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Factors affecting establishment and germination of upland prairie species of conservation concern in the Willamette Valley, Oregon

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dc.contributor.advisor Kaye, Thomas N.
dc.creator Jones, Katherine D.
dc.date.accessioned 2012-05-07T19:42:46Z
dc.date.available 2012-05-07T19:42:46Z
dc.date.copyright 2012-03-19
dc.date.issued 2012-03-19
dc.identifier.uri http://hdl.handle.net/1957/29047
dc.description Graduation date: 2012 en_US
dc.description.abstract Identifying mechanisms that determine who lives and dies is the first step in developing successful restoration techniques for rare species and endangered habitats. We studied interactions that affect establishment of native plant forbs of conservation concern at the seedling stage to support the theoretical basis for restoration activities in Pacific Northwest prairies. Specifically, we tested the hypothesis that seedling establishment is controlled by 1) competition with or 2) facilitation by existing vegetation and that the interaction is mediated in part by environmental stress. We direct-seeded or planted vegetative plugs of Lupinus oreganus, Castilleja levisecta, Erigeron decumbens, Iris tenax and Sidalcea malviflora ssp. virgata into 20 plots with a range of community compositions in high-stress upland prairies at each of three sites. We counted seedlings and estimated cover of plant functional groups as well as litter, bare soil and disturbance then used linear regression to test for effects of these factors on seedling establishment. We found evidence of indirect facilitation of grass on seedling establishment in the first year: higher accumulations of leaf litter increased seedling numbers at two sites. In the second year, there was evidence of facilitation by live vegetation and litter on seedlings at one site, but no net effect of either competition or facilitation at the other two sites. Overall, we found more evidence for positive interactions than we did for competition. In particular, litter appeared to have a positive effect on seedling establishment of L. oreganus and S. malviflora ssp. virgata. This is contrary to the common perception that litter inhibits plant establishment but supports the theory that facilitation is more common in high stress sites; practitioners should consider seeding into leaf litter at some sites. To support a robust approach to conservation and reintroduction of species with dormant seed, we characterized dormancy types and developed germination protocols for S. malviflora ssp. virgata and I. tenax. S. malviflora ssp. virgata has physical dormancy and may have physiological dormancy. Scarification followed by four weeks of cold moist stratification was effective in initiating germination. I. tenax has morphophysiological dormancy which is overcome by four weeks of warm moist stratification followed by 6-12 weeks of cold stratification. We also conducted a meta-analysis of experiments that tested pre-sowing seed scarification of L. oreganus and conclude that breaking physical dormancy prior to direct seeding does not support higher establishment relative to unscarified seeds in this species. en_US
dc.language.iso en_US en_US
dc.relation Oregon Explorer en_US
dc.subject upland prairie ecology en_US
dc.subject rare plant conservation en_US
dc.subject seed dormancy en_US
dc.subject plant community interactions en_US
dc.subject facilitation en_US
dc.subject Lupinus oreganus en_US
dc.subject Castilleja levisecta en_US
dc.subject Erigeron decumbens en_US
dc.subject Iris tenax en_US
dc.subject Sidalcea malviflora ssp. virgata en_US
dc.subject.lcsh Prairie restoration -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Prairie plants -- Reintroduction -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Prairie plants -- Seedlings -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Prairie plants -- Seeds -- Dormancy -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Prairie plants -- Sowing -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Prairie plants -- Planting -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Prairie plants -- Ecology -- Oregon -- Willamette River Valley en_US
dc.subject.lcsh Germination -- Oregon -- Willamette River Valley en_US
dc.title Factors affecting establishment and germination of upland prairie species of conservation concern in the Willamette Valley, Oregon en_US
dc.type Thesis/Dissertation en_US
dc.degree.name Master of Science (M.S.) in Botany and Plant Pathology en_US
dc.degree.level Master's en_US
dc.degree.discipline Agricultural Sciences en_US
dc.degree.grantor Oregon State University en_US
dc.contributor.committeemember Liston, Aaron
dc.contributor.committeemember Pyke, David
dc.description.peerreview no en_us


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