Graduate Thesis Or Dissertation
 

Influences of the duration of periodic sway on the stem form development of four-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/tb09jb63v

Descriptions

Attribute NameValues
Creator
Abstract
  • Stem form development of trees in response to wind has been established in the literature to be a response to stem sway induced by the wind. The response is manifested in modifications to height and diameter growth which strengthen the stem against wind stresses. Experiments in the literature show that significant responses result from short durations of sway daily. An experiment exploring the growth responses resulting from a wide range of daily durations of sway was conducted. Also, the influence of timing of periods of sway during the growing season and during different seasons was examined.The pooled mean leader length for seedlings swayed different durations daily at a rate of 0.8 Hz was 86 per cent of that for unswayedcontrols. Leader length for seedlings swayed only 10 seconds daily were not significantly different from unswayed controls. Growth during certain stages of apical bud burst seems to have been retarded by the longer durations of sway. Growth ring increment onthe compression side of the stem increased due to swaying, with the greatest response due to a 10 second daily duration and the least due to a 10 hour duration. Growth ring increment on the tension side responded in like manner, the longer durations of sway were not significantly different from the unswayed controls, but the short durations resulted in significant increases. In a separate experiment, seedlings were swayed 2.5 hours daily. Treatments were begun with the initiation of bud burst, and terminatedafter periods of 6, 12, and 18 weeks. Leader length growth was not found to differ between controls and the 6-week swaying treatment, but was reduced due to longer treatment periods. The stem diameter in the direction of sway increased as the period of swaying increased. These results suggest that the response system directing height and diametergrowth loses its effect, in time, if swaying is terminated before the completion of bud burst. A field experiment was conducted measuring growth responses of 17-year-old trees which were prevented from natural wind sway during certain seasons of the year. No differences between treatments were found, Wind strength at the study site may have been inadequate to provide measurable differences.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • Master files scanned at 600 ppi (256 Grayscale) using Capture Perfect 3.0 on a Canon DR-9080C in TIF format. PDF derivative scanned at 300 ppi (256 B+W), using Capture Perfect 3.0, on a Canon DR-9080C. CVista PdfCompressor 3.1 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Carlton__Ronald_MS.pdf 2017-12-08 Public Download