Across western Oregon, Washington, and British Columbia, forest management practices over the past century reduced the amount of late-successional forest while
simultaneously increasing the amount of young (less than 80 years old), managed
Douglas-fir (Pseudotsuga menziesii) dominated forests. Recently, concerns over loss of late-successional habitat pushed management objectives on public...
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....
The process of silvicultural thinning has become very controversial recently with regards to fire protection and management for old-growth conditions and biodiversity. Therefore, an unthinned control stand and 3 different thinning intensities were examined for their effects on the abundance, species richness, and diversity of arthropods in thinning treatments of...
Canopy gap formation is a major factor contributing to maintenance of overstory species diversity and stand structure in forests and may be integral to development of understory shrub and herb layers as well. Acknowledgement of gap formation as a fundamental feature of natural forests has led to consideration of gaps...
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...
Commercial thinning operations can result in damage to residual stems. A literature review revealed that little was known about the effects of residual logging wounds with regard to rotation-age commercial conifers, particularly Douglas-fir. An experiment to examine fungal colonization of Douglas-fir following logging damage showed that while damage was significant...
Young Douglas-fir stands were commercially thinned to achieve vegetation- and wildlife-related objectives. Harvesting and forwarding production and costs were compared among three mechanized thinning treatments: light thin [(115 residual trees per acre (tpa)], light thin with 0.5-ac openings (92 residual tpa), and heavy thin (53 residual tpa). The sites were...
• A technique for measuring in vitro respiration was investigated to understand why rates were higher than those reported in vivo and to elucidate trends within mature Pseudotsuga menziesii (Douglas‐fir) trees.
• Extracted increment cores were divided into 3–4 radial depths and a gas chromatograph was used to compare respiration...
In their recent Canadian Journal of Forest Research Comment 368 article, Wilson and Oliver (2000) developed an equation for predicting the average ratio of height to diameter at breast height for the largest 250 trees/ha (H/DL250) in unthinned stands as a function of initial density and dominant height of the...