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Identification of restoration potential on southwestern Oregon rangelands

The objectives of this research were to 1) evaluate the establishment and peak
standing crop of Berber Orchardgrass (Dactylis glomerata var. "Berber"), Palestine
Orchardgrass (Dactylis glomerata var. "Palestine"), and Sheep Fescue (Festuca ovina
var. "Covar") ; 2) to assess establishment and production changes resulting from
environmental gradients (elevation, slope, aspect, soil texture, precipitation, and
resident annual community) across the foothill landscape; 3) develop a mathematical
model that predicts site potential for restoration; and 4) evaluate the utility of
Geographic Information Systems for creation and analysis of spatial data which
identify site production potential.
Sixteen sites were chosen which reflect the general character of the foothill
rangelands in southwestern Oregon. A Randomized Complete Block design was used
to select treatment arrangement on each site. Seeded treatments received both
chemical (Glyphosate, Hoelon, and 2,4-D) and mechanical (residue removal)
disturbance. Test species were seeded into three replications at each site. Each
replication also included a non-treatment control. Standing crop data for test species
and resident exotics were collected after three growing seasons.
Berber orchardgrass did not establish at most sites and where establishment did take place production was less than 132 kgDM/ha. Palestine orchardgrass established on on a majority of the study sites and produced most aboveground phytomass at mid-elevations where coarser soil textures and deeper soil depths were common. Sheep fescue was the most successful of the three test species and did best on low elevation high clay sites. There was significantly (P=0.001) more phytomass produced by annual exotics on seeded plots than on undisturbed controls at most sites. Both Palestine orchardgrass and sheep fescue treatments significantly suppressed the annual exotics when compared to the Berber treatments. Generally, "Covar" sheep fescue can establish and successfully compete with exotics on heavier textured soils at low elevations. "Palestine orchardgrass is adapted to mid-elevation coarser soils. / Graduation date: 1995

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/35002
Date16 December 1994
CreatorsBarrington, Mack R.
ContributorsJohnson, Douglas E.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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