21 june 2004 western mensurationists meeting developing a whole-stand model for douglas-fir...

21 June 200421 June 2004 Western Mensurationists MeetingWestern Mensurationists Meeting

Developing a Whole-stand Developing a Whole-stand Model for Douglas-fir Model for Douglas-fir

PlantationsPlantations

Eric C. TurnblomEric C. Turnblom

Samuel D. PittmanSamuel D. Pittman


Whole-stand Model – TopicsWhole-stand Model – Topics

IntroductionIntroduction Model DevelopmentModel Development

Biological / Model TheoryBiological / Model Theory Equations / Data / FittingEquations / Data / Fitting Fit Assessment / Model evaluationFit Assessment / Model evaluation

Model Uses & Future Work Model Uses & Future Work ConclusionConclusion


IntroductionIntroduction

Stand Management CooperativeStand Management Cooperative MissionMission

To provide a continuing source of high-quality To provide a continuing source of high-quality information on the long-term effects of silvicultural information on the long-term effects of silvicultural treatments and regimes on stand and tree growth treatments and regimes on stand and tree growth and development and on wood and product qualityand development and on wood and product quality


IntroductionIntroduction

Stand Management Cooperative Stand Management Cooperative ObjectivesObjectives

To support modelingTo support modeling Installations contain a wider range of treatments Installations contain a wider range of treatments

than current practicethan current practice To support managersTo support managers

Provide timely information and guidance to those Provide timely information and guidance to those who are managing similar standswho are managing similar stands


Stand Management Stand Management CooperativeCooperative

MembershipMembership 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.



Organization:Organization:

Policy Committee Policy Committee (chair, vice-chair) DirectorDirector

Projects, Field Crew, Database Management, Office Staff Project (Technical Advisory Committees, or TAC’s)

Nutrition Silviculture Wood Quality Modeling



What’s measuredWhat’s measured Tree and derived Stand AttributesTree and derived Stand Attributes

Live: Species, DBH, Height, height-to-crown base, Live: Species, DBH, Height, height-to-crown base, crown width, damagecrown width, damage

Dead: size & condition of snags until fallenDead: 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 speciesAverage foliage height, coverage (%) by species



What’s MeasuredWhat’s Measured Habitat IndicatorsHabitat Indicators

Depth of duff to mineral soil, FSD (%)Depth of duff to mineral soil, FSD (%)

Site CharacterizationSite Characterization Soil Soil

0 - 6”, 6 - 12” composited from five sample points per 0 - 6”, 6 - 12” composited from five sample points per plotplot

Forest FloorForest Floor 1 sq. ft plots, four per measurement sample plot1 sq. ft plots, four per measurement sample plot

Foliar NutrientsFoliar Nutrients Upper 1/3 of crown, 1 year after fertilization, 12 trees Upper 1/3 of crown, 1 year after fertilization, 12 trees

per plotper plot



HistoryHistory Regional Forest Research Nutrition Regional Forest Research Nutrition

Project (RFNRP)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 1986Formed 1985, 1st operational year 1986 Western WA, OR, southwestern BCWestern WA, OR, southwestern BC In 1991, RFNRP rolled into SMC Nutrition In 1991, RFNRP rolled into SMC Nutrition

ProjectProject



CohortsCohorts RFNRPRFNRP

Phase IPhase I : Unthinned natural stands, originating : Unthinned natural stands, originating 1930’s1930’s

Phase IIPhase II : Thinned natural stands, originating 1930’s: Thinned natural stands, originating 1930’s Phase IIIPhase III : Young thinned plantations, planted 1940’s: Young thinned plantations, planted 1940’s Phase IVPhase IV : Precommercially thinned plantations; : Precommercially thinned plantations;

1960’s1960’s SMC SMC

Type IType I : Variously treated plantations; 1970’s: Variously treated plantations; 1970’s Type IIType II : Variously thinned plantations; 1950’s: Variously thinned plantations; 1950’s Type IIIType III : Range of planting spacings; late 80’s - 90’s: Range of planting spacings; late 80’s - 90’s Type IVType IV : Range of planting spacings, genetics; 2K’s: Range of planting spacings, genetics; 2K’s


Introduction …Introduction …

Study & Modeling ObjectivesStudy & Modeling Objectives Benchmark existing growth simulators Benchmark existing growth simulators

Summarize early growth & development of Summarize early growth & development of immature, managed stands of Douglas-firimmature, managed stands of Douglas-fir

Investigate and understand the influence of Investigate and understand the influence of stand structure on growth and yieldstand structure on growth and yield

Produce variable-density growth and yield Produce variable-density growth and yield tables in user-friendly formattables in user-friendly format


Whole-stand Model for Whole-stand Model for Douglas-firDouglas-fir

Model DevelopmentModel Development Biological / Model TheoryBiological / Model Theory Equations / Data / FittingEquations / Data / Fitting Fit Assessment / Model evaluationFit Assessment / Model evaluation

Model Uses & Future Work Model Uses & Future Work

ConclusionConclusion


Model DevelopmentModel Development

Biological TheoryBiological Theory Growing spaceGrowing space

As available space decreases, so does potential for As available space decreases, so does potential for growthgrowth

Allometric relationshipsAllometric relationships Relate growth in part of an organism to another partRelate growth in part of an organism to another part

Maximum (limiting) size - density relationshipsMaximum (limiting) size - density relationships Only so much biomass can be “packed” into Only so much biomass can be “packed” into

available spaceavailable space


Biological TheoryBiological Theory

Maximum Maximum (limiting) size (limiting) size – density – density relationshiprelationship

(Xue, et al. 1999)



Every stand Every stand has a unique has a unique self-thinning self-thinning boundary boundary line driven line driven by its by its unique unique stand stand allometryallometry

(Turnblom & Burk 2000)



Stand allometry is dynamic, not static; allometric Stand allometry is dynamic, not static; allometric relationships change with stage of developmentrelationships change with stage of development

The rate at which a stand variable changes is The rate at which a stand variable changes is found by differencing gross growth & respiration found by differencing gross growth & respiration (anabolic & catabolic processes, respectively)(anabolic & catabolic processes, respectively)

The magnitudes of the anabolic and catabolic The magnitudes of the anabolic and catabolic processes depend on the current state of the processes depend on the current state of the stand and is affected by site qualitystand and is affected by site quality


Model TheoryModel Theory

The current state of the stand can be The current state of the stand can be described by the triplet (stand basal area, described by the triplet (stand basal area, quadratic mean DBH, and dominant height) quadratic mean DBH, and dominant height)

Dynamic allometry is captured through Dynamic allometry is captured through simultaneous, coupled rate equationssimultaneous, coupled rate equations


Model EquationsModel Equations

dQdt y13S Q

y1By2H y3 Qy4 By2H y3

dBdt y14S Q

y5By6H y7 Qy5By8H y7

dHdt y15S Q

y9By10H y11 Qy9By10H y12


Model Fitting DataModel Fitting Data

Untreated, pure DF (> 80% by BA) plotsUntreated, pure DF (> 80% by BA) plots

Initial BHA averaged 14 years, ranging to 51 yearsInitial BHA averaged 14 years, ranging to 51 years

Site index from 85 to 145 ft @ 50 yrs BHA (King)Site index from 85 to 145 ft @ 50 yrs BHA (King)

459 plots total; 249 used in fitting, 210 for 459 plots total; 249 used in fitting, 210 for benchmarking benchmarking

Measured every 4 yr, ranging 1 to 6, averaging 4.4Measured every 4 yr, ranging 1 to 6, averaging 4.4

Single plot measurements span 4 to 26 yrsSingle plot measurements span 4 to 26 yrs


Model Fitting ParameterizationModel Fitting Parameterization

First order, centered differencing used to First order, centered differencing used to create a differential data set matching a create a differential data set matching a yield data set constructed from mid-point yield data set constructed from mid-point of yield valuesof yield values

System of three equations was fit to the System of three equations was fit to the data using the objective functiondata using the objective function

miny

eij y j1

m

i1

n

2


Fit EvaluationFit Evaluation

Residual graphs were examined Residual graphs were examined

Visual quality of predicted trajectories Visual quality of predicted trajectories were assessed for agreement with known were assessed for agreement with known biological behaviorsbiological behaviors

Attempts were made to augment the Attempts were made to augment the system of equations with other system system of equations with other system state variables (e.g. stand form) state variables (e.g. stand form)


Fit EvaluationFit Evaluation

Residual plottingResidual plotting


Model Evaluation Model Evaluation

Results - biological behaviorResults - biological behavior Growth & yield dynamics on two sitesGrowth & yield dynamics on two sites

High site (dashed): SI= 145High site (dashed): SI= 145

Low site (solid): SI= 85Low site (solid): SI= 85

Otherwise similar in Q, B, H, AgeOtherwise similar in Q, B, H, Age


Model EvaluationModel Evaluation

Biological behaviorBiological behavior


Model EvaluationModel Evaluation

Trajectory behaviorTrajectory behavior


Whole-stand Model for Whole-stand Model for Douglas-firDouglas-fir

Model Uses & Future Work Model Uses & Future Work

ConclusionConclusion


Model Uses & Future WorkModel Uses & Future Work

Boundary conditions to individual-based or Boundary conditions to individual-based or tree-list modelstree-list models

TreeLab (v1.0) TreeLab (v1.0)

Variable-density yield simulator for immature, Variable-density yield simulator for immature, managed Douglas-firmanaged Douglas-fir plantations plantations

Site productivity evaluation & modeling in Site productivity evaluation & modeling in management-oriented and process-based growth management-oriented and process-based growth model hybrids (proposal to USFS / AFPA collab.)model hybrids (proposal to USFS / AFPA collab.)


TreeLab (v1.0)TreeLab (v1.0)


Site productivity modelingSite productivity modeling

This proposed research seeks to:This proposed research seeks to: Better understand mechanisms driving forest Better understand mechanisms driving forest

growth & productivity in young DF standsgrowth & productivity in young DF stands

Examine & interpret association between Examine & interpret association between environmental & HydroGeoMorphic attributes environmental & HydroGeoMorphic attributes of a site / stand and parameters of the of a site / stand and parameters of the TreeLab whole-stand modelTreeLab whole-stand model

High potential to derive a site-characterization High potential to derive a site-characterization parameter to augment site indexparameter to augment site index


Conclusion …Conclusion … Whole-stand Model propositionsWhole-stand Model propositions

Unique self-thinning boundary for each standUnique self-thinning boundary for each stand

Stand allometry is dynamic, not staticStand allometry is dynamic, not static

Changes in stand attributes are represented as a Changes in stand attributes are represented as a coupled system of rate equations that govern coupled system of rate equations that govern allometryallometry

Whole-stand model with the most plantation Whole-stand model with the most plantation datadata Young data set (for stand development)Young data set (for stand development) Based on assumed maximums Based on assumed maximums (BA, QMD and H(BA, QMD and Htoptop))


… … ConclusionConclusion

Please visit <http:://www.standmgt.org/>Please visit <http:://www.standmgt.org/>

To download, click on the TREELAB link To download, click on the TREELAB link (LHS)(LHS)

Eric C. Turnblom <[email protected]>Eric C. Turnblom <[email protected]>

21 june 2004 western mensurationists meeting developing a whole-stand model for douglas-fir...

Documents

database management

western wa

young thinned plantations

tree growth

sphase iv

stype iv

treated plantations

range of planting spacings