Eighty-four potentially mycorrhizal macrofungi have been recorded with Sitka spruce in Scotland. They derive primarily from the native flora of birch and pine and many are fungi with a wide host range. Specific mycorrhizal associates do not occur. In its native range hypogeous fungi are important but these are largely absent from Scotland. The regularly encountered mycorrhizal flora is less abundant and less diverse than that of Norway spruce or European larch and reflects the importation of Sitka spruce by seed and the ecological conditions to which it gives rise. The saprotrophic macrofungi are species which are widespread and common in a range of vegetation types.

A current intensive mapping scheme for Forth seaweeds shows the normal attenuation gradient of species going upstream in the estuary with the existence of two areas of species depletion in the firth, around Kirkcaldy and Edinburgh. Ordination of species presence data suggests the continuation of estuarine influence into the firth and the possibility of slight differences in composition of the flora between the north and south banks in the mid and inner firth. Impoverishment of the flora around Edinburgh since the 19th century can be ascribed to increased pollution, but possibly also, to a lesser degree, to shore reclamation. Following abatement of sewage pollution, differences in the recovery of the algal flora on different shores may be related to the nature of the pollution-induced animal community. Recent work on the upper estuarine flora of the many small, highly-stratified sub-estuaries of the Forth system has revealed a marked shore zonation pattern of smaller mat-forming species.

Relatively little research has been done on mycorrhizas of Sitka spruce, although greenhouse studies have confirmed that its growth can be improved by the introduction of mycorrhizal fungi. Work in nurseries is difficult under British conditions and it probably will be necessary to disinfest soil in seedbeds before mycorrhizal treatment can be applied. Results from forest trials show that inoculation with selected mycorrhizal fungi can give significant early growth effects, though how long these will persist is unknown. In such work, careful attention must be given to selection of controls. Features covered in this review include a discussion of fungi mycorrhizal with Sitka spruce, identification of mycorrhizas, nutrient uptake, and growth enhancement of seedlings and transplants.

The Forth saltmarshes occur as a more or less continuous strip on the south bank of the middle Forth and as scattered fragments of varying sizes elsewhere on the banks of the estuary and the Firth of Forth. The most complex and important from a conservation viewpoint are those at Aberlady and Tyninghame. Floristically the Forth saltmarshes are poor and lack several plant species which are imporant in England, notably Halimione portulacoides and Limonium vulgare (the latter recently extinct at Aberlady). Most of the Forth saltmarsh vegetation apparently falls into the two most common and widespread Associations of British saltmarshes, Puccinellietum maritimae and Juncetum gerardii, although several other community types occur. The most distinctive features of the Forth saltmarshes are: (a) the presence of the physiographically distinct and nationally rare beach-head saltmarshes; (b) the occurrence locally of community types which have a predominantly northern or southern distribution in Britain; and (c) communities which are subtly different from more widespread examples nationally.

The history of Edinburgh's sewage disposal to the sea from the open ditch system of the 17th century to the present day, together with the changes in legislation affecting sewage discharges to the firth, are reviewed. During the last thirty years sewage discharges have been monitored monthly for levels of faecal coliform bacteria at approximately thirty-four shore sites and twenty offshore sites. These coliform counts are used as bacteriological indicators of sewage pollution, in order to assess the risk to humans of infections that might result from the consumption of contaminated shellfish or from bathing in sewage-polluted waters. Most of the areas sampled from the inner firth were shown to be grossly polluted, particularly in late summer, and regularly to exceed guideline levels throughout the year. Since the commissioning of the new Seafield sewage works in 1979, a general improvement in bacterial and viral counts has been recorded on the south shore of the inner firth. In the last decade two European Community directives relating to the quality of seawater for bathing and shellfish growing have been promulgated, which set guideline and mandatory levels for the number of faecal coli in seawater. The Scottish Development Department has recently designated five beaches as bathing beaches and two areas on the north and south shores of the firth as shellfish growing areas. These areas have been regularly monitored by the Forth River Purification Board and the published results of both surveys are analysed. The virological studies carried out by the Forth Pollution Group of Napier College before and after the major change in the sewage discharge pattern into the Firth of Forth are reviewed.

The growth and development of Sitka spruce roots is reviewed against the practical background of tree stability. Two features of the roots which make Sitka spruce liable to windthrow on upland sites are the shallow development in unfavourable soil conditions, and restricted lateral spread and anchorage caused by some forms of cultivation. Responses to different aspects of the soil environment are discussed, with emphasis on mineral nutrition, drying of the soil, waterlogging and temperature. The development of a small number of major woody roots from an assortment of primary laterals on the transplant occurs at an early age and is determined both by the relative size and vigour of the primary roots and by their local environment. The roots, which respond to increases in nitrogen and phosphorus supply with enhanced growth, are sensitive to drying of the soil and are particularly so to waterlogging, but they show no unusual response to soil temperature. Adventitious roots can play a role in the survival and development of the root system.

An account of the pathology of Sitka spruce in northern Britain is given based on enquiries dealt with by the Pathology Branch of the Forestry Commission Research Division in the last fifteen years. Sitka spruce occupies the major proportion of our forest estate but has given rise to only 15% of enquiries concerning tree damage. The most frequently diagnosed injuries have been those due to frost and to root diseases caused by Heterobasidion annosum and Armillaria spp. Two other root pathogens, Rhizina undulata and Phaeolus schweinitzii, and two needle pathogens, Lophodermiun piceae and Rhizosphaera kalkhoffii, have also been recorded in Sitka spruce plantations as have several wound-infecting stem decay fungi. Only five other fungal diseases, those caused by Botrytis cinerea, Phytophthora citricola, Helicobasidium purpureum, Sirococcus strobilinus and Pythium spp. have been recorded, all in nurseries.

A description of the community structure of the Forth estuary's zooplankton was obtained by sampling monthly at nine stations ranging from fresh water to fully marine conditions for an eighteen-month period. The variation in species abundance and distribution is related to environmental variables. The apparent spatial and temporal successions of members of the Acartia species complex are described, as are the episodes of predation spreading from the firth and the domination of the upper estuary by Eurytemora. It is observed that the estuary of the Forth is rare among British estuaries in its ability to support a truly pelagic self-maintaining assemblage of species.

The intertidal habitats of the Forth estuary are dominated by fine-grained muds, which experience a salinity range of 0–32%, j over the length of the estuary from Stirling to Queensferry. The current total area of the intertidal zone is 23.3 km2, the majority of which is found in the three central bays of Skinflats, Kinneil and Torry Bay. Over the centuries, agricultural and industrial reclamation has reduced by almost 50% the size of the Forth estuary intertidal habitat. The upper estuary has narrow intertidal shores, inhabited almost exclusively by oligochaete worms, which are very abundant due to organic enrichment of the area. The middle estuary is responsible for the greatest biomass and production of the intertidal benthic macrofauna. The lower estuary has a greater diversity of species than the upper and middle estuary, but has a lower biomass and abundance of macrofauna. It is shown that the production/biomass (P/B) ratio of several species in the Forth estuary is lower than that of the same species in other estuaries. This depression cannot be explained by natural environmental variables, and is suggested as being due to the levels of pollutants throughout the area. Despite this depressed productivity, and the threats from further reclamation, the Forth estuary retains abundant populations of intertidal animals, which are an important food source for birds and fish.

The status of insects on Sitka spruce in Britain is examined in relation to the attributes of this tree as a widely planted exotic. Both time in Britain and particularly the area planted influence insect species diversity. The abundance and status of selected insects of pest importance are examined. Future trends receive attention, particularly in relation to potential importation of pest insects and this is examined for a number of species from Europe and North America.

Sitka spruce comprises the largest single forest type in Britain and provides a vast habitat for wildlife. However, many improvements are still possible. No species of bird or mammal occurs equally throughout a conifer rotation, their distribution being affected by both the temporal and spatial dynamics of plantations. We suggest a number of practical improvements, including the modifications to felling-coup size and the incorporation of other tree and shrub species, to increase the diversity and abundance of wildlife in Sitka spruce forests without seriously affecting the forest enterprise.

The paper summarises and briefly discusses published and unpublished data relating to the physicochemical characteristics of the sediments and the occurrence and distribution of the intertidal macrobenthos of paniculate shores in the Firth of Forth. In general, the shores described are poor faunistically and in some areas this results partly from the influence of waste water discharges. Detailed information is available for only a limited number of the numerous beaches in the Firth of Forth. In consequence, this paper focusses attention on the results of a long term study of four beaches along the south shore of the firth which was undertaken as part of an environmental impact assessment in relation to the introduction of improved sewage treatment and disposal for the City of Edinburgh. Edinburgh Sewage Scheme and the firth into which it discharges are briefly described and data pertaining to changes in the intertidal sediments and the intertidal macrobenthic communities, which occurred in the Seafield Bay area of the firth following pollution abatement, are presented and discussed.

Sitka spruce grown from seed has a juvenile phase of about twenty years before coning commences; mature trees and grafted scions cone intermittently and produce good cone crops every three–five years. These characteristics have lengthened the breeding programme and reduced seed production in orchards. Production of male and female cones can be enhanced by treatments such as heat and drought and by application of a mixture of gibberellins A4 and A7 (GA4/7) to mature grafts. To enhance flowering consistently in container grown grafts the GA4/7 must be applied together with a cultural treatment, but with larger grafts in the field GA4/7 alone is often effective. Attempts to induce cone production in juvenile trees, however, have been less successful. Female cones initiated on field grown trees in response to inductive treatments yield seed of a similar quantity and quality to that from cones on untreated trees. The physiological mechanisms of coning, and cone induction techniques, are discussed.

Knowledge concerning the meiofauna of the Forth is reviewed and extended by presentation of the results of new surveys of the intertidal and subtidal provinces of the estuary. Most of the published information concerns the influence of sewage pollution on shores of the firth. Before 1979, the meiofaunal communities of sandy beaches along the Edinburgh coastline exhibited reduced species richness, although certain taxa displayed enhanced densities. Improvements in the sewage treatment process have initiated a phase of meiofaunal recovery.

In the estuary the salinity regime plays a key role in the determination of species composition, although the influence of local changes in sediment type and stability is recognised. Meiofaunal communities of lower shore mudflats in different salinity zones of the estuary are described. Pollution plays a major modifying role. In the upper reaches of the estuary, which suffer oxygen depletion in summer, only nematodes and oligochaetes were recorded in the oligohaline zone and impoverished nematode and copepod faunas in the mesohaline zone. In the polyhaline zone discharges from the industrialised region around Grangemouth modify meiofaunal community structure over an extensive area of mudflat. The subtidal meiofauna of the lower estuary is briefly described, particularly with respect to the copepods. Impoverishment again occurs in the vicinity of Grangemouth.

Molluscan species diversity decreased westward from the North Sea into the Forth with decreasing diversity of habitats, decreasing algae and increasing turbidity of water. Species diversity varied little from year to year or seasonally at individual sites. Adult Littorina littorea in particular were larger at lower than at higher shore levels, and larger in the outer than the inner firth or estuary, while Nucella lapillus adults were of more uniform size throughout the area.

Population parameters and reproductive output of L. littorea and L. saxatilis in the estuary varied without strict relation to mere position between open firth and up-estuary sites. On the other hand, shells of L. saxatilis became progressively wider, breeding seasons of L. littorea were longer and less defined, breeding in L. saxatilis became more sharply seasonal and eggs of L. saxatilis had greater weight, calorific value and inorganic content at up-estuary sites. L. littoreashowed two-weekly peaks in spawning on spring tides while L. saxatilis showed monthly peaks in release of young near times of full moon.

Comparison of fresh material and stranded shells with material from beach deposits up to 5500′ years old indicates changes in populations with changes in climate about 550 BC. Size of Littorina spp. continued to decrease while numbers of Mytilus edulis increased greatly near the onset of the industrial revolution.

A combination of two vegetative techniques is seen as a possibility for large-scale production of juvenile, rooted Sitka spruce cuttings of improved genotype. Tissue culture techniques, under development, would be used to produce large numbers of stock plants for stem cuttings production. Cuttings techniques, currently under commercial trial, would be used to produce the rooted plants for forest establishment.

The structure of the sublittoral benthic macro-invertebrate populations of the Forth estuary and firth, Scotland, is described, giving the species richness, abundance and biomass for the area from the freshwater tidal limit to the North Sea boundary. Eight faunal associations have been defined, which include classical Petersen communities in the marine area and transition associations within the estuary. The spatial distributions of the associations are predominantly the result of the physical environment, but superimposed on the effects of salinity, sediment type and bathymetry are the effects of urbanisation, industrialisation, dredging and spoil disposal and thermal discharges. The benthos of the major part of the firth has been little affected, although that of the peripheral and estuarine areas does show anthropogenic effects.

The water column-benthos and fisheries-benthos interactions are also discussed. Elevated levels of nutrients in the water column may be the cause of enriched benthic populations in the firth and an assessment of the fish-benthos coupling indicates an estuarine functioning similar to other northwestern European areas.

The wood properties of Sitka spruce (Picea sitchensis) which influence its use in the production of sawn timber, veneer, particleboard, fibreboard, pulp and paper are discussed. Although the low strength properties of Sitka spruce restrict its use as constructional timber, it is highly suitable for the manufacture of particleboard and fibreboard and is an excellent pulping species.

Man's use of the timber of Sitka spruce grown in North America and in the United Kingdom is reviewed. The contrast in character and properties of the timber from the two sources is considered and an explanation for the differences given in terms of the growth. The importance of Sitka spruce to the British forest and timber industries is examined and consideration given to how Sitka spruce should be managed to ensure the production of timber which will meet the requirements of the British timber user.

Until the late 1970s Edinburgh and the surrounding areas employed a series of relatively short sea outfalls to dispose of sewage to tidal waters. A centralised sewage treatment facility was provided in 1977, with disposal of liquid effluent by long sea outfall. The residual wet solids are dumped at two sites in the North Sea off the Firth of Forth. The sites, one near Bell Rock (56 25N 02 10W) and one ten miles north of St Abb's Head (56 04·5N 02 07·25W) are used on a rotational basis. The macrofauna at both sites shows a normal polychaete-dominated community exhibiting the normal low number/high diversity characteristics of many unimpacted communities in the North Sea. In general, seasonal differences in mean concentrations of lead, copper and zinc in sediments were small and within the limits of statistical variation. The concentrations of mercury and cadmium were mainly low and close to the detection limits of the analytical methods employed. The monitoring data from Bell Rock and St Abb's Head demonstrate that the dumping operation has had little effect on the benthic environment and that the macrobenthos showed no signs of stress due to the addition of sewage sludge.