Equations for predicting individual-tree height growth per 5-year period are presented for Douglas-fir, white fir, grand fir, ponderosa pine, sugar pine, and incense-cedar growing in the mixed-conifer zone of southwest Oregon. The data used to develop the equations came from 3,648 trees sampled from 391 stands in the study area....
Environmental restrictions have induced many sawmills to seek alternatives to pentachiorophenol (penta) and similar chlorinated phenols for controlling mold and fungal stains on green lumber during storage and shipment. For that purpose, ten alternative stain preventives were evaluated against a traditional penta product (Permatox 101) on studs of Douglas-fir [Pseudotsuga...
This paper presents equations developed to predict the height to live crown base of six species in the central western Willamette Valley of Oregon. Weighted nonlinear regression was used to fit a separate logistic equation for each species. The predictor variables are total tree height, crown competition factor in trees...
Equations for predicting tree height as a function of diameter
outside bark at breast height are presented for 16 tree species
from the central western Willamette Valley of Oregon. Foresters
can use these "height-diameter" equations to avoid the time consuming
task of measuring heights of all individual trees in an...
Equations are presented for predicting height to crown base (or bole ratio) for fourteen species of trees common to the mixed-conifer zone of southwest Oregon. Nonlinear regression was used to fit a weighted logistic function for each species. The independent variables include height, crown competition factor in larger trees, stand...
Equations for predicting total height as a function of diameter at breast height are presented for 17 tree species from southwest Oregon. Because basal area and site index often influence tree height, additional equations are presented which may include either or both of these as independent variables. Equation coefficients were...
Perennial woody plants have a complex annual cycle keyed to the environment. Temperate plants have an annual dormant period commonly broken by exposure to low temperatures, although daily photoperiods of 16 hours or longer may partially substitute for the chilling. Shoot growth in the spring is normally stimulated by rising...
Logging on skid trails restricted to 10 percent or less of the harvested stand can reduce the area of compacted soil by at least two-thirds, In a comparative study, productivity of Douglas-fir logs per hour was just as great In an area with designated trails as In an adjacent area...
Reliable estimates of plant biomass and leaf surface area are essential for studying primary production, nutrient cycling, hydrology, wildlife management, and fire. This paper presents equations that can be used to make such estimates for most plant species-trees, shrubs, and herbs-dominant in western and central Oregon.' We also document the...
Two intermediate cuttings were made in a Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand on the Wilark forest management research area in northwestern Oregon. Age of trees in the stand varied from 47 to 62 years at the first cutting. Crawler tractors were used in both extractions. In the first cutting,...
Black cottonwood (Populus trichocarpa Torr. & Gray) cuttings were collected from five Oregon provenances along a north-south gradient. Cuttings from each provenance were grown for 1 year at two locations, one on the Willamette Valley floor and the other on the Valley margin. Survival at both locations was poor. Stem...
The effects of artificial shading and aspect on the performance of 1-0 container-grown Douglas-fir seedlings were evaluated 1 year after outplanting on four different aspects in southwest Oregon. The test areas, all characterized by steep slopes and shallow, skeletal soils with a surface mantle of loose rock and logging slash,...
Growth was assessed for Douglasfir reproduction which had established naturally beneath three intensities of overstory thinning in a 65-year-old stand of Douglas-fir on the east side of the Oregon Coast Range. The age of advanced reproduction ranged from 4 to 15 years. Understory environments were described in terms of sunlight,...
The response of western hemlock (Tsuga heterophylla [Raf.] Sarg.) to two methods of site preparation for planting was compared. One site was cleared of mature brush by the "brown-crush-and-burn" method. The other was partially cleared by spraying with herbicides. Seedlings lifted and planted in December, January, February, and April were...
Stands of brush and tree species of low commercial value dominate many potentially productive forest lands in western Oregon. Site preparation to reduce competition from such vegetation will improve the success of reforestation efforts, as well as reduce the cost of controlling small mammals that destroy seeds and seedlings. Site...
Eight series of untreated posts (including five series of steel), 18 series of nonpressure-treated posts, and II series of pressure-treated posts remain in test at the Oregon State University post farm in western Oregon. So far all posts have failed in 36 untreated series, 33 nonpressure-treated series, and 2 pressure-treated...
Monitoring soil density on three sites during repeated trips with a high-speed skidder showed that: During the first 20 trips, soil density primarily increased between depths of 2 to 4 inches; Density increased most during the first few trips; Density continued to increase slowly in amount and depth with the...
A technique for solving efficiently the catenary problem encountered in surveying with tapes is presented. The theory of the catenary solution is outlined, and our technique is shown to solve correctly the catenary for all conditions. Analysis of error that compared the catenary correction to the more commonly used parabolic...