Turnblom, EricHarvey, Fletcher2018-07-312018-07-312018Harvey_washington_0250O_18973.pdfhttp://hdl.handle.net/1773/42363Thesis (Master's)--University of Washington, 2018University of Washington Abstract Using stand conditions, latitude, elevation, and allometric relationships to model coastal Douglas-fir crown biomass Fletcher Harvey Chair of the Supervisory Committee: Dr. Eric Turnblom School of Environmental and Forest Science Modern forest management goals require highly accurate measurement of more sophisticated forest metrics than those that were used in the past. This study aims to explore more accurate techniques for measuring crown (and crown component) biomass for coastal Douglas-fir trees. Although methods for estimating such metrics for Douglas-fir exist, many of these methods lack accuracy and very few, if any, even begin to account for relevant environmental information. In order to accomplish the aforementioned goals, 16 Douglas-fir trees were sampled in the Pacific Northwest using an orthogonal experimental design (accounting for stand density, latitude and social position) and combined to another data set of 30 destructively sampled Douglas-fir trees from Southwest Washington State. All sample trees were from planted, industrially managed forestland. Subsequent analysis produced five different component-specific equations for: [1] total live crown biomass, [2] total live branch biomass, [3] total foliar biomass, [4] total dead branch biomass, and [5] total (live and dead) crown biomass. Model accuracies range from 67% - 84% (1 – [MAE/mean component biomass]). A subset of these models ([1], [2], [3]) were then validated using a fully independent dataset of 32 Douglas-fir trees collected on a naturally regenerated Douglas-fir stand in Southwest Oregon with accuracies of 69% - 83%.application/pdfen-USnoneForestryForestryThesis