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...
Previous observations of light levels and phytoplankton abundances along the Oregon coast demonstrated that phytoplankton attenuated light sufficiently to potentially limit the growth of intertidal macrophytes and therefore structure local intertidal communities. Inspired by this observation, in spring 2004, I initiated a study to quantify the direct and indirect benthic...
Broilers grown in a conventional-type house under natural lighting with intermittent lighting at night were compared to continuous (24-hour) lighting in two experiments. Broiler growth and feed conversion at seven weeks were not affected by treatments in either experiment. Economic evaluation of the different treatments showed savings ranging from 2.43...
Light plays an important role in ecological processes in the ocean both day and night. While relatively inexpensive, off the shelf instruments are available to measure Photosynthetically Active Radiation or PAR during the day, efforts to quantify light levels at night have proven more difficult. The goal of this work...
Spectroradiometric analyses were made to examine the light filtering capacity of coniferous forests and to establish the lower light energy limits for growth of Pseudotsuga menziesii (Mirb. ) Franco, Abies concolor (Gord. and Glend.) Lindi. and Pinus ponderosa Dougi. Visible energy(400-750 nm) was recorded at 48 points under four mixed...
A plant's immediate neighborhood reflects its realized level of competitive stress, since competition and natural selection act at the individual level. In stands with continuous canopies competition for light is the dominant spatial interaction. Over 100 spatially explicit indices have been used to characterize the local competitive environment in models...
The role of disturbance in seed germination and first-year survival of red alder (Alnus rubra) was studied over two growing seasons at four sites representing a climatic gradient within the central Coast Range of Oregon. Disturbance affected red alder seed
germination and seedling establishment by altering the temperature and moisture...
Mountain hemlock forests in the Oregon Cascades exhibit wave-form dieback resulting from infection by laminated root rot (Phellinus weirii). Although Phellinus remains viable in dead roots after the wave of dieback passes, many regenerating mountain hemlock forests do not become
immediately reinfected. We measured at least a doubling of nitrogen...
Foliage from Douglas-fir(var. glauca) seedlings grown under two light intensities was bioassayed to examine palatability to the
western spruce budworm (Choristoneura occidentalis Free.). Samples were collected in Fall, Winter and early Spring to
identify seasonal changes in host foliage, as evidenced by the response of spruce budworms. Fall collected foliage...
Published October 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