Benefits of managing complex even aged stands in the SBSVama Vama Economic assessments • Real...

Benefits of managing complex even aged stands in the SBS

Chris HawkinsUniversity of Northern British Columbia, Prince George, BC

February 6, 2008February 6, 2008Timber Growth and ValueTimber Growth and Value

Smithers, BCSmithers, BC

Outline

• Musings – models and data• Background and rationale• The study (Vama Vama)• Findings• What does it mean?• What to do?

Mixed species (complex) stands

• Can mixtures– Provide greater yields or other benefits– c.f. single species plantation

• Combine species– Achieve goals

• Complementary – Different attributes

• Facilitation– Species +ve another– N fixing tree species

• Older literature– Suggests no!

02468

10121416

0 1000 2000 3000 4000 5000

Deciduous sph

Spru

ce d

bh

Aspen Birch

Assumption

• Aggressive vegetation management– Legislated

PresenterPresentation NotesBC = forestry dependent province44.5 million hectares of commercial forest land; Harvest = 70 million cubic meters20% of Canadian totalPlant more than 200 million seedlings annuallyValues of shipments = 24 billion CDN$; ~$14.6 billion EuroAccounts for 1/3 of Canada’s total forestry shipmentsEmploys 270 k: Direct = 90k and 180 indirect

Three models

• TWIGS– Individual tree distance independent– Mixedwood (complex stand) model

• TIPSY– Individual tree distance dependent– Even age (one species) model

• SORTIE-ND– Individual tree distance dependent– Mixedwood (complex stand) model

Model projections 2001 TIPSY

0100200300400500600700

2000 2020 2040 2060 2080 2100 2120

Year

Yie

ld

TIPSY Sx

Model projections 2001 TIPSY, TWIGS

0100200300400500600700

2000 2020 2040 2060 2080 2100 2120

Year

Yie

ld

TWIGS Sx TIPSY Sx


0100200300400500600700

2000 2020 2040 2060 2080 2100 2120

Year

Yie

ld

TWIGS Sx-Ep TWIGS Sx TIPSY Sx


0100200300400500600700

2000 2020 2040 2060 2080 2100 2120

Year

Yie

ld

TWIGS Sx-Ep TWIGS Sx TIPSY Sx

Broadleaf enhances conifer yield (Ep Sx): complementary?

Model projections

• TWIGS– Greater yield with broadleaf than without– Economic rotation in about 20 to 25 years

• TIPSY– Greater spruce yields than TWIGS– Economic rotation in about 50 years

Sinclair Mills

• 2002 stocking– No birch (No)

• 1052 sph Sx – 370 sph Ep– Little birch (Little)

• 1300 sph Sx – 1000 sph Ep– Middle birch (Mid)

• 1156 sph Sx – 2320 sph Ep– Lots birch (Lot)

• 1104 sph Sx – 3810 sph Ep

TWIGS model (dbh)

0

5

10

15

20

25

2000 2005 2010 2015 2020 2025

Year

dbh,

cm

No

TWIGS model (dbh)

0

5

10

15

20

25

2000 2005 2010 2015 2020 2025

Year

dbh,

cm

No Little

TWIGS model (dbh)

0

5

10

15

20

25

2000 2005 2010 2015 2020 2025

Year

dbh,

cm

No Little Mid

TWIGS model (dbh)

0

5

10

15

20

25

2000 2005 2010 2015 2020 2025

Year

dbh,

cm

No Little Mid Lot

TWIGS model (dbh)

0

5

10

15

20

25

2000 2005 2010 2015 2020 2025

Year

dbh,

cm

No Little Mid Lot

Small dbh difference over 20 year period: 14 – 34 years

Findings – model (dbh) & data (dbh)

0

5

10

15

2000 2002 2004 2006 2008

Year

dbh,

cm

No N data


0

5

10

15

2000 2002 2004 2006 2008

Year

dbh,

cm

Little L data


0

5

10

15

2000 2002 2004 2006 2008

Year

dbh,

cm

Mid M data


0

5

10

15

2000 2002 2004 2006 2008

Year

dbh,

cm

Lot Lt data


• None and little Ep– Track or exceed TWIGS projection

• Mid and Lot Ep– Starting to fall below TWIGS projection

• Below a threshold– Birch promotes spruce radial growth

• What is the threshold?• Complementary interaction?

Hypothesis test: fall 2002 – SBSvk

• Brush free radii plots around crop tree (Sx-Ep)– 0, 1, 2 and 4 m– dbh primary response variable

• Sensitive to competition

• Establishment dbh ± SEM prior to treatment– 0 m - 9.8 cm ± 0.26– 1 m - 10.0 cm ± 0.25– 2 m - 9.9 cm ± 0.22– 4 m - 10.3 cm ± 0.34

• Growth predictions?

Background and rationale

• Vegetation management – Investment

• Increase or maintain value of stand




• Value – Yield– Wood quality

• WPW attack




• Value – Yield– Wood quality

• WPW attack

• Change in stand’s value


• Cost of treatment – Compound

• What rate to use?




• Revenue from stand – $ per m3 * yield (DPG stats)– Ignore quality in determination– Ignore aspen and birch




• Revenue from stand – $ per m3 * yield (DPG stats)– Ignore quality in determination– Ignore aspen and birch

• Net present value (NPV)

Cozins’ Vama Vama study area

• Prince George District• 3 sites


• Prince George District• 3 sites• SBS wk1


• Prince George District• 3 sites• SBS wk1• Logged 1969


• Prince George District• 3 sites• SBS wk1• Logged 1969• Burned 1970


• Prince George District• 3 sites• SBS wk1• Logged 1969• Burned 1970• Planted 1971

– 2+1 bare root spruce


• Prince George District• 3 sites• SBS wk1• Logged 1969• Burned 1970• Planted 1971

– 2+1 bare root spruce

• High hazard WPW area

Vama Vama study

• 3 brushing treatments – 1985

Vama Vama study


• Treatments – Manual Brushed (50 X 115 m)– Natural (Control) (50 X 115 m)– Alternate brushed strips (7 m, retain 5 m strip)

• E – W orientation

Vama Vama study


• Treatments – Manual Brushed (50 X 115 m)– Natural (Control) (50 X 115 m)– Alternate brushed strips (7 m retain 5 m strip)

• E – W orientation

• Measured winters 01/02, 03/04, 06/07

Vama Vama study 5 year results (1989)

• WPW attack %– Brush – 21.3– Alternate – 14.8– Control – 15.1 – Increased attack may decrease

future wood quality• Defects first log (5 m)


• WPW attack %– Brush – 21.3– Alternate – 14.8– Control – 15.1 – Increased attack may decrease

future wood quality• Defects first log (5 m)

• Growth– Reduced in Alternate and

Control treatments


• WPW attack– Not different among treatments

• ~ 3 %

• Spruce growth (census)Alt Brush Brushed Natural

dbh, cm 11.16 (0.19) 11.22 (0.20) 9.83 (0.17)

height, m 8.52 (0.11) 7.80 (0.10) 7.89 (0.11)

Vama Vama study: Economic assumptions

• Crown is the owner– Stumpage is revenue rather than cost – inflate at 1.4%



• Brushing cost– $350, $400, $500 per ha




• Real interest rate– Interest – inflation rate– 2%, 3%, 4%, 5% 6%




• Real interest rate– Interest – inflation rate– 2%, 3%, 4%, 5% 6%

• Stumpage $ per m3– Sx – 30, 39– Pl – 18, 22– Bl – 5, 10– At – 1, 5

Vama Vama growth

• SORTIE-ND projections– Brushed 400 m3 at 66 years– Alternate brushed 400 m3 at 70 years– Natural 400 m3 at 73 years

0

100

200

300

400

500

600

30 40 50 60 70 80 90 100

Stand age

Yiel

d

Alt Brush Brush Natural

0

100

200

300

400

500

600

30 40 50 60 70 80 90 100

Stand age

Yiel

d


Vama Vama growth


• Brushing – Increases yield

0

100

200

300

400

500

600

30 40 50 60 70 80 90 100

Stand age

Yiel

d


Vama Vama growth


• Brushing – Increases yield– Increased value?

Vama Vama Economic assessments

• Base case: – Stumpage 30, 18, 5, 1– Brushing 350– 2% interest

$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ a

t 2%

Brushing Alternate Natural


• Sensitivity case 1: – Stumpage 30, 18, 5, 1– Brushing 400– 2% interest

$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ a

t 2%




$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ a

t 2%


Cost of brushing minimum impactNPV < $40,000



$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ at

2%


NPV > $40,000Stumpage > brushing cost



$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ a

t 3%


Natural best at 90 years



$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ a

t 4%





$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ at

5%





-$10,000

$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ at

6%



-$10,000

$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ at

6%




– Interest largest impact on NPV Natural best at 45 years



• Social discount

$0

$10,000

$20,000

$30,000

$40,000

$50,000

20 30 40 50 60 70 80 90 100

NPV

$ a

t 3%




• Real interest rate over stands’ life– Mutual funds (conservative) stocks, bonds, T bill, money

Inception Real Interest Type Inflation

1967 5.68 Stock 4.621972 3.59 Bond 4.711980 5.87 Energy 3.331986 4.51 Stock 2.491986 2.51 Money market 2.491987 5.59 Stock 2.411987 5.69 Stock 2.411988 12.27 Metals 2.331991 1.91 T Bill 1.9Mean 5.29


• Real interest rate over stands’ life– Mutual funds (conservative) stocks, bonds, T bill, money– 2% is not a reasonable real interest rate

Inception Real Interest Type Inflation



• Real interest rate over stands’ life– Mutual funds (conservative) stocks, bonds, T bill, money– 2% is not a reasonable real interest rate

• 4% may be appropriateInception Real Interest Type Inflation


Vama Vama Economic comparisons

• Comparison Control Brush & Alternate at 80 years and 4%– Increase stumpage – decrease difference at a given cost

-$6,000

-$5,000

-$4,000

-$3,000

-$2,000

-$1,000

$0Brush Alt Brush Alt Brush Alt

350 350 400 400 500 500

NPV

diff

eren

ce

Base stumpage Enhanced stumpage

Vama Vama Economic comparisons

• Comparison Control Brush & Alternate at 80 years and 4%– Increase stumpage – decrease difference at a given cost– Brushing was a negative investment

-$6,000

-$5,000

-$4,000

-$3,000

-$2,000

-$1,000

$0Brush Alt Brush Alt Brush Alt

350 350 400 400 500 500

NPV

diff

eren

ce

Base stumpage Enhanced stumpage

Conclusions Vama Vama Study

• Removing broadleaf component– Not a good investment on these sites

• 4% NPV best in Natural at projected rotation (80 years)


• Removing broadleaf component– Not a good investment in these stands


• Leaving broadleaf component (At, Ep)– Reduced WPW attack at critical stage

• Enhanced wood quality (1st log)




• Leaving broadleaf component (At, Ep)– Reduced WPW attack at critical stage

• Enhanced wood quality (1st log)– Increased structural and species diversity– Increased stand value



• 4% NPV best in Natural at projected rotation (80 years)• Leaving broadleaf component (At, Ep)

– Reduced WPW attack at critical stage• Enhanced wood quality (1st log)

– Increased structural and species diversity– Increased stand value

• Conventional management– Unexpected economic outcome

Recommendations•• Assess impact of silviculture treatments in mixed species standsAssess impact of silviculture treatments in mixed species stands

–– Future Future •• Forest health Forest health •• Diversity (structure and species)Diversity (structure and species)•• Value (quantity and quality)Value (quantity and quality)

Photo: K. Menounos



•• Where applicableWhere applicable–– Change management practicesChange management practices–– Reduce use of broadcast vegetation controlReduce use of broadcast vegetation control

Photo: K. Menounos



•• Where applicableWhere applicable–– Change management practicesChange management practices–– Reduce use of broadcast vegetation controlReduce use of broadcast vegetation control–– Promote growth of complex stands Promote growth of complex stands

•• Where applicable (do we know where?)Where applicable (do we know where?)

Photo: K. Menounos

Question from introduction

•• Impact of brush free radii: 0, 1, 2 and 4Impact of brush free radii: 0, 1, 2 and 4–– Spruce dbh growth with birchSpruce dbh growth with birch

Hypothesis test (2002): results fall 2007

• dbh growth after 5 years– 0 m – 5.6 cm– 1 m – 5.9 cm– 2 m – 5.4 cm– 4 m – 6.6 cm

• Significance after 5 years– 0, 1 and 2 m nsd– 4 m > 0, 1, and 4 m

• What is happening?– Positive effect of broadleaf?

0

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0 m 1 m 2 m 4 m

200220032004200520062007

**

Acknowledgements• Funding provided by

Forest Renewal British Columbia (FRBC)FRBC-Slocan Mixedwood ChairForest Investment Account British Columbia (FSP)

• Technical support provided byNicole Balliet Jennifer LangeKim Menounos Anne ColeTracy Murray Cindy BakerTodd Bondaroff Chris MaundrellDeanna Danskin Kari BondaroffKatie Krc Bob MadillKyle Runzer Shona SmithJenny Li Bruce Rogers

PresenterPresentation NotesAs usualThose who paid andThose who have done the work

Benefits of managing complex even aged stands in the SBSOutlineMixed species (complex) standsAssumptionThree modelsModel projections 2001 TIPSYModel projections 2001 TIPSY, TWIGSModel projections 2001 TIPSY, TWIGSModel projections 2001 TIPSY, TWIGSModel projectionsSinclair MillsTWIGS model (dbh)TWIGS model (dbh)TWIGS model (dbh)TWIGS model (dbh)TWIGS model (dbh)Findings – model (dbh) & data (dbh)Findings – model (dbh) & data (dbh)Findings – model (dbh) & data (dbh)Findings – model (dbh) & data (dbh)Findings – model (dbh) & data (dbh)Hypothesis test: fall 2002 – SBSvk Background and rationaleBackground and rationaleBackground and rationaleBackground and rationaleBackground and rationaleBackground and rationaleCozins’ Vama Vama study areaCozins’ Vama Vama study areaCozins’ Vama Vama study areaCozins’ Vama Vama study areaCozins’ Vama Vama study areaCozins’ Vama Vama study areaVama Vama studyVama Vama studyVama Vama studyVama Vama study 5 year results (1989)Vama Vama study 5 year results (1989)Vama Vama study 22 year results (2006)Vama Vama study: Economic assumptionsVama Vama study: Economic assumptionsVama Vama study: Economic assumptionsVama Vama study: Economic assumptionsVama Vama growthVama Vama growthVama Vama growthVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic assessmentsVama Vama Economic comparisonsVama Vama Economic comparisonsConclusions Vama Vama StudyConclusions Vama Vama StudyConclusions Vama Vama StudyConclusions Vama Vama StudyRecommendations Recommendations Recommendations Question from introductionHypothesis test (2002): results fall 2007Acknowledgements

Benefits of managing complex even aged stands in the SBSVama Vama Economic assessments • Real...

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