Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vii, 89 p. : ill. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vi, 68 p. : ill. (some col.), col. maps. Vita. Includes abstract. Includes bibliographical references (p. 61-67).

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 45-51). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Tennessee, Knoxville, 2007. / Title from title page screen (viewed on June 10, 2008). Thesis advisor: Henri D. Grissino-Mayer. Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). "May 2009." Includes bibliographical references (leaves 98-115). Also available via the World Wide Web.

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 127-136). Also available on the World Wide Web.

Invasive plants, animals, insects, and pathogens are a significant problem for land managers and conservationists as they can cause irreparable damage to local ecosystems. The emerald ash borer (EAB), an invasive beetle from China, was discovered in the U.S. in 2002, and has decimated ash populations throughout Michigan. It continues to move through Midwestern and some eastern states, usually killing a tree within 2-4 years of infection. Using a Global Positioning System (GPS) and Geographic Information System (GIS), all trees ≥ 45 cm and all ash ≥ 30 cm in diameter were measured and mapped within a 160 acre old-growth deciduous forest in northern Indiana. EAB was detected in 14 trees throughout the forest. A canopy map was generated, estimating 6.6 percent canopy loss due to EAB. Because of this research, the entire spread of EAB within this forest can now be documented and mapped. The methodological framework used in this research can assist land managers and property owners monitor their land by enabling them to: track changes in tree health more accurately; assess damage by creating forest inventory and canopy maps; and model potential damage over time. / Department of Natural Resources and Environmental Management

Graduation date: 2006 / Canopy gap formation is a major factor contributing to maintenance of overstory species diversity and stand structure in forests and may be integral to development of understory shrub and herb layers as well. Acknowledgement of gap formation as a fundamental feature of natural forests has led to consideration of gaps as an option in forest management regimes. This study examined understory vegetation communities across canopy gaps created as a part of the Density Management Study (DMS), which investigates the effectiveness of a thinning regime in promoting late-successional habitat development in young Douglas-fir forests of western Oregon. Patterns in understory vegetation community composition in and around 0.1 and 0.4ha gaps created as a part of the DMS treatment were investigated. The primary goal of this research was to investigate the potential role of canopy gap creation in fostering heterogeneity in understory vegetation communities, and to examine the extent of gap influence on the surrounding thinned forest matrix. Tree species distributions have been shown to partition across gaps in tropical forest systems through differential responses of species to gradients in resource availability, a pattern known as gap partitioning. In temperate forests, understory vegetation communities are much more diverse than the overstories, and display a greater array of habitat requirements. Therefore, understory communities may be more likely than overstories to exhibit gap partitioning in these forests. Patterns in understory community composition across gaps suggest that gap partitioning has occurred. The strength of this partitioning effect appears to differ between gap sizes, as smaller gaps showed a less powerful effect. Abundance of ruderal species was strongly related to gap partitioning in larger gaps, while smaller gaps were dominated by competitor species. Partitioning may be related to an interactive relationship between harvest-related ground disturbance and resource gradients. Therefore, considerations of gap partitioning processes should take into account intensity and spatial distribution of ground disturbance in relation to resource gradients. In addition, conditions necessary for the expression of gap partitioning in understory vegetation communities may be rare in natural gaps in this region. The influence of gaps on understory vegetation communities in the surrounding forest appears to be relatively small. This small influence extent may help explain the lack of a stand level response to gap formation in these stands. Larger gaps exhibit a slight influence on the understory plant community in the surrounding forest to the north of the gap. In small gaps, there seemed to be an influence of the surrounding forest on gap interiors, resulting in an area of influence smaller than the physical gap area. This relationship may indicate that the area of gap influence on understory vegetation may not scale linearly with physical gap size. Species diversity was higher in gap interiors than in surrounding thinned forests. However this effect was partially due to the presence of exotic species, which showed an affinity for gap interiors. Late successional associated species were negatively related to gap interiors, but only in the larger gap size. Gap creation appears to be promoting small scale species diversity in these stands, but creation of large gaps may also promote the establishment of exotic species and may have a negative effect on late successional associated species. However, any and all of these effects may be transient, as understory communities will be strongly affected by overstory re-establishment, and related changes in resource availability. In general, gap formation may influence small-scale stand heterogeneity as evidenced by understory plant communities, but this effect may rely strongly on the nature of gap formation and intensity of disturbance related to this formation.

Light spectra distributions were measured in two different montane forests: temperate and tropical. Spectral light measurements were made in different sized canopy gaps in the conifer forest at H. J. Andrews Experimental Forest in Oregon, USA. Researchers at Oregon State University created these gaps of 20 m, 30 m, and 50 m in diameter. In the tropical cloud forest, spectral light measurements were made in two plots that were permanently established at La Mucuy Parque Nacional in Venezuela, in collaboration with researchers at Universidad de Los Andes. In both studies, spectra and distributions of physiologically active light were analyzed: red, far-red, R/FR ratio, and blue light.

An inventory of vascular plants was conducted in Steele Creek Park in Sullivan County, Tennessee from March 2013 to September 2014. The park covers an area of 892 ha and lies within the Ridge and Valley Province. The inventory of vascular plants documented 547 species of 323 genera and 101 families. Two hundred sixteen taxa were newly reported for Sullivan County. Tennessee Special Concern Species included Cardamine rotundifolia, Castanea dentata, Lonicera dioica, Allium tricoccum, Cypripedium acaule, and Panax quinquefolius. A single species, Juglans cinerea L., is considered a Tennessee Threatened Species. Vegetation patterns were studied quantitatively by installing 10 study plots within forest canopy gaps and a comparable set of 10 in areas with intact canopy. Plots within a canopy gap recorded more vascular plant diversity when compared to plots of intact canopy when unshared species were considered. Steele Creek Park provides a botanically rich area for future studies.