• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 51
  • 5
  • 2
  • 2
  • Tagged with
  • 74
  • 74
  • 19
  • 17
  • 17
  • 12
  • 11
  • 8
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 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.

Monoterpene composition : response to stress in lodgepole pine seedilings /

Hyland, Steven Coolidge. January 1980 (has links)
Thesis (M.S.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Genetic variation in Pinus contorta Dougl. and related species of the subsection Contortae

Wheeler, Nicholas Collins. January 1981 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 129-151).

Effect of competition on the growth and crown form of lodgepole pine

Bailey, Gordon Raymond January 1964 (has links)
Tree growth and crown form of 131 open-grown and 63 forest-grown lodgepole pine were investigated. Areas sampled included representative sites in the Interior, Lower Mainland and Vancouver Island in British Columbia. Both graphical and multiple regression analyses were used. The best, but still inadequate, estimator of either radial or basal area growth for the last five years was the growth for the period six to ten years ago. Standard errors of estimate ranged from 21.4 percent for basal-area growth of individual open-grown trees to 43.5 percent for basal-area growth of individual forest-grown trees. More than 90 percent of the total variation in the crown width of open-grown lodgepole pine was accounted for by d.b.h. alone. For forest-grown trees only 56.8 percent was accounted for by d.b.h. This percentage may be increased to 81.1 percent by the addition of height-crown width (H/CW), and to 68.4 percent by the addition of crown width/diameter (CW/D). Average value for CW/D was 0.99 for the forest-grown, and 2.13 for 90 open-grown trees ten years of age or older. Both H/CW and CW/D are significantly related to site index and age. However, when d.b.h. is taken into account, only six percent of the variation in CW/D is affected by site index. Almost 50 percent of the height to the lowest dead branch, and over 90 percent of the height to the lowest live branch could be accounted for by tree age, d.b.h. and height. One of four "competition factors", all related to distance to, and size of, competing trees, accounted for an additional 13.7 percent of the variation in height to dead branches. However, basal area, H/CW, and CW/D were of little importance after the effects of age, d.b.h. and height were accounted for. The maximum growth rate for open-grown trees was determined graphically for ages from 30 to 50 years by site index classes. Comparison with normally grown trees showed that at least twice the normal yield-table-estimate of growth rate may be expected from open-grown trees. Using regression equations developed from the data, a theoretical conversion to lumber was made for a butt log from an open-grown tree. For boards, graded under the Western Pine Association's rules, it was shown that large knots may degrade lumber grown at the maximum rate. Therefore, use of an open-to-normal density model, which allows crowns to compete before excessive knot formation occurs, would be a desirable objective for management of lodgepole pine. / Forestry, Faculty of / Graduate

Variation in lodgepole pine and its role in the genetic improvement of coastal forms

Roche, Laurence January 1962 (has links)
This thesis is divided into two parts. Part one deals with variation in a number of important silvicultural and taxonomic characteristics of Pinus contorta. Variation in bark and growth habit was studied in the field and recorded by means of photographs. The data obtained in this manner are supplemented by information concerning variation in both these characteristics in Lodgepole pine plantations in Europe. It is concluded that the Shore form of Lodgepole pine is extremely intolerant of shade, and is not inherently a scrub tree, or inferior in form to the Inland variety of the species. The geographical position of some superior coastal stands is given. The field study further showed that because of its shade intolerance the Shore form is restricted to the forests' edge, to ocean cliffs, sand dunes and muskeg. There its potential growth habit and form are obscured by extremes of environment, and observed only when grown in plantations, or in its natural habitat when competing species are eliminated by fire. Under the latter conditions the Shore variety of Lodgepole pine is a rapidly growing tree, with normal growth habit and form, and is seldom contorted either in bole or branch. The Shore form has a characteristic bark type which is inherently different from the Interior form. A study of variation in needle morphology was made on material obtained from trees of the Lodgepole pine provenance trial at The Institute of Forest Genetics, Placerville, California. Needle width and length were measured, and it is demonstrated that a correlation between these two measurements exists. Because of this correlation the Shore and the Interior populations cannot be distinguished by either leaf width or length alone. Therefore the mean ratio of width to length is used to separate the variation in leaf morphology due to the place of origin of the trees from which the needles were collected. Analysis of variance shows that the mean ratio does not differ significantly between trees representing a particular site, between sites the difference is just significant, and between geographic regions highly significant. The Duncan multiple range test showed that the three major regions (Rocky Mountains, Sierra Nevada, Coastal) differed significantly from each other, but that there was no significant difference between the mean ratio of the Coastal and the Mendocino White Plains material. Data concerning the growth rate of the trees at Placerville, supplemented by data from European plantations, suggest that coastal Washington and Oregon provenances show the most rapid growth rate in North Temperate regions. Specimens of seed and foliage collected from natural populations show morphological differences between the Coast and Interior forms. A method of distinguishing Coast and Interior seed is demonstrated. Germination tests show that under standard conditions of temperature and humidity the rate of germination of the Coast seed is significantly different from Interior sources. Morphological differences in seed characteristics, can, therefore, be supplemented by germination data to effectively separate the Interior and Coast forms of Lodgepole pine. Part two of the thesis deals with the selection and breeding of the Shore form. The proposed breeding program takes into account the theoretical and practical objections to the Scandinavian method of tree improvement. Nevertheless, it incorporates this method insofar as it is designed to produce large quantities of seed which is not inferior in several desirable characteristics, while simultaneously working for the genetic improvement of the species. / Forestry, Faculty of / Graduate

An application of the average diameter method of preparing growth tables for lodgepole pine

Jewesson, Roy Stanley January 1954 (has links)
In the Foothills Region of Alberta lodgepole pine (Pinus contorta var. latifolia) frequently develops even-canopied, undifferentiated stands, the growth of which tends to be controlled by the density of stocking as well as by site and age. In order to consider all these factors, a method for the construction of tables to be used in the prediction of growth of lodgepole pine has been developed. A stand density factor based on basal area per acre and the average stand diameter is introduced and by means of the relationship of these two variables with age a series of basal area growth tables are devised. Similarly, by means of the relationships which stand age and the ratios of total cubic volume and number of trees per acre to basal area per acre, bear to average stand diameter, two more sets of growth tables have been constructed to show the manner in which these ratios progress with age. The site percent concept of describing site is discussed. A table showing the average stand diameter developed by a stand of given age and number of trees per acre on the regional average site was constructed, and the technique of measuring site quality of any individual area by expressing the actual stand average diameter as a percentage of the tabular value is described. The validity of using the site percent method is proven statistically and the method of using this measurement to introduce a site correction into the growth tables is shown. Site variation adds but a small refinement to the prediction of growth for this species, possibly because of an actual small variation in the quality of forest land upon which the species will develop in the Foothills region, or possibly because of a bias in the sample. The techniques discussed are based upon the data from 79 sample plots in the Foothills region of Alberta. While it is believed that the method of deriving the tables and their use is well substantiated by the discussions given, no claim is made for the accuracy of the tables themselves. The data has weaknesses in both the upper and lower classes of age and average diameter and the curves fitted therefrom have suffered accordingly. / Forestry, Faculty of / Graduate

Evolutionary responses of plants to seed-eaters : pine squirrel predation on lodgepole pine

Elliott, Phillip Franklin January 2010 (has links)
Digitized by Kansas Correctional Industries

Management decision-making tools for mountain pine beetle (Dendroctonus ponderosae) (Coleoptera: scolytidae) populations in lodgepole pine (Pinus contorta) stands /

Bentz, Barbara Joan, January 1991 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 148-163). Also available via the Internet.

Disturbance and the life history of Pinus contorta var. latifolia in western Montana

Muir, Patricia S. January 1984 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Growth analysis of heterogeneous stands of ponderosa pine and lodgepole pine in central Oregon /

Mainwaring, Doug B. January 2000 (has links)
Thesis (M.S.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references (leaves 129-134). Also available on the World Wide Web.

Stand models for lodgepole pine and limits to their application

Lee, Yam January 1967 (has links)
Intensive study of the growth of individual trees in the open and in stands, and of the growth of stands themselves, has provided the basic biological assumptions and equations, which then are used in simulation of stand growth. Simulation, emerging as a research technique since the advent of electronic computers, has helped solve many forestry problems previously considered unmanageable. Simulation is almost essential in building stand growth models. Stand growth models for lodgepole pine (Pinus contorta Doug.)¹, are needed to illustrate some economic consequences of alternative methods of management. Such analyses can provide guidelines for improved stand management. These better approaches are desirable because lodgepole pine is required to supply increasing demands of a rapidly developing pulp industry in British Columbia and in Alberta. Newnham's stand models are critically examined and fully described. A revised simulation model is built and the methods used are described. Principles and assumptions basic to the development of stand models in general are also outlined. The revised model is initiated with a 30 x 30 tree matrix. The dbh frequency distribution of these 900 trees is normal. A mean dbh of 1.2 inches at 15 years, with a standard deviation of 0.4 inches, is assumed to represent site index 70 feet at 80 years. The dbh growth of each of the 900 trees is predicted by 5-year periods using a regression of dbh on age for open-grown lodgepole pine, with appropriate reductions for crown competition. The crown width of each of the 900 trees is calculated from the regression of crown width on dbh for open-grown lodgepole pine trees. A factor is introduced to reduce the calculated crown width, as trees grow from open-grown initially to forest-grown conditions. Tree height is calculated from the multiple regression equation of height on dbh and basal area per acre. Individual tree volumes are calculated from ratios of volume to basal area for various heights. Techniques of testing confidence in the prediction of stand parameters are illustrated for the revised model. Combined standard errors of estimate (in per cent) are used to indicate the error estimates for the simulation model. These are large but, by comparison with all available data on tree growth and stand yield, the revised simulation model satisfactorily describes the growth of lodgepole pine stands in all four spacings tested. Moreover, much of the information calculated for each 5-year period cannot be obtained from conventional yield tables. In order to analyze the economic consequences of harvesting various kinds of products, yields of 8-foot logs and ratios of section volume to tree volume are calculated for ages 20 to 100. Maximum gross yields will come from 3.3 ft. x 3.3 ft. initial spacings. However many small trees included in gross yield estimates will be less than 6 inches in dbh and therefore not merchantable. The full range of influence of tree size on costs and values per tree is illustrated. Ratios of lineal feet per acre to cubic volume per acre are used to adjust logging and milling costs for tree size, based on the average cost per cunit which applies to lodgepole pine trees averaging about 11 inches in dbh. In all cases tested, initial spacings of 13.2 ft. x 13.2 ft. give the best net return per acre from plywood and lumber. Production of lumber is next best. Poles and piling are less attractive, under the present assumptions. Production of pulp chips alone would create a loss at present market value. Results are summarized in two comprehensive wood and product value yield tables (Tables 5A and 55). These tables may improve decision-making concerning initial spacing. The revised simulation model also can be used to simulate, in a few minutes, the growth of many other kinds of lodgepole pine stands from age 15 to age 100, or more. Economic consequences of many approaches to managing lodgepole pine can be illustrated now. Although greatly improved economic and biological data are desirable, the revised model can provide good preliminary answers to many important questions about management of lodgepole pine. / Forestry, Faculty of / Graduate

Page generated in 0.06 seconds