Assessment of a Douglas-fir/sheep silvopastoral system in western Oregon Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/qn59q662n

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • This research was designed to evaluate the effect of sheep grazing on Douglas-fir water potential, growth, and understory forage production in a small-scale silvopastoral agroforestry system, at Peavy arboretum approximately 13 km North of Corvallis, Oregon. Treatments examined included all possible combinations of two sheep grazing management treatments (grazed vs. ungrazed) and three Douglas-fir plantation types: 1) Pasture without trees, 2) Cluster of trees planted 7.5 in apart with 5 trees/cluster, and 3) 8 x 8 plantations with trees planted 2.4 in apart in a grid-like pattern. Xylem total water potential of tree twigs was determined at predawn, noon and sunset every two weeks from September 1985 to October 1985 and from May 1986 to September 1986, and monthly during the November through April 1985-86 period. Douglas-fir height and diameter were measured in November 1985 and 1986 in order to estimate tree growth and stem total volume increment under the two treatments (grazing and planting). Forage production and utilization data were recorded each year. Percent canopy cover and species composition of herbage in all plantations was estimated in May 1986 using a ten-point frame. Tree canopy cover was measured in October 1985 and November 1986 by direct measurement. Grazing or planting pattern did not affect Douglas-fir xylem total water potential (P > .05). Daily and monthly xylem total water potential was highest (least negative) in Winter through early Spring in both 1985 and 1986. High tree moisture stress was observed in September both years, probably reflecting normal seasonal patterns of low precipitation and high air temperature during Summer. No consistent effect of sheep grazing or planting types on either height or diameter growth of Douglas-fir was found. Differences noted between total annual volume of tree stem produced per hectare in cluster vs. 8x8 plots were largely due to differences in tree density between the two plantations (higher tree density in 8x8) rather than to greater growth per tree. Neither the presence of Douglas-fir trees nor their planting pattern affected total annual forage production. Grazing treatment increased total forage production (P = .003) by approximately 67% compared to ungrazed areas. Percent total forage utilization and sheep-days of use were higher (P <.01) in cluster and pasture plots than in 8x8 plantations.
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 ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2013-07-10T14:45:07Z (GMT). No. of bitstreams: 1 LamouriAbdelwahad1987.pdf: 506141 bytes, checksum: 662f983da3e883e8c064af76dc217224 (MD5) Previous issue date: 1987-03-26
  • description.provenance : Submitted by Katy Davis (kdscannerosu@gmail.com) on 2013-06-19T18:21:58Z No. of bitstreams: 1 LamouriAbdelwahad1987.pdf: 506141 bytes, checksum: 662f983da3e883e8c064af76dc217224 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2013-06-20T15:06:54Z (GMT) No. of bitstreams: 1 LamouriAbdelwahad1987.pdf: 506141 bytes, checksum: 662f983da3e883e8c064af76dc217224 (MD5)
  • description.provenance : Approved for entry into archive by Deborah Campbell(deborah.campbell@oregonstate.edu) on 2013-07-10T14:45:07Z (GMT) No. of bitstreams: 1 LamouriAbdelwahad1987.pdf: 506141 bytes, checksum: 662f983da3e883e8c064af76dc217224 (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items