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Physiological ecology of western juniper (Juniperus occidentalis hook. subsp. occidentalis)

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dc.contributor.advisor Eddleman, Lee E.
dc.creator Miller, Patricia M.
dc.date.accessioned 2009-10-21T18:14:07Z
dc.date.available 2009-10-21T18:14:07Z
dc.date.issued 1990-05-04
dc.identifier.uri http://hdl.handle.net/1957/13119
dc.description Graduation date: 1990 en
dc.description.abstract Patterns and costs of root/shoot allocations, response to reductions of above and below-ground tissue and to fertilization with nitrate and ammonium, and seasonal courses of physiological processes were measured on juvenile, small-adult, and large-adult Juniperus occidentalis growing in the field under ambient environmental conditions in eastern Oregon. Adult foliage had the highest heat of combustion, nitrogen concentrations, and construction cost. Allocation patterns indicated a larger investment in resources to above than below-ground tissue. J. occidentalis allocated larger proportions of dry mass to foliage, to maximize photosynthetic capacity, and to roots, to optimize water and nutrient acquisition; this was accomplished through reduction of allocation to branches and trunk. Removing [approximately] 50% of the foliage increased rates of CO₂ assimilation but did not increase growth, improve water status, or increase nitrogen concentration of remaining foliage. Cutting lateral roots reduced physiological processes and quantum-use-efficiencies and water-use-efficiencies. Fertilization increased foliar nitrogen concentrations and reduced CO₂ assimilation, leaf conductance, and transpiration. Juniperus occidentalis appears to be adapted to the low, ambient levels of soil nitrate and does not preferentially utilize ammonium. Highest daily total assimilation occurred during July and August. Juveniles had significantly higher assimilation and transpiration per gram foliage than did small or large-adults. Juveniles had the tightest control over water loss, but were not more water-use-efficient than small-adults or large-adults. Soil drought affected conductance independent of plant water potentials or vapor pressure deficits. Branchlet elongation was greatest in June and July. Juveniles were more responsive to the changing environment that were small-adults or large adults. en
dc.language.iso en_US en
dc.subject.lcsh Juniper -- Ecophysiology en
dc.title Physiological ecology of western juniper (Juniperus occidentalis hook. subsp. occidentalis) en
dc.type Thesis/Dissertation en
dc.degree.name Doctor of Philosophy (Ph. D.) in Rangeland Resources en
dc.degree.level Doctoral en
dc.degree.discipline Agricultural Sciences en
dc.degree.grantor Oregon State University en
dc.description.digitization PDF derivative scanned at 300 ppi (256 B&W), using Capture Perfect 3.0.82, on a Canon DR-9080C. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR. en
dc.description.other P.120, 125-126, 128-129, 169-173, 179-180, 214 HAVE HANDWRITTEN "CORRECTIONS MADE BY PATRICIA M. MILLER 04/23/91". LIBRARY IS UNABLE TO VERIFY THE VALIDITY OF THESE CORRECTIONS. en


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