Summary 1. Woody plant encroachment of grasslands is occurring globally, with profound ecological consequences. Attempts to restore herbaceous dominance may fail if the woody state is resilient or if intervention leads to an alternate, undesirable state. Restoration outcomes often hinge on biotic interactions – particularly on priority effects that inhibit...
The infrequent occurrence of large wildfires in the southern Appalachian Mountains over the last several decades has offered few opportunities to study their impacts. From 2000 to 2008, five wildfires burned a large portion of the area in and surrounding the Linville Gorge Wilderness in North Carolina. Areas were burned...
We used microsatellite DNA data and genetic stock identification methods to delineate the temporal and spatial distributions of juvenile Chinook Salmon Oncorhynchus tshawytscha occupying coastal habitats extending from central Oregon to northern Washington. Juveniles were collected in trawl surveys conducted during spring, summer, and autumn over 15 years. Distributions (mean...
The construction of Illinois Falls fish ladder on the Illinois River in Oregon was completed in November 1961. The ladder was opened and operated during the winter of 1961-62. Final cleanup and rock removal was completed in the fall of 1962. The ladder was installed on a natural barrier where...
The Pseudomonas aeruginosa antimetabolite L-2-amino-4-methoxy-trans-3-butenoic acid (AMB) shares biological activities with 4-formylaminooxyvinylglycine, a related molecule produced by Pseudomonas fluorescens WH6. We found that culture filtrates of a P.aeruginosa strain overproducing AMB weakly interfered with seed germination of the grassy weed Poa annua and strongly inhibited growth of Erwinia amylovora, the...
Estimating the stock proportions of mixed-stock fishery samples by means of genetic stock identification has played an important role in the management of salmon fisheries. In addition, stock identification of individual fish has applications for population studies, forensic cases, and management issues. We examined 11 microsatellite DNA loci in 84...
Calf death at or shortly after calving results in losses of over 3.5 million calves annually in the United States. About 45% of these losses are caused by dystocia (delayed and/or difficult parturition). The two principal factors involved in dystocia are size of calf and age of cow.
The objective of this study is to develop a mathematical model to relate the production of juvenile sockeye salmon in the Wood River
Lake system to parent stock size, primary and secondary production, population size of predators and competitors, and abiotic variables.
The Columbia River Basalt consists of dozens of seemingly identical flows of basalt covering thousands of square miles of Oregon, Washington, and Idaho. For years, detailed mapping of the units relied almost entirely on subtle petrographic distinctions, the presence or absence of interbeds, and actual walking along contacts in the...