Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003. / Thesis documentation sheet inserted. Errata sheet tipped in. Appendix consists of reproductions of three papers and a manuscript, two of which are co-authored with others. Includes bibliographical references. Also available electronically via World Wide Web in PDF format; online version lacks appendix of papers.

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Previously disturbed and regenerating forests make up a significant proportion of the North American land area, and therefore play an important role in the exchanges of heat and trace gases between the terrestrial biosphere and the atmosphere. Assessment of local to global variability in CO2 exchanges by forests requires a combination of CO2 measurements made by eddy covariance (EC), field measurements, remote sensing data, and ecosystem models. The integration of these is problematic because of a mis-match in scale between measurement techniques. Despite the importance of regenerating forests on the global carbon balance, the processes affecting the carbon cycle within these forests is not well understood. Airborne scanning light detection and ranging (lidar) instruments provide new opportunities to examine three-dimensional forest characteristics from the level of individual trees to ecosystems and beyond. Lidar is therefore an effective link between plot measurements, eddy covariance, and low resolution remote sensing pixels. This thesis dissertation presents new science on the use of airborne lidar for evaluating remote sensing products within heterogeneous and previously clearcut ecosystems. The goals of this thesis were to first understand the processes affecting CO2 exchanges within a previously disturbed boreal jack pine chronosequence located in Saskatchewan, Canada and then to apply this understanding to evaluate low resolution remote sensing data products from the Moderate Resolution Imaging Spectroradiometer (MODIS) using airborne lidar. The first objective of this dissertation examined the factors that control light use efficiency (LUE) within the jack pine chronosequence during dry and wet years. The second objective examined the importance of vegetation structure and ground surface elevation on CO2 fluxes within a mature jack pine forest. The third objective developed and tested a simple model of lidar fractional cover and related this to the fraction of photosynthetically active radiation absorbed by the canopy (fPAR). This was then used to evaluate the MODIS fPAR product across the lower part of a watershed. Finally, the fourth objective was to model gross primary production (GPP) from airborne lidar. Lidar estimates of GPP were then compared with those from the EC system at the jack pine chronosequence and with the MODIS GPP (Collection 5) product. / Thesis (Ph.D, Geography) -- Queen's University, 2008-08-22 08:50:51.44

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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.

The objective of this study was to assess tree species influence on forest floor fertility in a mixed forest stand using Redundancy Analysis (RDA). Eighty microsites were located in a beech-hemlock-red maple forest. Forest floor was analyzed for thirteen variables; total N, P, K, Ca and Mg, extractable Ca, Mg and K, mineralizable N (NH$ sb{4+}$), basal microbial respiration (CO$ sb2$), pH, thickness and bulk density. The influence of seven tree species was calculated as a function of tree diameter and distance from each microsite. Spatial patterns were detected by using correlograms and incorporated in a variation-partitioning model with trend surface analysis. Tree species, microtopography, and spatial structure explained 53% of the total variation in forest floor data. The fraction explained by tree species alone (16%) was studied with a RDA ordination biplot. The main source of variation in the soil data was related mainly to the opposite effects of American beech and eastern hemlock on calcium while most of the other species had a beneficial effect on soil fertility. This study showed the potential of RDA as a tool for studying the role of tree species in mixed forests.

There is growing interest in airborne lidar for forest carbon accounting and precision forestry purposes. Airborne lidar systems offer a cost-effective, versatile, operationally flexible and robust sampling tool for forest managers. The objective of this study was to develop and test lidar canopy surface enhancement and segmentation processes for estimating dominant above-ground biomass (DAB) in a harvested eucalypt forest on the Central Coast of New South Wales (Australia). The Crown Infill, Trim and Smooth (CITS) process, incorporating a series of filters, algorithms, and selective multi-stage smoothing, was used to enhance lidar canopy surfaces prior to segmentation. Canopy segmentation was achieved using a vertical crown template approach termed the Spatially and Morphologically Isolated Crest (SMIC) process. SMIC delineates dominant tree crowns by detecting elevated crown crests within a 3D lidar canopy surface. Consolidated crown units constitute the basic sampling, analysis and reporting units for wall-to-wall forest inventory. The performance, sensitivity and limitations of these procedures were evaluated using a combination of simulated forest models and actual lidar forest data. Automated crown polygons were used as a sampling template to extract dominant tree height values which were converted to DAB estimates via height-to-biomass relationships derived from field survey and on-site destructive sampling. Results were compared with field based tree height and biomass estimates. Compared against a manually derived crown map from a 2ha field plot, canopy segmentation results revealed a producer???s accuracy of 76% and overall accuracy of 67%. Results indicated a trend toward greater crown splitting (fragmentation) as trees increase in age, height, stem diameter and crown size. Extracted dominant tree height values were highly correlated with ground survey height estimates (r2 0.95 for precision survey and r2 0.69 for standard survey). There was also no significant difference between SMIC and manual crown height estimates. SMIC units overestimated ground-based DAB by 5%; this increased to 36% with the inclusion of segmentation errors. However, SMIC estimation of total plot above-ground biomass (AGB) was within 9% of the ground-based estimate. Results are encouraging considering the mixed-species, multi-aged composition of the forest, and the combined effects of SMIC segmentation and lidar height errors.

Black/white/male/female struggles over knowledge correctness and who is brave are examined inductively in the field of bushfires. The paradoxes of a white male icon are linked to contradictions in gender theories in disaster. In mainstream literature, assumptions of innate white male superiority in bravery justify white women???s diminution and white male domination. In feminist theory, women???s diminution is the problem and their bravery for struggling against hegemony applauded. Philosophies of bravery are explored in 104 semistructured interviews and 12 months??? fieldwork as a volunteer bushfirefighter. There is great variety in the ways volunteers cope with bushfires. However, evidence of white male hegemony emerges when volunteers complain of state and territory indifference to preventing property and environmental damage and injury and death. Evidence is examined that Indigenous Australians once managed bushfires better than a sprawl of bureaucracy. Bushfire service claims that Aborigines knew nothing about hazard reductions are contradicted. This debate over bushfire management leads to the discovery of a third epistemology breaking with claims of white male iconic bravery and bureaucratic mastery. To generalise about the habitus of claims to knowledge and bravery, I analyse Newcastle Herald articles from 1881-1981. Three competing knowledge fields and their associated struggles are examined; Indigenous Australians and white womens??? emancipatory struggles confront data on bushfirefighting. Bushfires emerge as a serious problem, a bureaucratic power base and a white male icon from the 1920s.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 115 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 84-91).

Thesis (Ph.D.)--York University, 2005. Graduate Programme in Geography. / Typescript. Includes bibliographical references (leaves 208-215). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://proquest.umi.com/pqdweb?index=0&did=1147174101&SrchMode=1&sid=14&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1195152232&clientId=5220