Unveiling the New Alder Unveiling the New Alder Growth and Yield Model and Growth and Yield Model and a Example of the Economics a Example of the Economics

of Growing Alderof Growing AlderDavid HibbsDavid Hibbs

Forest Ecosystems and SocietyForest Ecosystems and SocietyHardwood Silviculture CooperativeHardwood Silviculture Cooperative

Oregon State UniversityOregon State University

OutlineOutline

ModelingModelingRAP-ORGANONRAP-ORGANONEconomicsEconomics

What is a growth and yield What is a growth and yield model?model?

(and why does anyone care?)(and why does anyone care?)Models predict the futureModels predict the future

How big will the trees grow? By when?How big will the trees grow? By when?How many trees will there be?How many trees will there be?How much wood will those trees yield?How much wood will those trees yield?What is the quality of that wood?What is the quality of that wood?How does management change these How does management change these

answers?answers?Models are pretty good but ……Models are pretty good but ……

Forest Growth and Yield ModelsForest Growth and Yield Models

There are several modeling systems in There are several modeling systems in the PNW and each covers several the PNW and each covers several speciesspecies

All have their strengths and All have their strengths and weaknessesweaknesses

Some already include a poor natural Some already include a poor natural alder modelalder model

None include a managed alder modelNone include a managed alder modelWe worked with the ORGANON systemWe worked with the ORGANON system

ORGANONORGANON

Modeling system developed by David Modeling system developed by David Hann at OSUHann at OSU

Is the modeling system used by the Is the modeling system used by the UW Stand Management CooperativeUW Stand Management Cooperative

Are several versions of it for different Are several versions of it for different parts of the PNW (improved parts of the PNW (improved accuracy)accuracy)

New version: RAP-ORGANONNew version: RAP-ORGANON

RAP-ORGANONRAP-ORGANON

Built with data from the OSU Built with data from the OSU Hardwood Silviculture Cooperative and Hardwood Silviculture Cooperative and Weyerhaeuser Co.Weyerhaeuser Co.

Covers western OR and WA, southern Covers western OR and WA, southern BCBC

Oldest alder plantations in model are Oldest alder plantations in model are 18 years old18 years old

Model extrapolations beyond 30 or 35 Model extrapolations beyond 30 or 35 years may not be wiseyears may not be wise

Maximum predicted predicted D for a open D for a open grown tree grown tree

Red Alder Diameter Growth Rate Equation C From Weighted Summation Method

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 5 10 15 20 25 30

DBH

Ma

xim

um

An

nu

al

Dia

me

ter

Gro

wth

Ra

te

SI = 40 SI = 60 SI = 80

RAP-ORGANONRAP-ORGANON

Examples of what you can get from itExamples of what you can get from itThere are many more kinds of questions There are many more kinds of questions

one can askone can askA pretty productive place (but not the A pretty productive place (but not the

best, SI20=83ft) in SW Washington – best, SI20=83ft) in SW Washington – one ¼ ac plot of treesone ¼ ac plot of treesResults will vary with site quality and Results will vary with site quality and

management optionsmanagement optionsAre just beginning to explore what Are just beginning to explore what

ORGANON can tell usORGANON can tell us

Age of thinningAge of thinning

Stand age (yrs)

DIAMETER(in)

Thin at age 7 to different Thin at age 7 to different densitiesdensities

(results at age 30)(results at age 30)

Trees per acre Trees per acre

Thin at 7 to 217 Thin at 7 to Thin at 7 to 217 Thin at 7 to 178178

Tree diameter (inch) Tree diameter (inch)

EconomicsEconomics

Cost exampleCost exampleSite preparation: $85-Site preparation: $85-135/ac135/acPlanting: $315/acPlanting: $315/acThinning: $125/acThinning: $125/acHarvesting: $2600/acHarvesting: $2600/acTrucking: $1150/acTrucking: $1150/ac

Return exampleReturn example5” : $475/mbf5” : $475/mbf6-7” : $550/mbf6-7” : $550/mbf8-9” : $600/mbf8-9” : $600/mbf10-11” : 10-11” : $650/mbf$650/mbf12”+ : $700/mbf12”+ : $700/mbf

Mill-delivered valueMill-delivered valueA comparison of management choicesA comparison of management choices

Thin at age: Thin to tpa: Gross return at 30 yrs:

No No thin $11,683

7 178 $10,940

7 217 $11,529

7 247 $11,939

12 217 $11,120

Mill-delivered valueMill-delivered valueA comparison of management choicesA comparison of management choices

Thin at age: Thin to tpa: Gross return at 30 yrs:

No No thin(295) $11,683

7 178 $10,940

7 217 $11,529

7 247 $11,939

12 217 $11,120

DBH (in)

Age (yrs)

ConclusionsConclusions

RAP-ORGANON simulates alder plantations wellRAP-ORGANON simulates alder plantations well Example results will vary with:Example results will vary with:

Rotation lengthRotation lengthSite qualitySite qualityLog price structureLog price structureDiscount rateDiscount rateLog lengthLog length

Example highlights the questions about Example highlights the questions about management options and implications we management options and implications we need to explore and understandneed to explore and understand

Questions/DiscussionQuestions/Discussion

Red Alder Diameter Growth Rate Equation C From Weighted Summation Method

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 5 10 15 20 25 30

DBH

Max

imu

m A

nn

ual

Dia

met

er G

row

th R

ate

SI = 40 SI = 60 SI = 80