The balsam woolly aphid (Adelges piceae Ratz.) feeds by inserting its stylets intra- and intercellularly into the cortex or outer phloem of the true firs. While feeding, the aphid injects into the bark an unknown stimulatory substance which affects the adjacent cortical parenchyma cells, the activity of the vascular cambium...
The objective of this study was to determine how the
balance of carbon to nitrogen in a grand fir ecosystem affects
the chemistry of emerging grand fir foliage and the growth of
western spruce budworm larvae. Forest plots in the grand fir
zone of eastern Oregon were thinned, thinned and...
Douglas-fir and grand fir seedling establishment and plant community regeneration were examined in a western Oregon forest following harvest in three
different silvicultural systems: clearcut, two-story and patchcut. The two-story system
consisted of removing all but 10 to 12 trees per acre. The patchcut system consisted of
harvesting 1/2 acre...
This greenhouse study evaluates the influence of separately and
simultaneously imposed water stress, western spruce budworm (Choristorneura
occidentalis Freeman) defoliation, and inoculation with the root pathogen, Armillaria
ostoyae (Romagn.) Herink, on the growth and biochemical features of Abies .grandis
(Dougl.) Lindi. Seedling biomass, plant moisture status, bud phenology, and
allocation...
Equations for predicting diameter growth are an essential component of single-tree growth and yield models (Munro 1974). Diameter
growth predictions are used to characterize individual-tree development and to project the growth of stand basal area and volume. Both diameter growth and basal area growth have been used as the dependent...
