Published January 1955. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published March 1956. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published January 1957. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published June 1960. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published July 1965. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
The spatial distribution of plankton is highly aggregated, so one might expect that a vertically migrating animal enters a biotic environment that is markedly different each evening and that the changes in environment between daylight periods spent at depth are equally great. To measure the extent of these changes, as...
Axenic cultures of 25 species of unicellular marine algae were tested for their ability to utilize nine common amino acids, supplied at high concentrations in batch culture, as a nitrogen source; most species were able to use several amino acids, although growth was often slower than on nitrate nitrogen. The...
An attempt has been made to interbreed populations of Acartia clausi from Woods Hole, Massachusetts, and Yaquina Bay, Oregon. Individuals from these populations are morphologically similar, but differ somewhat in size. Cultures from both sources produced many successive generations in the laboratory, but interbreeding with production of viable offspring did...
The seasonal variation in the alongshore velocity field is inferred from direct current observations made over the Oregon continental shelf at various locations and irregular intervals since 1965. Monthly mean currents are computed and compared with earlier studies to give a description of the seasonal variation in the alongshore currents....
Particle size distributions (8-105-μm diameter), chlorophyll a, and particulate carbon
were measured off the Oregon coast during July 1973. The particle counts were transformed
to volume concentration and then subjected to characteristic vector analysis.
Ninety-two percent of the variance was accounted for by linear combinations of the first
two characteristic...
Stratified bongo net samples taken at depths between 0 and 500 m at Ocean Station “P” in the subarctic Pacific in early July 1971 have been analyzed to determine the vertical structure of the zooplankton community. Distributions for 99 categories of animals have been grouped by factor analysis into five...
Seasonal variations in the hydrography of the waters over the continental shelf off Oregon were observed in a set of hydrographic data collected along 44º39′N at intervals of a few weeks to a few months from 1961 through 1970. The temperature is determined only partly by the local heating and...
Several species of the copepod genus Acartia are shown from existing data to complete each molt-to-molt phase of the life cycle in a constant time period. This molting pattern is termed isochronal development. Increase in mass at each stage is a nearly constant fraction of the weight at the beginning...
Uptake of [14C]glycine by various size fractions of natural plankton communities was measured to determine if phytoplankton can compete effectively with other members of the plankton community for the free amino acids in seawater. The simultaneous occurrence of glycine uptake, plant pigments, and photosynthetic activity in the same size fractions,...
Horizontal transects of fluorescence measurements have been used extensively to investigate phytoplankton patchiness. Variance spectra have been calculated from these data, thus quantifying spatial heterogeneity as a function of length scale. Analysis of such fieldwork and associated theoretical investigations is based on the assumption that horizontal patchiness is isotropic. Three...
Using 15N-labeled NH4+, we assessed the time-course of NH4+ uptake, the parameters of saturation kinetics, and the rates of incorporation of NH4+ into trichloroacetic acid-insoluble material by Chesapeake Bay phytoplankton. The amount of NH4+ taken up by the phytoplankton increased linearly with time for 2 h for all samples growing...
The uptake of methylammonium (MA) by Chesapeake Bay phytoplankton was measured in short term experiments by using the 14C radioisotope. This uptake was inversely related to ambient NH4+ concentrations, and the specificity for uptake of both substrates was demonstrated by competitive inhibition. At stations with low ambient NH4+, MA uptake...
Chlorophyll-temperature profiles were measured across Lake Tahoe about every 10 days from April through July 1980. Analysis of the 123 profiles and associated productivity and nutrient data identified three important processes in the formation and dynamics of the deep chlorophyll maximum (DCM): turbulent diffusion, nutrient supply rate, and light availability....
Rates of molting of a specific copepodite stage can be determined by sorting the stage from a new collection, waiting, then counting the number that have molted to the next stage in the interval. In principle, stage duration can be determined as the inverse of the measured rate, and molting...
The western states include a complex combination of geological, topographical, climatic, and vegetative features. The region extends through 1900 km of latitude and contains three major north-south, storm-directing mountain systems. Most of the region is arid (annual precipitation < 50 em); however, sizeable agriculturally important areas west of the Cascade...
The concentration of dissolved molybdenum has been determined in several profiles from the Northeast Pacific Ocean. The salinity-normalized concentration is essentially constant in all open-ocean samples (107 nM, lσ = 2.5 nM). The dissolved distribution is not significantly affected by biological cycling.
Bacteria and algae isolated from a wastewater oxidation pond were inoculated onto opposing surfaces of double-layer agar plates (Lutri plates) to determine the usefulness of such plates for studying microbial interactions. The altered growth characteristics of various algae depending on the species of bacteria on the adjacent medium surface indicated...
The relative contribution of various inorganic and organic forms of nitrogen to the nitrogen requirements of picoplankton was examined with 15N tracers. Size fractionation was used to measure uptake by <1-μM size microorganisms, and inhibitors of protein synthesis were used to separate procaryotic from eucaryotic nitrogen uptake, Picoplankton utilized mainly...
Rates of sediment community oxygen consumption determined in situ are compared to fluxes predicted from oxygen microelectrode gradients measured in cores from ~3,750-m water depth in the eastern North Pacific. Oxygen concentrations decrease exponentially over > 1.5 cm and suggest that organic matter in the sediments is degraded most rapidly...
Small, aloricate ciliates with equivalent spherical cell diameters <20 µm (biovolume <4,000 µm3) compose, on average, 4–57% of the total biomass of heterotrophic (apochlorotic) nanoplankton in diverse marine systems. Biomass production of nanoplanktonic ciliates in a southeastern U.S. estuary was also a significant part of the total production of heterotrophic...
Uptake of nitrogenous nutrients by microplankton off the Washington and Oregon coasts was measured during the 1985 upwelling period. Nitrogen uptake rates in low-NO3- waters (<5 μM) were 0.020–0.258 μmol N liter-1 h-1 and were primarily supported by regenerated nitrogen (71% of total uptake). Nitrogen uptake rates in high-NO3- waters...
Aerobic oxidation is important in the cycling of methane in the sediments of Lake Washington. About half of the methane flux from depth is oxidized to CO, in the upper 0.7 cm of the sediments and the remainder escapes into the water column. In terms of the total carbon budget...
Diel periodicity in NH4+ uptake and regeneration in the nutrient-rich environment of the oceanic subarctic Pacific was examined. Surface water was incubated in large shipboard microcosms that allowed repeated sampling of the planktonic community for NH4+ cycling rates, bacterial production rates, and population densities of the dominant autotrophs and heterotrophs....
An expression is derived for the rate at which the diffuse attenuation coefficient for vector irradiance approaches its asymptotic value in a homogeneous medium. The asymptotic approach rate is shown to be a function of boundary conditions at the surface and the asymptotic diffuse attenuation coefficient which is an inherent...
Thirty-two chemoheterotrophic bacteria were isolated from unsaturated subsurface soil samples obtained from ca. 70 m below land surface in a high desert in southeastern Idaho. Most isolates were gram positive (84%) and strict aerobes (79%). Acridine orange direct counts of microbes in one subsurface sample showed lower numbers than similar...
A procedure has been developed to optimize designs of metal-clad post-frame buildings using an expert system. The novel part of the study is the development of a procedure that extends the solution of an engineering problem from a conventional algorithmic Computer Aided Design (CAD) program to be used by the...
The virus-encoded proteins of tobacco etch virus (TEV), a plant potyvirus, arise by proteolytic processing of
a large polyprotein precursor. The TEV genome codes for two proteinases, a 49-kilodalton proteinase and
helper component proteinase (HC-Pro), which cleave the polyprotein at specific sites. The only known cleavage
event catalyzed by HC-Pro...
The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even greater in...
A temporal record of oxygen and NO3- concentrations in the bottom water of the Santa Barbara Basin indicates that outside waters spill over into the basin seasonally. It is proposed that an annual bottom-water cycle leads ultimately to varve production.
As evidence in support of a benthic mechanism for varve...
Seasonal and diel changes in nutrient concentrations and nitrogen assimilation rates were used to assess the effects of NH4+ on NO3- assimilation. Surface-water NO3- concentrations ranged from 6 to 17 μM while NH4+ concentrations ranged from 0 to 0.4 μM. Total N assimilation ranged from 84 to 732 nM d–1...
The RNA genome of tobacco etch virus (TEV), a plant potyvirus, functions as an mRNA for synthesis of a
346-kilodalton polyprotein that undergoes extensive proteolytic processing. The RNA lacks a normal 5' cap
structure at its terminus, which suggests that the mechanism of translational initiation differs from that of a...
A general procedure is presented for calibrating a model
for rainfall erosivity based on daily rainfall. The approach
is based on probability distributions of wet-day
precipitation amount and monthly erosivities which are
inferred from published data summaries. The calibrated
model was tested by comparisons with erosivities
computed from hourly precipitation...
It has been suggested that production in offshore waters of the subarctic Pacific is limited by availability of dissolved Fe. Although that is not yet adequately established, the functional consequences of the limitation (if it exists) can be characterized from the results of the Subarctic Pacific Ecosystem Research (SUPER) program....
A comprehensive, joint Soviet-American study of the chemistry of Lake Baikal, the world’s deepest (1,632 m) lake, was carried out in July 1988. In this paper, we report the major, minor, and preliminary trace element concentrations for three profiles obtained at or near the deepest and central part of the...
The pentacyclic tritcrpene 17β(H), 21β(H)-hop-22(29)-ene (diploptence) occurs in sediments throughout the Columbia River drainage basin and off the southern coast of Washington state in concentrations comparable to long-chain plantwax n-alkanes. The same relationship is evident for diploptene and long-chain n-alkanes in soils from the Willamette Valley. Microorganisms indigenous to soils...
The potential for particle size-dependent bioturbation rates was experimentally tested at 1,240 m in the Santa Catalina Basin (eastern Pacific). Spherical glass bead tracers in five size classes (8- 16, 17-31, 32-62, 63-125, and 126-420 μm) were spread over the sediment surface and tube cored 997 d later. Downcore concentrations...
Theoretical scattering computations are performed on a phytoplankton model consisting of three
concentric spheres. The outer sphere represents the wall, membrane, or frustule and is assigned a
relatively high index of refraction with no absorption. The middle layer represents the chloroplasts
and is assigned a relatively low index of refraction...
Active inputs of thermally and chemically enriched fluids at the bottom of Crater Lake create small vertical and horizontal heterogeneities in the deep-lake temperature and salt distribution. Using an internally recording CTD and a precise definition for salinity as a function of in situ conductivity and temperature, we assess the...
Metal-plate-connected wood trusses with semi-rigid joints were investigated by the matrix method of structural analysis. The element-stiffness matrix and fixed-end forces of an individual member with one or both ends semi-rigid were derived as modifications of the idealized cases. The case of unequal elastic connections at two ends of a...
Probability density functions (normal, lognormal, and three-parameter Weibull) were used to characterize strength data for three different types of metal-plate-connected wood truss joints (web at the bottom chord, tension splice, and heel). Modulus of elasticity (MOE) of the lumber used to fabricate the joints was also characterized. A probability-plot technique,...
Grazing by phagotrophic flagellates and ciliates is a major source of mortality for bacterioplankton in both
marine and freshwater systems. Recent studies have demonstrated a positive relationship between clearance
rate and prey size for bacterivorous protists. We tested the idea that, by selectively grazing the larger (more
actively growing or...
We looked at the influence of temperature and salinity on the absorption coefficient of water with emphasis on the red and near-IR portions of the spectrum. The absorption coefficient of pure water was found to have a strong dependence on temperature and little dependence on salinity near the harmonics of...
We compared estimates of bacterial abundance and of average bacterial cell size based on direct counts of bacterioplankton cells stained with acridine orange (AO) or 4’-6-diamidino-2-phenylidole (DAPI). Estimates of numbers mll–1 of bacteria stained with DAPI were on average 70% (range 57–82%) of bacterial counts made with AO as the...
Algal chlorophyll and carotenoid distributions were measured periodically in the euphotic zone of Sta. ALOHA (22º45′N, 158º00′W) between February 1989 and October 1991 to document the variability in phytoplankton abundance and composition. The annual mean depth-integrated (O-200 db) concentration of Chl a displayed significant interannual variability. Seasonal patterns in Chl...
We made stable and rapid-responding pH and pCO2 microelectrodes. The pH microelectrode has a ~100-μm-diameter half-sphere bulb tip of pH glass, and the pCO2 sensor has a 200–300-μm-diameter silicone-membrane covered tip. Because the pH microelectrodes have electrical resistances that arc > 1O[to the tenth] ohms, all electrical connections are kept...
Chlorophyll a concentrations were measured as a function of depth from 28 to 48°N along 152°W in March 1991 with Whatman GF/F and 0.2‐µm Nuclepore filters. Surface Chl a concentrations measured with 0.2‐µm Nuclepore filters were up to fourfold higher than those measured with Whatman GF/F filters. The largest difference...
A method for predicting oceanic productivity from remotely sensed diffuse attenuation (488 nm) and
surface chlorophyll concentration is presented. The method uses a climatological approach which consists
of applying a set of regressions for each region and season to yield the depth of the chlorophyll maximum,
the exponential slope of...
On Oregon coastal rocky shores, filter‐feeders were relatively abundant and macrophytes were relatively scarce at Strawberry Hill, whereas opposite abundance patterns occurred at Boiler Bay. To determine whether nearshore oceanographic differences were associated with these patterns, we made shore‐based measurements of nutrient and Chl a concentrations. We used a three‐level...
The uptake rates of nitrate, ammonium, and urea were measured with a ¹⁵N technique during seven cruises in the marginal ice zone (MIZ) in the Barents Sea in 1984–1988. The results from all the cruises were pooled to obtain means for the prebloom, bloom, transition, and postbloom periods. New production—nitrate...
Despite its widespread use, forest health is frequently used without a clear definition, making its application to forest management difficult. Where the term has been defined (McIntire 1988, Monnig and Byler 1992, USDA Forest Service 1992, USDA Forest Service I993a), alternative definitions and viewpoints of forest health have not been...
The term "forest health" is being increasingly used in the context of forestry and natural resource management. For example, the term has been the subject of several articles in the JOURNAL oF FORESTRY and a recent Society of American Foresters task force report, Sustaining Long- 7•rm Forest Health and Productivity...
Detailed upper ocean profiles of 234Th in dissolved (< 10,000 Daltons), colloidal (10,000 Da–O.45 μm), and particulate (>0.45 μm) forms were measured at a station (46º45′N, 126ºW) in the northeast Pacific Ocean. On average, dissolved, colloidal, and particulate 234Th accounted for ~78, 12, and 10% of the total 234Th in...
PN-specific, absolute, and Chl a-specific nitrate uptake rates were measured during two upwelling seasons and one winter off Oregon. Although PN-specific and absolute uptake rates showed no dependence on nitrate concentration, Michaelis-Menten kinetics applied when the uptake rates were normalized to Chl a. Chl a-specific nitrate uptake rates were saturated...
Tobacco etch virus (TEV) encodes three proteinases that catalyze processing of the genome-encoded polyprotein.
The P1 proteinase originates from the N terminus of the polyprotein and catalyzes proteolysis between
itself and the helper component proteinase (HC-Pro). Mutations resulting in substitution of a single amino
acid, small insertions, or deletions were...
In situ attenuation (488 and 660 nm), absorption (488, 676, and 750 nm), backscattering (at 488 nm), and
stimulated fluorescence were determined as functions of depth in oceanic and coastal waters off Oregon,
using both commercial instruments and recently developed prototypes. The inability to perfectly constrain
scattered light in these...
The tobacco etch potyvirus (TEV) polyprotein is proteolytically processed by three viral proteinases (NIa,
HC-Pro, and P1). While the NIa and HC-Pro proteinases each provide multiple functions essential for viral
infectivity, the role of the P1 proteinase beyond its autoproteolytic activity is understood poorly. To determine
if P1 is necessary...
Flux estimates show that upward mixing of the deep-water nitrate pool accounts for more than 85% of the total new nitrogen input to the euphotic zone of Crater Lake. Because measured primary productivity (360 mg C m-2 d-1) is 10–30 times higher than a level supported solely by the input...
Small temporal and spatial variations in the distribution of dissolved oxygen in Crater Lake, Oregon, are used to estimate the mean age of the lake’s deep water, the flux of labile organic carbon to the deep lake, and the influence of hydrothermal activity on the concentration of dissolved oxygen within...
A commercially available, three-dimensional finite-element analysis software was used to model the load-displacement
behavior of metal-plate-connected (MPC) joints in wooden trusses. Model features included consideration
of material properties, teeth-to-grain-to-direction-of-force orientation, wood-to-wood interaction, and gaps between wood
members. To simulate wood-to-plate interaction, the main feature of the model, each tooth of...
A mutational analysis was conducted to investigate the functions of the tobacco etch potyvirus VPgproteinase
(NIa) protein in vivo. The NIa N-terminal domain contains the VPg attachment site, whereas the
C-terminal domain contains a picornavirus 3C-like proteinase. Cleavage at an internal site separating the two
domains occurs in a subset...
The applicability of anhydrous milkfat fractions in edible films and coatings was determined through moisture barrier, penetrometer, and stress-relaxation testing. Industrial milkfat fractions were compared along with tripalmitin:anhydrous milkfat blends which simulated milkfat fractions having different melting points. The water vapor permeability (WVP) was determined gravimetrically using a modified ASTM...
Iron is recognized as a key element regulating primary production in large regions of the ocean, but nothing is known of its direct effect on higher trophic levels. Two species of heterotrophic protozoa were thus fed iron-rich and iron-poor bacterial prey and their growth and metabolism examined. Maximum growth rates...
We present observations of the evolution of a deep-mixing event in a deep, temperate lake. The observations were obtained from thermistors mounted on a long-term mooring in the lake. The event seems to have originated near 150-m depth and resulted in a plume or layer of cold water from the...
A Russian–American fieldwork effort on Lake Baikal, its tributaries, and surrounding hot springs was undertaken in June–July 1991. Here we report on aspects of major ion (Ca2+, Mg2+, Na+, K+, Alk, Cl–, SO42–) and several minor and trace element (Li isotopes, Sr isotopes, Ba, Al, V, Cr, Ni, Cu, Ge,...
We have developed and successfully collected data with a unique, bottom-transecting vehicle (ROVER) that permits the first long time-series measurements of sediment community oxygen consumption (SCOC). This instrument has the, following capabilities: (1) it operates as an autonomous, free vehicle on the sea floor to 6,000-m depth for periods up...
A previously developed, three-dimensional (3-D) finite-element (FE) joint model and several two-dimensional
(2-D), beam-element based FE models with different joint-stiffness assumptions (pinned, rigid, and semi-rigid) were used
to analyze the full-scale behavior of a metal-plate-connected (MPC) wood scissors truss. The truss displacement and
force results were investigated for sensitivity with...
The impact of population abundance on the deposit-
feeding rate of Mediomastus ambisetu (Capitellidae:
Polychaeta) was studied in still-water laboratory experiments.
Mean individual pellet production rate (mg worm¯¹ d¯¹) decreased
monotonically with increasing worm abundance in the
range of 6.5 X 10³ to 1.3 X 10⁵ worms m¯². Worms fed...
Storage lipids of fifth copepodites (C5) of Culanus finmarchicus from Georges Bank and the Gulf of Maine were quantified from video images and by Iatroscan (thin-layer chromatography with flame-ionization detection, FID). Oil withdrawn from the oil sac by micropipette was pure wax ester (WE); triacylglycerols (TAG) were elsewhere in the...
Submillimeter depth distributions of total dissolved inorganic carbon (DIC) were derived from pH and PCO2 profiles measured with microelectrodes in an organic-rich, laboratory-maintained sediment. The DTC profiles were used to calculate diffusive fluxes of DIC across the sediment-water interface. In two experiments, the calculated diffusive fluxes fell within ±50% of...
Based on a long-term set of observations and measurements at a station in the subtropical North Pacific Ocean, it now appears that contemporaneous rates of primary production in low-nutrient open ocean regions and perhaps in the ocean as a whole may be greater than had been considered in field studies...
What value does federal designation add to open space resources that are not all federally owned and managed? Over the years the federal government, under the auspices of the National Park Service and USDA Forest Service, has designated trails across the United States as National Recreation Trails. A survey of...
The bacteria colonizing geologic core sections (attached) were contrasted with those found suspended in the groundwater (unattached) by examining the microbiology of 16 depth-paired core and groundwater samples using a suite of culture-independent and culture-dependent analyses. One hundred twenty-two meters was continuously cored from a buried chalcopyrite ore hosted in...
Bench scale column studies were used to examine the partitioning of microorganisms between groundwater
and a geologic medium and to examine the effect of hydrogeology (i.e., porous- versus fracture-flow) on
organism partitioning. Replicated columns were constructed with intact basalt core segments that contained
natural fractures and with the same basalt...
This study assesses the role of the atmospheric dry fallout as a source of new nitrogen and phosphorus to the surface Levantine seawater. Leaching experiments of inorganic nitrogen (LINO-3, LINH+4) and phosphorus (LIPO4), using SE Mediterranean surface seawater, were performed on 41 aerosol (hereafter dust) samples collected on Whatman 41...
Plum pox virus (PPV) is a member of the Potyvirus genus that, in nature, infects trees of the Prunus genus.
Although PPV infects systemically several species of the Nicotiana genus, such as N. clevelandii and N.
benthamiana, and replicates in the inoculated leaves of N. tabacum, it is unable to...
Intact core tetraether membrane lipids of marine planktonic Crenarchaeota were quantified in water column-suspended particulate matter obtained from four depth intervals (~70, 500, 1,000 and 1,500 m) at seven stations in the northwestern Arabian Sea to investigate the distribution of the organisms at various depths. Maximum concentrations generally occurred at...
Glucose-dependent growth of the luxCDABE reporter bacterium Pseudomonas fluorescens HK44 was monitored noninvasively in quartz sand under unsaturated-flow conditions within a 45- by 56- by 1-cm two-dimensional light transmission chamber. The spatial and temporal development of growth were mapped daily over 7 days by quantifying salicylate-induced bioluminescence. A nonlinear model...
Microbial communities in cores obtained from methane hydrate-bearing deep marine sediments (down to more than 300 m below the seafloor) in the forearc basin of the Nankai Trough near Japan were characterized with cultivation-dependent and -independent techniques. Acridine orange direct count data indicated that cell numbers generally decreased with sediment...
There is considerable interest in the biogeochemical cycling of cadmium (Cd) and phosphate (PO4) in surface waters, driven in part by the ongoing development of a paleonutrient proxy that utilizes Cd preserved in fossil planktonic foraminifera to determine past PO4 utilization efficiencies in ocean surface waters. The present article reports...
On average, the water column of Lake Superior is undersaturated with respect to dissolved oxygen and supersaturated with respect to carbon dioxide during the summer-stratified period. On the basis of temporal changes in water column dissolved oxygen, we calculate rates of oxygen consumption that range from 0.19 to 0.75 mmol...
Measurements of inherent optical properties (IOP) were conducted over bottoms with different substrates by use
of a sampling package mounted on and operated by a SCUBA diver. It was found that in areas of low ambient
currents the distribution of IOP varies with bottom type in (1) its value relative...
Few studies have examined the partitioning of organic matter in upwelling systems, despite the fact that these systems play a key role in carbon and nitrogen budgets in the ocean. We examined the production and partitioning of phytoplankton-derived organic matter in deck incubations off Oregon during the upwelling season. During...
We isolated a methanogen from deep in the sediments of the Nankai Trough off the eastern coast of Japan.
At the sampling site, the water was 950 m deep and the sediment core was collected at 247 m below the sediment
surface. The isolated methanogen was named Nankai-1. Cells of...
The objective of this study was to evaluate changes in the quantity, quality, and moisture of available forage in a riparian pasture, and shrub utilization by cattle during a 30-d late summer grazing period. A riparian pasture (44.7 ha) in northeast of Oregon was grazed with 30 yearlings (419 kg,...
A study was conducted to determine foraging efficiency of cattle, mule deer, and elk in response to previous grazing by elk and cattle. Four enclosures, in previously logged mixed conifer (Abies grandis) rangelands were chosen, and within each enclosure, three 0.75 ha pastures were either: 1) ungrazed, 2) grazed by...
Genomic libraries derived from environmental DNA (metagenomic libraries) are useful for characterizing
uncultured microorganisms. However, conventional library-screening techniques permit characterization of
relatively few environmental clones. Here we describe a novel approach for characterization of a metagenomic
library by hybridizing the library with DNA from a set of groundwater isolates, reference...
The objective of this study was to compare two techniques for estimating benthic fluxes of nutrients (nitrate, phosphate, and silicic acid) and Ge/Si flux ratios. In situ flux chambers were deployed, and cores were collected and incubated at 9 sites along the California margin in July 2001. Both techniques were...
Hop is a dioecious perennial with female plants grown commercially
for brewing purposes. Parent selection in hop breeding on the basis of
heterotic potential has not been reported in literature even though dominance
has been reported in hops for several economically important traits.
The objectives of this study were to...
The euphotic zone below the deep chlorophyll maximum layer (DCML) at Station ALOHA (a long-term oligotrophic habitat assessment; 22º45′N, 158º00′W) transects the nearly permanently stratified upper thermocline. Hence, seasonal changes in solar radiation control the balance between photosynthesis and respiration in this lightlimited region. Combining profiles of radiance reflectance, algal...
With fire suppression, many western forests are expected to have fewer gaps
and higher stem density of shade-tolerant species as light competition becomes a more
significant influence on stand pattern and composition. We compared species composition,
structure, spatial pattern, and environmental factors such as light and soil moisture between
two...
We adapted a commercially available flow‐injection autoanalyzer (Lachat Quik‐Chem 8000) to measure seawater nitrate concentrations at a rate of nearly 0.1 Hz and phosphate and silicate concentrations at a rate half that. Several minor improvements, including reduced sample‐loop size, high sample flushing rate, modified carrier chemistry, and use of peak...