Western dwarf mistletoe (Arceuthobium campylopodum Engelm.
1. campylopodum) is a parasite of ponderosa pine (Pinus ponderosa
Laws. ). The objectives of this investigation are: (a) to formulate a
mathematical description of the process of dwarf mistletoe disease
spread in a pine forest, (b) to use this description to predict the...
A biosystematic investigation was undertaken in 15
species and three subspecies of the genus Aster, in western
North America. Previous studies had been based entirely on
external morphological features, and it was believed that
much could be learned about the natural affinities of the
taxa by exploring their cytological and...
A physio-ecological study of Lobaria pulmonaria (L. ) Hoffm.
was done to determine if geographic variation occurred within the
species. Lobaria pulmonaria was collected from Table Mountain,
Oak Creek, and Lost Prairie, located in the Coast Range, Willamette
Valley, and Cascade Range respectively in Western Oregon.
During 1971 and 1972...
Ecological factors associated with the relictual distribution of
the endemic shrub Kalmiopsis leachiana (Ericaceae) were investigated.
A prostrate evergreen species with small coriaceous leaves,
K. leachiana is restricted to two disjunct populations in the Siskiyou
Mountains and southern Cascade Mountains of southwestern Oregon,
USA. Exact distributions of individual populations were...
Eastern Filbert Blight, caused by Anisogramma anomala (Peck) E. Miller, was first discovered in the Pacific Northwest in 1974. Orchard experiments suggest that the fungus completes its life cycle in two years. Infection takes place from mid-January to May, mainly through mite-galled-buds infested with an Eriophyid mite, Phytocoptella avellanae Nal....
In 1967, Lophodermella morbida Staley and Bynum, a recently described
hypodermataceous needle-cast fungus, became destructively
epidemic in a knobcone pine (Pinus attenuata Lemm.) plantation in
Del Norte County, California, and in several ponderosa pine (P.
ponderosa Laws.) plantations in western and southwestern Oregon.
This thesis presents information on this currently...
A study was undertaken to determine the reliability of the formation
of a line of demarcation between paired cultures of Fomes
cajanderi Karst. as an indicator of dissimilar compatibility genotypes.
The results were applied to an assay of the number and location of
compatibility genotypes in each of four glaze-damaged,...