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...
Cell aggregate size in both Douglas-fir and poplar suspension cultures was reduced by the addition of the chelator compounds EDTA and CDTA at concentrations under 100 ppm. Reduced cell aggregate size increased growth efficiency of suspension cultures of both species. Cell aggregates 550 j.z. or smaller in size were used...
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade tolerant species, were compared to learn more about the temporal pattern of release from suppression in both species, whether hydraulic architecture or photosynthetic capacity constrain release and how wood functional properties change...
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...
In forest trees from temperate and boreal regions, cold acclimation is an important
adaptive trait that involves changes in gene expression and physiology. Genecological, quantitative genetic, and QTL studies have been used to study the genetics of cold acclimation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), but the genes responsible for...
Two-year old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings from two seed lots of different predicted hardiness levels were grown in two separate nurseries. Seedlings were lifted every four weeks from early October 1991 through March 1992 and exposed to controlled freezing temperatures. Fluorescence emissions of the seedlings were measured prior...
Water potential, leaf conductance, growth, nitrogen
content, and seedling survival of Wyoming Big Sagebrush
(Artemisia tridentata ssp. wyomingensis) following
defoliation of the herbaceous understory were assessed
during two growing seasons. Precipitation was 107% and 63%
of the long-term mean (283 mm) in 1989 and 1990,
respectively, which presented an opportunity...
Summer drought is a major factor limiting the regrowth of perennial ryegrass seed crops. This phase of crop development has a strong influence on seed yield because most of the tillers that contribute towards next season's seed crop are produced or regrown during this period. In recent years many seed...
Protracted drought in the southwest U.S. has had significant impacts on the region’s keystone ecosystem, the pinyon-juniper (PJ) woodlands. Drought conditions in 9 of the last 10 years, exacerbated by extreme drought in one year, stressed the pinyon pine (Pinus edulis) trees, making them highly vulnerable to native ips beetles...
Published March 1980. 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