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...
The effects of five cytokinin antagonists on the growth
of cytokinin-autonomous lines of Phaseolus lunatus cv.
Kingston, Phaseolus vulgaris cv. Great Northern, and
Nicotiana tabacum cv. Wisconsin 38 callus tissues have been
compared. The antagonists tested included four N⁴-substituted 4-amino-2-methylthiopyrrolo[2,3-d]pyrimidines
bearing the following N⁴ side chains, 4-n-pentyl-
(ms²pnN⁴Prp), 4-n-hexyl- (ms²HxN⁴Prp),...
Wetlands and wet prairies are economically and environmentally valuable ecosystems, but many have been degraded or converted to other uses. As human understanding of wetlands' value has increased, restoration efforts have grown correspondingly. Restoration attempts use a diversity of methods, which often include seeding with native plant species. This thesis...
The root disease fungus Inonotus tomentosus, common in the old
growth boreal forests of British Columbia, poses a threat to the
health of second growth forests established on sites with a previous
history of root disease. Colonized stumps occur in groups of 1 to 6;
the groups are clumped within...
The fungus Nothophaeocryptopus gaeumannii is the causative agent of Swiss needle cast (SNC), a foliar disease of Douglas-fir. Disease is characterized by premature loss of foliage and reduced growth resulting from the inhibition of photosynthesis due to the occlusion of stomata by the ascocarps of N. gaeumannii. Although the disease...
Field surveys in 2006 confirmed that the
exotic rust fungus Phragmidium violaceum was widespread
on Rubus armeniacus and Rubus laciniatus in
the Pacific Northwest of the USA. The origin and
dispersal pattern of this obligate biotrophic pathogen in
the USA were investigated by comparing the genetic
diversity and structure of...
Plant-pollinator mutualisms are one of the most prevalent and economically important mutualisms in nature. Like many other ecological systems, plant-pollinator communities are threatened by anthropogenic activity, both directly (e.g., habitat conversion and fragmentation) and indirectly (e.g., climate change). While we are aware of many of the activities that adversely impact...
Native prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor rare and endangered species such as the Fender's blue butterfly (Icaricia icariodes fenderi) and its preferred host plant, Kincaid's lupine (Lupinus sulphureus ssp....
Native upland prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor many rare and endangered species such as the Fender's blue butterfly and its host plant, Kincaid’s lupine. Invasion of remnant prairies by...