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The Forestry Authority, as the country's leading authority on forestry practice, has Design Guidelines which aim to offer designers sound relevant and appropriate advice on the theory, process and practice of forest landscape design. The guidelines therefore represent the FA's vision of how designed Britain's forest landscapes should appear. The aim of this study is to rigorously evaluate the advice offered in the FA's guidelines in relation to the FA's objective to offer an aid to design. A literature review and series of interviews with those responsible for the advice explores the motivation behind the introduction and development of the guidelines. The review concludes that the unusual circumstances surrounding the inception of guidelines are likely to have resulted in the advice having a strong forestry bias, a weak theoretical framework and to be offering advice that is divorced from other land-use interests. An analysis of the nature and contents of the guidelines and the subsequent critical discussion suggests that the advice is not always complete, consistent, logical or relevant. The concept of an alternative approach to offering forest landscape design guidelines is tested through both a postal questionnaire and a field survey. The findings for the postal questionnaire suggest that the FA's advice is generally well used and found useful but that it is at times limited and fails to respond to the needs of the current user group. The findings for the field survey show that enough evidence exists to support the concept and further investigation along these lines. The study concludes by making 20 recommendations for changes or additions to the FA's current advice, which address the issues raised by the research findings. These recommendations are offered as a framework within which alternative advice could be further developed.

The coexistence of plant species in highly diverse communities is one of the enduring questions in ecology. The Hutchinsonian niche is defined as an n-dimensional hypervolume incorporating every aspect of the life history of a plant but in practice very few of those aspects have been examined in detail for a suite of coexisting tropical forest plants. In this thesis I examine the germination and seedling growth and mortality responses of up to 20 species of neotropical pioneers in relation to abiotic arid biotic factors in their environment. Variation in the germination response to the environmental indicators of the presence of a gap was strongly related to seed mass and the environmental constraints seed mass places on regeneration. Smaller seeded species required irradiance to stimulate germination and emergence occurs from the superficial depths of soil that receive irradiance. Both within the small-seeded group of species and in comparison with the larger seeded species, seed mass was positively related to the degree of discrimination in requirements to stimulate germination. Seed mass was related to the amount of resources and the amount of physical defences, both of which enhance seed longevity. Larger seeded species (seed mass > 1.5 mg) were able to persist in the seed bank and emerge from lower in the soil profile. Some large-seeded species possessed a positive germination response to increasing magnitude of diel temperature fluctuation, and measurements suggested that temperature fluctuations penetrated lower in the soil profile than irradiance. The seedling growth and mortality of three species in relation to gap size predicted the known differences in adult distribution for these species at my study site. Differences between species in response to gap size were enhanced but not created by herbivory. Trade-offs between rate of growth at high irradiance and growth and survival rates in low irradiance, and between growth at high irradiance and growth when water and light were simultaneously limiting contributed to the contrasts in response to gap size among six species. I found no evidence of maintenance of the rank of species' growth rates across irradiance treatments or for a trade-off between maximum rate of growth and susceptibility to herbivory. These results illustrate contrasting responses to environmental heterogeneity within the pioneer functional group at my study site. These differences represent a potential mechanism for coexistence of ecologically similar species at one site. I conclude that niche differentiation contributes to the maintenance of tropical forest diversity.

Annual losses of nitrogen from existing glasshouse crop production substrate systems could be as high as 600 kg ha 1, using an average of 30% drainwater containing a nitrate-nitrogen concentration of 200 mg 1". The use of nutrient recirculation systems such as nutrient film technique (NFT) helped to reduce nutrient losses to the environment but the commercial area of NFT has decreasedd ue to high initial capital costs, concernso ver diseaset ransmissionw ithin the system and an absence of recent research and development. Most substrate systems rely on the provision of liquid nutrient feeds at every watering. This study examines clinoptilolite which is able to selectively store, supply and exchange cations with plant roots. The use of the naturally-occurring volcanic aluminosilicates pumice and clinoptilolite zeolite in the intensive production of edible and ornamental protected crops, tomatoes, sweet peppers and standard carnations was studied. Pumice from Sicily, Italy and clinoptilolite (84-87%) from Beli Plast, Bulgaria were used in the experiments. The management of the pumice and unloaded clinoptilolite systems involved provision of all the plant growth nutrients via a drip irrigation system. In comparison, the nutrient-loaded clinoptilolites were examined using only water in the irrigation cycles which allowed relatively unimpeded cation exchange to take place between the clinoptilolite and the surrounding solution, thus providing nutrients for plant roots. The total cation exchange capacity of clinoptilolite was measured as 132.0-158.3 meq 100g'', compared with 1.8 meq 100g-' for pumice. Unloaded clinoptilolite irrigated with nutrient-balanced liquid feeds gave yields and quality equivalent to those of tomatoes, peppers and standard carnations grown on rockwool, pumice and peat / peat alternatives. For the first nine months of an eighteen month experiment, the yield and quality of standard carnation flowers from high nutrient-loaded clinoptilolite matched those from pumice receiving liquid feeds at every watering. Thereafter, lower concentrations of available nitrogen and, to a lesser extent phosphorus, limited production by up to 25%. Drainwater nutrient concentrations were, however, extremely low and reduced the potential pollution risk to the surrounding environment. Drainwater nitrate-nitrogen concentrations of below 10 mg 1'' were measured, compared with 100-300 mg 1.1 for pumice. Drainwater potassium concentrations were also comparatively low at < 20 mg 1'' for clinoptilolite and 200 mg 1" for pumice. Phosphorus concentrationsi n the drainwater did not exceed1 2 mg 1.1c, omparedw ith a maximum of 70 mg 1'1 in drainwater from pumice. The inclusion of phosphate rock (apatite) in with the clinoptilolite provided a source of phosphorus available to plants and the dissolution of apatite was regulated by the rate of absorption of phosphorus and calcium by plants. In all the experiments, clinoptilolite adsorbed ammonium-nitrogen and potassium, releasing calcium and sodium. However, concentrations of sodium released into the root zone were not harmful to plant growth. The average nitrate-nitrogen concentration of new, fully-expanded carnation leaves was 51.7% lower than the target levels. The nutrient loading of nitrogen and phosphorus regulated the overall yield of the crops evaluated in the experiments. The use of nutrient-loaded clinoptilolite to produce commercial crops and reduce environmental pollution by regulating the concentration of nutrients in the drainwater over long periods of time is further explored in the study.

Blackcurrant (Ribes nigrum L.) is a perennial shrub grown for its black piquant berries, rich in a variety of nutrients, phytochemicals and antioxidants. Blackcurrants are commercially grown in 21 countries mainly across temperate zones of Europe, Russia, and New Zealand and to a lesser extent North America. The berries can be harvested by hand and consumed raw, however the main market lies within the mechanically harvested crop used for processing. Demand for juices, and fruit juices in particular, continues to rise mainly due to increasing consumer awareness of the health benefits of a balanced diet. The rich nutritional content of blackcurrant makes it a desired commodity for production of juice and other innovative products. Breeding of new blackcurrant cultivars is dominated by the processing industry and the emphasis in recent years has been to increase the nutritional value of the crop. New berry fruit cultivars in the UK have recently focused more on fruit quality traits than agronomic characters (Brennan and Graham, 2009), and the main quality traits of blackcurrant have been associated with antioxidant, colour and flavour properties. Quality-focused breeding is challenging due to long timescales and low precision as quality traits are complex, show continuous variation, polygenic control, genes of small effects and strong influence by the growing environment; additionally, blackcurrant is a minor crop with no reference genome and existing sequence annotation is based on homology to Arabidopsis. In this study high throughput phenotyping, and metabolome and transcriptome profiling analysis contributed to a comprehensive overview of blackcurrant physiology and regulation during fruit development. Combination of a novel correlation platform and database mining of metabolite and transcript abundances contributed to identification of genes associated with anthocyanin content in blackcurrant and provided functional gene annotation for Ribes sp. Sixty three genes were identified as having major roles in blackcurrant anthocyanin accumulation with putative functions of catalytic proteins, transporters and regulatory proteins; a number of cytochrome P450 family proteins were also implicated. Moreover, a range of proteins with unknown functions in Arabidopsis were shown to correlate strongly with flavonoid accumulation in blackcurrant. The developed approach for functional gene orthology annotation (genes with similar functions) can also be utilised for several other (~200) traits analysed in this study and can provide a functional systems biology platform for other woody perennial species with no reference genome. In parallel, mapping population analysis and a new high-density quality-specific genetic linkage map and quantitative trait loci association with major quality compounds such as anthocyanins, sugars, organic acids and other polyphenols were developed. This contributed to the identification of significant associations between 28 quality traits and 978 markers present on genetic linkage map and created a functional tool for future quality-orientated blackcurrant breeding. The genetic linkage map assisted further functional annotation of several new Ribes SNP based markers obtained through GbS technology through their association with quality traits for which polymorphism can be analysed using existing blackcurrant genomic resources. Integration of functional candidate genes identified in fruit ripening analysis and on genetic linkage map with several blackcurrant genomic resources formed a platform for assisting further developments in quality-orientated blackcurrant breeding at The James Hutton Institute. This platform provides a holistic view of the mechanisms that underlie fruit compositional quality and may provide a means for germplasm selection with no prior phenotypic information. Knowledge and tools developed in this study can be further developed with new developing genomic technologies.

The effects of processing (irradiation and heat treatment) and storage on the main nutrients (carbohydrates, proteins and lipids) of almonds (Prunus amyqdalus Batsch) have been investigated. Two varieties of Iranian almonds: P. amygdalus var. hard shelled, and P. amygdalus var. fragile, and one American variety, P. amygdalus var. semi-hard have been used in the present study. Variations between the nutrient composition of the different varieties were observed, and the range was between 93 and 132 mg/g for carbohydrates; 170 and 180 mg/g for proteins and 400 and 500 mg/g for lipids. The almonds were then subjected to the following three processes:1. A sample of shelled almonds was subjected to 2 Mrad irradiation using 60Co. Changes followed similar trends in the three almond varieties after irradiation. There were no significant losses in total available carbohydrates, total proteins and total lipids, whereas increases were observed in free amino acids, free sugars and free fatty acids. Storage of the irradiated almonds at 22°C for one year did not bring about any changes in total available carbohydrates, total protein and total lipids. However, there were changes in the individual free sugar fractions, while no changes were observed in free amino acids and in free fatty acids.2. Samples of shelled almonds were pre-soaked in 17% salt solution for 4 hours with slow agitation. After removing them from the solution, the salted nuts were transferred to a rotary drum and dried at 70°C for one hour, until the moisture taken up during the soaking treatment was removed. The temperature was then raised to 120°C within 30 minutes and roasted for 20 further minutes. Losses occurred in both carbohydrates and proteins, while the total lipid content remained unchanged after the above processing. Decreases were noted in free amino acids and in free sugars, but there were increases in free fatty acids. Storage at 22°C for one year resulted in no further losses of carbohydrates and proteins. Free amino acids increased, indicating some protein hydrolysis. A further increase in free fatty acids was observed. 3.A sample of shelled almonds was first roasted as described under (2) and then irradiated as described under (1); this being referred to as combined processing (dual treatment). The same three nutrients followed very similar trends to those found in roasted samples. So, on the whole, irradiation at 2 Mrad seems to preserve the nutrients of almonds much better than does roasting, especially during storage for one year.

Comparative work on the structure of the cell walls of red kidney bean hypocotyls and mesocarp from unripe and ripe mango fruits showed significant differences. Cell-wall fractions from each were obtained using solvent extraction (water, alkali and acid) and enzymic (endopolygalacturonase) degradation procedures. The monosaccharide composition of each fraction was determined after TFA-hydrolysis by TLC-analysis. Greatest variation in monosaccharide compositions was observed in the water-soluble fractions which accounted for 18%, 48% and 11% of the cell walls of the bean, unripe and ripe mango, respectively. Water-soluble carbohydrates present in the mango pulp were examined by TLC, gel-filtration and ion-exchange methods. Only sucrose, fructose, glucose and high-MW polysaccharides were detected. The ripe mango contained 8 times more soluble polysaccharide than the unripe. In the ripe fruit the approximate MW of the polysaccharide fraction, which was rich in uronic acid was 40,000. In the unripe fruitpolysaccharides with MW's ranging from 40,000 to > 300,000 were detected. These polymers contained much smaller proportions of uronic acid than those from the ripe mesocarp. A crude 3 M LiCl enzyme extract from the cell walls of the ripe mango was able to solubilize 14% of prepared cell walls from the unripe fruit. The mechanism of this process was investigated. Endo-enzymes involved could not be identified. The involvement of b-galactosidase in cell-wall degradation was examined. Using p-nitrophenyl-b-D-galactopyranoside as substrate, 3 wall-bound forms of the enzyme were found in the ripe fruit and 2 in the unripe. Four soluble forms which were different from the wall-bound forms were observed in the ripe fruit. Three of these were present in the unripe fruit. The action of the enzyme forms on mango pectin and cell walls was examined. There was no evidence that any were directly implicated in cell-wall degradation. Wall-bound exopolygalacturonase was detected for the first time in the mango fruit.

Two pathogens Septoria pistaciarum and S. pistacina, causing leaf spot diseases of Pistachio (Pistacia vera) were studied. The morphology and ultrastructure of the two pathogens and also the ultrastructure of the host-pathogen interface were investigated. The conidia spores of both pathogens were narrowly elongate with several transverse septae and each cell contained one nucleus. Spore length and cell number were positively correlated. Spore germination was shown in detail in S. pistaciarum. Spore germination, initially an increase in volume followed by an increase in length by cell division, and germination by the production of twin-pairs of secondary septate spores and/or hyphal germ tubes. A pattern of cell division, polarity and germination was established and an interactive model was described. The spore growth initially followed linear kinetics and then became exponential. The production of hyphal tips hecame continuous exponential at the same time and the hyphal growth unit stabilised at 40-60 urn. The germination pattern could be altered by manipulation of the nitrogen or phosphate source and levels in the medium. In the resting spore the wall was composed of three layers an outer layer (o) and two inner layers I1 and I2. Each primary septum was a duplex layer derived from I1 and I2 with an intermediate electron lucent layer. Perforation was simple with paired Woronin bodies. During increase in lengththe development of new (secondary) septa showed the crosswall material was derived from layer I2 and development was centripetal. The germ-tube wall was formed from wall layer I2 and wall layers 0 + I1 were disrupted. Secondary spores were formed enter oblastically. S. pistaciarum and S. pistacina were used in the ultrastructure of host-pathogen investigation, infection of the host by S. pistaciarum was by inoculation with conidia produced on culture whereas with S. pistacina inoculation was obtained from previously infected leaves. The spores germinated on the leaf surface and penetration was made by fine hyphae through the stomatal aperture in both species, growth of pathogen within the leaf was limited to the intercellular spaces. Penetration of the host cell wall did not occur. The hyphae were attached to mesophyll and palisade cells by an accumulation of extra-hyphal sheathing material. The initial host response to infection was shown by an accumulation of electron-dense material and disruption of the tonoplast, followed by disruption of chloroplasts and disorganisation of the host cell cytoplasm. Pycnidia were produced within the lesion. Pycnidial initials were formed in sub-stomatal spaces and spore tendrils were released on the leaf surface.