Timber cruise data can provide useful information not available elsewhere. Measurements of timber volume (timber cruises) from the early 20th century for Coos County, Oregon, were used to assess the degree to which tree species distribution and timber volume varied with edaphic and climatic factors. The study area has diverse...
Drought resistance among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murr.) Pan., Cupressaceae) seedlings was evaluated both in the field and in the greenhouse. Field water potentials (Ψ) of 5-year-old seedlings were measured at two high-elevation plantation sites where summer drought occurs. Measurements of Ψ were compared to survival two years...
Seedlings from 25 provenances of Abies grandis and Abies
concolor were studied at two plantations, 12 at Philomath, Oregon,
and 13 at Camino, California. Native seedlings were studied at four
of the provenances' field sites. Stomatal infiltration pressure
measurements and plant moisture stress measurements were made
throughout one summer on...
The effects of burial by tephra (volcanic aerial ejecta) on
forest understory plants were examined northeast of Mount St. Helens,
Washington, in the area where the 18 May 1980 eruption deposited
tephra but did not destroy canopy trees. At six sites along a tephra
depth gradient from 2-15 cm, understory...
Twelve plots at six sites in southwestern Oregon were studied to determine the degree to which various soil characteristics are related to the occurrence and growth of Chamaecyparis lawsoniana and Thuja plicata. Soil profiles and vegetation were described in each plot, and measurements were made of insolation, soil and litter...
I studied the water relations traits, twig conductivity, C'3 isotopic composition,
and wood density of three conifer and five angiosperm species in western Oregon. This
study took place from spring 2002 to fall 2003 on four sites. Species were selected to
represent the diversity of drought tolerance of woody plants...
Corydalis aquae-gelidae is a large herbaceous perennial
in the Fumariaceae that has high habitat specificity. It is
endemic to the western Cascade Range of Oregon and
Washington, almost entirely on the Mt. Hood and Gifford
Pinchot National Forests. It is a federal C2 candidate
under the Endangered Species Act and...