Thinning has the potential to increase structural diversity of managed forests for wildlife. During 1994-1996, I conducted experimental and observational studies using pitfall trapping to assess short-term and potential long-term effects of thinning on abundance and reproduction of forest-floor vertebrates in Douglas-fir (Pseudotsuga menzeisii) forests of the Oregon Coast Range....
A trait based approach was used to assess impacts of overstory density and thinning on understory vegetation components related to wildlife habitat. The relationship between overstory basal area and understory vegetation for species grouped by traits, such as production of flowers, fleshy-fruit and palatable leaves, was characterized in thinned and...
The objectives of this research were to study: a) the effect of thinning and treatments consisting of pruning
and multinutrient fertilization on aboveground biolnass increment, growth efficiency (GE), and foliar nutrients;
b) the influence of topoedaphic variables (soil nutrients, slope, aspect, and rock content) and foliar nutrients on both leaf...
This research examined thinning effects on stand structure and species composition in
50- to 120-year-old Douglas-fir forests. Thirty-two paired stands (thinned and unthinned)
were measured throughout western Oregon, as were 20 old-growth stands for comparison. Thinnings occurred 10 to 24 years previously and ranged in intensity from 8 to 60%...
Harvesting costs were determined for commercial thinning of young stands to
achieve vegetation and wildlife objectives. This included replicated comparisons of
thinning treatments. Treatments were defined based on residual tree stocking after
thinning. Study procedures were developed and evaluated to improve statistical
relevance. Multiple linear regression models were used to...
A 20-year-old Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] stand in the Oregon Coast Range was thinned from about 1,700 to about 350 trees/ac. Subsequent thinnings, under eight different regimes, occurred at ages 23, 27, 30, and 32. Average net periodic cubic-volume growth was strongly influenced by thinning regime, varying from about...
The Levels-of-Growing-Stock Studies in Douglas-fir is a regional cooperative to investigate the effects of levels of growing stock on young stand growth. The Hoskins
installation, in western Oregon, was established in a dense, high site natural stand at total age 20 years. The initial thinning resulted in an immediate 131...
Contract harvest operations have become the preferred approach to reducing the largest cost component of timber production through free market competition amongst logging contractors bidding or negotiating for work. The goal of this research was to investigate economic components of harvesting operations not previously studied for steep slope thinning harvests...
Harvesting productivity rates and costs were determined for three
silvicultural treatments used in commercial ground-based thinning of
young stands to achieve timber management objectives and enhance
wildlife habitat. Treatment definitions were based on residual trees
per acre (tpa) after thinning. The treatments were light thin (115
residual tpa), light thin...