© 2010, H.Lee Allen

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Potential Productivity forSpruce Forests

f M i d E t C dof Maine and Eastern Canada

H. Lee AllenDepartment of Forestry & Environmental Resources

North Carolina State University

ProFOR ConsultingCary, NC

Progressive Forestry for Production Forests

Questions

• What are the MAIs of stands that you are• What are the MAIs of stands that you are currently cutting?

• What will be the MAIs of their replacements?

© 2010, H.Lee Allen

2

20

25

What is Potential Productivity?

10

15

20

al G

row

th

m3 /h

a/yr

MAI=6 m3/ha/yr

Future?

Present

MAI=15 m3/ha/yr

0

5

0 10 20 30 40 50 60 70

Ann

u

Age years

y

Past MAI=3 m3/ha/yr

What is Possible? Southern Pine Example - 2 to 20 m3/ha/yr

Fox, Jokela, Allen 2004

© 2010, H.Lee Allen

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Managing ProductivityManaging Productivity Requires an Understanding

of the Factors Affecting ProductivityProductivity

Stand Productivity

• Physiological processes– Light interception– Carbon gain (photosynthesis)– Carbon partitioning

© 2010, H.Lee Allen

4

Productivity = ƒ(Intercepted Light)Norway Spruce - Flakaliden

Optimum Nutrition

Bergh et al 1999, FEM

INCOMING RADIATIONLatitude Location MJ/m2/day

54N Central Canada 9.8

48N Seattle, USA 11.5

36N Raleigh, NC 14.8

22N Jamshedspur, India 19.6

3S M B 17 13S Manaus, Br 17.1

34S Sidney, Aust 17.2

43S Hobart, Aust 14.8

Landsberg and Gower 1997

© 2010, H.Lee Allen

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Estimated Radiation by Month – 47°NPhotosynthetically Active Radiation

350

400

100

150

200

250

300

nthl

y PA

R M

J/m

2 /mo

0

50

100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mo

Slope and Aspect Effects on Radiation47°N

10%

15%

-10%

-5%

0%

5%

Cha

nge

in R

adia

tion

0%

10%

20%

Slope

-20%

-15%

0 45 90 135 180 225 270 315 360

C

Aspect - Degrees from North

30%

© 2010, H.Lee Allen

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Factors Affecting Light Interception

• Leaf area• Canopy gap fractionpy g p• Seasonal duration

– Production– Senescence

• Crown ArchitectureClumpiness of foliage)– Clumpiness of foliage)

– Crown shape– Angle of foliage display

Light Interception and Leaf Area Index

100

Beer’s-Lambert Law

I = 1 – (e (-k *L))

e = 24.7

e = 4.1

30405060708090

Ligh

t Int

erce

ptio

n

LAI = LAI = 44

k = 0.6

01020

0 1 2 3 4 5 6 7

Leaf Area Index

%

LAI LAI = 1= 1

© 2010, H.Lee Allen

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30

35yr

Productivity – Leaf Area Index

10

15

20

25

ual P

rodu

ctio

n m

3 /ha/

y

Growth Efficiency

<1 to ? m3/ha/yr per unit of LAI

0

5

0 1 2 3 4 5 6 7 8

Annu

Leaf Area Index

MOST FORESTSARE NOT EFFECTIVELY

CAPTURING OR UTILIZINGLIGHT ENERGY TO PRODUCE

STEMWOOD

© 2010, H.Lee Allen

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Factors Affecting Leaf Areaand Growth Efficiency

• Genetics

• Stand Density

• Resource AvailabilityResource Availability

• Age

30

35

ha/y

r

Factors Affecting Leaf Area & Growth Efficiency

10

15

20

25

Ste

m P

rodu

ctio

n m

3 /h

Nutrients

Water

Temperature

Genetics

?Stocking

CO2

0

5

0 1 2 3 4 5 6

Annu

al

Leaf Area Index

Stocking

© 2010, H.Lee Allen

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What is POSSIBLE for Spruce?Norway Spruce – Sweden

25

30nt yr

Control Water Nutrients W + N

10

15

20

odic

ann

ual i

ncre

men

ce tr

eatm

ent

m3 /h

a/y

0

5

Asa (57° N) - 28 yrs old Flakaliden (64° N) - 40 yrs old

Perio

sinc

16 years of treatment

Albaugh et al, 2009 FEM

17 years of treatment

Norway SpruceFlakaliden Nutrient x Water Study

Control +Nutrients

1992

© 2010, H.Lee Allen

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Norway SpruceFlakaliden Nutrient x Water Study

Control +Nutrients

2009

LAI = 7

Response to Nutrient and Water AdditionsNorway Spruce – Northern Sweden

© 2010, H.Lee Allen

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203 /h

a/yr

C

Stem Production and Leaf Area IndexFlakaliden 1987- 2001

5

10

15

Ann

ual I

ncre

men

t m

3 I

IL

F

Flakaliden maximum GE2.5 m3/ha/yr per unit LAI

00 1 2 3 4 5 6 7 8

Per

iodi

c

Projected Leaf Area IndexData from Bergh et al 2005, FEM and Sune Linder

30

35

3 /ha/

yr

Genetics

Factors Affecting ProductivityNorway Spruce in Sweden

10

15

20

25

Ann

ual I

ncre

men

t m

3

Nutrients

Temperature

Water

Genetics

0

5

0 1 2 3 4 5 6 7 8 9 10 11

Cur

rent

A

Projected Leaf Area Index

Stocking

Liberally interpreted from Bergh et al 2005 and others

© 2010, H.Lee Allen

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Questions Remain for the Acadian Forest!

• What are the factors that limit stand leaf area production and retention on a site and standproduction and retention …on a site and stand development (time) specific basis?

• What are the factors that limit growth efficiency …on a site and stand development specific basis?

• Is it biologically possible to ameliorate any of these• Is it biologically possible to ameliorate any of these limitations?

• Should these limitations be ameliorated?