Debris flows are a major cause of disturbance to riparian vegetation. Both observational and experimental studies were used to examine the initial recovery of riparian vegetation after debris flows on headwater streams in the western Cascades of Oregon. My goal was to determine the roles of seedlings and vegetative sprouts,...
Prior to European settlement, native prairie dominated the landscape of the
Willamette Valley. Today, due to urbanization, agriculture, and the cessation of
burning, only isolated remnants of these grasslands still exist. In response to
conservation concerns, there has been a move to restore the remaining prairies in the
Willamette Valley,...
Reducing the cover of non-native species is one of the challenges of ecosystem restoration. The goal of this study is to identify native species traits that will increase native species cover and reduce non-native species cover in the first growing season at upland and wetland prairie restoration sites. Native and...
Active habitat management plays a key role in the preservation of native ecosystems and rare species, especially in the Willamette Valley of Oregon, where natural succession to woodlands threatens the few wetland prairies remaining after 150 years of agriculture and urbanization. Sidalcea nelsoniana, listed as threatened under the federal Endangered...
The influence of overstory openness on the reproductive
ecology of Pacific yew (Taxus brevifolia Nutt.) was
investigated on 4 sites in western Oregon over 2 years. The
breeding system of T. brevifolia was found to deviate from
pure dioecy under a broad range of canopy and site
conditions. Production of...
Cheatgrass (Bromus tectorum L.) is a widespread exotic weed in the Intermountain sagebrush steppe. An annual grass, it is highly prolific and very competitive with native perennial grass seedlings. A clipping experiment carried out at two cheatgrass-dominated sites (Lincoln Bench and Succor Creek) in eastern Oregon analyzed effects of defoliation...
In ecological restoration, species that are sown to increase the native plant
diversity range in establishment ability. Some species readily establish, while others
rarely do. This study set out to investigate some of the potential processes influencing
species establishment, as well as the traits that are associated with the success...