Budburst, the initiation of annual growth in plants, is sensitive to climate variation and is therefore used to monitor physiological responses to climate change. Budburst timing can vary between regions of an individual tree, but this phenomenon it is unaccounted for in current monitoring efforts and may contribute to the...
Tissue differentiation of the primary root and its associated
laterals is reported. Secretory elements are the first of the primary
tissues to mature. They appear to be located between the precursory
phloem and pericycle in the primary root, but are more closely
associated with the pericycle in long lateral roots....
The Pacific Coast form of Douglas-fir in natural forest succession
is an intermediate species thriving in the Coast Range and
Cascade Mountains of the Pacific Northwest. This species constitutes
26 percent of the standing timber in the United States, and 24 percent
of the nation's annual timber harvest. Characteristics of...
Mitotic activity in the vascular cambium was determined from
ten samples from a single internode in each of four Douglas-fir
[(Pseudotsuga menziesii (Franco.) Mirb.)]trees. Counts of interphase and mitotic nuclei from nine cores in each sample piece
were averaged and expressed as the frequency and mitotic index.
The sampling error...
Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the tree species most widely distributed outside its natural range. The species has been introduced to Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir is an accepted and integral part of...
To obtain data on the decomposition of the forest floor, a battery operated electrolytic respirometer was developed making it possible to measure CO₂ evolution from field moist forest floor samples in situ independent of root respiration. Banks of four respirometers powered by two 12-volt batteries were installed in three old...