http://hdl.handle.net/1957/7548 Search the Channel search http://ir.library.oregonstate.edu/dspace/simple-search http://hdl.handle.net/1957/7886 Title: Reanalysis of the SMC-ORGANON equations for diameter-growth rate, height-growth rate, and mortality rate of Douglas-fir <br/> <br/>Description: Using existing data from untreated research plots, we developed equations for predicting 5-yr diameter-growth rate (ΔD₅), 5-yr height-growth rate (ΔH₅), and 5-yr mortality rate (PM₅) for Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in the coastal region of the Pacific Northwest. These equations are revisions of the equations constructed in 1995–1997 for the Stand Management Cooperative's (SMC) version of the ORGANON growth-and-yield model, and they have been developed with substantially larger and more comprehensive data sets than were available in 1995–1997. The new ΔD₅ and ΔH₅ equations were validated with an independent data set. The PM₅ equation was evaluated by comparing 100-yr predictions of Reineke's (1933) stand density index to behavior previously reported from measurements taken on long-term research plots. The new ΔD₅, ΔH₅, and PM₅ equations appear to be considerably superior in predictive ability and behavior to the original equations. The effects of the new equations on stand-level predictions were evaluated by comparing the maximum mean annual increments (MAI) in total stem volume (ft³) and associated rotation ages (RA) predicted from the original SMC-ORGANON model to predictions from the revised SMC-ORGANON model. This analysis was done by making 100-yr projections using 170 plots in young stands from the SMC data sets. Some of the ending values for average crown ratio (CR) after 100 yr of projection were near 15%, however, and predictions of basal area (BA) for some of these stands peaked and then declined over stand age. Substituting the HCB equation published by Hann and Hanus in 2004 for predicting crown recession (ΔHCB₅) eliminated the problem with BA peaking over stand age and resulted in somewhat larger average ending CRs. The 100-yr projections were then made again with the 2004 HCB equation of Hann and Hanus. On average, the revised model reduced RA by 2.1 yr (or 4.3%) and maximum MAI by 55.7 ft³/ac/yr (18.9%). Sat, 29 Oct 2005 22:58:59 GMT http://hdl.handle.net/1957/7885 Title: Tractor thinning productivity and costs : experience from the Willamette Young Stand Project <br/> <br/>Description: 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 with 0.5-ac openings (92 residual tpa), and heavy thin (53 residual tpa). The three study sites were 44- to 46- yr-old stands of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] located in the Cascade Mountains of west central Oregon. Detailed time studies were conducted on timber fallers and crawler tractors and used to develop multiple linear regression models to predict delay-free felling and skidding cycle times for each site. The independent variables common to the regression models to determine delay-free felling cycle time at all sites were diameter at breast height, number of cuts, and number of limbs cut. Only skidding distance was common to all regression models for determining delay-free skidding cycle time. Total costs for each treatment were obtained by combining felling, skidding, and moving costs for the entire operation. Felling costs ranged from $7.20/CCF to $17.73/CCF. Skidding and loading costs ranged from $15.42/CCF to $38.69/ CCF. The cost and productivity results from this study emphasize the importance for forest managers to consider factors such as volume removed and skidding distance when prescribing alternative silvicultural treatments for young Douglas-fir stands. Sat, 29 Oct 2005 22:58:59 GMT http://hdl.handle.net/1957/7884 Title: Production and costs of cut-to-length thinning : experience from the Willamette Young Stand Project <br/> <br/>Description: 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 40- to 50-yr-old stands in the Willamette National Forest in the Cascade Mountains of central western Oregon. Using multiple linear regression equations with indicator variables, we compared both harvesting and forwarding cycle times among treatments. We conducted detailed time studies on a harvester and a forwarder and used these data to develop two regression equations to predict delay-free harvest cycle times and delay-free forwarding cycle times. Delay information was gathered from both shift-level and detailed time studies. Total costs for each treatment were obtained by combining costs for harvesting, forwarding, and moving equipment in and out for the entire operation. Harvesting and forwarding costs did not differ significantly between light and heavy treatments, but were higher in the light-thin-with- openings treatment. Total thinning costs among the three treatments ranged from $28.08 to $34.62/100 ft³. Wed, 29 Oct 2003 22:58:59 GMT http://hdl.handle.net/1957/7883 Title: College of Forestry Integrated Research Project : ecological and socioeconomic responses to alternative silvicultural treatments <br/> <br/>Description: The College of Forestry Integrated Research Project (CFIRP) is an on-going experiment in the eastern Coast Range foothills of western Oregon. Started in 1989, a team of scientists, resource managers, and students at Oregon State University designed and implemented silvicultural alternatives to clearcutting. These silvicultural practices aimed to create and retain features of mature and old-growth Douglas- fir (Pseudotsuga menziesii) forests while also producing timber. Fine-, moderate-, and large-scale natural disturbance patterns served as the basis for prescriptions. The study includes replicates of three silvicultural treatments (n = 27 stands) wherein 33% to 95% of the timber volume was removed, three non-replicated demonstration treatments wherein 33% of timber volume was removed in variable sized and shaped patches, and untreated controls (n = 3 stands). Additionally, clumped or randomly distributed snags were created from green trees in each stand. In this book, CFIRP scientists describe harvest challenges and economics; short-term (10-yr) responses of vegetation, wildlife, and humans to silvicultural treatments; and additional studies conducted using CFIRP study sites. A synopsis of past and present research and management directions also is included. Work continues on CFIRP today, and data collected from previous studies are available to other researchers. By comparing characteristics of forests managed under different silvicultural systems, we will be better able to assess their potential economic, social, and ecological contributions to managed forest landscapes. Fri, 29 Oct 2004 22:58:59 GMT