Remote sensing of variables necessary to estimate net primary
production of vegetation over large temporal and spatial scales has been a
goal of climate change research. This thesis consists of two studies that
address the reliability of satellite and airborne sensors to quantify a basic
component of all production models,...
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...
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...
Seasonal trends in forage production and environmental parameters
for five plant community types within a northeastern Oregon riparian zone
were described and modeled using correlation and path analysis. Wet
meadows produced the greatest amount of herbage biomass, followed by moist
bluegrass meadows, gravel bars, forests and dry bluegrass meadows. Trends...
Tree growth and soil nutrient responses to prescribed underburning were determined for a period of up to 12 years at four sites in northcentral and central Oregon ponderosa pine stands (Pinus ponderosa Dougl. ex Laws).
Differences reported are significant at a = 0.10. During the first 4-growing-season-measurement period after
underburning,...
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...
