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!
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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
Model projections 2001 TIPSY, TWIGS
0100200300400500600700
2000 2020 2040 2060 2080 2100 2120
Year
Yie
ld
TWIGS Sx-Ep TWIGS Sx TIPSY Sx
Model projections 2001 TIPSY, TWIGS
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
Findings – model (dbh) & data (dbh)
0
5
10
15
2000 2002 2004 2006 2008
Year
dbh,
cm
Little L data
Findings – model (dbh) & data (dbh)
0
5
10
15
2000 2002 2004 2006 2008
Year
dbh,
cm
Mid M data
Findings – model (dbh) & data (dbh)
0
5
10
15
2000 2002 2004 2006 2008
Year
dbh,
cm
Lot Lt data
Findings – model (dbh) & data (dbh)
• 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
Background and rationale
• Vegetation management – Investment
• Increase or maintain value of stand
• Value – Yield– Wood quality
• WPW attack
Background and rationale
• Vegetation management – Investment
• Increase or maintain value of stand
• Value – Yield– Wood quality
• WPW attack
• Change in stand’s value
Background and rationale
• Cost of treatment – Compound
• What rate to use?
Background and rationale
• Cost of treatment – Compound
• What rate to use?
• Revenue from stand – $ per m3 * yield (DPG stats)– Ignore quality in determination– Ignore aspen and birch
Background and rationale
• Cost of treatment – Compound
• What rate to use?
• 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
Cozins’ Vama Vama study area
• Prince George District• 3 sites• SBS wk1
Cozins’ Vama Vama study area
• Prince George District• 3 sites• SBS wk1• Logged 1969
Cozins’ Vama Vama study area
• Prince George District• 3 sites• SBS wk1• Logged 1969• Burned 1970
Cozins’ Vama Vama study area
• Prince George District• 3 sites• SBS wk1• Logged 1969• Burned 1970• Planted 1971
– 2+1 bare root spruce
Cozins’ Vama Vama study area
• 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
• 3 brushing treatments – 1985
• 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
• 3 brushing treatments – 1985
• 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)
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)
• Growth– Reduced in Alternate and
Control treatments
Vama Vama study 22 year results (2006)
• 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%
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
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%
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%
• 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
Alt Brush Brush Natural
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
• Brushing – Increases yield
0
100
200
300
400
500
600
30 40 50 60 70 80 90 100
Stand age
Yiel
d
Alt Brush Brush Natural
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
• 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
Vama Vama Economic assessments
• 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%
Brushing Alternate Natural
Vama Vama Economic assessments
• Sensitivity case 2: – Stumpage 30, 18, 5, 1– Brushing 500– 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
Cost of brushing minimum impactNPV < $40,000
Vama Vama Economic assessments
• Sensitivity case 3: – Stumpage 39, 22, 10, 5– 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
$ at
2%
Brushing Alternate Natural
NPV > $40,000Stumpage > brushing cost
Vama Vama Economic assessments
• Sensitivity case 4: – Stumpage 30, 18, 5, 1– Brushing 350– 3% interest
$0
$10,000
$20,000
$30,000
$40,000
$50,000
20 30 40 50 60 70 80 90 100
NPV
$ a
t 3%
Brushing Alternate Natural
Natural best at 90 years
Vama Vama Economic assessments
• Sensitivity case 5: – Stumpage 30, 18, 5, 1– Brushing 350– 4% interest
$0
$10,000
$20,000
$30,000
$40,000
$50,000
20 30 40 50 60 70 80 90 100
NPV
$ a
t 4%
Brushing Alternate Natural
Natural best at 75 years
Vama Vama Economic assessments
• Sensitivity case 6: – Stumpage 30, 18, 5, 1– Brushing 350– 5% interest
$0
$10,000
$20,000
$30,000
$40,000
$50,000
20 30 40 50 60 70 80 90 100
NPV
$ at
5%
Brushing Alternate Natural
Natural best at 63 years
Vama Vama Economic assessments
• Sensitivity case 7: – Stumpage 30, 18, 5, 1– Brushing 350– 6% interest
-$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%
Brushing Alternate Natural
Natural best at 45 years
-$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%
Brushing Alternate Natural
Vama Vama Economic assessments
• Sensitivity case 7: – Stumpage 30, 18, 5, 1– Brushing 350– 6% interest
– Interest largest impact on NPV Natural best at 45 years
Vama Vama Economic assessments
• Sensitivity case 4: – Stumpage 30, 18, 5, 1– Brushing 350– 3% interest
• 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%
Brushing Alternate Natural
Natural best at 90 years
Vama Vama Economic assessments
• 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
Vama Vama Economic assessments
• 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
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
Vama Vama Economic assessments
• 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
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
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)
Conclusions Vama Vama Study
• Removing broadleaf component– Not a good investment in these stands
• 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)
Conclusions Vama Vama Study
• Removing broadleaf component– Not a good investment in these stands
• 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
Conclusions Vama Vama Study
• Removing broadleaf component– Not a good investment in these stands
• 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
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)
•• Where applicableWhere applicable–– Change management practicesChange management practices–– Reduce use of broadcast vegetation controlReduce use of broadcast vegetation control
Photo: K. Menounos
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)
•• 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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**
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
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