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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effect of trade related environmental measures on the forest sector and timber trade of Peninsular Malaysia

Shanmugam, Sugumari January 2015 (has links)
Global concern on illegal logging has led to the imposition of binding trade related environmental measures on trade of timber and timber products by developed countries like the US, EU and Australia. This dissertation examines the effect of the binding measures on Peninsular Malaysia’s forest sector and timber trade. Putnam’s two-level game theory is applied, to demonstrate the interdependence of politics at the international level with the domestic level. There is a need to have a “win-set” between the international and domestic levels whereby an agreement reached by stakeholders at Level II (discussions at the domestic level) will help to make the bargaining at Level 1 a success (bargaining between negotiators which leads to a tentative agreement). In the case of Peninsular Malaysia’s forest sector and timber trade, it has been acknowledged that the measures imposed by the EU through FLEGT VPA/EUTR and to a lesser extent by Australia through its ILPA/ILPAR as well as the US with its Lacey Act amendments, have brought about changes in policy and administration. Thus, the Federal Government of Malaysia, specifically in the FLEGT VPA negotiations have an important task in managing domestic stakeholders’ demands for development, taking into account the unique Federal-State relations on land and forest matters as well as managing its international commitments to ensure trade in sustainable and/or legal timber. The policy reaction of the Federal Government of Malaysia to the measures imposed was analysed using Schoppa’s analysis of the concept of “synergistic linkages” and “reverberation”. On this note, case studies were conducted on Peninsular Malaysia’s forest sector and timber industry as well as the binding measures with specific focus on EU FLEGT VPA/EUTR. To substantiate the findings of the case studies, empirical evidence were gathered from primary interviews with experts from government or agency officials, Timber Industry Associations, environmental and social NGOs and international organizations. Further, focus group discussions were held with four states in Peninsular Malaysia to understand the position of the states. The findings show that it is important for the Federal Government to gain the support and commitment of State Governments on such measures. Therefore, the demands of State Governments for extra funding, resources, equipment and manpower to implement the sustainable and/or legal commitments need to be addressed. Furthermore, NGO criticism about not being properly consulted or given an effective role in government initiatives or meetings, also needs to be taken into account. There is also a need for greater political will by the Malaysian Government, to ensure the success of any negotiations or binding measures imposed. This dissertation indicates the importance of a Level II agreement to ensure the success of a Level I agreement of current negotiations pertaining to Peninsular Malaysia’s forest sector and timber trade.
2

The impact of changing climate on tree growth and wood quality of Sitka spruce

Adams, Steven Henry January 2014 (has links)
The recent trend in climate has shown that UK temperatures are increasing, summers are getting drier and winters are getting wetter. It is thought that this trend is set to continue for the foreseeable future and that this will have an impact on the growth and quality of timber in the UK. Sitka spruce (Picea sitchensis (Bong.) Carr) is one of the most widely planted and important commercial tree species in the UK but our knowledge of tree growth and wood properties is based on tree growth in the climate of the past 40 – 80 years. The rotation time for Sitka spruce is approximately 40 years so trees planted now will mature in the 2050s, when the climate could be different from today leading to impacts on the quality and quantity of the wood being produced. This project aims to predict the effect that changes in climate will have on Sitka spruce, by looking not only at growth but also at different properties of the wood and their susceptibility to any change in climate. This information could then be used to help make decisions as to whether Sitka spruce is the best tree to be planting now, at any specific site in the UK, to obtain the best quality wood in the future. The effect of seasonally changing weather on growth was measured at two sites by the use of LVDT point dendrometers to record changes in the radius of the tree stems. The data were compared to meteorological data collected from the site and from local weather stations, to determine how weather affected the growth of the trees. Data collection from the site at Griffin Forest near Aberfeldy was initiated in 2008 as part of a long term project at that site. Measurements taken during 2008 and 2009 were used as part of a previous PhD study and continued as part of the present study from 2010. The second site was newly established at Harwood Forest in Northumberland, northern England. At both sites the onset of growth at the beginning of the season was found to correspond to temperature >5°C. Deficit of soil moisture was found to decrease the growth rate during the peak growth period. Radial density, radial growth and the radial profile of longitudinal stiffness were investigated by analysing increment core samples taken from sites covering the full latitudinal range that Sitka spruce grows in Great Britain, with the aim of quantifying the effect of site factors such as latitude, longitude, initial spacing and elevation. The cores were measured from density and ring width using an ITRAX x-ray densitometer and analysed using Windendro software. Stiffness was investigated using acoustic velocity measurements taken directly on the increment cores using an ultrasonic scanner, modified to measure cores. A wide range of published radial growth models and a smaller number of radial density models were explored to see which were able to describe the data and compared to simpler linear segmented models. The sample population was found to be highly variable and the ability of the models to predict ring width or density from ring number alone was limited. Improved prediction of density was possible when ring width was included along with ring number as a predictor. The linear segmented models were found to be able to predict growth and density from ring number alone and this provides a useful and powerful tool. In practice ring width may not always be available and so there is a need for models which can predict density from ring number alone. Ring width was found to be negatively correlated with density, although the nature of the relationship was different between juvenile and mature wood. Most of the variation in both density and growth was between trees at the same site. Initial spacing was found to be the only significant effect on growth and then only by having a positive effect on the growth rate of the juvenile wood, which had a knock on effect on the size of the trees at the end of the juvenile phase. Both spacing and latitude were found to have significant effects on the mean density of the juvenile wood with spacing having a negative effect and latitude a positive effect. In the mature wood, cambial age was found to be the only significant effect on radial density.
3

Influence of site factors and climate on timber properties of Sitka spruce (Picea sitchensis (Bong.) Carr.)

Vihermaa, Leena January 2010 (has links)
In plantation grown Sitka spruce, timber density is an important quality concern. Currently Sitka spruce timber meets the requirements for C16 strength grading which is the minimum requirement for construction uses. However, the margin is not exceeded by much and a small reduction in density could lower the log grading. Therefore it is essential to understand how timber density is impacted by site factors and climate in order to predict the potential effects of climate change on timber quality in Sitka spruce in the future. This has important economic implications for UK forestry. To assess the influence of site factors and climate on growth and resulting timber properties in Sitka spruce, three experiments were established; a large scale wood quality survey (“The Benchmarking experiment”), a detailed inter-site density study (“The Level II experiment”) and a continuous growth monitoring experiment (Dendrometer experiment). In the ‘Benchmarking’ experiment, increment cores were collected from 68 sites over a geographically wide area in Scotland and Northern England in order to quantify the effect of selected site factors on density. These samples were not suited for climate analysis at annual ring level and therefore disks that allowed reliable dating of the tree rings were collected from three Level II sites. The Level II samples were also used in an acoustic velocity study and an assessment of the within-tree patterns in density. Material from both Benchmarking and Level II sites was used for modelling radial density. In addition to this the Level II data functioned as a test dataset for the different density models that were developed on the Benchmarking data. Density and other tree ring variables were measured with an ITRAX X-ray densitometer and WinDENDRO software. Some acoustic measurements were also carried out with a purpose built ultrasonic scanner to allow calculation of radial variation in stiffness. A dendrometer experiment was established to monitor short term growth variation in Sitka spruce in real time. The aim was also to use the growth data to date density profiles and hence identify causes for the density differences. Data analysis was carried out in R mainly using linear and non-linear mixed effects models, the dendrochronology software package dplR and methods of time series analysis. It was found that the largest part of the variation in density was between trees within each site. Both density and stiffness were mostly influenced by the growth rate or by another variable describing the tree vigour. Fast growth decreased density both by increasing earlywood proportion as well as decreasing the density of both earlywood and latewood. Models for the radial behaviour of density and stiffness could be fitted to the data, but random tree effects remained large. This limits the applicability of these models to new sites as reparameterisation would be required, which requires data from time consuming density and acoustic velocity measurements. The possibility of modelling the model coefficients from easily measurable stand and tree variables was investigated but the results were not promising. The Dendrometer experiment indicated that annual growth in Sitka spruce was initiated in late May and terminated by mid September. Ring widths detected by the dendrometers, micro core measurements and X-ray density based tree ring analysis differed, which caused difficulties in dating the density profile. To decrease these problems in the future the microcore sample storage protocol was revised. The dendrometer data indicated that the growing season was divided into several sections between which the growth rate differed. Latewood density and maximum density had the strongest correlations with the climatic variables. At one site the correlations included temperature and rainfall in April whereas at the other precipitation throughout the growing season or during the May-August period were important. Temperature was correlated positively with density variables and rainfall negatively.
4

Traditional forest management in Psiloritis, Crete, c.1850-2011 : integrating archives, oral history and GIS

Arvanitis, Panteleimon January 2011 (has links)
The research scope of this thesis focused on traditional forest management practices in eastern Psiloritis Mountain in Crete, employing oral history, archival information and GIS. The main focus was over the end of the 19th century till present. The useful and productive forest of the past, extensively exploited by local populations, is often considered nowadays as unproductive and thus neglected by modern society. Historical and social incidences influenced the behaviour of local population towards natural resources and their interaction with their natural environment has changed over time. Therefore, different traditional management practices were applied locally in the past and recorded in this thesis. A unique forest landscape was evolved based on a complex system of interactions among the trees with animals and the human population that were dependent on the forest. The use of GIS helped unveil a wealth of information further elucidating archival material and explain better different geographical phenomena. Several management practices of the past contributed for the creation of a rich biodiversity and cultural elements helped shape the forest landscape of Psiloritis. The importance of this traditional management was highlighted with regard to the conservation of the forest today. In this way the thesis shows that forest history can help modern forestry to establish a more effective management of the forests for the benefit both of the environment and the society.
5

Debating the public benefits of community woodlands on degraded land : claims, aspirations and experiences at reclamation sites in the northwest of England

Curtis, Richard David January 2007 (has links)
No description available.
6

Large scale spatial modelling of soil organic carbon dynamics

Falloon, Peter Daniel January 2001 (has links)
Under the Kyoto Protocol, participating nations are required to reduce National CO₂emissions according to their 'reduction commitment' or 'quantified emissions limitation', over the first commitment period, 2008-2012. One way in which nations could achieve this would be by increasing soil carbon storage through different management practices. Most former estimates of regional scale C sequestration potential have made use of either linear regressions based on long-term experimental data, whilst some have used dynamic soil organic matter (SOM) models linked to spatial databases. Few studies have compared these two methods, and none have compared regressions with two different SOM models. This thesis presents a case study investigation of the potential of different land management practices to sequester carbon in soil in arable land, and preliminary estimates of other potential C savings. Two dynamic SOM models were chosen for this study, RothC (a soil process model) and CENTURY (a general ecosystem model). RothC and CENTURY are the two most widely used and validated SOM models world-wide. Methods were developed to enhance use and comparability of the models in a predictive mode. These methods included a) estimation of the IOM pool for RothC, b) estimation of C inputs to soil, c) investigation of pool size distributions in CENTURY, and d) creation of a program to allow use of C inputs derived from CENTURY with the RothC model. This thesis has also investigated the importance of errors in C inputs to soil for predictive SOM modelling, and performed sensitivity analyses to investigate how errors in setting the size refractory SOM pools might affect predictions of SOC. RothC and CENTURY were compared at the site scale using datasets from seven European long-term experiments, in order to a) verify their ability to predict SOC changes under changes in land use and management relevant to studies of C sequestration potential, b) evaluate model performance under European climatic conditions, and c) compare the performance of the two models. Finally, a Geographic Information System (GIS) containing soil, land use and climate layers, was assembled for a case study region in Central Hungary. GIS interfaces were developed for the RothC and CENTURY models, thus linking them to spatial datasets at the regional level. This allowed a comparison of estimates of the C sequestration potential of different land management practices obtained using the two models and using regression-based estimates. Although estimates obtained by the different approaches were of the same order of magnitude, differences were observed. Encouragingly, some of the land management scenarios studied here showed sufficient C mitigation potential to meet Hungarian CO₂reduction commitments.
7

Remote sensing and GIS application for monitoring forest management operations

Ratnayake, Ranitha January 2004 (has links)
Satellite data potentially provide a useful tool for estimating forest cover and monitoring changes. Traditional forest surveying methods involve time consuming measurements of a large number of trees. Remotely sensed data may enable forest cover changes to be estimated very rapidly over large areas and with a minimum of ground data collection. At present the role of forest management in Britain is expanding, so that looking at forest cover changes is extremely useful for management purposes. The main task of this study was to detect plantation forest cover change information especially on thinned and clear cut areas. These changes were estimated using Normalised Difference Vegetation Index (NDVI) derived from SPOT HRV data, compared with Forestry Commission (FC) records and field investigations. To detect whether areas have been thinned and felled during the period of concern (1994-1997), three fundamental aspects were considered. First the pattern of forest cover was identified by using FC records and field investigations. This pattern was linked to SPOT data using NDVI. At this stage relationships between forest cover and structural variables (age, top tree height, mean diameter and basal area) were also examined. Second, changes over time were analysed by using NDVI measurements (1994-1997) and change detection methods, particularly to identify the pattern of felling. Third, pixel based forest cover changes in selected compartments were related and compared to FC thinning records and information collected by forest managers. A number of points about the ability of remote sensing techniques to provide an estimate of forest cover for management operations emerged from this study. First, it was found that NDVI changed spatially with different forest cover; spatial patterns were mainly identified in areas where major management operations (thinning and felling) were carried out. Second, temporal patterns of forest cover change, mainly due to felling operations were identified. Finally with a detailed analysis of thinned compartments, this study recognised changing patterns of forest cover, which were related to management operations. These findings should be very useful for operational planning in plantation forests. In particular, knowledge of spatial and temporal changes of forest cover may be useful in management operations where the availability of ancillary information is unreliable. These results appear to be sufficient for the initial stages of operational planning. However further investigations need to be undertaken to better understand a number of factors related to changes of forest cover.
8

The growth and quality of UK grown Douglas-fir

Drewett, Thoams Ashley January 2015 (has links)
Timber is a local, sustainable and valuable building material, but it is highly variable compared to other building materials (e.g. concrete, steel). The quality of wood is its suitability for the end-user, in this case the construction industry (via timber processors). Douglas-fir is a tall conifer capable of producing high construction grade timber. Native to the north-western Pacific regions of America and Canada, Douglas-fir was introduced to the UK in 1827. After World War 1, the planting of conifers greatly increased due to the establishment of the Forestry Commission. Despite being a high value timber crop in North America, Douglas-fir was not highly utilised in Great Britain due to a perceived lack of suitable growing sites (requiring nutrient-rich soil) and a lack of knowledge on its qualities (mechanical). Consequently, it still to this day covers a relatively small amount of the total UK conifer plantation area, but under predicted climate change projections an increased range of sites will become more suitable for Douglasfir, thus investigation now is imperative. To investigate the quality of Douglas-fir timber and its biological variation, a variety of sites were sampled in Scotland and Wales. The variation in the physical and mechanical properties of UK-grown Douglas-fir were investigated to determine how strength and stiffness of Douglas-fir compares to other commercially important timber species in the UK (as well as compared to Douglas-fir grown in different countries). Standing and felled tree measurements relating to tree architecture and important for timber volume (e.g. size, height, branching habits and taper) were collected in the forest. This was followed by laboratory testing of wood samples obtained from those trees to determine important raw material properties. Ultimately this will enable some explanation and prediction of the variation in mechanical and physical properties in Douglas-fir. It was found that Douglas-fir is stronger, stiffer and denser than the UK's most planted conifer, Sitka spruce. Wood adjacent to the pith (middle of tree) termed as juvenile was weaker, less stiff and less dense. Within-tree variation accounted for most of the variation for the key properties of strength, stiffness and density. It was possible to build models for some of these properties based on cambial age (ring number from the pith). Considering branches, it was found that within-tree variation in size, frequency, angle and status (alive or dead) were highly variable but it was possible to build empirical models to describe branch architecture for a typical tree. It was possible to measure the rate of swelling in oven dry Douglas-fir in the radial and tangential dimensions, but swelling of the longitudinal dimension was below the limit of detection for the apparatus. Heartwood area can be successfully predicted from the diameter of tree at a given point. It is hoped the information in this study will detail some characteristic Douglas-fir traits that may be deemed beneficial for the timber construction industry and allow understanding of its variability plus provide important models to use in helping to describe Great Britain's forest resource.
9

Modelling climate change impacts on the productivity of short rotation coppice

Aylott, Matthew January 2010 (has links)
Fast growing hybrids of Salix and Populus can be grown in a short rotation coppice (SRC) system to produce renewable energy. This PhD investigates the interactions between the environment and productivity, with a view to finding the key limiting factors to yield and the potential of these crops to fulfil UK renewable energy obligations, now and in the future. An empirical modelling technique, using partial least squares regression was developed to extrapolate actual field observations to a national scale. Genotype x age x environment interactions were studied to examine the key limiting factors to productivity. Modelled yields differed between genotypes, with mean annual aboveground biomass ranging from 4.9 to 10.7 oven dry tonnes (odt) per hectare for Populus trichocarpa x P. deltoides genotype ‘Beaupré’ and Salix triandra x S. viminalis genotype ‘Q83’, respectively. Variation in yield was primarily described by spring and summer precipitation, suggesting water availability is the key limiting factor to yield. Output from the model was up-scaled across the UK using a geographic information system (GIS), and scenarios were developed to better understand the role and impact of land use management and policy development on potential crop distribution. For example, to meet UK biomass and biofuel targets without compromising food security or ecosystem services, would require 5 % of grade 3 land, 56 % grade 4 land and 47 % of grade 5 land. This quantity of biomass would produce 7.5 M tonnes of biomass per annum and would theoretically generate 15.5 TWh yr-1 of electrical energy, displacing 3.3 M tonnes of oil – approximately 4% of current UK electricity demand. The South West and North West alone producing over a third of this figure (5.2 TWh yr-1). These results suggest that SRC has the potential to become a significant component of a mixed portfolio of renewables. Furthermore, climate change is predicted to have far reaching consequences on crop growth. Process-based models can help quantify these interactions and predict future productivity. Here we use ForestGrowth-SRC, a process-based model originally designed for high-forest species and parameterised for a coppice system. Climate change scenarios (UK Climate Projections) were run with the model to assess the impact of a changing climate on the growth and spatial distribution of SRC poplar. Results suggest ForestGrowth-SRC is capable of accurately simulating growth over a large spatial and temporal scale. However, pests and disease were found to significantly affect yield. In the absence of pests and disease, productivity could increase by 20 % nationwide by 2080 (under a medium emissions scenario), suggesting we will see a future increase in the value and production of these crops as feedstocks for heat, power and liquid transportation fuels
10

The history of coppicing in south east England in the modern period with special reference to the chestnut industry of Kent and Sussex

Bartlett, Deborah Mary Frances January 2011 (has links)
This thesis focuses on coppice woodland management in South East England, the region with the greatest concentration of woodland in the UK, with Kent the county with the highest proportion of ancient semi-natural broadleaved woodland. The woodland management practice of coppicing has declined, particularly since the Second World War, generally attributed to loss of markets for products fashioned from small diameter roundwood. This thesis begins by asking questions about the decline in the coppice industry particularly the extent of the decline and the significance this has for ecology and landscape, as well for the livelihoods of both woodland owners and the workforce. This is set in context by a review of the historical background, focusing on the modern period, the previous research into the industry, and the changes in policy that have taken place over the last fifty years. The evidence for the decline and the attempts that have been made to address it are evaluated. A series of investigations have been undertaken, including interviews, questionnaires and focus groups. These provide evidence that coppicing is still taking place over a wide area, and that there is a strong demand for products, both here and abroad, particularly for chestnut fencing. Claims by earlier researchers that the workforce is diminishing, with the majority nearing retirement, are refuted. Profiling the workforce has revealed the existence of separate groups, with distinct characteristics. These do not operate in the same way, indicating that considering the industry as a single entity is no longer valid. The importance of the chestnut workers, with a craft tradition handed down through the generations should be acknowledged. The current political context highlights the importance of involving all stakeholders in decision making. Recommendations are made for further research to incorporate this and so enable more successful development of the coppice industry in the future, whether this is for environmental, economic or social reasons.

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