Graduate Thesis Or Dissertation

 

Cardaria draba (L.) Desv. in the sagebrush ecosystem of northeastern Oregon Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/zk51vn108

Descriptions

Attribute NameValues
Creator
Abstract
  • Ranchers and resource managers have become concerned about the role and spread of Cardaria draba (L.) Desv. (whitetop) in the sagebrush steppe of Northeastern Oregon. This area is an important natural resource for livestock production and big game winter range. An area near Keating, Oregon was selected to study the influence of environmental conditions on whitetop seed germination, mode of spread and species displacement by whitetop. Whitetop seeds were placed in the field at four different topographical positions (toe slope, mid-slope, north slope and south slope) and placed at three different locations in the soil profile (0, 1, and 3 cm). Seed placed on the toe slope position at 0 cm had the greatest germination. At the south aspect greater germination occurred at lower soil profile locations. Increases in whitetop populations were evaluated by establishing permanent transects in two locations in the study area. Whitetop shoot density increased during the three year study. Whitetop density increase was restricted to previously infested plots and was due to vegetative reproduction. In whitetop infested areas, crested wheatgrass density was less than in non-infested areas. Whitetop germination at different topographical positions was apparently related to moisture conditions. Once established, whitetop populations increase through vegetative reproduction. This phenomenon is reflected in a reduction of crested wheatgrass density and production as the level of whitetop infestation increases.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items