Silvicultural impacts of sheep grazing in Oregon's Coast Range Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/5h73pz491

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • A three-year investigation was conducted during 1980-1982 to evaluate the potential of using herded sheep as a silvicultural tool to suppress brush in Douglas-fir (Pseudotsuga menziesii) plantations of Oregon's Coast Range. Sheep browsing of Douglas-fir was highest in May soon after bud break. Averaged over the 2 years of grazing, sheep consumed 28% of the Douglas-fir current year's growth (CYG) in two May-grazed plantations. Browsing was generally light (2% CYG) during July and August. Browsing of terminal leaders by sheep decreased as seedling height increased. Less than 3% of the study trees were mechanically impacted by sheep. In a 2-year-old plantation in which seedlings were heavily browsed by sheep in both May and August, annual height and mean diameter increment were reduced by sheep grazing. However, annual mean diameter increment was 8 to 17% higher in the grazed portion of three 4-6-year-old study plantations. Survival of regeneration over the 2 years of investigation was high in all study plantations and was unaffected by grazing. Increased available nitrogen deposited as urine in grazed plantations may have contributed to the increased diameter growth. Vegetational composition of sheep diets varied by year, season, and plantation age class. Averaged over the 2 years of grazing, graminoids and forbs were nearly equal, at approximately 40% each, in sheep diets from older plantations. In contrast, diets of sheep in young grass seeded plantations averaged 70% graminoids and only 16% forbs. Ferns were a minor component (<2%) of sheep diets in both plantation age classes. Browse averaged 15 and 12% of sheep diets in older and younger plantations, respectively. Douglas-fir comprised less than 3% of sheep diets throughout the grazing season. Weight gains followed seasonal trends typical of sheep grazing non-irrigated hill pasture in western Oregon. Average daily gain (ADG) of ewes and lambs during the 1981 grazing season was -.03 and .12 kg/sheep/day, respectively. Yearling ewes gained .08 kg/ewe/day in the 1982 gazing season. Death losses were relatively low, averaging 3% for the ewes and 5% for the lambs in 1981 and 2% for the yearlings in 1982.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
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
Additional Information
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2013-07-11T21:03:08Z (GMT) No. of bitstreams: 1 LeiningerWayneCarl1984.pdf: 2691935 bytes, checksum: 6fa64bfed9a1bbf8b3fa4e535e2a473f (MD5)
  • description.provenance : Submitted by Kirsten Clark (kcscannerosu@gmail.com) on 2013-07-11T20:01:48Z No. of bitstreams: 1 LeiningerWayneCarl1984.pdf: 2691935 bytes, checksum: 6fa64bfed9a1bbf8b3fa4e535e2a473f (MD5)
  • description.provenance : Made available in DSpace on 2013-07-17T17:39:55Z (GMT). No. of bitstreams: 1 LeiningerWayneCarl1984.pdf: 2691935 bytes, checksum: 6fa64bfed9a1bbf8b3fa4e535e2a473f (MD5) Previous issue date: 1983-11-28
  • description.provenance : Approved for entry into archive by Deborah Campbell(deborah.campbell@oregonstate.edu) on 2013-07-17T17:39:55Z (GMT) No. of bitstreams: 1 LeiningerWayneCarl1984.pdf: 2691935 bytes, checksum: 6fa64bfed9a1bbf8b3fa4e535e2a473f (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items