21 June 2004 Western Mensurationists Meeting Developing a Whole-stand Model for Douglas-fir Plantations Eric C. Turnblom Samuel D. Pittman

21 June 2004Western Mensurationists Meeting Whole-stand Model – Topics Introduction Introduction Model Development Model Development Biological / Model Theory Biological / Model Theory Equations / Data / Fitting Equations / Data / Fitting Fit Assessment / Model evaluation Fit Assessment / Model evaluation Model Uses & Future Work Model Uses & Future Work Conclusion Conclusion

21 June 2004Western Mensurationists Meeting Introduction Stand Management Cooperative Stand Management Cooperative Mission Mission To provide a continuing source of high-quality information on the long-term effects of silvicultural treatments and regimes on stand and tree growth and development and on wood and product quality To provide a continuing source of high-quality information on the long-term effects of silvicultural treatments and regimes on stand and tree growth and development and on wood and product quality

21 June 2004Western Mensurationists Meeting Introduction Stand Management Cooperative Stand Management Cooperative Objectives Objectives To support modeling To support modeling Installations contain a wider range of treatments than current practice Installations contain a wider range of treatments than current practice To support managers To support managers Provide timely information and guidance to those who are managing similar stands Provide timely information and guidance to those who are managing similar stands

21 June 2004Western Mensurationists Meeting Stand Management Cooperative Membership Membership Companies: Companies: Boise Cascade, Longview Fiber, Port Blakely Tree Farms, West Fork Timber, etc. (15 in total) Tribal Lands: Tribal Lands: Quinault Dept. Natural Resources Federal Agencies: Federal Agencies: Bureau of Land Management State & County Agencies: State & County Agencies: ODF, WA DNR, King Co. DNR Institutions: Institutions: BC Ministry Of Forests, FORINTEK Canada, USFS PNW Research Station Universities: Universities: OSU, UBC, UW Suppliers: Suppliers: Agrium UJS, Inc., JR Simplot Co., etc.

21 June 2004Western Mensurationists Meeting Stand Management Cooperative Organization: Organization: Policy Committee Policy Committee (chair, vice-chair) Director Director Projects, Field Crew, Database Management, Office Staff Project (Technical Advisory Committees, or TAC’s) Nutrition Silviculture Wood Quality Modeling

21 June 2004Western Mensurationists Meeting Stand Management Cooperative What’s measured What’s measured Tree and derived Stand Attributes Tree and derived Stand Attributes Live: Species, DBH, Height, height-to-crown base, crown width, damage Live: Species, DBH, Height, height-to-crown base, crown width, damage Dead: size & condition of snags until fallen Dead: size & condition of snags until fallen Branch Measurements (BH) Branch Measurements (BH) Largest Branch diameter, branch count (live & dead) Largest Branch diameter, branch count (live & dead) Understory Vegetation Understory Vegetation Average foliage height, coverage (%) by species Average foliage height, coverage (%) by species

21 June 2004Western Mensurationists Meeting Stand Management Cooperative What’s Measured What’s Measured Habitat Indicators Habitat Indicators Depth of duff to mineral soil, FSD (%) Depth of duff to mineral soil, FSD (%) Site Characterization Site Characterization Soil Soil 0 - 6”, ” composited from five sample points per plot 0 - 6”, ” composited from five sample points per plot Forest Floor Forest Floor 1 sq. ft plots, four per measurement sample plot 1 sq. ft plots, four per measurement sample plot Foliar Nutrients Foliar Nutrients Upper 1/3 of crown, 1 year after fertilization, 12 trees per plot Upper 1/3 of crown, 1 year after fertilization, 12 trees per plot

21 June 2004Western Mensurationists Meeting Stand Management Cooperative History History Regional Forest Research Nutrition Project (RFNRP) Regional Forest Research Nutrition Project (RFNRP) Commenced in 1969 (western WA, OR) Commenced in 1969 (western WA, OR) Stand Management Cooperative (SMC) Stand Management Cooperative (SMC) Formed 1985, 1st operational year 1986 Formed 1985, 1st operational year 1986 Western WA, OR, southwestern BC Western WA, OR, southwestern BC In 1991, RFNRP rolled into SMC Nutrition Project In 1991, RFNRP rolled into SMC Nutrition Project

21 June 2004Western Mensurationists Meeting Stand Management Cooperative Cohorts Cohorts RFNRP RFNRP Phase I: Unthinned natural stands, originating 1930’s Phase I: Unthinned natural stands, originating 1930’s Phase II: Thinned natural stands, originating 1930’s Phase II: Thinned natural stands, originating 1930’s Phase III: Young thinned plantations, planted 1940’s Phase III: Young thinned plantations, planted 1940’s Phase IV: Precommercially thinned plantations; 1960’s Phase IV: Precommercially thinned plantations; 1960’s SMC SMC Type I: Variously treated plantations; 1970’s Type I: Variously treated plantations; 1970’s Type II: Variously thinned plantations; 1950’s Type II: Variously thinned plantations; 1950’s Type III: Range of planting spacings; late 80’s - 90’s Type III: Range of planting spacings; late 80’s - 90’s Type IV: Range of planting spacings, genetics; 2K’s Type IV: Range of planting spacings, genetics; 2K’s

21 June 2004Western Mensurationists Meeting Introduction … Study & Modeling Objectives Study & Modeling Objectives Benchmark existing growth simulators Benchmark existing growth simulators Summarize early growth & development of immature, managed stands of Douglas-fir Summarize early growth & development of immature, managed stands of Douglas-fir Investigate and understand the influence of stand structure on growth and yield Investigate and understand the influence of stand structure on growth and yield Produce variable-density growth and yield tables in user-friendly format Produce variable-density growth and yield tables in user-friendly format

21 June 2004Western Mensurationists Meeting Whole-stand Model for Douglas-fir Model Development Model Development Biological / Model Theory Biological / Model Theory Equations / Data / Fitting Equations / Data / Fitting Fit Assessment / Model evaluation Fit Assessment / Model evaluation Model Uses & Future Work Model Uses & Future Work Conclusion Conclusion

21 June 2004Western Mensurationists Meeting Model Development Biological Theory Biological Theory Growing space Growing space As available space decreases, so does potential for growth As available space decreases, so does potential for growth Allometric relationships Allometric relationships Relate growth in part of an organism to another part Relate growth in part of an organism to another part Maximum (limiting) size - density relationships Maximum (limiting) size - density relationships Only so much biomass can be “packed” into available space Only so much biomass can be “packed” into available space

21 June 2004Western Mensurationists Meeting Biological Theory Maximum (limiting) size – density relationship Maximum (limiting) size – density relationship (Xue, et al. 1999)

21 June 2004Western Mensurationists Meeting Biological Theory Every stand has a unique self-thinning boundary line driven by its unique stand allometry Every stand has a unique self-thinning boundary line driven by its unique stand allometry (Turnblom & Burk 2000)

21 June 2004Western Mensurationists Meeting Biological Theory Stand allometry is dynamic, not static; allometric relationships change with stage of development Stand allometry is dynamic, not static; allometric relationships change with stage of development The rate at which a stand variable changes is found by differencing gross growth & respiration (anabolic & catabolic processes, respectively) The rate at which a stand variable changes is found by differencing gross growth & respiration (anabolic & catabolic processes, respectively) The magnitudes of the anabolic and catabolic processes depend on the current state of the stand and is affected by site quality The magnitudes of the anabolic and catabolic processes depend on the current state of the stand and is affected by site quality

21 June 2004Western Mensurationists Meeting Model Theory The current state of the stand can be described by the triplet (stand basal area, quadratic mean DBH, and dominant height) The current state of the stand can be described by the triplet (stand basal area, quadratic mean DBH, and dominant height) Dynamic allometry is captured through simultaneous, coupled rate equations Dynamic allometry is captured through simultaneous, coupled rate equations

21 June 2004Western Mensurationists Meeting Model Equations

21 June 2004Western Mensurationists Meeting Model Fitting Data Untreated, pure DF (> 80% by BA) plots Untreated, pure DF (> 80% by BA) plots Initial BHA averaged 14 years, ranging to 51 years Initial BHA averaged 14 years, ranging to 51 years Site index from 85 to yrs BHA (King) Site index from 85 to yrs BHA (King) 459 plots total; 249 used in fitting, 210 for benchmarking 459 plots total; 249 used in fitting, 210 for benchmarking Measured every 4 yr, ranging 1 to 6, averaging 4.4 Measured every 4 yr, ranging 1 to 6, averaging 4.4 Single plot measurements span 4 to 26 yrs Single plot measurements span 4 to 26 yrs

21 June 2004Western Mensurationists Meeting Model Fitting Parameterization First order, centered differencing used to create a differential data set matching a yield data set constructed from mid-point of yield values First order, centered differencing used to create a differential data set matching a yield data set constructed from mid-point of yield values System of three equations was fit to the data using the objective function System of three equations was fit to the data using the objective function

21 June 2004Western Mensurationists Meeting Fit Evaluation Residual graphs were examined Residual graphs were examined Visual quality of predicted trajectories were assessed for agreement with known biological behaviors Visual quality of predicted trajectories were assessed for agreement with known biological behaviors Attempts were made to augment the system of equations with other system state variables (e.g. stand form) Attempts were made to augment the system of equations with other system state variables (e.g. stand form)

21 June 2004Western Mensurationists Meeting Fit Evaluation Residual plotting Residual plotting

21 June 2004Western Mensurationists Meeting Fit Evaluation Residual plotting Residual plotting

21 June 2004Western Mensurationists Meeting Model Evaluation Results - biological behavior Results - biological behavior Growth & yield dynamics on two sites Growth & yield dynamics on two sites High site (dashed): SI= 145 High site (dashed): SI= 145 Low site (solid): SI= 85 Low site (solid): SI= 85 Otherwise similar in Q, B, H, Age Otherwise similar in Q, B, H, Age

21 June 2004Western Mensurationists Meeting Model Evaluation Biological behavior Biological behavior

21 June 2004Western Mensurationists Meeting Model Evaluation Biological behavior Biological behavior

21 June 2004Western Mensurationists Meeting Model Evaluation Biological behavior Biological behavior

21 June 2004Western Mensurationists Meeting Model Evaluation Trajectory behavior Trajectory behavior

21 June 2004Western Mensurationists Meeting Whole-stand Model for Douglas-fir Model Uses & Future Work Model Uses & Future Work Conclusion Conclusion

21 June 2004Western Mensurationists Meeting Model Uses & Future Work Boundary conditions to individual-based or tree-list models Boundary conditions to individual-based or tree-list models TreeLab (v1.0) TreeLab (v1.0) Variable-density yield simulator for immature, managed Douglas-fir plantations Variable-density yield simulator for immature, managed Douglas-fir plantations Site productivity evaluation & modeling in management- oriented and process-based growth model hybrids (proposal to USFS / AFPA collab.) Site productivity evaluation & modeling in management- oriented and process-based growth model hybrids (proposal to USFS / AFPA collab.)

21 June 2004Western Mensurationists Meeting TreeLab (v1.0)

21 June 2004Western Mensurationists Meeting TreeLab (v1.0)

21 June 2004Western Mensurationists Meeting Site productivity modeling This proposed research seeks to: This proposed research seeks to: Better understand mechanisms driving forest growth & productivity in young DF stands Better understand mechanisms driving forest growth & productivity in young DF stands Examine & interpret association between environmental & HydroGeoMorphic attributes of a site / stand and parameters of the TreeLab whole- stand model Examine & interpret association between environmental & HydroGeoMorphic attributes of a site / stand and parameters of the TreeLab whole- stand model High potential to derive a site-characterization parameter to augment site index High potential to derive a site-characterization parameter to augment site index

21 June 2004Western Mensurationists Meeting Conclusion … Whole-stand Model propositions Whole-stand Model propositions Unique self-thinning boundary for each stand Unique self-thinning boundary for each stand Stand allometry is dynamic, not static Stand allometry is dynamic, not static Changes in stand attributes are represented as a coupled system of rate equations that govern allometry Changes in stand attributes are represented as a coupled system of rate equations that govern allometry Whole-stand model with the most plantation data Whole-stand model with the most plantation data Young data set (for stand development) Young data set (for stand development) Based on assumed maximums (BA, QMD and H top ) Based on assumed maximums (BA, QMD and H top )

21 June 2004Western Mensurationists Meeting … Conclusion Please visit Please visit To download, click on the TREELAB link (LHS) To download, click on the TREELAB link (LHS) Eric C. Turnblom Eric C. Turnblom