Astragalus diaphanus is a rare plant endemic to the
John Day River drainage of north-central Oregon. This
species has several interesting features, including the
dimorphism of its fruit and its geographical isolation from
the two nearest taxonomically related species, which occur
in Colorado. This study addressed the species' distribution
and...
Knowledge of regional-scale patterns of plant community structure and controlling factors is largely qualitative and based on numerous local studies. Data from a subsample of 10,000 field plots were used to quantify and map compositional gradients of woody plant communities across Oregon forests. Canonical correspondence analyses explained 9-14% of the...
Devil's club (Oplopanax horridum (J. E. Smith) Miq.) is an indigenous shrub of the Pacific Northwest, often found in the Tsuga heterophylla (western hemlock)/Devil' s club association in western Oregon. In the same family as ginseng, Devil's club is gaining attention for its medicinal properties. While traditional uses of Devil's...
The relationship between ground vegetation and light intensity under a 60 to 65-year-old Douglas-fir forest was investigated. Biomass and height of ground vegetation were measured and cover was estimated on small sample units (30 centimeters in diameter) on permanent research plots, one-acre in size, on the George T. Gerlinger Experimental...
The purpose of this study was to determine plant species composition, community structure, successional relationships, vegetational development and plant distributions in estuarine salt marshes on the Pacific Coast of Oregon.
Quadrat and transect samples of plant presence and cover, collected from April 1971 - June 1974, were subjected to phytosociological...
Studies were conducted to determine the competitive ability of
medusahead, Taeniatherum asperum (Sim.), for nitrogen when grown in
association with perennial range grass species. The method used to
determine this competitive ability was to compare the dry weight,
percent nitrogen, and total nitrogen of medusahead and perennial
wheatgrass species growing...
The seasonal duration of snow cover is a primary factor influencing the patterns of vegetation in high subalpine and alpine environments, but little is known concerning the responses of plant reproduction and
seedling recruitment to gradients of snow-release. Vegetation patterns of a high subalpine site in the Oregon High Cascades...