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...
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,...
We examined natural regeneration following operational-scale variable density retention treatments in 40-60 year old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests at seven sites for a decade following treatment. Treatments included residual overstory densities of 300, 200, and 100 trees/ha, with leave islands and gaps of three sizes (0.1, 0.2, and...
With fire suppression, many western forests are expected to have fewer gaps
and higher stem density of shade-tolerant species as light competition becomes a more
significant influence on stand pattern and composition. We compared species composition,
structure, spatial pattern, and environmental factors such as light and soil moisture between
two...
Mixed conifer and hardwood stands in southwestern Oregon were studied to explore the hypothesis that competition effects on individual-tree growth and survival will differ according to the species comprising the competition measure. Likewise, it was hypothesized that competition measures should extrapolate best if crown-based surrogates are given preference over diameter-based...