Raptors that inhabit sagebrush steppe and grassland ecosystems in the western United States may be threatened by continued loss and modification of their habitat due to energy development, conversion to agriculture, and human encroachment. Actions to protect these species are hampered by a lack of reliable data on such basic...
Studies of anthropogenic impacts on wildlife may produce inconclusive or biased results if they fail to account for natural sources of variation in breeding performance and do not use probabilistic sampling at a scale functional for management. We used stratified random sampling and generalized linear mixed models to test hypotheses...
Grassland and shrubland birds are declining globally due in part to anthropogenic habitat modification. Because population performance of these species is also influenced by non-anthropogenic factors, it is important to incorporate all relevant ecological drivers into demographic models. We used design-based sampling and occupancy models to test relationships of environmental...
This summary of the 1958 inspection of the T. J. Starker Post Farm is issued as a supplement to the detailed Progress Report 11, October 1957. Complete Progress reports to be issued at intervals of 2-5 years will describe post series mentioned here and will summarize previous work.
In summary, as detailed below in Section III, we recommend the 2007 Legislature put
Measure 37 back on the track of fair and honest compensation for all claimants, and corral the
threat to Willamette Valley agriculture at the same time, by providing as follows:
• Whether in the form of...
Mortality due to infectious diseases is seldom reported in the Greater Sage-Grouse (Centrocercus urophasianus). A case of necrotic enteritis associated with Clostridium perfringens type A is described in a free-ranging adult male sage-grouse in eastern Oregon. Clostridial enteritis is known to cause outbreaks of mortality in various domestic and wild...
Aldo Leopold, perhaps best known for his revolutionary and poignant essays about nature, was also an eloquent advocate during the 1930s and 1940s
of the need to maintain wolves and other large carnivores in forest and range ecosystems.He indicated that their loss set the stage for ungulate irruptions
and ecosystem...
The kinetic mechanism of the unidirectional
H2-oxidizing hydrogenase from soybean nodule bacteroids has
been investigated with highly purified enzyme. Measurements
of the K, for H2 vary from 0.97 to 2.6 pM, and the K,,, for
methylene blue varies from 6 to 17 pM. With H2 and
methylene blue as substrates,...
We investigated how large carnivores, herbivores, and plants may be linked to the maintenance of native species biodiversity through trophic
cascades. The extirpation of wolves (Canis lupus) from Yellowstone National Park in the mid-1920s and their reintroduction in 1995 provided the
opportunity to examine the cascading effects of carnivore–herbivore interactions...
Idealized numerical simulations utilizing the Regional Ocean Modeling System (ROMS) are carried out to examine the response of buoyant river plume systems to offshore-directed wind stresses. It is found that after a few inertial periods of wind forcing the plume becomes detached from the coast and reaches a steady state...
Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park in 1995-96, thus completing the park’s large predator guild. In the fall of 2010, approximately 15 years after wolf reintroduction, we sampled ten genera/species of berry-producing shrubs within 97 aspen (Populus tremuloides) stands in the park’s northern ungulate winter range....
Data attacks on state estimation modify part of system
measurements such that the tempered measurements cause
incorrect system state estimates. Attack techniques proposed
in the literature often require detailed knowledge of system
parameters. Such information is difficult to acquire in practice.
The subspace methods presented in this paper, on the...
We characterized the structure and composition of unmanaged riparian forests in three river basins in Oregon’s coastal mountains. Our objective was to evaluate stand attributes at three spatial scales: streamside (site), drainage network (stream order), and basin (subregion). Data on basal area, species composition, snag density, canopy cover, and tree...
We have investigated the depinning process of magnetic flux vortices in twinned crystals of YBa₂Cu₃O₇₋δ in intermediate applied magnetic fields parallel to the crystallographic c axis through precise resistivity measurements before and after fast-neutron irradiation. Of particular interest for each field is the power-law dependence of the electric field on...
Terrestrial lichen biomass is an important indicator of forage availability for caribou in northern regions, and can indicate vegetation shifts due to climate change, air pollution or changes in vascular plant community structure. Techniques for estimating lichen biomass have traditionally required destructive harvesting that is painstaking and impractical, so we...
The 1995/96 reintroduction of gray wolves (Canis lupus) into Yellowstone National Park after a 70 year absence has allowed for studies of tri-trophic cascades involving wolves, elk (Cervus elaphus), and plant species such as aspen (Populus tremuloides), cottonwoods (Populus spp.), and willows (Salix spp.). To investigate the status of this...
This paper addresses some issues involving the application of discontinuous Galerkin (DG) methods to ocean circulation models having a generalized vertical coordinate. These issues include the following. (1) Determine the pressure forcing at cell edges, where the dependent variables can be discontinuous. In principle, this could be accomplished by solving...
This paper is part of an effort to examine the application of discontinuous Galerkin (DG) methods to the numerical modeling of the general circulation of the ocean. One step performed here is to develop an integral weak formulation of the lateral pressure forcing that is suitable for usage with a...
Recreational fishing has a long history in the USA, developing from the subsistence fisheries of Native Americans together with a partial subsistence fishery of later immigrants. Marine, diadromous, and aquatic taxa are targeted, including both vertebrates and macroinvertebrates. This paper defines recreational fishing, describes the main fishing techniques, identifies target...
Bulk magnetic properties of soils and sediments are often sensitive proxies for environmental change but commonly require interpretation in terms of the different sources of magnetic minerals (or components) that combine to generate them. Discrimination of different components in the bulk magnetic record is often attempted through endmember unmixing and/or...
Changes in the spatial distribution of U.S. west coast bottom-trawl effort in relation
to areas of prime habitat for rockfish Sebastes spp. were evaluated between 1992 and 2001. Prime trawlable rockfish habitat (PTRH) was defined based on the spatial distribution of high rockfish catches from logbook data for 1992–1995. Bottom-trawl...
To investigate the extent and causes of recent quaking aspen (Populus
tremuloides) recruitment in northern Yellowstone National Park, we measured browsing
intensity and height of young aspen in 87 randomly selected aspen stands in 2012, and
compared our results to similar data collected in 1997–1998. We also examined the
relationship...
Tumours arising from the dorsal surface of the tongue occurred in 3 horses from 14-23 years of age. Tumours were surgically excised at a referral hospital (1 case) and on the farm (2 cases) and submitted for histopathology. All tumours were multilobular and composed of vaguely nested, bland, oval to...
This study investigated how lidar-derived vegetation indices, disturbance history from Landsat time series (LTS)
imagery, plot location accuracy, and plot size influenced accuracy of statistical spatial models (nearest-neighbor
imputation maps) of forest vegetation composition and structure. Nearest-neighbor (NN) imputation maps were
developed for 539,000 ha in the central Oregon Cascades,...
Refractive indices of In₂O₃, In₂₋ₓSnₓO₃, InBO₃ and 2 different gahnite crystals (ZnAl₂O₄ and Zn.₉₅Fe.₀₅Al₂O₄) were measured at wavelengths of 435.8 to 643.8 nm and were used to calculate n at λ = 589.3 nm ( nD ) and at λ = ∞ (n∞) using the one-term Sellmeier equation 1/(n²-1) =...