The importance of pheromones in insect control relies both on
their ability to reduce pest populations and on their relatively benign
effects on nontarget organisms. This study was conducted to test the
effectiveness of a pheromone application for mating disruption of the
ponderosa pine tip moth, Rhyacionia zozana (Kearfott), and...
This research assessed the effect of western juniper (Junlperus
occldentalls) removal on understory plant production and cover and
ponderosa pine (Pinus ponderosa) growth and plant water status.
A complete randomized block design, with four blocks and four
treatments was established in the summer of 1984 near Prineville,
Oregon. The four...
Xylem conducting tissue or sapwood is an important storage organ
for water, carbohydrates, and nutrients, and this storage helps trees
accommodate environmental change. However, the living ray parenchyma
cells in sapwood, which store the carbohydrates and nutrients,
require energy for maintenance. I examined how sapwood maintenance
costs vary among species,...
Improving vegetation management decisions in Pacific Northwest forests requires a better understanding of the interactions between
planted conifers and associated vegetation. A practical index of interspecific competition, and quantitative models predicting conifer performance from such an index are particularly needed. To meet this
need, neighborhood models of interspecific competition were...
The role of disturbance in seed germination and first-year survival of red alder (Alnus rubra) was studied over two growing seasons at four sites representing a climatic gradient within the central Coast Range of Oregon. Disturbance affected red alder seed
germination and seedling establishment by altering the temperature and moisture...
Ungerminated seed and recent germinants from 39 open-pollinated Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco)
families were planted in each of three competitive environments in order to determine the degree to which growth differences among families are influenced by competitive environment, seed weight, and
date of emergence. The three competitive...
Competitive interactions between Douglas-fir seedlings (Pseudotsuga menziesii), and seedlings of a nitrogen-fixing hardwood
associate, red alder (Alnus rubra), were investigated in an addition series experiment. The primary objective of the research was to identify and quantify key processes underlying intra- and interspecific competitive interactions of Douglas-fir and red alder seedlings....
This study dealt with research problems at the landscape level. The objectives of this thesis were to develop tools to study and characterize landscapes and to interface with a geographic information system (GIS), to evaluate landscape indices, and to examine development of forest cutting patterns under different cutting methods and...
Red alder (Alnus rubra Bong.) seedlings fertilized with NH4NO3 or inoculated with a pure culture Fran/cia and inoculated with live or dead spores of the mycoirhizal fungus Alpova diplophloeus (Zeller & Dodge) Trappe & Smith were grown in a growth
chamber or in a greenhouse for six months Frankia inoculation...
The objective of this research was to determine which
environmental resources, light, water, and nutrients,
control understory plant production and composition in a
Pinus ponderosa forest in northeastern Oregon. A split-plot
experimental design, with three blocks, four
treatments, and 44 plots, was established in the summer of
1985. Twenty plots...