the biology of bracken and the mode of action of herbicides used in its control
Authors: Kirkwood R. C. , Hinshalwood Anne
Published: March 2014

Synopsis

The biology of bracken (Pteridium aquilinum L. Kuhn) is reviewed with particular reference to its importance as a troublesome weed of upland grasslands. The problem of control is discussed, particularly with regard to the role of the rhizome system and its associated buds. The modes of action of glyphosate and asulam are described with particular reference to their foliage-absorption, translocation, and the nature of activity in the buds, the ultimate target sites.
Recent studies on the potential for biological control of bracken using fungi
Authors: Burge M. N. , Irvine J. A.
Published: March 2014

Synopsis

Curl-tip disease of bracken (Pteridium aquilinum) is recorded from many sites in Great Britain. Evidence is presented which corroborates the findings of earlier workers that more than one organism is associated with the disease. Three fungi (Phoma aquilina, Ascochyta pteridis and Septoria sp.) are commonly isolated, even from the first visible necroses, suggesting that synergism may operate in pathogenesis. However, Phoma aquilina Sacc. and Penz. is more pathogenic than the others when used independently in inoculations via wounds into bracken raised in growth cabinets or the greenhouse. Field trials of a formulation of spores of P. aquilina, suspended in a dilute solution of the herbicide ioxynil with broth and glycerol, are reported. The potential of such a mycoherbicide for bracken control is considered.
Mobilisation of storage reserves during fern spore germination
Authors: DeMaggio A. E. , Stetler D. A.
Published: March 2014

Synopsis

We have studied morphological and biochemical aspects of storage reserves and their degradation in fern spores during the germination process. The results presented here are concerned with the fate of lipid, protein and phytic acid. Depletion of lipid reserves and breakdown of lipid bodies was directly correlated with increased activity of glyoxylate cycle enzymes during early stages of germination. Degradation of protein reserves coincided with the depletion of salt soluble proteins (globulins) from the spores and was related to the time when high activity of aminopeptidase and carboxypeptidase was observed. Lipid and protein appeared to play an important role in germination. Phytic acid reserves were present in the spore and were hydrolysed by phytase after germination occurred. This storage material was implicated in growth of the prothallus.
Mobilisation of carbohydrates during germination of spores ofOnoclea sensibilis L.
Authors: Towill Leslie R.
Published: March 2014

Synopsis

A high percentage of germination ofOnoclea sensibilisL. spores is initiated by a low fluence of red light while imbibed but unirradiated spores exhibit a very low percentage of germination.Onocleaspores contain lipid, protein and sucrose reserves. Sucrose is degraded and starch is synthesised during germination while lipid reserves are mobilised during early gametophytic development. The amount of protein remains constant during both developmental stages. There is very little detectable mobilisation of any of the reserves in the imbibed but ungerminating spores maintained in the dark for up to 18 days. Sucrose degradation and starch synthesis are not interrelated because photoenhanced sucrose degradation can occur without starch synthesis and photoinduction of starch synthesis can occur without sucrose degradation. Evidence is presented to suggest that the mode of action of light in enhancing starch synthesis is to increase the availability of a starch precursor rather than the activities of starch synthesising enzymes. Sucrose may be mobilised after irradiation because it becomes accessible to the sucrose degrading enzymes which are in abundance in the spores.
Pteridophyte evolutionary biology: the electrophoretic approach
Authors: Haufler Christopher H.
Published: March 2014

Synopsis

While only in its infancy, the application of electrophoretic analysis in studying the evolutionary biology of pteridophytes is proving to be of considerable value. Since the technique identifies subtle differences in protein structure, it can generate an improved picture of the genetic composition of organisms. To date electrophoresis is (1) providing us with new information about the structure of the pteridophyte genome, (2) interfacing well with laboratory studies of breeding system mechanisms to indicate that some pteridophytes are predominantly outcrossing species, and (3) generating genome-specific markers for detecting hybrids and analysing patterns of evolution. Electrophoretic data suggest that species of Bommeria are very distinct from one another and may not be congeneric. Further, enzyme characters indicate that the sexual Bommeria species have maintained a mechanism to promote outcrossing in populations, in spite of the limitations that this breeding system places on colonising ability. In Cystopteris, electrophoretic markers are of value in deciphering species relationships and origins, especially among neopolyploid taxa. The indication in Cystopteris that extant diploids are outcrossing may help to explain the complex systematic patterns that currently exist within and among its taxa. Further investigations may demonstrate that similar mechanisms are prevalent among other systematically challenging ferns and fern allies.
Life-history studies of ferns: a consideration of perspective
Authors: Cousens Michael I. , Lacey Deborah Grimm , Kelly Eugene M.
Published: March 2014

Synopsis

Autecology of pteridophytes may be refined by defining the plant community and habitat, and phytogeographic occurrence, of the species studied. Work withBlechnum spicantin the Pacific Northwest, and withLorinserea areolatain the Southeastern U.S.A. has uncovered autecological differences for these species across habitats differing in overstory and hydrology. Natural history observations are necessary to suggest the most appropriate hypotheses to investigate objectively. A modification of Daubenmire's Canopy-Coverage method provides a grid across which many factors may be recorded or tested in repeatable objective manner. Such an analysis was used to test the association betweenL. areolatalife-history classes and hummocks in hardwood swamps. Contingency tables were used to disprove the null hypothesis thatL. areolatawas distributed randomly with regard to hummocks. Hummocks were thus ‘safe sites’ for the completion of the life-cycle ofL. areolata, and additional considerations of safe sites forLygodium japonicumandDryopteris ludovicianaare introduced. Analysis of biomass and coverage ofOnoclea sensibiliswhere it is very abundant suggests that it is highly susceptible to competition where it shares plots withL. areolata.The concept of the optimum habitat with regard to abundance of the taxon, frequency of the habitat-type, successful reproduction, and susceptibility to competition between similar life forms is discussed.
The arthropod cuticle and its inhabitants
Authors: Mellanby Kenneth
Published: March 2014

Synopsis

The skin of arthropods is also the exoskeleton and as this gives them mechanical protection, they have comparatively few ectoparasites. Those which are present are removed during the periodic moulting of the skin. However, some organisms, particularly mites, have become adapted to living on the cuticle of arthropods.
Penetration of mouse and human skin by cercariae ofSchistosoma mansoni; immunological and histological observations
Authors: Smith H. V. , McQueen A. , Kusel J. R.
Published: March 2014

Synopsis

Sera from patients suffering from the autoimmune skin diseasespemphigus vulgarisandbullous pemphigoidwere used to demonstrate the presence of intercellular substance (ICS) orbullous pemphigoidantigen (BPA) on the surface of the schistosomula ofSchistosoma mansoniwhich had penetrated mouse and human cadaver skin, and mouse skin percutaneously. Both ICS and BPA were absent from mechanically transformed schistosomula or those formed in the peritoneal cavity of mice. Schistosomula which penetrated slowly through mouse or human skinin vitro, acquired more ICS or BPA than those which penetrated rapidly.

During percutaneous infections of mice, schistosomula recovered from skin after 2h and 24h had acquired large quantities of these materials whereas those which were recovered from skin after 10min had no detectable ICS or BPA. These materials must be shed during subsequent migration since schistosomula from lungs and liver, and 7-week old adults do not possess them.

Histological examination of both mouse and human skin revealed that the schistosomula remained in the epidermis for varying lengths of time. Schistosomula which remained there for more than 2h became vacuolated, whereas schistosomula which were present in the dermis at 2h appeared undamaged.

On cercarial penetration of human skin, the granular layer of the epidermis became disrupted or condensed. The implications of these findings are discussed.
Anin vivostaining technique for the demonstration of micro-organisms on the stratum corneum
Authors: Malcolm S. A.
Published: March 2014

Synopsis

Anin vivostaining technique has been developed for the demonstration of micro-organisms on human skin. This technique permits the study of the relationship between micro-organisms and the stratum corneum and its associated structures. It also aids an understanding of the factors involved in the nutrition and survival of micro-organisms on the skin surface.

In skin sites with large populations of coryneform species the bacteria tend to accumulate at the edges of corneocytes. This tendency is not shared by members of the micrococcaceae.

Agar impressions of the skin surface confirm observations of other workers and suggest that the surface of the stratum corneum is composed of domed corneocytes with a network of troughs or channels surrounding them. It is proposed that the association of coryneform bacteria with the edges of corneocytes may be due to the creation of an environment within the troughs which favours microbial colonisation.
Conclusions
Authors: Jenkinson D. McEwan
Published: March 2014

The collected evidence of the Symposium illustrates that sufficient information is now available to enable initial broad definition of the skin surface ecosystems for the different animal classes. As may be expected more is known about the ecosystems of classes (mammal, fish) and genera (e.g. Bos, Salmo) of commercial interest. A notable exception is the skin surface of the bird, about which, despite the development of intensive poultry husbandry, surprisingly little is known. The work to date on the morphology, chemical nature and inhabitants of the different ecosystems, however, provides only limited data on the dynamic processes, actions and co-actions occurring within them and the interchange of inhabitants between them. In particular, the role of the surface micro-climates in the development, survival and transfer of micro-organisms has still to be determined. Our present knowledge is thus almost entirely limited to recognition of the basic elements of the skin surface ecosystems and there is still a paucity of data on the variation between species, individuals and body regions, some of which appear to have specialised functions or like the joints of arthropods may be more susceptible to colonisation and invasion. Nonetheless, although the definition of the various surface ecosystems has by no means been completed, a stage has been reached where identification, classification and comparison of the defence mechanisms operating at the skin surface of different classes of animals can be attempted.
Agricultural science and practice
Authors: Blaxter Kenneth
Published: March 2014

Agriculture is one of the most basic activities of mankind. The production of food and fibre from a resource of land might be regarded simply as an example of the application of the biological and physical sciences and the progress of farming could be chronicled in such terms. Farming, however, takes place in a political, economic and social environment and has indeed been responsible for, as well as responsive to, changes that have taken place in all these aspects of society. The ownership of land, the tenancy of land, the availability of capital for land improvement, the costs of essential inputs into farming, the prices obtained for its final products, the conditions under which men and women work on the land, the rewards they receive and the whole infrastructure of rural life, constitute a complex fabric in which science is but one thread. It is difficult to assess when technical innovation occurs and, if it takes place, who has taken the major steps, or whether it alters farming practice or disturbs what is rarely, if ever, a stable economic, social and political equilibrium in the countryside. It suffices to state that a wholly scientific account of agricultural improvement and an analysis of the origins of agricultural discovery cannot explain the extent of the advances which have been made in the past two centuries in Scottish agriculture.
Brewing
Authors: MacLeod Anna M.
Published: March 2014

When the Royal Society of Edinburgh was founded, the art of beer brewing had already been practised for well ov,er five thousand years, initially in Mesopotamia, then in Egypt and, for the last two millennia, in Continental Europe and in Britain. The procedures used were —and still are —essentially simple. First, barley is malted by growing the grain to allow it to form an assortment of enzymes, some of which, particularly the proteinases and β-glucanases, gradually free the starch granules of the endosperm from their enclosing organic matrix. The enzyme-amylase is also synthesised during malting and, though it has a limited action on the starch in the intact grain, it assumes major importance later during mashing. As a result of the enzymic activity during malting, the endosperm becomes friable instead of tough and the germinated barley, now known as malt, is kiln-dried so that it can be safely stored.
Genetics
Authors: Robertson Forbes W.
Published: March 2014

The basic principles of inheritance were not established as a consequence of an immense accumulation of descriptive evidence. In this respect, the history of genetics differs from that of many other branches of biology. Before Mendel's conceptual tour de force and indeed, until his rules of diploid inheritance were rediscovered at the turn of the century, the phenomenon of heredity remained a mystery. A number of plant hybridists grappled with the apparently inscrutable properties of variation and even Darwin, the most incisive and comprehensive thinker among nineteenth-century biologists, remained baffled. Nevertheless, in the space of some 80 years, a staggering explosion in our understanding of heredity and in the development of analytical techniques has propelled the science of genetics into the middle of the biological stage where it plays a role rather analogous to that of atomic physics vis-à-vis the physical sciences.