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...
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...
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...
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,...
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...
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.
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...
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.
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...