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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

Environmental controls on clonal willow growth

Harrington, Robin Ann. January 1984 (has links)
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 39-41).
2

Analysis of some factors influencing the distribution and abundance of the poplar and willow borer (Sternochetus lapathi (L.)) on scouler willow (Salix scouleriana Barratt).

Safranyik, Laszlo January 1963 (has links)
A study was carried out during the summer of 1963 to determine the importance of some factors influencing the distribution and abundance of S. lapathi (L), on scouler willow, on Spur 17 of the University Research Forest, near Haney. The investigation was done through the observation and sampling of populations in the field, supported by laboratory experiments designed to determine the number of larval instars and the rate of dispersion by means of walking. The following items were investigated: 1) Number of larval instars, 2) Inter- and intra-tree differences in insect mortality, 3) Differences in within-tree distribution of different life stages, 4) Differences in between-tree distribution of combined, adult-plus-pupal stages and of larval instars, 5) Rate of dispersion of starved and fed beetle populations, 6) Influence of tree height, d.b.h., age, and number of crevices per square inch of bark area on infestation intensity and, 7) Sampling method to determine larval population levels. Five larval instars were found for the larval stage of the weevil. Tree height, d.b.h., age, and number of infestations per tree had no marked influence on trend of weevil mortality. Mortalities of first and second instar larvae were higher within the lower three foot trunk sections of sample trees than those in the higher sections of the trunks. The vertical distribution of larval galleries had no marked influence on the mortality of the other life stages of the weevil. Mean infestation height of combined, adult plus pupal stages was significantly lower (significant at 0.05 level) than that for the combined larval stages. Starved beetles dispersed more than their fed counterparts. D.b.h., and tree height were the most important variables in determining the intensity of infestation on an individual tree. A two-stage sampling method was developed to ascertain larval population levels. / Forestry, Faculty of / Graduate
3

Willow resilience on Yellowstone's Northern Elk Winter Range a function of environmental gradients /

Cary, Karri Lee. January 2005 (has links)
Thesis (M.S.)--Montana State University--Bozeman, 2005. / Title from PDF t.p. (viewed on July 4, 2006). Chairperson, Graduate Committee: Duncan T. Patten. Includes bibliographical references (leaves 93-100).
4

Habitat parameters associated with the distribution of seven willow species on a stream in southeastern Oregon /

Gilbert, Griffith J. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 94-99). Also available on the World Wide Web.
5

Ecological conditions of secondary sexual dimorphism in salix glauca fundamental and realized dimorphic niche /

Dudley, Leah S., January 2006 (has links)
Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / 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 27, 2007) Vita. Includes bibliographical references.
6

Uptake, assimilation and toxicity of cyanogenic compounds in plants

Yu, Xiaozhang. January 2009 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 195-224) Also available in print.
7

The poplar-and-willow borer, Sternochetus lapathi (L.), (Coleoptera: Curculionidae)

Harris, John Walter Edwin, January 1964 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1964. / Typescript. Abstracted in Dissertation abstracts, v. 25 (1965) no. 7, p. 4310. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 170-190).
8

A program for improvement of basket willow on the Carpathian Plains of Hungary

Sziklai, Oscar January 1961 (has links)
An inventory of the most important indigenous and exotic Salix clones for basket making was carried out in Hungary. Eleven clones were selected from those presently growing in various parts of the country. The vegetative and generative characteristics of the shoots were described. Interspecific hybridization was carried out using five different combinations. The germination of Salix seed was studied by taking a series of photographs. Vegetative propagation by means of shoot cuttings and by "T" bud grafting were tried. A selection method was used for evaluating the different clones within the country. Five experimental plantations were set out on the more important soil regions and the eleven clones were planted in randomized blocks, each 10 by 10 meters in size. Each clone was replicated four times and 170 cuttings of each were planted in a block. The height growth of the 5th and the 10th ramets in each row were measured bi-weekly during the growing season in 1955 and in 1956. More than 100,000 height measurements were recorded. The influence of the clone, year, and locality on the average height attained was evaluated by means of an analysis of variance, and an attempt was made by using the components of variance to estimate the heritability. The simple correlation coefficients were calculated to approximate the degree of association of the average tree height, weight and volume of different clones in the five localities during the years 1955-1959 inclusive. Form of sprouts, cellulose content of one-year-old shoots, and meteorological conditions were studied. Experiments were undertaken concerning spacing and fertilization as part of the basket-willow improvement work. / Forestry, Faculty of / Graduate
9

Effects of environmental variables and grazing on planted willow (Salix boothii Dorn) cuttings

Lowson, Katherine L. 13 January 2004 (has links)
The influence of streambank location and timing of herbivory on success of planted Booth's willow (Salix boothii Dorn) cuttings along a Rosgen C5-type stream in an eastern Oregon meadow was determined. Willow cuttings were planted on two morphological locations (i.e. point bar and floodplain) in May of 2002 and 2003. Gravimetric soil moisture and depth to water table data were collected periodically on each planting location during the growing season, May through September, in both years. Three grazing treatments, early season, late season, and none (control) were conducted. Percent survival, leader density, and number of browsed leaders of willows were recorded prior to and after each grazing treatment, as well as stubble height of forage species. Simple linear regression was used to determine if a relationship between residual stubble height and percent willow browse existed. Multiple linear regression was used in an attempt to develop a predictive equation for percent browse based on pre-grazing stubble and willow heights. It was hypothesized that depth to water table and percent soil moisture throughout the growing season would significantly influence willow survival and growth; that survival would be higher on point bar locations; and that willows would be browsed at different intensities according to season of grazing. Soil moisture content at point bar locations was greater than that of floodplain locations for the majority of the growing season in both years. In 2003, groundwater levels were higher on point bar than floodplain locations from May through September. Willow survival was higher for point bar locations than floodplain locations, in both years, regardless of grazing treatment. Willows were browsed more intensively later in the growing season. Results from the simple linear regression suggest that percent browse of willows was related to the residual stubble height, but did not explain the variability observed. An attempt to develop a predictive equation, i.e., expected browse based on pre-grazing stubble height, was made, however no apparent relationship between the willow height, stubble height, and percent browse was found. Grazing treatment did influence willow survival; survival on floodplain locations within the late grazing treatment was less than that of the ungrazed floodplain locations. Our results suggest that planting willows in locations where the planting depth remains within 40 cm of the groundwater depth will increase planting success. Protection from grazing for at least the first year of growth is recommended for optimum planting survival; grazing early in the season is more favorable to survival than grazing later in the season. / Graduation date: 2004
10

A comparison of vegetative and non-vegetative regeneration strategies in Populus nigra and Salix alba

Barsoum, Nadia January 1998 (has links)
No description available.

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