The effects of precommercial thinning on the understory vegetative cover of 16- to 18-year-old spruce–hemlock (Picea sitchensis (Bong.) Carrière – Tsuga heterophylla (Raf.) Sarg.) stands were studied in seven replicate areas over seven growing seasons postthinning. Vegetative cover was analyzed at the class level, but species-specific effects were examined in...
Post-thinning natural regeneration in the Pacific Northwest of USA was evaluated 13 years after thinning
50-year-old Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) stands on a drier, interior
Coast Range site (McDonald) and 10 years after thinning 50- to 55-year-old Douglas-fir/western hemlock
(Tsuga heterophylla [Raf.] Sarg.) stands on a moister,...
In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had...
The waving-wand system of broadcast chemical application implemented in swath widths to 40 ft (>12 m) is capable of simulating broadcast deposition patterns for herbicides similar to those delivered by helicopter. Drop sizes vary from center to edge of swaths, which can range from >1,000 to 5,000 microns (μ). Any...
This thesis examines the competitive aspects of Douglas-fir trees growing with two commonly associated competitors--red alder and grass--at varying densities. Two Nelder plots in three different environments in the Oregon Coast Range were studied. The sites represented the warm, dry climate of the Willamette Valley; the warm, moist climate of...
