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...
The effects of light incident on leafy cuttings is
quite complex because' light influences several factors
which may affect root formation. One effect of light is
to influence the carbohydrate status of the cutting by
influencing photosynthesis. The role of current photosynthate
in the rooting of leafy cuttings is uncertain....
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...
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...
Investigation was made into the influence of changing light
intensity on the organic and elemental composition of two species of
marine diatoms, Ditylum brightwellii and Skeletonema costatum.
Analysis was made of the relative changes in soluble and insoluble
carbohydrate; polar, non-polar, and total lipid; amino acids; proteins;
and total carbon,...
Published April 1928. 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
A study on the effects of light quality and periodicity on the germination of Douglas-fir seed and the growth of Douglas-fir seedlings was conducted. Interest was focused on responses that could be measured and observed without biochemical assay. It was found that .Douglas-fir seed,s would respond to red-light treatments by...
Photosynthetic energy allocation strategies were investigated in the marine diatom, Thalassiosira pseudonana, grown under a wide range of light limitation. Steady-state, continuous cultures were established at three light-limited growth rates. Simultaneous measurements of photosynthetic activity were made that targeted different points in photosynthetic energy flow from gross to net photosynthesis....
