Spawning salmon create patches of disturbance through redd digging which can reduce macroinvertebrate abundance and biomass in spawning habitat. We asked whether displaced invertebrates use non-spawning habitats as refugia in streams. Our study explored how the spatial and temporal distribution of macroinvertebrates changed during a pink salmon (Oncorhynchus gorbuscha) spawning...
Satellite altimetry has previously been used to map the magnitude of the surface eddy variability of the global oceans, but the direction of the time-variable velocities have been more difficult to determine. Here, a technique is presented for resolving both magnitude and direction of residual surface geostrophic velocities at Geosat...
Pratylenchus neglectus and P. thornei reduce wheat yields in the Pacific Northwest USA. Resistant landrace cultivars have been identified using controlled environments. Field resistance and tolerance characteristics were compared over three years and two locations for four spring wheat cultivars; the susceptible cultivars Alpowa and Louise, and the resistant landraces...
The root-lesion nematode Pratylenchus (hornet is one of the most important pests restricting productivity of wheat in the Pacific Northwest (PNW). It is laborious and difficult to use microscopy to count and identify the nematodes in soils. A SYBR Green I-based real-time polymerase chain reaction (PCR) assay was developed to...
Greater Sage-Grouse (Centrocercus urophasianus) depend on sagebrush habitat for food and cover during winter, yet few sage-grouse winter ecology studies have been conducted. During January and February 2007, we monitored 22 radio-collared sage-grouse (7 females and 15 males) in central Oregon to characterize winter habitat use and movement patterns. We...
Understanding groundwater conditions in the upland parts of volcanic island aquifers is critical for sustainable groundwater development in these resource-limited environments. Yet groundwater conditions in such settings are generally difficult to characterize because of sparse well drilling (high cost and/or limited access). Information needed for resource evaluation includes upland depth...
Heterodera avenae and H. filipjevi are economically important cyst nematodes that restrict production of cereal crops in the Pacific Northwest United States and elsewhere in the world. Identification of these two species is critical for recommending and implementing effective management practices. Primers were designed from the internal transcribed spacer (ITS)...
Eastern boundary current (EBC) upwelling zones are among the most productive of marine ecosystems globally and have been generalized in terms of their food web structure. Little empirically based evidence exists to suggest that there is any one form of trophic control of EBC systems and, because of logistical constraints,...
This is a student report which studies the effects of wave action on intertidal zonation at Yaquina Head. It includes hand-drawn diagrams of quadrants sampled at the location.
The pathogenic nematodes Pratylenchus neglectus (Rensch, 1924) Filipjev and Schuurmans Stekhoven, 1941 and Pratylenchus thornei Sher and Allen, 1953 cause severe yield losses in wheat (Triticum aestivum L.). The objectives in this study were to assay a collection of Iranian landrace accessions collected from 12 provinces in Iran to identify...