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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

Chloroplast DNA variability and phylogeny in the California closed cone pines /

Hong, Yong-pyo, January 1991 (has links)
Thesis (Ph. D.)--Oregon State University, 1992. / Includes mounted photographs. Typescript (photocopy). Includes bibliographical references (leaves 157-171). Also available on the World Wide Web.
2

Competitive relations for soil water in an experiment of soil compaction and organic residues in a young ponderosa pine-mixed shrub community /

Swearingen, Kurt A. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references (leaves 71-77). Also available on the World Wide Web.
3

Physiological and genetic response of Pinus strobus L. clones to sulfur dioxide and ozone exposures

Houston, Daniel Brown, January 1971 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.
4

The effects of water and shade treatments on photosynthesis and root-rhizosphere respiration in young ponderosa pine /

Johnson, Theresa J. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references. Also available on the World Wide Web.
5

Micrometeorological fluxes and controls on evapotranspiration for a jack pine stand growing on reclamation soil cover, Fort Mcmurray, Alberta /

Moore, Paul Adrian. January 1900 (has links)
Thesis (M.Sc.) - Carleton University, 2008. / Includes bibliographical references (p. 138-145). Also available in electronic format on the Internet.
6

Stem sapwood water transport and storage strategies in three conifers from contrasting climates /

Barnard, David M. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 93-100). Also available on the World Wide Web.
7

Drought Stress Detection using Hyperspectral Imaging

Felländer, Gustav January 2024 (has links)
This master’s thesis project investigates the utilization of a low-cost hyperspectral (HS) imaging rig to identify and classify drought stress in pine plants. Drought stress is a widespread environmental challenge affecting global forestry, requiring more resources as the industry grows and global warming rises. This provokes a need for affordable, and efficient monitoring methods. HS imaging, with its ability to capture a wide range of spectral information, offers promising methods for quick and precise measurements of plant stress. The project methodology is comprised of redesigning an existing HS imaging rig, with the camera employing push-broom technology, to yield precise and consistent HS images. This involved exploring the camera’s spectral range, designing components to ensure consistent artificial lighting using blackbody radiation sources, and calibrating the HS camera for focal depth and aberrations like smile and keystone. Two experiments were conducted to obtain the data for pine stress detection, first for two binary categories: Control, and 100% Drought, and later introducing a third semi-drought category in the second experiment. The data analysis encompassed preprocessing the HS images to correct the lighting intensity distributions and normalization of pixel values. Accompanied by filtering, resampling spectral data, and feature extraction facilitating consistent drought identification, and data management. To identify stress patterns in pine plants and temporal decay rates, methods such as spectral reflectance analysis, various vegetation indices (VI), and statistical learning techniques like discriminant analysis and logistic regression were evaluated for distinguishing between stressed and healthy plants. The results demonstrate the accuracy of the HS imaging rig in measuring spectral reflectances from plants, capturing changes between 550 − 670 nm in the visible spectrum and 750 − 890 nm in the near-infrared (NIR) spectrum due to increasing stress affecting chlorophyll levels. Both well-established VIs and empirically designed indices indicate reliable early detection. Comparing multiple VIs to statistical learning models shows similar performances in binary classification tasks. Feature selection methods using correlation matrices, and L1 penalty for logistic regression support stress effects visible in the data, paving the way for cost-effective strategies in sustainable forestry management.

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