Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 100-107).

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 13, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Systematics and Evolution, Department of Biological Sciences, University of Alberta. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 143-148).

The main objectives of this thesis were to: determine the roles of the minor components, 89/11 (E/Z⁰) 1 1-tetradecenyl acetate (AC) and 85/15 (E/Z) 11-tetradecenol (OH), of the sex pheromone of the western spruce budworm, Choristoneura occidentalis Freeman, in the orientation and pre-copulatory behaviors of the male moth; and, to evaluate various combinations of pheromone concentration, trap design, and maintenance regime for monitoring the budworm. The behavior of the male moths was observed, in a wind tunnel and in the field, in response to virgin females and to synthetic sex pheromone components, alone and in blends. The pheromones were incorporated into polyvinyl chloride rods at concentrations from 0.00005-0.5% (w:w) and release rates were estimated by gas-liquid chromatography of volatiles captured on Porapak-Q. OH contamination in lures of the major component, 92/8 (E/Z)-11-tetradecenal (ALD), and the AC, made it impossible to determine precisely the effects of either AC, ALD, or ALD+AC on the behavior of the male moth, but still allowed the testing of blends of ALD+AC+OH which resembled those released by virgin females. The moths were from three sources: a long-established non-diapausing laboratory colony; wild budworms collected near Ashcroft, B.C.; and crosses between laboratory males and wild females (lab-wild). The threshold concentration of ALD necessary to stimulate upwind flight was between 0.0005 and 0.005%; response peaked at 0.05% and dropped off above this concentration. The net upwind ground speed of flight decreased significantly at higher concentrations of ALD in the laboratory moths, and as the moths approached the lure with all three populations. In most experiments, the virgin female stimulated a greater percentage of males to contact the lure, and a faster upwind net ground speed of flight, than did ALD at about the same release rate. AC and OH stimulated response on an electroantennogram, but by themselves were not attractive to males in the wind tunnel. The addition of OH to 0.05% ALD significantly decreased the percentages of males locking-on (0.5% OH) and flying upwind (0.005% OH) in wild and lab-wild moths respectively, and significantly increased the percentage copulatory attempts of lab-wild males (0.005% OH). In the lab-wild males, a blend of ALD+AC+OH approximating that from a virgin female significantly increased the percentages of upwind flights, lure contacts, and copulatory attempts over those to ALD alone. The total blend, and not just the major component, affected long range behavior of the male moth. The laboratory males appeared less sensitive to the addition of minor components to 0.05% ALD than did the wild or lab-wild males. The mean total season's catch/plot in five non-maintained Uni-traps, baited with 0.05% ALD, was significantly correlated with the number of larvae/m² foliage in the same generation (r = 0.97), but only when a lower valley plot with very low larval density was excluded (plot 12). Correlations were significant (P ≤ 0.10) between larval density/plot in 1985 and the total moth catch/plot (n = 1 trap/plot) in 1984 in sticky traps (r = 0.45) and Uni-traps (r = 0.44) baited with 0.05% ALD and maintained. The latter correlation was significantly improved (r = 0.67; ≤ 0.05) when plot 12 was excluded. The addition of plot basal area/ha or foliage biomass/ha as independent variables significantly improved the coefficient of determination for the regression of larval density/plot in 1985 vs total seasons catch/plot in 1984, but again only when plot 12 was excluded. Of the trap systems evaluated, the Uni-trap, baited with 0.05% ALD, showed the most promise for monitoring the western spruce budworm, but permanent sample plots will have to be established and followed for several years to determine whether the system can be operational. / Forestry, Faculty of / Graduate

Thesis (M.A.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains xi, 80 p. : ill. (some col.), maps (some col.). Vita. Includes abstract. Includes bibliographical references (p. 72-77).

No description available.

Tree-ring chronologies from ten mixed conifer stands in the Colorado Front Ranges and New Mexico Sangre de Cristo Mountains were used to reconstruct timing, duration, and radial growth impacts of past outbreaks of western spruce budworm, Choristoneura occidentalis Freeman. Graphical and statistical comparisons of tree-ring chronologies from host and non-host tree species, in conjunction with Forest Service records of outbreaks during the twentieth century, revealed that outbreaks were identifiable only in the host chronologies as sharply reduced growth periods. These comparisons also showed that host and non-host tree-ring chronologies were generally similar between outbreaks and that both were responding in a similar manner to climatic variation. A study of defoliation and insect population data that was available for the New Mexico stands demonstrated that host radial growth from 1978 to 1983 was highly correlated with budworm activity. The non-host chronologies from each stand were used to correct the host chronologies for climatic and other non-budworm environmental variations by a differencing procedure. The corrected chronologies were then used to estimate the dates and radial growth effects of past budworm outbreaks. Tree-ring characteristics of twentieth century documented outbreaks were used as criteria for inferring the occurrence of outbreaks in previous centuries. At least nine periods of increased budworm activity were identified in the region from 1700 to 1983. The mean duration of reduced growth periods caused by known and inferred budworm outbreaks was 12.6 years, and the mean interval between initial years of successive outbreaks was 34.9 years. The mean maximum radial growth loss was 50 percent of expected growth, and the mean periodic growth loss was 21.6 percent. There was an unusually long period of reduced budworm activity in the first few decades of the twentieth century, and since that time outbreaks have been markedly more synchronous between stands. Increased synchroneity of outbreaks in the latter half of the twentieth century suggests that areal extent of outbreaks has increased. This phenomenon may be due to changes in the age structure and species composition of forests following harvesting and fire suppression in the late nineteenth and early twentieth centuries.

Thesis (M.S.)--Oregon State University, 1984. / Typescript (photocopy). Includes bibliographies. Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 1994. / Typescript (photocopy). Includes bibliographical references (leaves 126-143). Also available on the World Wide Web.

Forest disturbances and the spatial patterns they create affect ecosystem processes through their influence on forest vegetation from individual trees to landscapes. In the boreal and mixed-wood forests of eastern Canada the main agents of disturbance are logging, fire, and defoliation by the spruce budworm (SBW, Choristoneura fumiferana). These disturbances are similar in that they remove forest biomass and influence forest succession but also distinct in that logging creates patterns that are different than those created by natural disturbances. All disturbances are indirectly linked to each other through their mutual effects on forest spatial structure and succession. Through such feedbacks, spatial disturbance legacies can facilitate or constrain further disturbances, including forest management. Surprisingly, the long term spatial consequences of interactions among multiple natural and anthropogenic disturbances remain largely unexplored. This thesis investigates how, and at what spatial scale, legacies in forest composition and age structure influence natural disturbance dynamics, and how natural disturbances constrain forest management. I address four specific questions: (i) For how long do spatial legacies of different forest management strategies persist on the landscape? (ii) How do interactions among logging, fire, SBW, and succession affect timber availability and long term forest patterns in age and composition? (iii) How do these patterns differ from those created by each disturbance individually? And, (iv) How can management be used to reduce the extent and severity of fires and SBW defoliation through the manipulation of forest structure? The key scientific innovations of this thesis are: (i) Characterization of the duration and influence of spatial legacies on forest disturbances and sustainability; (ii) Development of a dynamic spatial forest simulation model that includes distinct successional rules that respond to different types of disturbance and shifts in disturbance regimes; and, (iii) Development and application of a wavelet-based significance testing framework to identify key scales of expression in forest spatial patterns. These innovations provide a scientific basis for landscape level forest management strategies designed to reduce the long term impacts of defoliating insects and to meet multiple objectives.