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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.
821

The UAV logger as a potential alternative for timber transportation in the Canadian boreal forest

Wychreschuk, Alena 14 August 2012 (has links)
The Canadian boreal forest has substantial natural resources located in remote isolated areas that are of economic interest. Requirements of the log extraction operation are to minimize impact on the ecosystem and its inhabitants. Transportation is one of the largest direct costs of forestry operations and many potential harvest areas are left untouched because of the high costs to build and maintain logging roads and water crossings. Alternatives to the traditional surface transportation system could benefit the industry, the residents and the ecosystem. The economics of a Lighter-Than-Air UAV Logger concept for log transportation is compared to the current truck and road build option using a cost comparison model and three harvest area case studies. At the engineered price estimate of $4.1 million, the results suggest that the UAV Logger is an uneconomic transportation alternative in the boreal forest at current product prices and supply availability. Conditions that favour the UAV Logger as a competitive economic alternative include small harvest volumes and high road build costs.
822

Assessment of two spectral reflectance techniques for the estimation of fuel moisture content, equivalent water thickness, and specific leaf weight in Douglas-fir (Pseudotsuga menziesii (Mirb) Franco) needles

Visintini, Fabio 09 June 2011 (has links)
In the wildfire community fuel moisture content (FMC) is the quantity of choice when it comes to assess vegetation water status in relation to fire risk and fire behaviour. Field measurements of FMC are both expensive and time consuming and, in addition, sampling is often spatially inadequate. Remote sensing could represent an almost ideal solution both in terms of spatial and temporal coverage, if a consistent relationship between FMC and spectral reflectance could be established. A review of the literature suggests that it is difficult to retrieve FMC for dense forest canopies with remote sensing platforms. This study took a step back and explored the relationship between spectral reflectance and vegetation water content at the leaf level, where several confounding factors present at the canopy level are eliminated or controlled for. It also considered a conifer species, because relatively little research has been produced on this topic for this type of vegetation. The main goal was to establish if FMC can be derived directly from spectral reflectance in the solar spectrum using two well known approaches, such as spectral indices and continuum removal. It is also aimed at exploring if an alternative, indirect way to measure FMC as ratio of Equivalent Water Thickness (EWT) and Specific Leaf Weight (SLW) is feasible and accurate. The results derived from Douglas-fir (Pseudotsuga menziesii (Mirb) Franco) needles used in this study suggested that FMC was not directly retrievable from spectral reflectance but vegetation water content could be assessed with sufficient accuracy in terms of EWT. Also the retrieval of SLW from reflectance of fresh foliage proved to be challenging. Finally, the study also highlighted several aspects in the relationships among foliar water content, dry matter content and reflectance that require additional research. / Graduate
823

50 Years of Vegetation Change in a Holly Maritime Forest

Raphael, Jordan 12 February 2015 (has links)
<p> The Sunken Forest, located on Fire Island National Seashore, is a critically imperiled habitat and is one of only two known old-growth maritime holly forests in the world. Analysis of a dataset that dates back to nearly half a century has helped to identify major drivers influencing changes within the forest. These major drivers include; white-tailed deer herbivory, erosion, sea level rise, increased storm events, and canopy-gap dynamics. As of 2013, the Sunken Forest canopy is still analogues of 1967, but over the last 35 years vegetation recruitment within the forest has become limited due to white-tailed deer (<i>Odocoileus virginianus</i>) herbivory. The bayside of the Sunken Forest has also been eroding. Erosion with added pressure from sea-level rise is causing mortality of trees/understory vegetation, limiting seedling and herb recruitment, and shifting vegetation toward the bayside and low elevation areas within the interior of the forest.</p>
824

Forest ecological studies in the northern conifer hardwood region of Central Southern Ontario.

Davies, Bryan W. January 1968 (has links)
No description available.
825

Behavioral choice and demographic consequences of wood frog habitat selection in response to land use

Rittenhouse, Tracy A. Green, January 2007 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 28, 2008) Vita. Includes bibliographical references.
826

The design and development of a manually operated broadcasting machine for forest tree seeds /

Henson, Keith Turner. January 1956 (has links)
Thesis (M.S.)--Oregon State College, 1956. / Typescript. Includes bibliographical references (leaves 74-75). Also available on the World Wide Web.
827

Timber industry consolidation and the need for scale appropriate harvesting mechanisms in Alabama's black belt

Brodbeck, Arnold M. January 2005 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2005. / Abstract. Includes bibliographic references.
828

Towards a farming systems approach to tree nut research in Malawi /

Hancock, Wayne Mitchell. January 1992 (has links)
Thesis (MSc. (Honours))--University of Western Sydney, Hawkesbury, 1992. / "Thesis submitted for the Award of Master of Science (Hons) from the University of Western Sydney Hawkesbury 1992."
829

The relationship between the woodwasp Sirex notilio F. and the wood-rot fungus Amylostereum Sp. /

Boros, Catherine Beatrice. January 1968 (has links) (PDF)
Thesis (M. Ag. Sc.)--University of Adelaide, Dept. of Entomology, 1968. / Includes bibliographical references.
830

An input-output model of Northland's economy : with application to forestry /

Moore, Chris January 1981 (has links)
Thesis (PhD--Theoretical and applied mechanics, School of Engineering)--University of Auckland. / On cover: Ministry of Works and Development. Development and Programming Branch.

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