http://hdl.handle.net/1957/7548 Search the Channel search http://ir.library.oregonstate.edu/jspui/simple-search http://hdl.handle.net/1957/12584 Title: Including wood stiffness in tree improvement of coastal Douglas-fir in the US Pacific Northwest: a literature review and synthesis<br/><br/>Authors: Jayawickrama, K. J. S.; Ye, T. Z.; Gupta, R.; Cherry, M. L. 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/>Authors: Hann, David W.; Marshall, David D.; Hanus, Mark L.; Oregon State University. Forest Research Laboratory<br/><br/>Description: Using existing data from untreated research plots, we developed equationsfor predicting 5-yr diameter-growth rate (ΔD₅), 5-yr height-growthrate (ΔH₅), and 5-yr mortality rate (PM₅) for Douglas-fir [Pseudotsugamenziesii (Mirb.) Franco] in the coastal region of the Pacific Northwest.These equations are revisions of the equations constructed in 1995–1997for the Stand Management Cooperative's (SMC) version of the ORGANONgrowth-and-yield model, and they have been developed withsubstantially larger and more comprehensive data sets than were availablein 1995–1997. The new ΔD₅ and ΔH₅ equations were validated with anindependent data set. The PM₅ equation was evaluated by comparing100-yr predictions of Reineke's (1933) stand density index to behaviorpreviously reported from measurements taken on long-term researchplots. The new ΔD₅, ΔH₅, and PM₅ equations appear to be considerablysuperior in predictive ability and behavior to the original equations. The effects of the new equations on stand-level predictions were evaluatedby comparing the maximum mean annual increments (MAI) intotal stem volume (ft³) and associated rotation ages (RA) predicted fromthe original SMC-ORGANON model to predictions from the revisedSMC-ORGANON model. This analysis was done by making 100-yrprojections using 170 plots in young stands from the SMC data sets.Some of the ending values for average crown ratio (CR) after 100 yr ofprojection were near 15%, however, and predictions of basal area (BA)for some of these stands peaked and then declined over stand age. Substitutingthe HCB equation published by Hann and Hanus in 2004 forpredicting crown recession (ΔHCB₅) eliminated the problem with BApeaking over stand age and resulted in somewhat larger average endingCRs. The 100-yr projections were then made again with the 2004 HCBequation of Hann and Hanus. On average, the revised model reduced RAby 2.1 yr (or 4.3%) and maximum MAI by 55.7 ft³/ac/yr (18.9%). http://hdl.handle.net/1957/7885 Title: Tractor thinning productivity and costs : experience from the Willamette Young Stand Project<br/><br/>Authors: Kellogg, L. D. (Loren D.); Davis, Chad T. (Chad Thomas); Oregon State University. Forest Research Laboratory<br/><br/>Description: Harvesting productivity rates and costs were determined for threesilvicultural treatments used in commercial ground-based thinning ofyoung stands to achieve timber management objectives and enhancewildlife habitat. Treatment definitions were based on residual treesper acre (tpa) after thinning. The treatments were light thin (115residual tpa), light thin with 0.5-ac openings (92 residual tpa), andheavy 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. Detailedtime studies were conducted on timber fallers and crawler tractorsand used to develop multiple linear regression models to predictdelay-free felling and skidding cycle times for each site. The independentvariables common to the regression models to determinedelay-free felling cycle time at all sites were diameter at breast height,number of cuts, and number of limbs cut. Only skidding distancewas common to all regression models for determining delay-freeskidding cycle time. Total costs for each treatment were obtainedby combining felling, skidding, and moving costs for the entireoperation. 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 emphasizethe importance for forest managers to consider factors such as volumeremoved and skidding distance when prescribing alternativesilvicultural treatments for young Douglas-fir stands. http://hdl.handle.net/1957/7854 Title: Guide to reforestation in Oregon<br/><br/>Authors: Rose, Robin, Dr.; Haase, Diane; Oregon State University. Forest Research Laboratory<br/><br/>Description: This manual describes the rules for reforesting after harvest of small woodlands, gives guidance for the decisions the landowner must make, and gives step-by-step instructions for planting and taking care of seedlings.