When Douglas-fir and red alder grow in mixture, interactions between the two species can be competitive, facilitative, or a combination of both over time. A number of factors have recently led to increased interest in ma ...

Aphids are a widespread family of plant pests, whose abilities to suppress shoot and root growth are well documented for many terrestrial plants. Only a few studies have been conducted on conifer aphids of the genus Ci ...

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade tolerant species, were compared to learn more about the temporal pattern of r ...

The overall purpose of this study was to examine the root and shoot development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings at two distinct time periods in seedling establishment (after I and 3 grow ...

This thesis examines the competitive aspects of Douglas-fir trees growing with two commonly associated competitors--red alder and grass--at varying densities. Two Nelder plots in three different environments in the Orego ...

Endogenous concentrations of indole-3-acetic acid (IAA) and cytokinins were compared to the tendency for plagiogravitropjc growth in rooted stein cuttings of Douglas-fir. A chromatographic method was developed for the p ...

The increased interest in red alder (Alnus rubra Bong.) management instigated research in growth and yield and stand development of red alder in pure and mixed red alder/Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) ...

Wood stiffness is one of the most important properties of lumber and veneer. We studied wood stiffness (modulus of elasticity, MOE), wood density, microfibril angle, and knots in a 25 year-old wind pollinated progeny te ...