Limited information is available on the effects of applied spring nitrogen (N) and cultivar on winter canola (Brassica napus L.) production in high-rainfall environments. The objectives of this investigation were: (i) to determine the effects of spring N and winter canola cultivars on seed and oil production characteristics, and (ii)...
With the reauthorization of the 2013 Violence Against Women Act all Title IV higher education institutions will now be required to provide "primary prevention and awareness programs for all incoming students." Yet, more research is needed to find prevention programs that are effective (White House Task Force to Protect Students...
Studies were conducted from 1962 to 1966 to investigate the
effectiveness of several practices in manipulating medusahead
(Taeniatherum asperum (Sim. ) Nevski) infested and/or dominated
ecosystems by releasing competition in favor of perennial grasses.
Several herbicide treatments were evaluated for selective
control of medusahead and cheatgrass (Bromus tectorum L. )...
A species of Ephedra found in southeastern Oregon,
identified as Ephedra viridis Coville is reported of medicinal
value among the American Indian tribes and other
dwellers of that locality in various affections such as
venereal diseases, kidney and bladder disturbances, in
stomach ulcers and abdominal pains, in delayed menstruation,
as...
Blue-striped Brodiaea or Leach's Brodiaea (Triteleia hendersonii Greene var. leachiae [Peck] Hoover, or Brodiaea hendersonii Wats. var. leachiae ) Lily Family (Liliaceae) is found in the foothills of the Siskiyou Mountains of Curry, Coos and Josephine Counties of southwestern Oregon. It is occurs in a variety of habitats including meadow...
In 1959, a large scale grazing study in western Oregon was
initiated to compare the value of perennial ryegrass (Lolium perenne
L.) with subclover (Trifolium subterraneum L.) and tall fescue
(Festuca arundinacea Schreb.) with subclover, and to evaluate common
use grazing on them. The present investigation was undertaken
to determine...
The data used in the design of this hydro-electric
generating station was furnished by Hon. Walter M. Pierce
from a survey conducted by T. R. Barry C. E. in the service
of the Grande Ronde Water Co. during the summer of
1906.
In the preparation of this thesis there were...
Astragalus diaphanus is a rare plant endemic to the
John Day River drainage of north-central Oregon. This
species has several interesting features, including the
dimorphism of its fruit and its geographical isolation from
the two nearest taxonomically related species, which occur
in Colorado. This study addressed the species' distribution
and...
Knowledge of regional-scale patterns of plant community structure and controlling factors is largely qualitative and based on numerous local studies. Data from a subsample of 10,000 field plots were used to quantify and map compositional gradients of woody plant communities across Oregon forests. Canonical correspondence analyses explained 9-14% of the...
Devil's club (Oplopanax horridum (J. E. Smith) Miq.) is an indigenous shrub of the Pacific Northwest, often found in the Tsuga heterophylla (western hemlock)/Devil' s club association in western Oregon. In the same family as ginseng, Devil's club is gaining attention for its medicinal properties. While traditional uses of Devil's...
The relationship between ground vegetation and light intensity under a 60 to 65-year-old Douglas-fir forest was investigated. Biomass and height of ground vegetation were measured and cover was estimated on small sample units (30 centimeters in diameter) on permanent research plots, one-acre in size, on the George T. Gerlinger Experimental...
The purpose of this study was to determine plant species composition, community structure, successional relationships, vegetational development and plant distributions in estuarine salt marshes on the Pacific Coast of Oregon.
Quadrat and transect samples of plant presence and cover, collected from April 1971 - June 1974, were subjected to phytosociological...
Studies were conducted to determine the competitive ability of
medusahead, Taeniatherum asperum (Sim.), for nitrogen when grown in
association with perennial range grass species. The method used to
determine this competitive ability was to compare the dry weight,
percent nitrogen, and total nitrogen of medusahead and perennial
wheatgrass species growing...
The seasonal duration of snow cover is a primary factor influencing the patterns of vegetation in high subalpine and alpine environments, but little is known concerning the responses of plant reproduction and
seedling recruitment to gradients of snow-release. Vegetation patterns of a high subalpine site in the Oregon High Cascades...
For the last fifty years, meadow foxtail (Alopecurus pratensis L.) has been invading native flood meadows throughout the Harney Basin in southeastern Oregon. The expansion of this grass species has been the result of its broad climatic requirements and ability to withstand drought while thriving in saturated soil conditions for...
Biology of Scaptomyza apicalis Hardy (Diptera: Drosophilidae) was studied in
relation to its host, meadowfoam, Limnanthes alba, a recent oil seed crop grown in the
Willamette Valley, Oregon. Populations of flies and larvae were monitored weekly over
three consecutive crop-years beginning in 1996. Yellow sticky traps gave relative
population estimates...
Few landscapes are immune to invasion by exotic plant species. The forested landscape in the western Cascade Range of Oregon appears to have some barriers to invasion, but the extensive road network provides a corridor and habitat for a suite of exotic species to enter and become established. This study...
This guide provides keys, descriptions, and stand tables for 122 native freshwater plant associations (14 forest and woodland, 28 shrub, 78 herbaceous, 2 nonvascular) in northwestern Oregon, based on analysis of data from 1,992 plots distributed throughout the study area. Descriptions are provided for eight other plant associations for which...
Published October 1911. 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
Forest species classifications are becoming increasingly automated as advances are made in machine learning. The algorithms used to identify tree species range from simple decision trees to intricate neural networks, and often excel in accurately delineating tree species. However, complex algorithms can have high input costs, including the cost of...
An experiment was conducted to determine the best method to
establish subterranean clover on medusahead infested ranges in
Western Oregon. Secondary objectives of this study were to determind
the effects of management treatments on (a) subterranean
clover density, (b) density of medusahead and other vegetation, and
(c) yield of subterranean...
More than 200 sites between 500 and 2000 meters elevation
were examined utilizing a reconnaissance sampling technique for a
portion of the eastern slopes of the northern Oregon Cascade Mountains.
Twelve different forested plant communities were described
with data on vegetation, soils and topography. A map of their distribution
and...
Objectives of this investigation were two-fold: (l) to determine
crested wheatgrass production on selected range sites and (2)
to evaluate present and potential production on public and private
lands in the study area. Field studies were carried out in 1953 and
1964 near Jordan Valley, Malheur County, Oregon, on the...
Growth and replacement patterns of four successionally important
species occurring on Douglas fir clear-cuts were investigated
from September 1964 to June 1967. The study was carried out
on the Marys Peak watershed located near Corvallis, Oregon.
Species used in the study include Holcus lanatus, Senecio
jacobaea, Lotus crassifolius var. subglaber,...
A 1.5 ha mixed conifer stand in the Blue Mountains of Oregon
was intensively examined to assess the impact of logging disturbance
on soils and herbaceous vegetation. Sampling was conducted six
years after much of the timber overstory was removed in a
shelterwood cut and yarded by crawler tractor. A...
The effects of late spring defoliation on the winter forage quality of bluebunch wheatgrass
(Agropyron spicatum [Pursh] Scribn. & Smith), Idaho fescue (Festuca idahoensis Elmer) and elk sedge
(Carex geyeri Boott) and the response of wintering Rocky Mountain elk (Cervus elaphus nelsoni Bailey) to
changes in winter range forage quality...
This classification lists the native plant associations known to occur in Oregon, and includes both successional and climax vegetation types that were an important part of the presettlement landscape of Oregon. It serves as an index to the diversity, distribution and relative rarity of the state's native plant associations, and...
The structure and components of riparian areas influence the rate, amount, and timing of water, nutrients, organic debris, and inorganic materials that enter streams and rivers. The energy of floodwaters and their ultimate volume, timing and erosive power is influenced by the soils, vegetation and geomorphology of fluvial surfaces within...
Craterellus tubaeformis is a small to medium-sized forest mushroom that is fairly common in the Douglas-fir/western hemlock forests of the Pacific Northwestern United States and is most often associated with decayed coarse woody debris. In this study, the mycorrhizae of Craterellus tubaeformis in western Oregon is identified by DNA analysis...
The amount and quality of competition among
individuals in developing plant communities is an important factor determining community structure, composition and development. In perennial plant communities, this competition is reflected by shifts in carbon allocation among plant parts and can result in long-term structural differences between neighboring individuals. This study...
Map delineations of soil and vegetation for a 14,000
acre (5,800 hectare) site in the Oregon Coast Range were
compared. Research objectives were to ascertain the
types of information that could be extracted from delineation
comparisons and to develop a methodology suited
to this purpose. The latter objective was achieved...
ORNHIC maintains extensive databases of Oregon biodiversity, concentrating on rare and endangered plants, animals and ecosystems. The program is managed by OSU, but has been a
cooperative project, with significant support from The Department of State Lands, The Nature Conservancy in Oregon, USFWS, the Bureau of Land Management (BLM), the...
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...