Mangroves are a group of woody plants that occur in the dynamic tropical and subtropical intertidal zones. Mangrove forests offer numerous ecosystem services (e.g. nutrient cycling, coastal protection and fisheries production) and support costal livelihoods worldwide. Rapid environmental changes and historical anthropogenic pressures have turned mangrove forests into one of the most threatened and rapidly vanishing habitats on Earth. Yet, we have a restricted understanding of how these pressures have influenced mangrove abundance, composition and functions, mostly due to limited availability of mangrove field data. Such knowledge gaps have obstructed mangrove conservation programs across the tropics. This thesis focuses on the plants of Earth’s largest continuous mangrove forest — the Sundarbans — which is under serious threat from historical and future habitat degradation, human exploitation and sea level rise. Using species, environmental, and functional trait data that I collected from a network of 110 permanent sample plots (PSPs), this thesis aims to understand habitat preferences of threatened mangroves, to explore spatial and temporal dynamics and the key drivers of mangrove diversity and composition, and to develop an integrated approach for predicting functional trait responses of plants under current and potential future environmental scenarios. I found serious detrimental effects of increasing soil salinity and historical tree harvesting on the abundance of the climax species Heritiera fomes. All species showed clear habitat preferences along the downstream-upstream gradient. The magnitude of species abundance responses to nutrients, elevation, and stem density varied between species. Species-specific density maps suggest that the existing protected area network (PAN) does not cover the density hotspots of any of the threatened mangrove species. Using tree data collected from different salinity zones in the Sundarbans (hypo-, meso-, and hypersaline) at four historical time points: 1986, 1994, 1999 and 2014, I found that the hyposaline mangrove communities were the most diverse and heterogeneous in species composition in all historical time points while the hypersaline communities were the least diverse and most homogeneous. I detected a clear trend of declining compositional heterogeneity in all ecological zones since 1986, suggesting ecosystem-wide biotic homogenization. Over the 28 years, the hypersaline communities have experienced radical shifts in species composition due to population increase and range expansion of the disturbance specialist Ceriops decandra and local extinction or range contraction of many endemics including the globally endangered H. fomes. Applying habitat-based biodiversity modelling approach, I found historical tree harvesting, siltation, disease and soil alkalinity as the key stressors that negatively influenced the diversity and distinctness of the mangrove communities. In contrast, species diversity increased along the downstream – upstream, and riverbank — forest interior gradients, suggesting late successional upstream and forest interior communities were more diverse than the early successional downstream and riverbank communities. Like the species density hotspots, the existing PAN does not cover the remaining biodiversity hotspots. Using a novel integrated Bayesian modelling approach, I was able to generate trait-based predictions through simultaneously modelling trait-environment correlations (for multiple traits such as tree canopy height, specific leaf area, wood density and leaf succulence for multiple species, and multiple environmental drivers) and trait-trait trade-offs at organismal, community and ecosystem levels, thus proposing a resolution to the ‘fourth-corner problem’ in community ecology. Applying this approach to the Sundarbans, I found substantial intraspecific trade-offs among the functional traits in many tree species, detrimental effects of increasing salinity, siltation and soil alkalinity on growth related traits and parallel plastic enhancement of traits related to stress tolerance. My model predicts an ecosystem-wide drop in total biomass productivity under all anticipated stress scenarios while the worst stress scenario (a 50% rise in salinity and siltation) is predicted to push the ecosystem to lose 30% of its current total productivity by 2050. Finally, I present an overview of the key results across the work, the study’s limitations and proposals for future work.

The high floristic biodiversity value of ancient woodland is widely acknowledged, as is its status as a fragmented habitat of limited spatial extent. The distinctive vegetation of ancient woodland is an important factor in its conservation. Specifically, Ancient Woodland Indicator (AWI) species have been shown to be poor dispersers and incompatible with a fragmented habitat that is subject to environmental change. In recognition of their ecological importance, both Ancient Semi-Natural Woodland (ASNW) and Ancient Replanted Woodland (ARW) are protected by legislation. This thesis took the novel approach of examining the distinctiveness and community ecology of vegetation communities in all three woodland types of ASNW, ARW, and recent woodland. Importantly, analyses were based on new high-granularity primary vegetation and soil data. To address questions raised in the literature regarding the accuracy of ancient woodland and AWI identification, this research examined the metrics used to distinguish these habitats and species. Increasingly, the literature calls for further understanding of the ecological drivers of ancient woodland vegetation distinctiveness. In response, this research tested for differences in species composition of canopy, shrub, herb layer, AWI, and moss communities across all three woodland types. For AWI species, biotic, abiotic, and biogeographical variables were analysed for their contribution to community distinctiveness. Results highlighted the importance of consistency in metric selection when assessing the distinctiveness of ancient woodland and determining indicator species. In addition to the usual alpha scale measure of distinctiveness, assessing richness and community composition at the beta and gamma scales is recommended to inform conservation. Life traits and dispersal mechanisms were important differentiators for herb layer community composition among the woodland types. AWI richness was equally strongly explained by biogeographical variables as by ASNW, ARW, and recent status. Overall, this thesis supported ecological and biogeographical explanations for the distinctiveness of ancient woodland vegetation.

This thesis is concerned with the changes to a forest landscape, that of St. Leonard's Forest, Horsham, West Sussex, changes that were wrought by human activity over two and half centuries. In order to uncover and understand these changes the author has focused on five private estates within the Forest core, Holmbush, Buchan Hill, St. Leonard's, Coolhurst and Leonardslee, and two villages in the Forest, Colgate and Lower Beeding. The five estates are considered with regard to ownership and control, land use and workers on the estates. The two villages are examined for their growth, the profile of the population, poverty and wealth. The establishment and endowments of the parish churches are outlined along with the development of the parish of Lower Beeding and its ties to Magdalen College, Oxford. Paternalism was a theme in the Victorian and Edwardian period, and the 1900 Footpath Dispute demonstrated a move away from these attitudes towards a more individualistic concern with private property rights. For the first time this study pulls together the numerous and complex strands which make up the landscape history of St. Leonard's Forest. It explores the factors both social and economic which impacted on the Forest. The juxtaposition of the nearby expanding market town of Horsham with its large common, improving communications, sales of land, and the attitudes of individual Forest landowners all combined to transform the Forest from a wild barren heathland in 1750 to a place of desirable picturesque estates and expanding villages by 1914, before the impact of the Great War was to change the Forest landscape yet again.

No description available.

Within the UK, levels of timber processing are set to increase as the plantation grown forest resource reaches financial maturity. Made up predominately of exotic coniferous species, this resource has been the focus of many recent studies as wood users look to improve their fundamental knowledge of the primary characteristics that will enable them to make more appropriate decisions and capitalise on future opportunities. As a further contribution to this knowledge base, it was the aim of this thesis to determine moisture content variation within Sitka spruce (Picea sitchensis (Bong.) Carr) standing trees and roundwood logs. Within standing trees, moisture content was found to vary significantly in both the longitudinal and radial directions (P<0.001). Longitudinally, the base and top of the trees contained higher quantities of moisture than did the lower and mid sections. Radially, the moisture content at the centre of each disk was very low and this extended outwards before rapidly increasing mid-radius and then reaching a plateau near to the cambium. A sigmoid regression model successfully explained two-thirds of the radial moisture content variation as well as explaining the longitudinal moisture content variation. The radial variation with tree height was described by a shortening of the low moisture content extending outwards from the pith and a softening of the steepness of the increase with the duration extending as tree height increased. Seasonal variation within standing spruce trees was assessed within a plantation forest in northern England. Removing samples from 81 trees throughout a period covering 42 calendar weeks of 2012 revealed no significant effect of season on the moisture content although a link was identified with short-term variation in temperature. However, further analysis on the radial sections confirmed that when the moisture content data were converted to a percentage of total lumen saturation, a significant effect of seasonal variation was observed within the outer sapwood region (P<0.001). Whilst the standing trees as a whole did not demonstrate seasonal variation in moisture content, variation due to seasonal weather did have an effect on the drying of roundwood within the forest. Analysis of c. 25,000 samples, collected over a 6-year period, confirmed that season (dormant or growing) had a significant effect on sample moisture content (P<0.001). Temperature was recorded as having the greatest effect on moisture variation within roundwood whilst the effect of rainfall was not significant, due principally to the unpredictable nature of this variable throughout the year. To identify the radial and longitudinal moisture content change of roundwood during drying, an experiment was carried out to accelerate the drying process on short logs using an industrial oven at a constant temperature (40°C). Total drying time varied between 7 and 28 days prior to post drying analysis of the logs to determine the longitudinal and radial moisture profiles. All logs lost a constant quantity of moisture each day with the logs dried for 28 days losing more than 50% of their starting weight. Longitudinally, moisture was lost from all points along the length of each log with the log ends remaining driest, although these dry areas only accounted for 40% of the total log length. Radially, moisture declined across the log with the greatest amount removed from the outer radius. In order to provide some relevance of the impact moisture content variation has on the forest industry value chain, data collected from a working timber harvesting operation confirmed that variation existed between volume to weight conversions of different products. Within this even-aged Sitka spruce clearfell, volume to weight conversion factors ranged from 1.02 to 1.19. Differences of this magnitude can not only lead to a lack of understanding of between tree variation within a single site, but can also result in an impact on the optimum value recovery expected by each of the parties engaged within the value chain. The results presented within this thesis will help guide timber growers, agents, managers and purchasers in their future decision making when considering the most suitable markets for standing trees or roundwood logs. Improving knowledge of spatial and temporal moisture content variation will potentially result in maximising the forestry value chain and enable the forestry sector in the UK to make more from wood.

Large wood and its accumulations are poorly understood despite being an important feature in the functioning of forested river channels and floodplains. Large wood has previously been removed from rivers in order to reduce flow resistance and increase channel conveyance. However, recently there has been an appreciation of the role of large wood accumulations in creating important aquatic habitat, increasing geomorphic diversity, re-connecting river channels to their floodplains and in the development of multi-channel anastomosed river patterns. This thesis examines the role that large wood plays at a range of scales in a low-order forested stream in the New Forest, Southern England. The study river was subject to restoration measures, involving the addition of large wood to the river channel, as part of an EU LIFE III project. An empirical and Froude-scaled flume approach is taken to determine the role of large wood accumulations upon the reach-scale flow resistance values. Large wood accumulations from a variety of environments are assessed to determine the hydraulic effects of accumulations of different architecture in different environments. Field data from the study catchment is used to show the role of large wood in increasing the frequency and duration of reach-scale, floodplain inundation. Hydrological data shows the impact the restoration has upon both flood peak magnitude and flood peak travel time highlighting the potential benefits of large wood to downstream flood risk. A 2-Dimensional model is produced which simulates the effect of a range of large wood accumulations upon the inundation extent. An approach using spatial diversity metrics, widely used in ecological sciences, is conducted in an attempt to quantify the flow depth and flow velocity diversity, which can influence flow habitat diversity. Results show that large wood can initiate an anastomosing flow pattern which allows increases flow depth diversity by up to 49% and flow velocity diversity by up to 48%

Building on work in the field of rural geography, this thesis considers the changes which have taken place to the ways in which woods are managed and how the market for woodfuel has evolved following the considerable growth in demand for firewood and woodchip over the past decade. Through the use of in-depth interviews and field visits to woods and woodfuel businesses across the Midlands, it is demonstrated that the growth of the market has encouraged private woodland owners to carry out more management. This is a significant change from the latter half of the 20th Century when falling timber prices, and the lack of a market for wood products generally, resulted in many woodlands being neglected. In particular, the woodfuel markets have stimulated the removal and restoration of ‘Plantation on Ancient Woodland Sites’ (PAWS) by creating a market for the products of first and second thinning operations. Woodland owners are now able to make small, but significant, profits from their woods which is a marked change from a decade ago. A principal driver of the woodfuel market is the ‘Renewable Heat Incentive’ (RHI), whereby the Government is subsidising the use of woodchip-fed biomass boiler systems as part of the transition towards a greater use of renewable energy sources. Whilst the Forestry Commission’s principal objective remains the production of high quality timber, this thesis demonstrates it is reviewing how it may contribute to the woodfuel market’s growing share of the UK’s energy sector. In the thousands of small, privately-owned woods across England, the majority of which are owned for amenity and wildlife purposes, the thesis explores how the growing demand for firewood and woodchip is encouraging greater management. The many ways in which woodfuel management is complementary to other management objectives like timber production, wildlife and shooting are highlighted. The changes which have taken place to the UK’s forestry sector with the growing use of woodfuel is contextualised by exploring the extent to which they typify a ‘post-productivist’ shift. In many ways, the UK’s forestry sector appears to have entered a post-productivist era, with less emphasis placed on timber production since the 1980s and more policies to promote wildlife. The doctrine has been widely critiqued by examining the changes to agriculture but the forestry sector has been largely neglected, barring the work of Mather et al. (2006) who claim it has undergone a post-productivist shift. This view is contested by exploring how the growth of the woodfuel markets is promoting greater timber harvesting, as well as affecting how public and private woodland owners view their woods as money-making assets. The market from the perspective of the woodfuel merchants is also explored. Their histories and backgrounds are presented, revealing a diverse community of people with different business aims. Following an analysis of the ways in which merchants operate, from the types of machinery used to the methods of delivery, a typology of merchants is proposed. Whilst a ‘professionalisation’ of the sector has taken place over the past decade, with more standardised units of sale and improved customer service, an informal firewood market exists whereby some customers are unwillingly sold unseasoned firewood. With wood burning becoming a more popular activity in the UK following a surge in the use of dedicated wood burners, people are becoming more knowledgeable about the burning properties of different species of wood. However, the growth in demand for wood has led merchants to question whether the UK’s woods and forests can continue supplying the market at the current rate. Many merchants struggle to source timber for woodfuel and this had led them to supplement their stocks by purchasing from European suppliers. A contrasting view, however, is that the UK has a surplus of timber across its many unmanaged woods, as demonstrated by the Forestry Commission’s most recent national survey. The thesis therefore highlights a perception amongst merchants that the country’s timber supplies are at risk from the growing demand for woodfuel.

This thesis is an intersectional study of forest rights of forest-dwellers in the tribal territory of Koraput, India. The thesis is developed around a piece of path-breaking legislation, the Forest Rights Act (FRA) of India 2006, under which land titles and resource use rights are being granted to many forest-dwelling households and communities. This work exclusively deals with the individual title holders of forest land under the FRA. It explores three important questions: 1) what is the history of forest-rights delineation in Koraput?, 2) how are the rights of forest-dwelling people being settled under FRA? and, 3) what are the complexities of land use in these tribal forestlands?} The thesis has used a mixed-methods approach to build and connect its three focus areas. Historical aspects of local forest rights have been explored through the lens of colonial and post-colonial forest policy analysis. The investigation of the various aspects of FRA implementation and ground realities combines cross-disciplinary approaches from political and gendered micro geography. The analysis of emerging land use on forest lands allotted under FRA is influenced by the Sen’s theory of entitlements, endowments and capabilities {Sen, 2001}. A multi-approach assessment methodology has been used by analysing a wide range of data streams including historical documents, household surveys, interviews, participatory maps, observations, group discussions and secondary data sets. Key findings that have emerged from this thesis are, 1) the consequences of the implementation of colonial and post-colonial forest policy measures on Koraput's forest-dwellers are substantial and unique geography of Koraput has produced new insights to the existing knowledge of history of forest rights in India, 2) FRA is a promising piece of legislation that has achieved significant political and bureaucratic collaboration in Koraput, but it is marred by major operational inefficiencies, and 3) the newly created FRA-lands will provide opportunities for policy makers and title owners to reconsider many existing norms including legal versus illegal occupation of forest land, forest-farming practices on FRA lands, and a need for renewed forest and land management goals for FRA territories in tribal India.

The term extractives defines chemical compounds of different classes that can be extracted from wood or bark by means of polar or non-polar solvents. Extractives are derived mostly from the metabolic processes of the tree, particularly the sapwood to heartwood transformation. The first objective of the research was to study the distribution of extractives within Sitka spruce trees at different heights in the trunk, as well as the distribution between bark, rootwood, knotwood, heartwood and sapwood. The second aim of the work was to learn about the influence of yield class, site elevation, North/East location and thinning on the extractives content and composition of Sitka spruce across Scotland. The samples were sawdust obtained in different ways from either discs, knots or roots sawn from Sitka spruce trees freshly cut in the forest, or collected during the coring of trees from 64 sites all around Scotland and northern England. The extraction was carried out on Soxhlet extractors using acetone as solvent. Two analytical techniques were used: gas chromatography and Fourier transform infrared spectroscopy. The results of the research showed that the extractive content and composition of Sitka spruce differed according to the type of wood studied with the largest amount detected in bark and the lowest in heartwood and sapwood. The last two types of wood were studied in more detail, showing that the difference in extractive content between heartwood and sapwood was consistent at all heights in the trunk. The chromatographic analysis of heartwood, sapwood, knotwood, rootwood and bark showed that their compositions differed slightly from published data on Norway spruce.

Public goods such as environmental conservation, amenity and carbon sequestration are increasingly emphasised in forest policy agendas. However, many public benefits in woodlands have occurred incidentally, rather than on the basis of socio-economic logic and often at locations relatively inaccessible to major centres of population. In fact, data reveal a concentration of privately owned woodland in densely populated areas, especially in central and southern England, and that woodland is often factored into residential location decisions and lifestyle behaviours. However, the provision of public goods is likely to be contingent on the value systems of private forest and woodland owners and their flexibility of response to measures promoted under the devolved forest strategies. A combination of qualitative and quantitative research methods were employed to construct a robust typology of private woodland owners with respect to their willingness and ability to deliver public good benefits in three study areas in England: the Lake District, Cornwall and the High Weald AONB. Building on an exploratory scoping study, Q Methodology interviews were conducted with 10 woodland owners in each study area, followed by a self-completion survey, administered using Dillman's Total Design Method. Data from 600 woodland owners was subjected to a Factor and Cluster Analysis, with the emergent model validated using Discriminant Analysis. Six discrete private woodland owner types were revealed: Individualists, Multifunctional Owners, Private Consumers, Conservationists, Investors and Amenity Owners. Important distinctions between owner groups are associated with the likely provision of particular benefits and disbenefits, and the classification suggests that a move from a production versus consumption/protection framework to one that includes intersecting goals may be more appropriate. Policy implications are discussed to facilitate use of the typology in targeting particular woodland owner groups with more nuanced policy mechanisms, including incentive schemes, market mechanisms and advisory services.