soil and site productivity concepts for forestry sustainability?

29
© 2012, H.L. Allen, ProFOR Consulting 1 Soil and Site Productivity Concepts for Forestry H. Lee Allen ProFOR Consulting Cary, NC [email protected] Progressive Forestry for Production Forests Sustainability? Broad view Maintain capacity of a landscape to provide the range of products, services, and values desired by society for future generations Narrow view Maintain capacity of the soil to produce a nondeclining amount of woody biomass System inputs? Required, desired, not feasible, not allowed

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Page 1: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting1

Soil and Site Productivity Concepts for Forestry

H. Lee AllenProFOR Consulting

Cary, [email protected]

Progressive Forestry for Production Forests

Sustainability?• Broad view

– Maintain capacity of a landscape to provide the range of  products, services,  and values desired by society for future generations

• Narrow view– Maintain capacity of the soil to produce a non‐declining amount of woody biomass

• System inputs?– Required, desired, not feasible, not allowed

Page 2: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting2

SoilI am soil.Look at me!Smell me, touch me, feel mewalk on me with your bare feetsing and dance on meobserve me closely…as a living, changing , vital linkin a vast and ancient webintricate and delicateof which you too are part…

Nurture meplant in meshelter me with treesrescue me whereI am thin and wornbut above allteach your children…to know meand to value me…I am soil.                          

Excerpts from Shelia M. Weaver’s 1987 poem “Soil”The Canadian Theosophist 68(4).

0

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150

200

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0 2 4 6 8 10 12 14 16 18 20 22 24 26

Annu

al Growth     ft3/acre/yr

Age   years

Narrow View of Sustainability

Next Rotation? MAI =65 ft3/acre/yr

Next Rotation? MAI = 200 ft3/acre/yr

This Rotation MAI = 130 ft3/acre/yr

Page 3: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting3

Managing for Sustained Productivity Requires an Understanding of the Factors Affecting Productivity

Production Varies Across SitesWhy?

• Species composition• Stocking• Site conditions

– Soil– Climate

• Age• Management

Page 4: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting4

Southern Pine Success Story1 to10 tons/acre/yr

Fox, Jokela, Allen 2004

Stand Productivity• Physiological processes

– Light interception– Light use efficiency

• Carbon gain (photosynthesis)• Carbon partitioning

Page 5: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting5

Light Interception and Leaf Area Index

Beer’s-Lambert Law

I = 1 – (e (-k *L))

k = 0.6

0102030405060708090

100

0 1 2 3 4 5 6 7

Leaf Area Index

% L

ight

Inte

rcep

tion

LAI = 1

LAI = 4

Page 6: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting6

0

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200

300

400

500

600

0 1 2 3 4 5

VOLU

ME GRO

WTH

     ft3/acre/yr

LEAF AREA INDEX

Light Interception

Growth Efficiency

Stand Productivity• Factors affecting physiological processes

– Genetics• species, genotype within species

– Stand density– Resource availability

• Light, water, NUTRIENTS, temperature

– Age• Size and maturity

Page 7: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting7

0

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0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Ann

ual V

olum

e G

row

th f

t3 /ac

/yr

Leaf Area Index

Nutrients

Genetics

Water

Temperature

Factors Influencing Leaf Area and GrowthLoblolly Pine – Southeast USA

Density

Biomass HarvestingQuestions about Sustainability and Nutrition

• Will repeated harvest of timber crops deplete soil organic matter and nutrients enough to reduce productivity?

• How do intensive management practices affect soil nutrient availability? 

• How do we determine if a forest stand's growth is limited by nutrients?

• If nutrients are limiting, what elements, rates, sources, and timing of application should be used?

Page 8: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting8

Nutrient Cycling Primerfor

Foresters

Vegetation

Forest Floor

Soil

REMOBILIZATION

CANOPYLEACHING

LITTERFALLPLANT

UPTAKE

IMMOBILIZATIONLITTER

LEACHING

MINERALIZATION

WEATHERING LEACHING

RAIN,DUST

GASEOUSCYCLES

Page 9: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting9

Carbon and Nutrient Cycling

• Pools – what is out there today  ‐ “yield”– Important for estimating removals

• Fluxes – movement between pools– Geochemical – ecosystem inputs and outputs

• Important for long term sustainability

– Biochemical – within vegetation cycling• Conservation of nutrients already taken up

– Biogeochemical – within ecosystem cycling• Important for current production

Switzer and Nelson, 1972

020406080

100120140160180200220240

0 10 20 30 40 50 60

Stan

d Nutrie

nts (lbs/acre)

Age (years)

NCaKMgSP

Above‐ground Nutrient AccumulationLoblolly Pine

Page 10: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting10

DISTRIBUTION OF BIOMASS AND NUTRIENTS16‐Year Old Loblolly Pine Stand

Wells et al. (1975)

16.4

6.8

48.9

10.4

5.7

Carbon

57

3271

54

122

Nitrogen

46.433.9

66

46.2

22.3

Calcium

1000 lbs/acre lbs/acre lbs/acre

Roots Bark Wood Branch Foliage

DISTRIBUTION OF BIOMASS AND NUTRIENTS40‐Year Old Upland Oak Stand

Frederick et al. (1988)

12.7

4.50.8

6.7

Carbon

6454

46 62

0

Nitrogen

244

201

27 185

0

Calcium

1000 lbs/acre lbs/acre lbs/acre

Overstory Wood Overstory Branch Overstory Foliage Understory

Page 11: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting11

Henderson Site Productivity StudyHarvest Removals @ 22 years

Stem Only

Complete Tree

AdditionalRemoval(tops)

% Increase

in Removal

Nutrients Removedlbs/dry ton of stem 

Nutrients Removedlbs/dry ton of tops  

Biomass (dry tons/acre) 30.9 37.9 7.0 23

C (dry tons/acre) 15.4 18.9 3.5 23 1000 1000

N   (lbs/acre) 54.2 120.7 66.5 123 1.8 9.5

P  (lbs/acre) 4.4 9.9 5.5 127 0.1 0.8

K   (lbs/acre)     33.7 57.4 23.8 71 1.1 3.4

Ca  (lbs/acre) 49.6 76.3 26.6 54 1.6 3.8

Mg  (lbs/acre) 13.2 20.4 7.1 54 0.4 1.0

Adapted from Tew, Morris, & Allen, 1986

Wood Nutrient Concentrations ‐ Species Differences

0.50 0.25 0.00 0.25 0.50 0.75 1.00 1.25

Loblolly Pine

Chestnut Oak

Yellow‐poplar

Hickory

White Oak

N % Ca %

From Johnson et.al., 1990

Page 12: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting12

Nutrient Pool SizesMature Forest Stands in the SE USA

N P K Ca Mg

lbs/acre

Vegetation 300 – 500 20‐60 100‐350 200‐700 40‐120

Forest Floor 200‐400 10‐30 20‐40 100‐200 20‐40

Soil 2000‐8000

100‐500 >500 >1000 >500

Total 3000‐9000

100‐600 600+ 2000+ 550+

Soil N is total, soil P is extractable, soil K, Ca, and Mg are exchangeable

Vegetation

Forest Floor

Soil

REMOBILIZATION

CANOPYLEACHING

LITTERFALLPLANT

UPTAKE

IMMOBILIZATIONLITTER

LEACHING

MINERALIZATION

WEATHERING LEACHING

RAIN,DUST

GASEOUSCYCLES

Page 13: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting13

Nutrient Outputs Below Rooting Zonekg/ha

N P K Ca Mg

Loblolly PineSantee, SC 0 0 1.0 9.3 2.1

Loblolly PineClemson, SC 0 0 0.7 1.2 0.9

Loblolly PineDuke Forest 0 0 7.0 10.6 3.3

Mixed HardwoodsMaryland

0.3 0 3.8 4.3 3.5

From: Binkley et.al. 1989

Vegetation

Forest Floor

Soil

REMOBILIZATION

CANOPYLEACHING

LITTERFALLPLANT

UPTAKE

IMMOBILIZATIONLITTER

LEACHING

MINERALIZATION

WEATHERING LEACHING

RAIN,DUST

GASEOUSCYCLES

Page 14: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting14

RETRANSLOCATION FROM FOLIAGE

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N P K Ca Mg

% Retranslocated

LoblollySweetgumSycamore

Mobility

• Very mobile– N, P, K

• Intermediate mobility– Mg, S, Mn, Cu, Zn

• Immobile– Ca, B, Fe 

Page 15: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting15

Vegetation

Forest Floor

Soil

REMOBILIZATION

CANOPYLEACHING

LITTERFALLPLANT

UPTAKE

IMMOBILIZATIONLITTER

LEACHING

MINERALIZATION

WEATHERING LEACHING

RAIN,DUST

GASEOUSCYCLES

How much N, P, K…. are needed to grow a ton of wood?

Page 16: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting16

Loblolly Pine Nutrient UseSETRES Control – Age 8,  CAI = 1.8 tons/acre/yr  ‐ LAI = 0.6

N P K Ca Mg

lbs/acreFoliage 18.6 1.9 5.9 3.5 1.6

Branch 2.6 0.4 1.2 1.7 0.4

Stem 2.6 0.4 1.8 1.6 0.5

Coarse Roots 1.7 0.3 1.6 1.3 0.4

Fine Roots 12.8 1.3 4.0 3.8 1.1

Total 38.2 4.1 14.5 11.9 3.9

Nutrient/ton wood

21.2 2.3 8.0 6.6 2.2

From Albaugh, Allen, & Fox 2008

Page 17: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting17

Loblolly Pine Nutrient UseSETRES Fert Only – Age 21,  CAI = 7.1 tons/acre/yr  ‐ LAI = 2.6

N P K Ca Mg

lbs/acreFoliage 75.3 6.8 28.3 9.4 5.1

Branch 8.4 1.0 4.1 4.0 1.3

Stem 7.2 0.4 3.1 3.6 1.3

Coarse Roots 6.3 0.5 4.7 1.8 0.4

Fine Roots 14.4 1.3 3.8 3.3 1.1

Total 111.5 10.1 44.0 22.1 9.2

Nutrient/ton wood

15.7 1.4 6.2 3.1 1.3

From Albaugh, Allen, & Fox 2008

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Nitrogen

   lbs/acre/year

Age

REMOBILIZED

UPTAKE FROM SOIL

Potential Nutrient Use

Adapted from Allen et al 1991

Page 18: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting18

How much N, P, K…. are needed to grow a ton of wood?

How much N, P, K… can the soil supply?

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Nitr

ogen

lb

s/ac

re/y

ear

Age

Soil Supply

Adapted from Allen et al 1991

Page 19: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting19

0

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Nitrogen

   lbs/acre/year

Age

SOILSUPPLY

POTENTIAL USE

ACTUAL USE REMOBILIZED

UPTAKE FROM SOIL

Nitrogen Deficiency

Adapted from Allen et al 1991

Nutrient Limitations 

develop where or when 

Soil Supply < Potential Stand Use

Page 20: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting20

Where does the nitrogen come from?

Fixation of atmospheric Ninto organic matter

Factors Influencing N Mineralization• Environmental conditions that influence microbial activity– Temperature– Aeration– Moisture

• Substrate (Labile Carbon)– Quantity– Type of compounds

Page 21: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting21

Big Questions• What is the capacity of soils to supply nutrients to forest stands?

• What nutrient(s) already limit stand growth?

• Can fertilization be used to effectively ameliorate existing and future nutrient limitations?

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kg/h

a/ye

ar

Stand Age

Soil Supply

?

Phosphorus (P)Potassium (K)Calcium (Ca)Iron (Fe)Sulfur (S)Magnesium (Mg)Boron (B)Copper (Cu)Manganese (Mn)Zinc (Zn)

?

Page 22: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting22

Unavailable Nutrients Available Nutrients

Cation and anionexchange

Long Term Short Term

Soil Solution

Colloids

Soil Minerals

Organic Material

Silviculture in the 21st Century• Manipulation of:

– Species composition• Species, genotypes, clones

– Stocking• Quantity and distribution of crop and non‐crop vegetation

– Site resource availability• Quantity and quality of the soil rooting environment

to optimize value for the current landowner and future generations 

Page 23: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting23

Site Resource AvailabilityNatural variation through time and potential for management

Potential for change with management 

activity

Natural change through time 

No Yes

No FixedNon‐manipulatable

VariableNon‐manipulatable

Yes FixedManipulatable

VariableManipulatable

Soil Resources• Quantity ‐ Soil Volume

– Depth to restrictive layer (water table, bedrock, hardpan, ironstone)

– % rock

• Quality ‐ Physical environment– Soil strength, available water holding capacity– Aeration

• Quality ‐ Chemical environment– Nutrient availability, acidity/alkalinity 

Page 24: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting24

Soil, Site, and Climatic Factors Affecting Soil Strength

Potential for change with management 

activity

Natural change through time 

No Yes

NoTexture                         Precipitation

Type of Clay            

Yes

Organic MatterPorosity

Water Table Soil Water Content

Soil, Site, and Climatic Factors Affecting Soil Water Availability

Potential for change with management

activity

Natural change through time 

No Yes

NoTexture                            Precipitation

Type of Clay               Vapor Pressure DeficitLandscape Position

Yes

Soil DepthOrganic Matter

PorosityWater Table                        

Irrigation

Page 25: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting25

Seasonal Fluctuations in Soil Strength and Water Content – Poorly Drained Clay Loam  

0

5

10

15

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25

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35

40

45

50

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

N D J F M A M J J A S O N D J F M A M J J A S

Soil

Wat

er C

onte

nt (%

)

Soil

Stre

ngth

(MPa

)

Time (Months)

Kelting 1999

Critical Level

Soil Water Content

Soil Strength

Page 26: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting26

Soil CompactionCompression of an unsaturated soil resulting in areduction in pore volume

Undisturbed

Compacted

1.32 g/cm350% Solid50% Pores

1.60 g/cm360% Solid40% Pores

Key Factors Affected:

Bulk Density

Soil Strength

Soil Aeration

Water Movement

Soil PuddlingDeformation of a saturated soil resulting in the destruction of soil structure

Key Factors Affected:

Soil Aeration

Water Movement

Undisturbed Puddled

Page 27: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting27

Soil, Site, and Climatic Factors Affecting Soil Nitrogen Availability

Potential for change with management

activity

Natural change through time 

No Yes

NoTexture                            Precipitation

Type of Clay                       TemperatureLandscape Position

Yes

Soil DepthOrganic Matter

Aeration PorositySoil Water ContentMicrobial Populations

Nitrogen Additions                         

Page 28: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting28

Soil, Site, and Climatic Factors Affecting Soil Phosphorus Availability

Potential for change with management

activity

Natural change through time 

No Yes

No

Parent Material         Texture                            Precipitation

Type of Clay                        TemperatureLandscape Position

Yes

Soil DepthOrganic Matter

Aeration PorositySoil Water ContentMicrobial Populations

Phosphorus Additions                         

Soil, Site, and Climatic Factors Affecting Soil Calcium Availability

Potential for change with management

activity

Natural changes through time 

No Yes

No

Parent Material         Texture                            Precipitation

Type of ClayLandscape Position

YesSoil Depth

Soil Water ContentCalcium Additions

Page 29: Soil and Site Productivity Concepts for Forestry Sustainability?

© 2012, H.L. Allen, ProFOR Consulting29

Geology of South Carolina

Nutrients in Piedmont Rocks

Nutrient Granite Diorite Gabbro Ultrabasic Shale Sandstone Argillite

- - - - - - - - - - - - - - ppm - - - - - - - - - - - - - - - - -

P 600 920 1,100 220 700 170 1,500K 42,000 25,200 8,300 40 26,600 10,700 25,000

Ca 5,100 25,300 76,000 25,000 22,100 39,100 29,000Mg 1,600 9,400 46,000 204,000 15,000 7,000 21,000S 300 300 300 300 2,400 240 1,300

Mn 390 540 1,500 1,620 850 0 6,700Cu 10 30 87 10 45 0 250Zn 39 60 105 50 95 16 165B 10 9 5 3 100 35 230

Adapted from Turekian and Wedepohl (1961)