Publications
Filter Total Items: 1971
Gonad organochlorine concentrations and plasma steroid levels in white sturgeon (Acipenser transmontanus) from the Columbia River, USA
Sturgeon are an important fishery resource world-wide, providing food and income through commercial, sport, and tribal fisheries. However, sturgeon populations are imperiled in many areas due to overharvest, habitat loss, and pollution. White Sturgeon (Acipenser transmontanus) are found along the west coast of North America from San Francisco Bay, USA to British Columbia, Canada. The Columbia Rive
Authors
E.P. Foster, M.S. Fitzpatrick, G.W. Feist, C.B. Schreck, J. Yates
Biological Soil Crusts: Webs of Life in the Desert
Although the soil surface may look like dirt to you, it is full of living organisms that are a vital part of desert ecosystems. This veneer of life is called a biological soil crust. These crusts are found throughout the world, from hot deserts to polar regions. Crusts generally cover all soil spaces not occupied by green plants. In many areas, they comprise over 70% of the living ground cover a
Authors
Jayne Belnap
Association of amphibians with attenuation of ultraviolet-b radiation in montane ponds
Ambient ultraviolet-b (UV-B) radiation (280–320 nm) has increased at north-temperate latitudes in the last two decades. UV-B can be detrimental to amphibians, and amphibians have shown declines in some areas during this same period. We documented the distribution of amphibians and salmonids in 42 remote, subalpine and alpine ponds in Olympic National Park, Washington, United States. We inferred re
Authors
M. J. Adams, Daniel E. Schindler, R. Bruce Bury
Exotic plant invasion alters nitrogen dynamics in an arid grassland
The introduction of nonnative plant species may decrease ecosystem stability by altering the availability of nitrogen (N) for plant growth. Invasive species can impact N availability by changing litter quantity and quality, rates of N2-fixation, or rates of N loss. We quantified the effects of invasion by the annual grass Bromus tectorum on N cycling in an arid grassland on the Colorado Plateau (U
Authors
R.D. Evans, R. Rimer, L. Sperry, Jayne Belnap
Unusual bacterioplankton community structure in ultra-oligotrophic Crater Lake
The bacterioplankton assemblage in Crater Lake, Oregon (U.S.A.), is different from communities found in other oxygenated lakes, as demonstrated by four small subunit ribosomal ribonucleic acid (SSU rRNA) gene clone libraries and oligonucleotide probe hybridization to RNA from lake water. Populations in the euphotic zone of this deep (589 m), oligotrophic caldera lake are dominated by two phylogene
Authors
Ena Urbach, Kevin L. Vergin, Ariel Morse
The influence of biological soil crusts on mineral uptake by associated vascular plants
Soil surfaces dominated by cyanobacteria and cyanolichens (such as Collema sp.) are widespread in deserts of the world. The influence of these biological soil crusts on the uptake of bioessential elements is reported for the first time for six seed plants of the deserts of Utah. This sample almost doubles the number of species for which the influence of biological soil crusts on mineral uptake of
Authors
K.T. Harper, Jayne Belnap
Genetic and morphologic variation in Phyllodoce empetriformis and Phyllodoce glanduliflora (Ericaceae) in Mount Rainier National Park, Washington
Genetic and morphological diversity of Phyllodoce empetriformis (Sw.) D. Don and Phyllodoce glanduliflora (hook.) Cov. were surveyed in Mount Rainier National Park in the Cascade Mountains of Washington State. Paired populations at high and low elevations were sampled at three study areas between 1720- and 2451-m elevation. Allozyme analysis of four polymorphic loci indicates high levels of geneti
Authors
Regina M. Rochefort, D. L. Peterson
Recent growth of conifer species of western North America: Assessing spatial patterns of radial growth trends
We explored spatial patterns of low-frequency variability in radial tree growth among western North American conifer species and identified predictors of the variability in these patterns. Using 185 sites from the International Tree-Ring Data Bank, each of which contained 10a??60 raw ring-width series, we rebuilt two chronologies for each site, using two conservative methods designed to retain any
Authors
D. McKenzie, Amy E. Hessl, D. L. Peterson
Diversity and succession of epiphytic macrolichen communities in low-elevation managed conifer forests in western Oregon
We examined epiphytic macrolichen communities in Pseudotsuga menziesii (Douglas-fir) forests across the western Oregon landscape for relationships to environmental gradients, stand age and structure, and commercial thinning. We used a retrospective, blocked design through the Coast and the western Cascade ranges of Oregon. Each of our 17 blocks consisted of a young, unthinned stand (age 50-110 yr)
Authors
E.B. Peterson, B. McCune
Response of juvenile softshell turtles (Apalone mutica) in a thermal gradient
No abstract available.
Authors
A.V. Nebeker, R. Bruce Bury
Using resampling to assess reliability of audio-visual survey strategies for marbled murrelets at inland forest sites
Marbled Murrelets (Brachyramphus marmoratus) are threatened seabirds that nest in coastal old-growth coniferous forests throughout much of their breeding range. Currently, observer-based audio-visual surveys are conducted at inland forest sites during the breeding season primarily to determine nesting distribution and breeding status and are being used to estimate temporal or spatial trends in mur
Authors
Patrick G.R. Jodice, S.L. Garman, Michael W. Collopy
Using transplants to measure accumulation rates of epiphytic bryophytes in forests of western Oregon
We sought a simple and effective transplant method that could be used to measure biomass accumulation rates of epiphytic bryophytes. Trials were carried out in the Pseudotsuga menziesii-dominated forests of western Oregon. We tested multiple transplant methods over a 13-month period while comparing accumulation rates of Antitrichia curtipendula (Hedw.) Brid. and Isothecium myosuroides Brid. among
Authors
A.L. Rosso, Patricia S. Muir, T. Rambo