This research looks to present a reinterpretation of medieval forests, the least well understood landscapes of medieval Western Europe. The thesis focuses on the Forest of High Peak and Sherwood Forest and seeks to address several key themes, including the diversity of forest landscapes, the long-term impact of Forest Law, and evidence for power-relations and social dynamics within the forests. A wide variety of sources are utilised within this research, including map analysis and regression techniques, analysis of material culture, documentary sources, place names, church architecture, and funerary monuments. Evidence is found for forests having had a dynamic landscape character, including not only woodland, but also moorland, farmland, industrial areas, and urban areas, as well as a range of human activities that included mining, glass and charcoal manufacture, ironworking, leatherworking, carpentry, construction, and intensive arable and pastoral farming. Far from being universally oppressive, it emerges that through its protection of woodland Forest Law also preserved common rights and areas of royal demesne, the impact of which was a high degree of peasant agency during the medieval period.

This thesis investigated the ecology and dynamics of Douglas fir (Pseudotsuga menziesii var. menziesii) dominated plantations at Coed-y-Brenin, Wales, whose transformation to continuous cover forestry has been delayed due to the presence of non-native invasive rhododendron (Rhododendron ponticum L). The literature review highlighted the complementary evolution of silviculture and modelling concepts to meet societal expectations and advance knowledge and understanding. It highlighted the development of hybrid, individual-based models, facilitated by advances in technology and complex systems theory to address contemporary pressures on forests. Three permanent sample plots of different ages, collectively covering 1.6ha of forest, were resurveyed in 2011, producing a 5-year growth series of mensuration data to parameterise an individual-based spatially-explicit forest growth model, SORTIE-ND. Vegetation, soil and light were surveyed to construct a statistical model of rhododendron seedling establishment and determine Ecological Site Classification. The limiting factors identified by the ecological site classification were a slightly dry Soil Moisture Regime and a poor Soil Nutrient Regime with moderate to high phosphorus and low nitrogen availability. SORTIE-ND was successfully parameterised using a maximum likelihood technique and simulated annealing. Parameterised relationships achieved an excellent level of fit to the data (R2 of 0.785 to 0.971), and the stand simulations produced DBH density plots comparable to observed size distributions. A Bayesian statistical model of rhododendron seedling establishment was produced. The cross-validated model predicted 81.3% of 24 survey stations with rhododendron seedlings, and 75% of 16 stations without seedlings, with an overall accuracy of 77.5%. Seedling establishment probability increased with soil O layer depth and decreased with increasing summed tree height in a 12x12 m neighbourhood. SORTIE-ND was then parameterised, using published literature, for the rhododendron lifecycle, to highlight knowledge gaps and as the novel first step towards full parameterisation from field data and the creation of decision support systems enabling foresters to interrogate the impact of different harvest regime scenarios on rhododendron invasion vulnerability.

Spatial patterns of forest trees, stand level effects of cyclones, and factors affecting mortality and growth of individual trees were investigated in 20 experimental plots (0.5 ha) in North Queensland tropical rain forests, Australia. Cyclone disturbance has been recorded in individual plots for 20 times since establishment in 1971. Spatial point patterns of trees were mapped, and pair correlation and mark correlation function were used to investigate relationships between the trees. Effects of cyclones on stand level properties of the forests (total basal area, stem densities, stem size inequality, species diversity, recruitment, mortality) were estimated using generalised additive modelling. Factors affecting individual tree mortality and growth were analysed in generalised mixed effects modelling. The spatial pattern analysis showed minor changes of tree density and tree death in the forest spatial patterns following cyclones. The models revealed that the forest properties were changed significantly. Cyclones decreasing total basal area and increased tree mortality rates and number of abundant species. Higher mortality rates are likely influenced by individual tree characteristics of low wood density, negative growth rates and belonging to particular sets of families. Factors that increase growth rates are include higher crowding effects of tree density, cyclone occurrence, crowding effects by smaller trees, and trees of some families. Slower growth rates are likely influenced by higher wood density, higher surrounding basal area of competing trees and in certain families. From this research, evidence has found for cyclones to be a factor increasing stand level mortality rates but not individual tree mortality. The dynamics from individual trees in mortality and growth, forest spatial patterns and stand level properties has characterised the tropical rain forests of North Queensland in facing frequent cyclone disturbances.

The research concerns the potential for using the native plants of the Negev Desert in southern Israel in the Negev, which will help to promote more sustainable landscape development in the region. The study combines the data collection in the field of 163 plant species located in the Negev desert and the literature review of these species. The plants’ key physical, visual and aesthetic characteristics as well as their natural growing conditions are analysed. The analysis leads to an evaluation of the Negev plants in terms of suitability for particular uses in the Negev landscape. The conclusion reached is that the main reason for the non-use of the native plants is that they are still considered a part of the hostile desert environment. They have not as yet been ‘culturalised’. The advantages/disadvantages of using the native plant species is considered for each plant using a natural/quasi-experimental method, where each of the 163 species located by the author is analysed in terms of its physical and aesthetic characteristic and potential use. Furthermore, the individual species are matched with an exotic species and evaluated according to their potential landscape and ecological effects, water use and their potentials for environmental use in natural areas, the middle landscape and garden locations. The analysis and evaluation of the native Negev species confirms that 95%-96% of the native Negev plants have the potential for environmental use in natural areas and the middle landscape and 69% have the potential for garden use. A scientific study of the shade characteristics of 6 native Negev trees confirms that these trees provide an equal, if not better shade, compared to two control species and thus their potential for use in creating shade and altering micro-climate has been proven. The research also proposes a series of micro-landscape solutions, which will help to promote plant establishment and growth in the Negev as well as other desert environments. These proposals are seen as part of the agenda for establishing more sustainable landscape development in the Negev.

Climate change is caused by rising quantities of greenhouse gases, particularly CO2, in the atmosphere, largely through consumption of fossil fuels. There is interest in sustainable energy generation from renewable resources, particularly biomass crops to reduce reliance on fossil fuels. A key advantage of such energy systems is that they assimilate atmospheric CO2 and thus help mitigate climate change. Soil represents one of the largest pools of C in the biosphere and there is potential to use soil as a sink to sequester C to mitigate climate change. The aim of this project was to investigate soil C storage and sequestration in short rotation coppice (SRC), which is one of the major biomass cropping systems in temperate climates. 14 year old plantations of willow and poplar established at Rothamsted Research in Harpenden were used to investigate how the quantity and quality of organic matter under the SRC compare to that under adjacent land uses, including arable cropping, set-aside grassland and natural woodland. It was shown that change in land use to SRC led to increased C storage in soil relative to alternative agricultural systems, while conversion to setaside had no effect on soil C stocks. There was no difference in C storage under different poplar or willow cultivars. Differences in C storage between arable, SRC and set-aside plots reflected changes in C stocks at 0-30 cm depth with no change occurring to C at 30-60 cm. The quality of C was investigated by analysis of the light fraction organic matter pool which acts as an early indicator of long term changes in total soil organic matter. The work showed that the free LFOM pool responded to land use change while the physically protected intra-aggregate LFOM pool did not. While changes to amounts of LFOM following land use change occurred in soil at 0-30 cm depth, there were no changes at 30-60 cm depth. Fourier Transform Infra Red spectroscopy showed that the chemical composition of free and intra aggregate LFOM was different, and that composition of both pools was affected by land use. Fourier Transform Ion Cyclotron Resonance Mass spectroscopy was shown to provide fine level resolution of the composition of soluble organic matter, and demonstrated that the aromaticity and chain length of C was higher in woodland than arable soil. The potential to sequester C in soil as biochar is a promising option to promote longterm sequestration of C in soil. The potential to use a fluidised bed reactor to produce biochar was investigated. Life Cycle Analysis showed that 4700C was the optimal temperature to promote retention of C in biochar during pyrolysis, while minimising losses of C as bio-oil and gases. Addition of steam during pyrolysis was shown to increase the surface area of the resulting biochar. Addition of biochar to soil reduced net C mineralisation of soil organic matter and litter at a rate of 2 % w/w, but not at 0.5 % w/w. However both concentrations of biochar affected net mineralisation of N. Phospholipid fatty acid analysis showed that both concentrations of biochar altered microbial community structure, with fungal biomass in particular promoted by the addition of biochar. Overall the work demonstrates that SRC promotes significant storage of C within soil organic matter, which has implications for the overall energy budget of SRC biomass. Furthermore, conversion of biomass to biochar for land application provides opportunities for sequestration of C within soil. Application of biochar to soil would provide further benefits to the overall energy balance of SRC by reducing mineralisation rates of native soil organic matter and litter.

Methane (CH4) is one of the most potent greenhouse gases and its increasing concentration in the Earth’s atmosphere is linked to today’s global warming. The types of land and land-use have an impact on net CH4 fluxes, e.g. wetlands are generally net CH4 emitters while upland forest soils are a sink for CH4. This project aimed to elucidate the effect of afforestation and reforestation on net CH4 fluxes and to determine the control of the CH4-oxidising bacteria (methanotrophs) on net CH4 flux rate. This was investigated using a combination of molecular (T-RFLP, cloning/sequencing, microarray) and activity-specific (PLFA-SIP) approaches. Several sites were selected to analyse soil methanotrophs under shrubs regenerating after a fire compared to a native mature forest (in New Zealand), and under bog, grass, heath, pine and birch vegetation (in Scotland). Furthermore, a simple bottom-up approach was applied to seasonal measurements of local net CH4 fluxes in Scotland. These were upscaled to annual values in order to estimate the contribution to the national CH4 budget for each habitat investigated. The effect on CH4 mitigation of the conversion of different types of non-forested habitat to forests was then estimated. Afforestation/reforestation was always found to induce net CH4 oxidation at rates much faster than previously estimated. This preliminary analysis suggests that heathland conversion to birch forest was beneficial in term of CH4 sinks but it also induced large and permanent losses of soil C. However, bog afforestation with pine trees can potentially neutralise the national CH4 emissions from non-forested areas, while preserving soil C stocks. This project also revealed that changes in net CH4 flux due to land-use changes were closely related to shifts in the structure of the methanotrophic community. The relative abundance of members of the USCα cluster (high-affinity methanotrophs) was a strong predictor of net CH4 fluxes. Finally, the sole presence of trees suggested a niche-specific adaptation of the methanotrophs, which may have been correlated to some of the soil characteristics.

The aim of this project was to combine species distribution modelling (SDM) with the results of a molecular genetic diversity study to make suggestions for sites on which to locate genetic reserves. This work was complemented by a molecular genetic diversity and a forest management policy study, to examine the potential for in situ conservation of the crop wild relative species, Prunus avium. In order to identify the species distribution, the most widely available occurrence data were in the form of historical records, gathered from online repositories and herbaria. A selection of environmental variables were incorporated with occurrence records in the SDM software, MaxEnt, to estimate the existing and possible future distribution of this species. Different sampling methods and combinations of accessions were used to evaluate model performance. This work was supplemented by the use of microsatellite marker analysis, to identify genetic distance among samples collected, covering the species‘ range. Clear separation was found between the individuals from the south-eastern edge of the range, and all other European samples. The effect of management practices on the persistence of wild cherry in managed forests and the impact of conservation policy was also considered, using case studies from the UK and Belgium, interviews and grey literature. Results showed that the difficulties of obtaining reliable, unbiased data can be overcome, as long as these factors are considered in conservation planning. Suggestions are made for several potential reserve sites across Europe, in a variety of forested environments, with differing management priorities.

As the global population continues to increase, so will the demand for timber (and other raw materials) for building, construction, and also for the pulping industry. The high demand for wood and the increasing human population mean that natural forests are being lost and degraded. A potential solution to this problem is to improve the productivity of our plantation forests to relieve the pressure on natural forests in terms of sustainable wood production. This project is the first to use newly available microarray technology to study differential gene expression in cambial tissue of high versus low wood density field grown samples from two contrasting species, Sitka spruce (gymnosperms) and poplar (angiosperms). Genes up-regulated in high-density Sitka spruce and poplar samples had functions in cell formation and expansion, with down-regulated genes having functions in lignin biosynthesis, stress-response and defence. Plantation trees could be screened at a young age to assess their expression of candidate genes to speed up the breeding and selection process.

Non timber forest products are the neglected resource of Scotland’s woodlands, used by many, but with little provision in law, policy or management. Drawing on new research conducted in Scotland, and comparative studies in Finland, the Pacific Northwest USA and Canada, this thesis examines issues relating to the practice, politics and ecology of NTFPs. The methodological approaches used in the field research are set out in Chapter One. Chapters Two to Five explore the perspectives of stakeholder groups, who either use NTFPs directly or who influence the availability of resources and the ability of others to access them. The first of these groups is harvesters, with Chapter Two examining how issues of legal pluralism or the coexistence of both legal and customary rights for harvesting has resulted in the dominance of common practice over management and policy. Chapter Three discusses buying and processing activity, focussing on its contribution to both livelihood and lifestyle and its position ‘somewhere in between’ commercial and non-commercial benefit. The influence of land managers is examined in Chapter Four, reviewing the contrast between the privileged knowledge that enables harvesters to use resources, and the reliance on professionalised knowledge that renders land managers comparatively powerless. In Chapter Five the influence of organisations is explored, particularly in relation to the difficulty of accommodating the interests of such disparate groups without formal channels for representation. The thesis concludes by addressing policy and management concerns, both practical and ideological, and considering mechanisms for the management of NTFPs as a resource. It demands that ethical questions over benefits, values and rights be addressed, as well as issues surrounding sustainability and resource use. The conclusion seeks to present a new system for the self-governance of NTFP resources by the stakeholders themselves.

The work reported here aimed to provide a comprehensive database of core information to support the development and validation of process-based models of resource capture and growth in semi-arid overstorey agroforestry systems. Intensive field studies were carried out in Kenya over a 30 month period and the results obtained were combined with data from a previous project to produce a dataset spanning a 4.5 year period. This dataset was then used to verify output from the HyPAR model. Allometric procedures developed from the pipe model theory (Lott et al., 1998) were used to estimate tree growth non-destructively throughout the observation period. Significant differences in tree size between the sole (Td) and dispersed agroforestry (CTd) treatments were established during the first 130 days after planting, probably because of competition with the associated crops. The above-ground biomass and trunk length and taper characteristics of the CTd trees remained inferior to those of Td trees throughout the observation period, seriously undermining the economic potential of this agroforestry system. The biomass and grain yield of CTd understorey crops were similar to the corresponding sole crops during the first three seasons, but were negligible in three of the final four seasons, with maize yields reaching 50 % of the equivalent sole crop values only when seasonal rainfall was well above average. This observation suggests that water availability was the primary limitation for CTd maize during the final seasons of the trial, a conclusion supported by the superior performance of maize grown under net enclosures which simulated tree shade in the absence of below-ground competition. Cowpea and maize were grown concurrently in two seasons to examine the impact of grevillea on C4 and C3 crops with contrasting responses to shade; biomass and grain yield were less affected in cowpea than in maize. The tree canopy in the dispersed agroforestry (CTd) treatment reduced the daily mean quantity of radiation incident upon the understorey crops by c.30 % during the final four growing seasons, although the discontinuous nature of the tree canopy caused substantial local variation in shading intensity. Seasonal mean fractional interception was greater for the combined canopies of the CTd treatment when soil moisture status was relatively high than for either of the sole canopies, suggesting the occurrence of spatial complementarity. Tree shade had a substantial moderating influence on meristem temperature since the mean diurnal temperature range was reduced from a maximum of 20°C in sole maize to 13 °C under the trees, and maximum meristem temperature was decreased by up to 6 °C relative to sole maize. However, the non-uniform shading provided by the trees caused substantial spatial variation in thermal time accumulation and hence crop development. Grevillea continued to grow during dry seasons and was therefore able to capture off-season rainfall which might otherwise have been lost from productive use. In addition, adaptation of heat balance gauges for use on grevillea roots (Lott et al., 1996) showed that substantial quantities of water could be extracted from deep-seated reserves below the crop rooting zone during dry periods, indicating the potential for spatial and temporal complementarity. However, transpiration by grevillea greatly exceeded rainfall during the dry season, rapidly depleting residual water supplies which might otherwise have been available for crop growth. In addition, approximately two thirds of the water used by the trees during cropping seasons was extracted from the soil surface horizons by lateral roots at distances of up to 2 m from the trunk. Thus, the potential for above and below-ground complementarity may be seriously undermined by the extensive capture of water by tree roots from the crop rooting zone. Comparison of output from the HyPAR model against the observed results provided information pertinent to future model development. The model proved to be insufficiently flexible for end-users wishing to simulate the growth of different crops during the same simulation cycle, or to use model output to aid management decisions such as the timing of pruning. The allometric procedures used by the model to estimate canopy size from trunk diameter at breast height also proved incapable of accounting for reductions in canopy size resulting from pruning. Estimates of tree height are rounded to the nearest metre within the model, representing a potentially serious loss of resolution when annual increments often do not exceed 2 m. In addition, the numerous parameters required by the model would force most end-users to rely heavily on published information, potentially undermining the reliability of simulations.