To investigate the movement of elements (N, P, k, Ca, and Mg) from the tree crowns by natural litterfall and leave wash, plots were established on six 450 year-old growth stands at the H. J. Andrews Experimental Forest. The following are the results of the data analyses. Elemental concentrations contained...
Several hundred two year old Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco) seedlings were planted in an enclosure
designed to permit control of soil moisture. The seedlings came
from five seed sources in southern Oregon and one seed source in
northwestern Oregon. Mortality terminal and lateral budburst,
and soil moisture were recorded...
The physiological and biochemical responses of Douglas-fir seeds to stratification, redrying, storage and subsequent germination were determined. Stratification increased seed vigor, embryo and gametophyte
phosphorylative efficiency and RNA synthetic ability. Redrying seems to increase the rate of enthryonic nucleic acid synthesis, speed of germination and seedling vigor. ATP, total adenosine...
Chapter 1 Growth and Survival of Root-Wrenched Douglas-fir Seedlings Root wrenching of seedlings (severing the roots 15 cm below the soil surface) was investigated as a nursery practice to improve growth and survival of field-planted Douglas-fir from six local seed sources
in the Pacific Northwest. At lifting, shoots of wrenched...
A rapid and efficient procedure that required no partitioning was developed for the purification of abscisic acid (AbA) from the needles of Douglas-fir seedlings. Extracted needle pigments were removed by a
PVP column and the eluted AbA was concentrated on a DEAE column. The AbA was eluted from the DEAE...
Methanolic extracts of the dormant Douglas-fir shoots (buds, leaves, and stems) were fractionated by solvent partitioning (sodium bicarbonate-diethyl ether). The acidic portion of the extract was subjected to column (Sephadex LH-2O, Silica Gel and Polyvinylpyrrolidone), preparative thick-layer and gas-liquid chromatography.
Fractions collected from chromatographic separations were collected and tested for...