Published January 1964. 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 April 1964. 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 tolerance of woody plants to picloram (4amino-3,5,6-trichloropicolinic acid) has been shown by field applications to vary from mild to extreme. A laboratory study was done to investigate the basic causes for this range of tolerance known to exist among three woody plant species, Fraxinus pennsylvanics, March, (green ash) resistant,...
Prairies were once the dominant vegetation type in Oregon's Willamette Valley. Land use conversion, fire suppression, succession, and invasive species have reduced Willamette Valley prairies to less than 1% of their historical area. The remnant prairies that persist today are small in size and are highly fragmented. Marginal strips of...
The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. The hydrological cycle involves mutually-dependent biological and physical processes that operate at multiple scales of time and space, and this...
The effects of ¹⁵N-labeled fertilizer applied to mature summer-bearing red raspberry (Rubus idaeus L.) plants were measured over two years. Four nitrogen (N) treatments were applied singularly at 0, 40, or 80 kg·ha⁻¹ of N in early spring (budbreak), or split with 40 kg·ha⁻¹ of N (unlabeled) applied at budbreak...
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
Ultraviolet-B radiation (UV-B) has been suggested as a factor contributing to global amphibian population declines. While ambient UV-B levels damage the eggs and embryos of some amphibian species, few studies have addressed how UV-B affects other life history stages or sublethal responses. My dissertation focuses on (1) investigations of sublethal...
"... One goal of this document is to synthesize the literature on the effects of mechanical thinning on understory plant species. A second goal is to document the effect of prescribed burning on rare, threatened, or endangered species. We review current literature on studies that address effects of prescribed fire...
This study was designed to learn the effect a specific herbicide practice on plant communities. Data were obtained from brushfields that had been aerially sprayed with 2,4-D (2,4 dichiorophenoxyacetic acid) and/or 2,4,5-T (2,4,5 trichlorophenoxyacetic acid). Qualitative data on species composition, cover percent, height, response to herbicide and site description were...
The effect of low temperatures given at different times and duration
upon the time of bud burst, shoot elongation, number of needles
developed and needle length in Douglas-fir plants from the Oregon
Cascades and three coastal areas ranging from Washington to California
were determined. The plants were grown outside in...
Herbicides are being used as a tool by forest managers to speed
the restocking of sites where tree seedlings face competition from
grasses for limited moisture, light and nutrients. Retarded growth
or, more commonly, death of the seedlings would occur if a selective
herbicide was not used to control competing...
The role of moisture stress in seedling physiology and establishment
was studied in both the field environment and laboratory
experiments. Plant moisture stress was measured using the pressure
chamber technique. This technique was modified and tested using a
fascicle of pine needles as a sample, an improvement which allows the...
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...
Spectral patterns of three brush species under the influence of herbicide treatment were investigated to evaluate the effectiveness of monitoring forest vegetation management using ground-based and remote sensing techniques. Foliage of Pacific rhododendron (Rhododendron macrophyllum D. Don), golden chinkapin (Castanopsis chrysophylla Dougl.), and hairy manzanita (Arctostaphylos columbiana Piper) sprayed with...
The effect of solution nitrogen (N) and phosphorus
(P) concentrations on biomass production and N₂ fixation
of red alder (Alnus rubra Bong.) seedlings grown in
perlite-filled pots in a climate controlled growth room
were studied. Nodulated seedlings were subjected to 12
different nutrient solution combinations of nitrogen and
phosphorus and...
The objective of this study was to determine how the
balance of carbon to nitrogen in a grand fir ecosystem affects
the chemistry of emerging grand fir foliage and the growth of
western spruce budworm larvae. Forest plots in the grand fir
zone of eastern Oregon were thinned, thinned and...
Mayweed chamomile (Anthemis cotula L.) is an annual weed in the Asteraceae family that is commonly found in fields of the Pacific Northwest. Acetolactate synthase (ALS)-inhibiting herbicides are frequently used to control a broad spectrum of weed species including mayweed chamomile. Seeds of four biotypes of mayweed chamomile (KJ, KL1,...
Ten herbicides (atrazine, azafenidin, chlorsulfuron, clopyralid, hexazinone, imazapic, imazapyr, metsulfuron, pendimethalin, and sulfometuron) were evaluated for phytotoxicity in first-year seedlings of eight conifer species (Douglas-fir, grand fir, noble fir, redwood, Sitka spruce, western hemlock, western red cedar, and western white pine). Six of these herbicides (atrazine, clopyralid, hexazinone, imazapyr, metsulfuron,...