Stand establishment plays a significant role in the development
and yield of winter wheat (Triticum aestivum L.). Availability of
soil moisture to the germinating seed is one of the most critical
factors affecting stand establishment. Water injection is a method
of applying supplemental moisture to the soil in direct contact...
Native flood meadows are important for hay production and winter feeding areas in many western states. With the introduction of meadow foxtail (A lopecurus pratensis L.) and other new species, the botanical composition of the meadows has been steadily changing. With shifting priorities occuring on public lands, these flood meadows,...
Desert plant communities are among the most sensitive to changes in soil water conditions. In areas with shallow aquifers, it is important to understand both the effects of groundwater alterations on vegetation and how changes in surface-soil water affect plant water uptake. Studies in arid environments have evaluated the effect...
Under adverse soil moisture conditions a critical water stress
or water potential develops in the plant and productivity is reduced,
or in extreme cases, terminated. Research to determine the soil
moisture status for maximum production of specific crops has been
conducted for decades. The results have done much to increase...
Published March 1943. 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
Approximately 3-4 month-old containerized Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings (seed zone 262 and 271) were subjected to 6 moisture stress treatments (65, 53, 41, 29, 17 and 7% soil water content by volume of dry soil) starting July 4 to September 22, 1991 at Forest Research Laboratory's greenhouse at...
Significant post planting mortality of young conifer seedlings often occurs on drought prone sites because seedlings fail to either establish, or maintain favourable water relations. Survival is contingent upon growth which occurs when turgor pressure is above a threshold level. Since growth after planting is influenced by nursery cultural practices,...
Water use restrictions are continuing to have an impact on the way turf is managed today and will be managed in the future. The objective of this research was to evaluate the irrigation requirements of ten newly established cool-season turfgrass species maintained under two different mowing height and nitrogen fertility...
Three Nelder plots of 3-year-old red alder (Alnus rubra Bong) were used for this study at the Cascade Head Experimental Forest, Oregon in the growing season of 1988 at an elevation of 330 meters. Each Nelder plot
represented a range of densities from 238 to 101,219 trees per hectare. The...
This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well...
Introduction The Willamette River Flow Project The Nature Conservancy (TNC) and the U. S. Army Corps of Engineers (USACE) are collaborating on a project to determine environmental flow requirements for the Willamette River and its tributaries and to design and test alternative flow releases from the dams that can meet...
No-tillage winter wheat (Triticum aestivum L.) grown in a
wheat-fallow cropping system has consistently produced lower grain
yields than conventionally tilled soils in the semiarid Pacific
Northwest. A 2-year study was conducted in a long-term tillage trial
at Moro, OR to determine factors responsible for differences in wheat
growth and...
Effects of bedrock water availability on growth and ecophysiology of Douglas-fir [Pseudotsuga TnenzieSii (Mirb.) Franco) and Pacific madrone (Arbutus inenziesii Pursh) were studied in southwest Oregon in 1990. Bedrock physical features, including bulk density, water holding capacity, and available water capacity, were examined at
different depths from 1.0 to 3.0...
Published September 1966. 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 1968. 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
Several methods of infering plant water stress for
irrigation scheduling are based upon measurements of the
environment in which the plants grow. These measurements
include parameters such as soil water content, air
temperature, pan evaporation and incident radiation. It is
hypothesized that improved estimates of plant water deficit
can be...
Estimations of plant water use can provide great assistance to growers, irrigators,
engineers and water resource planners. This is especially true concerning the introduction
of a new crop into irrigated agriculture. Growing hybrid poplar trees for wood chip stock
and veneer production under agronomic practices is currently being explored as...
A perennial grass grown in strips between the rows of grapevines, with a bare soil herbicide strip under the rows of vines, is a common form of vineyard soil management. Irrigation, though not practiced for grape culture in western Oregon at this time, could be used to supplement the soil...
This study was prompted by the need for improving the efficiency of irrigation systems at the Oregon South coastal areas. Accurate information about evapotranspiration (ET) rates is essential for maximizing the efficiency of irrigation systems. Currently, ET estimates provided by Bureau of Reclamation AgriMet Program are derived from the Kimberly...
Two case studies were designed to study the effects of using off-stream water developments and water gap configurations to modify watering behavior of cattle. There were two objectives: 1) to evaluate an off-stream water source to reduce water quality impacts of grazing cattle on a mountain riparian zone during summer...
Both red (Trifolium pratense L.) and white (Trifolium repens L.) clover
seed yields can be highly variable and low in western Oregon. The objectives of
this study were to: i) determine crop water requirements and supplemental
irrigation timing, and ii) quantify the effects of soil and water status on
inflorescence...
Published May 1931. 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
Provides consumptive use and net irrigation requirements for economically important crops in 27 climatic regions in Oregon. Computations are based on the modified Blaney-Criddle calculation method and climatic database information. Contains tables of: 1) The typical growing seasons of selected Oregon crops by region and 2) Crop water (ETcrop) and...
Veratrum californicum (common name: corn lily) is a wild plant species that grows in the Intermountain West, its range extending from British Columbia to Mexico. Corn lily is of interest because it has the potential to provide pharmaceutical precursors for use in the treatment of cancer. Pharmaceutical companies are currently...
Exotic ponderosa pine (Pinus ponderosa Doug. ex Lawson) plantations are being planted within the natural distribution area of cordilleran cypress (Austrocedrus chilensis (D.Don) Pic. Ser. et Bizzarri) in Patagonia, Argentina. The productivity of these exotic plantations is much greater than that of native forests, suggesting greater water use. Before these...
Laboratory experiments were used to investigate the mechanism
of plant response to water stress by determining the sensitivity of leaf
elongation, photosynthesis and transpiration in young corn plants to a
decrease in leaf water potential.
In initial experiments, 9 day old corn plants were grown at soil
water potentials of...
An adequate stand at the optimum time is an important factor
affecting potential yield and soil erosion control. However, obtaining
adequate stands of fall planted winter wheat in the dryland areas of the
Pacific Northwest is often complicated by marginal seed zone soil
moisture. The purpose of this laboratory study...
A series of experiments was designed to investigate differential
flood-tolerance and the phenomenon of flood-induced stomatal closure
of several fruit tree species. The first two experiments were conducted
with potted plants submerged outdoors 5-10 cm above the soil line.
Plant morphology, growth, leaf conductance (cL), and soil oxygen diffusion
rate...
The use of chemicals such as the triazines (especially atrazine) and mixtures of the triazines and 2,4-D or 2,4,5-T has become almost standard practice in some parts of the world for selectively controlling grasses and other herbaceous weeds to conserve moisture for and/or prevent the smothering of newly-planted conifers. In...
Irrigated agriculture constitutes the greatest consumptive water use globally, so that irrigation efficiency measures are an important part of global efforts to best utilize this limited resource. However, greater irrigation efficiency must be achieved while simultaneously maintaining or increasing crop yields and farming profitability. Incremental water use decisions are made...
This study examined features of deep pool (>0.8 m mean depth) used by
adult summer steelhead in Steamboat Creek (1991-1992). Steamboat Creek had
a heterogenous thermal profile, with some segments exceeding preferred
temperature of steelhead. Deep pools were scarce (4% of the total habitat units)
and 39% of them were...
The major objectives of this study were an
evaluation of the Meteorological Office Rainfall and
Evaporation Calculation System (MORECS) evapotranspiration
(ET) model using the Penman-Monteith equation and
comparison of the MORECS and measured surface resistance.
Meteorological, soil and plant parameters were measured in
an alfalfa field over two growing seasons....
Coffee trees growing in the Kona district of Hawaii
were treated with different concentrations of either BA,
GA3, or Promalin, and pruned at the time of flowering. No
significant differences in the flowering and fruit ripening
pattern were found. High concentrations (100 mg/1) of
growth regulators decreased fruit fresh weight....
Faidherbia albida is a widely used tree species in sub-Saharan Africa, promoted for use in parkland agroforestry systems based on reduced competition with crops during the rainy season from its reverse leafing phenology and positive effect on soil fertility. Increases in growth and yield have been reported for crops such...
Flexible cropping systems allow for an opportunistic change in an established rotation. Plant-available soil water is the most reliable indicator of potential yield.
Field investigations were implemented to study the interrelationships between streamflows and salmonid production during the summer-fall low flow period in two natural stream channels. Elk Creek, near Cannon Beach in Clatsop County, was the site selected for intensive investigation.
Construction of streamflow control and diversion facilities was completed in November...
This report presents data collected during the first full field season of
a project designed to examine the streamflow requirements of juvenile salmonids. Problems encountered in the original design, changes made in the design and the application of the expected results are discussed.
This archive is a compilation of SWMM input files and STELLA models, augmented by R scripts to perform various processing for sensitivity analysis, data import / export, plot generation and computation of various summary outputs. Part I is the sensitivity analysis of a SWMM model representative of the case study...
Most studies of bacteria in water have concerned public health; little attention has been given to organisms which are indigenous to
the aquatic environment. Myxobacteria are known to occur in soil,
in the marine environment, and several have been studied in relation
to diseases of salmonid fishes. However, little information...
Concern about noise pollution has swept the country.
People are conscious of their environment and are trying to
preserve or to improve it. When the City of Lake Oswego
selected a site for their water treatment plant, they had
to assure the neighbors that it would not increase the
ambient...
Published January 1982. 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
This thesis research examines the effects of film-forming antidesiccants applied to dormant pondexosa pine (Pinus ponderosa Dougl.) seedlings after being lifted and to actively growing seedlings. The basic proposition was that antidesiccants would have a positive effect on reducing water loss in ponderosa pine seedlings. In order to evaluate the...
Comparisons were made of the tissue water relations, stomatal conductance and growth of grand fir (Abies grandis), white fir (Abies concolor) and their hybrids growing in a western Oregon plantation. The grand fir were naturally-regenerated trees native to the study site. White fir and hybrids were the progeny of controlled...
The relationships among total water potential (psi), osmotic potential ([pi]), pressure potential (P), and relative water content (R*) were determined during four consecutive soil drying cycles for shoots of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings. In each cycle, seedlings were sampled for pressure-volume determinations as soil water was depleted gradually...
The principles of continuum mechanics provide a consistent
framework for the derivation of mathematical statements describing
transport of water and solute, and growth in plant tissue. These
derivations are based upon the explicit consideration of the tissue as
a mathematical continuum composed of a cell wall matrix, water, and
solute...
Understanding the tradeoff between water use and productivity is critical for modeling growth of intensively managed Douglas-fir forests in the Pacific Northwest. Evapotranspiration is closely linked to carbon dioxide intake during the process of photosynthesis. However, summer drought characterizing the growing season in this region imposes a limit on carbon...
I studied the water relations traits, twig conductivity, C'3 isotopic composition,
and wood density of three conifer and five angiosperm species in western Oregon. This
study took place from spring 2002 to fall 2003 on four sites. Species were selected to
represent the diversity of drought tolerance of woody plants...
Evaluation and sensitivity analysis of a soil-water---
atmosphere-plant simulation model, SWATRE, developed by
Feddes et al (1978) in The Netherlands was conducted.
The evaluation was performed with the observed data
obtained by Cuenca (1978) for three different irrigation
levels in UC82 variety tomato fields in Davis,
California. SWATHE requires about...
CTSPAC is a mathematical model for coupled transport of water, solutes, and thermal
energy in the soil-plant-atmosphere continuum. The mathematical structure consists
of coupling a model for transport through soil (soil submodel) to one for xylem and phloem
transport (plant submodel). The modeling approach is based on discrete space conceptualization...
One of many important physical properties that must be known
to understand transport phenomena in soils is pore size distribution.
Presently the pore size distributions of soils are most commonly
obtained from soil water characteristic curves. The soil water characteristic
curves are usually obtained by the pressure plate technique.
It...
The OSU/APEX thermal hydraulic test facility models the passive safety systems
of the Westinghouse AP600 advanced light water reactor design. Numerous experiments
have been performed to test these systems, the one of focus here is the station blackout
scenario. This experiment simulated the complete loss of AC power to all...
Published January 1973. 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
Xylem anatomy is a strong determinant of water transport efficiency and is therefore an important component of the overall hydraulic strategy of any woody plant.
However, in addition to its role in water transport, xylem also serves in mechanical
support, and these two functions may represent conflicting design requirements. To...
Water treatments were applied to young ponderosa pine trees in the Eastern Cascades, Oregon during the 2003 growing season, and shade treatments were applied during the 2003 and 2004 growing seasons to understand how photosynthesis and soil respiration, particularly the root/rhizosphere fraction (R[subscript rrh]), would respond to increased moisture availability...
Understanding how the interactions and feedbacks between plant function, climate, and soils ultimately affects the terrestrial water balance and subsurface flow processes is major challenge in scientific hydrology. This dissertation summarizes the findings of a manipulative climate warming experiment, an observational field study that utilized stable-isotope tracers, and associated modeling...
Water availability is a critical limiting element in semi-arid ecosystem productivity and presents particular challenges in Sahelian countries such as Senegal. The landscapes are characterized by the presence of two common semi-arid shrubs (Piliostigma reticulatum and Guiera senegalensis), both of which may be important hydraulic regulators in these water-limited ecosystems....
Coastal vegetation dampens waves which can provide benefits to the local area, but existing literature shows large variations in the degree of wave height attenuation depending on plant properties and wave conditions. Better knowledge of how to predict the wave height decay accurately in different types of vegetation may help...
In deciduous species, water exits stems mainly through leaf traces
attached to the outer growth ring and yet we know that water ascends
throughout the entire cross-section of the sapwood. There is an increasing
amount of information on sap flow and sapwood hydraulic properties from
separate studies, but little information...
The Warm Springs Reservation is located in central Oregon. Livestock production consists of beef (commercial with an Angus, Horned Hereford base) and roping (Corriente and Longhorn) cattle and horses that forage most of the year on the open range within reservation boundaries. Forage consists of annual and perennial grasses and...
Field experiments were conducted with cauliflower (Brassica oleracea var.
botrytis cv. Snowball Y ) to determine crop development, yield, quality and
maturity response to various seasonal water levels, and to specific water stress
timing in relation to curd initiation. The effects of nitrogen rate, timing, and
source and the application...
Uptake, in-plant transport, and local accumulation of organic
chemicals by plants are influenced by plant characteristics, properties
of the chemical and the soil, and by environmental conditions. Evaluations
of plant contamination required by regulatory agencies cannot be
made experimentally for the many thousands of xenobiotic chemicals in
existence or being...
The role of riparian forests in maintaining temperatures of headwater streams is well established and is a foundation of forest practice rules designed to protect streamwater quality. However, detailed investigation is still needed quantifying specific characteristics of stream systems that affect streamwater temperature including riparian features, stream morphology, and subsurface...
The nuclear industry has long relied upon bounding parametric analyses in predicting the safety margins of reactor designs undergoing design-basis accidents. These methods have been known to return highly-conservative results, limiting the operating conditions of the reactor. The Best-Estimate Plus Uncertainty (BEPU) method using a modernized version of the Code-Scaling,...
Waste water lagoons have been used as a satisfactory means of
treating domestic and certain industrial wastes in many parts of the
country. Many of the parameters that govern the applicability of this
type of treatment process are climatic in nature, and critical evaluation
of local climatic conditions, as well...
Evaluation of meta-sedimentary bedrock as a source of stored water available
to plants in a mediterranean climate is presented based on: root length distribution
(RLD), root morphology, rock water holding capacity and seasonal pattern of water
depletion. Studies were performed in southwestern Oregon under young stands of
whiteleaf manzanita, ponderosa...
Diurnal changes in stem circumference at the 1954 and 1963 internodes of a 22-year-old Douglas-fir were monitored using automated
band dendrometers. Determinations of internal tree water potential and estimates of transpiration were used to characterize the water status of the tree. Environmental monitoring included the measurement
of air temperature along...
During spring and early summer hydropower projects are often forced to spill water through their spillways due to increased river flows of the runoff season. Flows which are directed through spillways--instead of through turbines--contain a substantial amount of energy. Stemming from the high energy content, spillway flows entrain air at...
Preliminary results of a comprehensive study of hydraulic fluctuations in Douglas-fir (Pseudotsuga menziesii) stems in response
to plant water status and environment are presented. Diurnal changes in stem circumference near DBH of a dominant Douglas-fir were monitored using automated band dendrometers. Measurements of transpiration rate, internal moisture stress and stomata...
In many regions of the world, a significant portion of the surface water originates in mountain headwaters where the timing and magnitude of streamflow is largely dictated by the seasonal storage of precipitation as snowpack and long-term storage as glaciers. Accumulation, persistence, and melt of snow and ice are functions...
The Upper Grande Ronde River Watershed in northeastern Oregon is considered important habitat for threatened stocks of chinook
salmon (Oncorhynchus tshawytscha). Documented reductions in channel complexity and riparian vegetation within the watershed have increased concern over loss of viable habitat. An important component of salmonid habitat is stream temperature during...
In the Coniferous Forest Biome, many of the understory as well as
dominant plants are evergreen and thus water uptake is a year around
process. The flow of water from the soil through plants to the atmosphere
affects the entire forest ecosystem. As water is evaporated, it absorbs
heat and...
Riparian areas in the arid western United States are critical ecosystems that have been severely degraded by a variety of land and water uses over the last 100 years. In this study, the composition and structure of floodplain vegetation along the Lower Owens River in eastern California was quantitatively described...
This PhD dissertation describes and evaluates a geographical analysis of candidate areas for siting nuclear plants utilizing a wet cooling tower in the Columbia River Basin (CRB). It focuses on the analysis of water availability for cooling and how it may be limited by climate change effects on river streamflow....
This project was a proof of concept of the use of the RAVEN software, a tool developed for the Risk Informed Safety Margin Characterization (RISMC) approach, with RELAP5-3D. This novel approach combines older probabilistic and mechanistic approaches to look at how and why the complex systems of a nuclear power...
Until the 1930s, flows of the Colorado River maintained approximately 781,060 hectares of wetlands in its delta. These wetlands provided important feeding and nesting grounds for resident and migratory birds as well as spawning and protection habitat for many fish and other invertebrate species. However, the Delta's wetlands started to...
During the summer of 1971, diurnal patterns of water status were monitored in Acer circinatum. Measurements of transpiration rate, internal moisture stress, and relative leaf resistance were used to characterize
the water status of the tree. For the days examined, the diurnal and seasonal
fluctuations of water status in relation...
The state of Oregon has two distinct climate types bisected by the crest of the Cascade Mountain range. The western side of the Cascades experiences high levels of precipitation and mild temperatures due to the maritime influence of the Pacific Ocean, while the eastern side lies in the rain shadow...
Measurement of plant moisture stress of 1-2 m understory conifers
was made in "reference stands" on the H. J. Andrews Experimental
Forest in 1970-1972. Maximum stress each year (measured between midnight
and dawn) is closely correlated with the position of each community
along one axis of an ordination of the...
I tested the hypothesis that there is a correlation between inundation period and net primary production (NPP) in estuarine salt marshes through an observational experiment at South Slough National Estuarine Reserve, Oregon. I estimated primary production and inundation period for selected monotypic plant communities in (1) a naturally restored wetland...
Emissions largely associated with the combustion of fossil fuels and agriculture has caused elevated atmospheric deposition of nitrogen (N) and sulfur (S) throughout much of the developed world. Increased atmospheric deposition of N and S can lead to soil and surface water acidification and affect forest soil nutrient supply. The...