Semi-natural chalk grassland is an internationally important habitat characterised by high species richness at a fine scale. In both the United Kingdom and other European Countries however, significant areas of chalk grassland have been lost to intensive agriculture practices. In the United Kingdom, conservation and expansion of existing chalk grassland sites has become a high priority. Research that leads to a better understanding of the processes that structure chalk grassland communities may aid these objectives. A number of field trials have been conducted to examine the role of grazing in structuring grassland plant communities, but the role of arbuscular mycorrhizal fungi (AMF)/plant symbiosis has received less attention. In this research project the structure (presence and abundance of species) of chalk grassland communities growing on the South Downs in the United Kingdom is defined. This is achieved by detailed analysis of extensive plant survey data collected in 1991. Analysis revealed strong patterns relating to species presence and abundance in the chalk grassland communities. In particular evidence of 'nestedness' and a frequency abundance relationship was found. From these patterns it was deduced that AMF/ plant symbiosis may have a significant role in structuring chalk grassland communities. In the experimental component of this research project two separate, but connected, trials were conducted. In the first trial chalk grassland turf was sampled for study in the laboratory under controlled environmental conditions. The second trial was conducted on chalk grassland turf, in situ, at the same site from which the laboratory turf had been collected. In both trials the method adopted was to weaken AMF /plant symbiosis by apply increasing doses of the fungicide Iprodione. In the laboratory trial this was conducted over one growing season and in the field trial over two seasons. There was a good level of consistency between the two trials. At low levels of fungicide there was no discernible change in community structure. But at the higher fungicide dose rates (2gm-2 and 4gm-2), changes to community structure (presence and percentage cover were observed). The results from the field trial suggest that approximately 50% of plants 1 in the community benefited from the presence of AMF, around 25% were unaffected, whilst the remaining 25% benefited from the absence of AMF. The largest changes in cover were in the mycorrhizal grass Brachypodium pinnatum which declined in percentage cover with increased fungicide dose rates. This was associated with a corresponding increase in the cover of the non-mycorrhizal grass Bromus erectus. Examination of the roots of selected forbs and grasses suggests that in species that benefit from AMF/plant symbiosis the levels of root infection in individual plant species may be related to percentage cover in the community. The research suggests that restoration of species rich chalk grassland communities might be better achieved by a process involving several stages. Initially this would involve creating a community consisting of the most abundant grasses and forbs (core species). These would be established in the presence of a full compliment of mycorrhizal fungi species native to chalk grassland. When this matrix community is established less abundant including scarce species would be added in a sequential process.

A range of tools have been proposed to support decision making in contaminated land remediation (collectively referred to as Decision Support Tools or DSTs). From a European perspective it is clear, however, that there are considerable national differences in the decision support process, and more generally in the extent to which this process supports the se lection of less invasive, alternative and potentially more sustainable remediation options such as phytoremediation, in situ immobilisation etc. (referred to here as "gentle" remediation technologies or options). This thesis critically reviews available DSTs in terms of their fitness for purpose for the application of "gentle" remediation technologies, using published literature and data from two stakeholder surveys: the first from a European perspective (completed in the European Union ERANET SNOWMAN project SUMATECS (Sustainable Management of Trace Element Contaminated Sites)) (sample size of 130) and the second focused on contaminated land consultants and managers in the UK (sample size of 71). In general stakeholder feedback from both surveys indicates a lack of knowledge of currently available DSTs and the requirement for a simple OST using a tiered approach that can be integrated into an existing national framework. Based on this stakeholder feedback, a novel OST has been developed that will interface with an existing national framework and which will act as a guide to selection of "gentle" remediation approaches. This DST is a literature based tool that will direct users to collated information on successful practical pilot/field scale studies on " gentle remediation approaches and ensures that the elements or sustainability are considered during selection. The proposed approach is validated against data from three large-scale remediation projects, involving both gentle and more invasive remediation methods, in the UK, France and Belgium.

In recent years, contemporary western society has played witness to a growth in the production, promotion, and consumption of ostensibly ‘ethical’ products such as Fair Trade goods. Such commodities are characterised by an emphasis on rebalancing inequalities that ‘mass’ production/consumption are said to create. This thesis takes sustainable tourism as a novel example of such concerns. With recent inroads in psychology and the social sciences suggesting that the practice of consumption represents a prominent ‘mode’ for ‘identity work’ (including class identities), the consumption of ‘ethical’ products may arguably signify the manifestation of ‘ethical identity/identities’. However, ‘ethics’ and ‘identity’ are ambiguous words with significant concerns surrounding the ‘ethics’ of ‘ethical’ products, and the extent to which individuals exhibit ‘ethical identity/identities’ through the consumption of such goods. Building on Michael Foucault’s ‘technologies of self’ and ‘ethics’, this thesis seeks to contribute to our understanding of ‘ethics’, ‘identity’, and ‘practice’ in relation to sustainable tourism.

Climate change has already led to an increase in the frequency and intensity of storm events in many parts of the world. With further increases predicted, and growing evidence of the link between extreme precipitation and waterborne disease, it is important to elucidate the role of sediments in pathogen transmission. Intense rainfall can trigger discharges from combined sewer overflows, increase surface and subsurface faecal inputs and can re-suspend microorganisms already present in sediments. Previous research has shown that sediments can act as environmental reservoirs of numerous waterborne pathogens, including enteric viruses and antibiotic resistant bacteria. Sediments are therefore a growing public health concern and are an increasing focus of human health protection strategies. However, further research is needed in order to elucidate the behaviour of microorganisms within these matrices. Routine monitoring for pathogens within sediments has not to date been considered feasible in many parts of the world and although low-cost microbial tools to detect faecal pollution of human origin, such as those that detect phages infecting Bacteroides fragilis (GB-124), have shown promise in many situations, they have seldom been applied to sediment matrices. Sediments might offer a more sensitive and longer-term assessment of contamination sources and hazards to health, compared with analysis of overlying waters from the same location. This study therefore sought to determine an effective elution method to extract GB-124 phages from sediments and to use it in an intensive six month investigation of the River (Ouse) catchment in Southeast England. The results (ANOVA with post-hoc Tukey) revealed that a low-cost elution method, involving 10% beef extract, provided the most effective means of recovering GB-124 phage from a range of river sediments (66% recovery). GB124 phages were subsequently enumerated in sediment and overlying water collected from 25 sites across the study catchment, along with somatic coliphage (SC), faecal coliforms (FC), and intestinal enterococci (IE). Physicochemical data were also collected. Analyses revealed evidence of faecal contamination at all sites, and human contamination at 13 of the 25 sites. Whilst levels of microorganism in the water and sediment were significantly correlated: GB-124 (p= 0.015); SC (p= 0.000); FC (p= 0.018); and IE (p= 0.038), importantly GB-124, SC, FC and IE (p= 0.00) were detected at significantly higher levels (Mann-Whitney) in the sediment samples. Significant correlations (p= < 0.01) were also observed between levels of FC, IE and SC and sediment temperature, but not between water temperature and any of the parameters in the water column. Interestingly, GB-124 phage showed no significant correlation with the non human-specific parameters (SC, FC, and IE) in the sediment matrices, which were found to co-correlate with one another (p= 0.00). The findings suggest that the application of low-cost monitoring approaches to analyse river sediments may not only provide a better assessment of dominant pollution sources than grab samples of overlying water (due to the higher levels and incidence of phages in sediments), but that they may also provide a better indication of potential risks to health from human enteric viruses. As such, the findings of this study add significantly to the body of extant knowledge relating to the behaviour of GB-124 phages in the environment and further support their use for microbial source tracking (MST) and as a potential component of quantitative microbial risk assessment (QMRA) studies.

Mould growth affects a significant proportion of dwellings in the UK and Europe. The house dust mite is also known to inhabit most dwellings and is one of the key factors affecting the health of the occupants. One of the key variables affecting mould growth and house dust mite populations is relative humidity. The relative humidity in a dwelling is dependent upon both the moisture levels and the temperature. The ability to assess the impact of different interventions on the relative humidity depends upon the ability to model both the internal temperature and the internal vapour pressure. This thesis develops, tests and assesses the impact of four combined moisture and thermal models which predict micro-environmental relative humidity. Two thermal models are tested, the BREDEM-8 monthly model, and the BREDEM-12 seasonal model. To each of these, two moisture models have been integrated including Loudon's steady-state moisture model and Jones' admittance moisture model. The BREDEM-8 Loudon model has been shown to be the most accurate model for predicting the airspace relative humidity in 36 dwellings during the heating season. The BREDEM-8 Loudon model has then undergone further development and testing and the applications of the model are investigated. A variable infiltration calculation has been implemented and tested within the BREDEM-8 Loudon model and the results show no improvement in the model prediction accuracy. Surface relative humidity calculations have also been incorporated for all dwelling surfaces, including cold bridges, and the significance of predicting surface conditions has been evaluated. The impact of fuel poverty is tested using simple versions of the BREDEM-8 Loudon model which have been adapted to account for situations where the expenditure available for fuel is limited and where the heating system is inadequately sized. Finally, a Mould Index has been developed which indicates the risk of mould growing on the coldest surfaces in a dwelling and various interventions in dwelling design and use are tested against this index and against the Affordable Warmth Index which defines the affordability of a particular dwelling. The results demonstrate a number of significant limitations in the current British Standard for condensation in buildings, BS 5250: 1989. It has been shown that the geographical and seasonal variations in internal relative humidity are significant, and that the highest relative humidity is unlikely to coincide with the coldest period of the year. It has also been shown that the modelling of surface conditions is critical in the assessment of mould growth in dwellings. Sensitivity studies carried out on the BREDEM-8 Loudon model have shown the most significant variables affecting the relative humidity predictions are the demand temperature, the heating pattern, the number of occupants, the ventilation rate and the level of insulation. The adequate sizing of the heating system and the ability of the occupants to afford to heat the dwelling to a comfortable temperature have been shown to be essential. It has also been shown that a change in the dwelling design or use may improve the affordability but may also lead to an increased risk from mould growth.