The need for increased efficiency in regeneration of western hemlock (Tsuga heterophylla (Raf.) Sarg.) requires greater understanding of seedling physiology. Experiments examined western hemlock seedling growth responses to in-bed root pruning, and pruning of shoots or roots prior to transplanting. Measurement of plant
moisture stress (PMS) after physical root disturbance,...
Definitive evidence for the occurrence and seasonal variation of indole-3 -acetic acid (IAA) in shoots 0 DougLas-fir (Pseudotsuga rrienztesii (Mirb. ) Franco) was sought. Collections obtained in December and June were extracted by solvent using methanol arid diethyl ether arid by certtrtfugatiori. Extraction by ceritrifugation appeared to be twice as...
Vegetative propagation is most effective when individuals of demonstrated superior characteristic can be propagated. For this
reason, a method for the induction of adventitious buds on cultured Douglas-fir shoot tips from 20-25 year old trees was developed. Douglas-fir shoot tips failed to survive and grow on a full strength Murashige...
Three experiments were conducted on containerized seedlings to examine the short-term and long-term effects of environment on the root regeneration potential, and to examine the fate of the current photosynthate and its relationship to the root regeneration potential. The short-term effects were studied first in a 3x3x2 factorial experiment comprising...
Most of the methods currently used to measure root respiration introduce various disturbances which may lead to biased results, and require destruction of roots which does not permit repeated measurements of root growth and respiration. A root box method was developed for measurement of root respiration, as well as root...
The physiological condition of tree seedlings at the time they are planted can have a profound impact on their subsequent field performance. Damaged or low vigor seedlings have a much greater chance of dying in the field, or at best, of growing slowly during their initial establishment period. Several methods...
The goal of this thesis was to determine the physiological mechanisms that link adverse preplanting treatments of Douglas-fir, such as exposure and root pruning, to the phenomenon of transplanting shock. The objective of experiments 1 and 2 was to measure the effect of exposure and pruning on the physiology and...
An understanding of the gibberellins present in Douglas-fir is essential to understanding and controlling the growth and development
of this species. A technique was developed which permits the separation of certain gibberellins with high performance liquid chromatography and their identification with mass spectrometry. An extraction technique
for the isolation of...
Three Nelder plots of 3-year-old red alder (Alnus rubra Bong) were used for this study at the Cascade Head Experimental Forest, Oregon in the growing season of 1988 at an elevation of 330 meters. Each Nelder plot
represented a range of densities from 238 to 101,219 trees per hectare. The...
