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The study of uncertainty in Geographic Information Systems (GIS) and environmental models has received increasing attention in recent years, due in part to the widespread use of GIS for resource management. This study used GIS-based techniques in order to compare several different forest inventory and forest cover datasets. These datasets pertain to an area of the boreal mixedwood forest in northeastern Alberta which covers roughly 73,000 km2, and which has recently been approved for logging. The datasets include two forest inventories based on aerial photographs, and a forest cover classification based on remotely sensed satellite data. Simple logical operations were used to transform the datasets to a form suitable for comparison. Standard GIS overlay techniques were used to compare the agreement among different datasets. Visualization techniques were used to display patterns of agreement in attribute space (contingency tables), and in geographic space (maps of uncertainty). Agreement between the two forest inventories was about 50% (Percent Correctly Classified), with a Kappa value of 0.4, for a classification based on species composition. In general, much of the misclassification was between ecologically similar types, particularly between different combinations of aspen and white spruce. Comparison of the forest inventories with the classified satellite image was done using a simplified land cover classification with five categories. Agreement was about 55% (Percent Correctly Classified), with a Kappa value of 0.3. Possible sources of discrepancy among datasets include change over time, differences in spatial scale, differences in category definitions, positional inaccuracy, boundary effects and misclassification. Analyses were conducted to characterize the effect of each of these sources of disagreement. The agreement was strongly affected by the distance to boundary, indicating a boundary effect extending to more than 100 meters. Differences in spatial scale accounted for a small proportion of discrepancy. None of the other possible sources had a measurable effect on the discrepancy. It was therefore inferred that misclassification accounted for a large proportion of the discrepancy. Estimated levels of uncertainty were propagated through models including simple growth and yield tables and a more complex harvest scheduling model. It was found that uncertainty in model outputs was strongly affected by uncertainty in inventory data, uncertainty in volume yield curves, and perhaps most importantly, by a poor understanding of disturbance and forest dynamics in the region. The results of the analysis show that these uncertainties may have significant economic and ecological implications.

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In this thesis, I analyze the potential for a REDD+ program to succeed in Uganda at this time, and I explore why this may or may not be possible. REDD+, which stands for Reducing Deforestation and Forest Degradation, aims to enhance carbon stocks while also conserving and sustainably managing forests. In doing so, REDD+ not only works to offset carbon emission levels and conserve forests and forest biodiversity, but also provides financial benefits to REDD+ participant countries, thus improving the livelihoods of local people living adjacent to forests. This program is widely regarded as the most effective and least risky solution to deforestation and forest degradation in developing countries, however, I argue that this may not be the case. Government documents reveal a rather simplistic and idealistic view of the policy, its implementation process, and desired outcomes, while specific case studies in countries outside of Uganda in which the REDD+ program has been implemented or is in the process of being implemented reveal unaddressed concerns with the mechanism itself and within the surrounding communities. Based on my research, I believe that if the recommendations that I propose are not included in the REDD+ preparation and implementation phases, the REDD+ mechanism is not only predestined to fail, but also to harm the most at-risk stakeholders that it is meant to benefit.

Miombo is dry deciduous woodland dominated by leguminous tree species, covering a significant area of Africa south of the equator, including large parts of Angola, Malawi, Mozambique, Tanzania, Zaire, Zambia and Zimbabwe. This woodland type reaches its driest, most species-poor limit in Zimbabwe. Brachystegia spiciformis and Julbernardia globiflora are the two main dominants of the drier form of miombo. Miombo woodland represents a rich and diverse resource base for small-scale farmers throughout the region, the importance of which has been ignored in the past by managers and policy-makers. The development of sustainable management strategies for this resource has therefore been hampered by a lack of knowledge. For this reason, the overall objective of this research was to define the basis for sustainable management of these woodlands, firstly by developing techniques for measuring biomass and monitoring woody growth; secondly, by examining the effect of site conditions on productivity; and thirdly, by investigating biological and social aspects of the management of these woodlands. This research has found that good estimations of standing wood biomass of these two species can be derived from diameter and stem length measurements, thus providing woodland managers with a means of assessing the standing stock. The finding that B. spiciformis forms annual rings can be used in ageing the trees, projecting future yields more accurately, as well as monitoring the effects of management on growth. In the investigation of the effects of climatic and edaphic conditions on tree growth, soil depth was found to have the greatest influence, followed by mean annual rainfall and clay content. Dominant height was found to be the best morphological variable to estimate site potential, in the absence of detailed studies of soil characteristics. The experimental findings from silvicultural trials have important implications for management. Regrowth from coppice stools was vigorous even in dry years, and greatest from medium to large stools. Productivity in general was extremely variable, both of coppiced and uncoppiced trees, due to site effects. The most productive sites are also potentially the best for agriculture and are therefore unlikely to be left exclusively for woodland management. The silvicultural techniques of coppice reduction and water harvesting were not found to enhance coppice regrowth. Browsing by livestock was found to severely reduce coppice regrowth, particularly of J. globiflora, at least in the initial stages, so that protection from browsing in the first year or two after felling is recommended if maximum regrowth is desired. An assessment of the use and management of the indigenous wood resources in a resettlement area in central Zimbabwe suggests that the present harvesting of wood products is unsustainable, due largely to the lack of any woodland management policy for these areas. Local villagers feel powerless to exclude outsiders from their resource, and thus the incentives to manage it sustainably are low. Major changes in government legislation are necessary to alter this situation. In the interim, resource-sharing schemes are suggested as a method of improving the sustainability of use. Some of the results reported here have a direct application in miombo management; these are summarised at the end of this work in the form of guidelines for management. Others identify the need for further work to expand these initial findings. One of the outcomes of this research has been the reminder of how little is known of the appropriate management of this important vegetation type.

The objective of this study was to develop integrated systems for measurement and modelling of site quality, timber yields and carbon sequestration of Pinus pinaster established on farms in south-west Australia. Established farm plantings were identified for the necessary sampling and measurements but, as broadscale P.pinaster planting on farms is a relatively new venture, those available for study were mostly small-scale and not managed for current timber production objectives. Therefore new methods for sampling, data analysis and modelling were developed or adapted to indicate the growth and carbon sequestration that will be achieved in the new plantations. The system developed for site quality assessment is a two-stage process. Firstly, survival rate is predicted from annual pan evaporation and soil salinity. Then, site index (SI) is predicted from annual rainfall and six soil variables: soil salinity, depth to bedrock, depth to gravel layer, depth of pale soil, presence of high watertable, and soil colour at 5 cm soil depth. A difference equation form of the Chapman-Richards growth model is applied to predict future stemwood volume yield from measurement of current or past stemwood volume. Alternatively, in the case where P.pinaster has not been grown at a site, or no growth measurements are available, yield is predicted from SI. In both cases the yield prediction models were developed for fully-stocked block plantings, wider-spaced block plantings and belt plantings. A thinning model simulates the response of stemwood volume to thinning operations in block plantings. (For complete abstract open document)

Thesis (M.S. - Watershed Management)--University of Arizona. / Includes bibliographical references.