The effects of clonal variability, crown position of cones, and top-pruning of ramets to reduce height growth, on 1) the proportion of viable self-fertilized progeny (s) and 2) the proportion of filled seeds (PF), were investigated in a 20 year-old Douglas-fir (Pseudotsuga menziesii [Mirb.1 Franco) seed orchard. Cones were collected...
Infestations of the western pine shoot borer (Eucosma sonomana Kearfott) in young stands of ponderosa pine (Pinusponderosa Lawson), were surveyed on the Deschutes National Forest. Elevation, slope, aspect, tree height, tree diameter, number of shoots in the terminal whorl, stand density, stand age and plant association for each stand were...
After three-quarters of a century of introduction of 152 conifer and broadleaf species,
no promising candidate exotic was found for the Douglas-fir region. Growth curves
spanning 50 years or longer are figured for many species. Firs, pines, larches, spruces,
hemlocks, and cedars originating in northwestern North America had superior growth...
Twenty-year-old Douglas-fir trees in provenances from Arizona,
New Mexico, and southern Colorado survived better and grew taller;
but incurred more winter injury in eastern Nebraska than trees from
provenances from northern Colorado, southern and western Montana,
northern Idaho, Canada, and eastern Washington. However, surviving
trees from Pacific Coast, and northern...