1. Crop Tree Strategies
H. Lee Allen
ProFOR Consulting
Cary, NC
Progressive Forestry for Production Forests

2. Uncertainty - 70% Drop in Housing Starts
From US Census Bureau - www.census.gov/briefrm/esbr/www/esbr020.html

3. Uncertainty - 40% Drop in Sawtimber Prices
From Timber Mart-South - www.timbermart-south.com/prices.html

4. What are appropriate strategies for
managing forests and especially crop
trees in the face of uncertainty?

5. First Principles
• Continue to invest
• Maintain flexibility
• Reduce risk
• Practice good silviculture
– Use appropriate genetic material
(species, families, varieties) for site/management
conditions
– Manage density – crop and competing vegetation
– Ameliorate soil physical and nutritional limitations

6. Southern Pine
Silviculture
A Success Story
4X yield
in
>1/2 the time
1 to 10 tons/acre/year
1/3 to 3 cords/acre /year
Fox, Jokela, Allen 2004

7. Optimizing Value Requires
an Understanding of the
Factors Affecting
Productivity

8. What is Potential Productivity?
600
Investing in the RIGHT Silvicultural Prescriptions
ft3/acre/yr
500
Intensive Plantations
400
Annual Growth
300
200
Traditional Plantations
100
Natural Stands
0
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Age years

9. 600
ft3/acre/yr
500
400
Growth Efficiency
VOLUME GROWTH
300
200
100
Light Interception
0
0 1 2 3 4 5
LEAF AREA INDEX

11. What are the factors affecting leaf area and
growth efficiency?
Genetics Water
Temperature ? Nutrients
CO2
Stocking

12. Factors Affecting Leaf Area
and Growth Efficiency
• Genetics
• Stand Density
• Resource Availability

13. JONES 5 EDAPHIC STUDY
8-Year Old Loblolly Pine
550
CURRENT GROWTH ft3/acre/yr
92 Volume Growth
500
450
400
350
300
250
200
150
100
50
0
61
74
01
59
68
5
7
2
6
6
06
3
0
3
8
5
8
10
8-
8-
8-
8-
8-
10
10
-1
10
10
10
8-
11
8-
7-
8-
8-
8-
FAMILY
From Svensson 1996

14. JONES 5 EDAPHIC STUDY
8-Year Old Loblolly Pine
4.0
92 Peak LAI
PEAK LEAF AREA
3.5
3.0
2.5
2.0
61
74
01
59
68
05
37
06
82
56
86
3
10
10
10
-1
10
10
10
8-
8-
8-
8-
8-
8-
11
8-
7-
8-
8-
8-
FAMILY
From Svensson 1996

15. 42
ANNUAL GROWTH ft3/acre/yr Fam 8-103 11 Families
35
28
21
14
2.0 2.5 3.0 3.5 4.0 4.5 5.0
PEAK LEAF AREA
From Svensson 1996

16. Factors Affecting Leaf Area
and Growth Efficiency
• Genetics
• Stand Density
• Resource Availability

17. Age 14 UGA PMRC
Volume Increases Reaches Inflection at 400tpa
Pienaar, L. V., B. D. Shiver and W. M. Harrison. 1997. Growth potential of loblolly pine plantations in the Georgia Piedmont: A spacing
study example. PMRC Technical Report 1997-1. 15pp.

18. Factors Affecting Leaf Area
and Growth Efficiency
• Genetics
• Stand Density
• Resource Availability
– Water
– Nutrients
– Temperature

19. Southeast Tree Research and Education Site
SETRES1
U.S. Forest Service
North Carolina State University
Duke University
Virginia Tech

21. SETRES1
Control
+ Nutrients

22. SETRES: Peak leaf area index
4.0
Control
Peak leaf area index
3.5 Irri
Fert
3.0
Fert+Irri
2.5
2.0
1.5
1.0
0.5
0.0
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Data from Albaugh et al 1998, 2004 Year

23. SETRES1
Control +Nutrients

24. SETRES: Standing volume
4000
3500 Control
Standing Volume (ft3/ac)
Irrigated
3000
Fertilized
2500 Fert+Irri
2000
1500
1000
500
0
1991 1993 1995 1997 1999 2001 2003 2005
Year

25. SETRES: 1992-2000 Volume growth - leaf area
450
400
Volume growth (ft 3/ac/yr)
Control Vol gro = 94 x LAI
350 Irrigated
300 Fertilized
Fert+Irri
250
200
150
Vol gro = 65 x LAI
100
50
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Peak leaf area index

26. Factors Influencing Leaf Area and Growth
800
Loblolly Pine – Southeast USA
Annual Volume Growth ft3/ac/yr
700
600
500
400 Temperature
Genetics
300
Water
200
Nutrients
100 Density
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Leaf Area Index

27. Potential Current Annual Increment
LAI =4.0
Legend
CAI (ft^3/acre/yr)
0 - 350
350 - 400
400 - 450
450 - 500
500 - 550
> 550
Flores and Allen unpublished

28. Minimize per acre establishment and
tending costs
Minimize per unit production costs and
maximize value with an integrated
system

29. Suitability of coastal plain soils for
intensive silviculture
Subsoil Horizon – Texture of Argillic and Presence of Spodic
Drainage Class Argillic Argillic Argillic Weak to no Spodic with Spodic
C, SiC SC, CL, SCL, SiCL L, SL argillic, LS, S Argillic Only
Very Poorly
Organic
Very Poorly
Poorly
Somewhat
Poorly
Moderately Well
Well
Excessively Well
Green – strong candidates , Yellow – possible candidates, Red – not appropriate (too wet), Purple – strong caution
(severe nutrient limitations and seasonal water deficits).

30. Many acres are suitable for intensive
silviculture… but not all
Green = strong candidates, Yellow = possible candidates, Red = not appropriate for
intensive management (soils too wet)

31. Suitability of coastal plain soils for
intensive silviculture
Subsoil Horizon – Texture of Argillic and Presence of Spodic
Drainage Class Argillic Argillic Argillic Weak to no Spodic with Spodic
C, SiC SC, CL, SCL, SiCL L, SL argillic, LS, S Argillic Only
Very Poorly
Organic None None None None None None
Very Poorly
<40/75 <40/80 <40/80 <40/80 <40/75 <40/70
Poorly
45/75 45/80 45/80 45/80 45/75 40/70
Somewhat
Poorly 45/75 50/85 50/85 50/80 50/80 45/75
Moderately Well
50/80 55/85 55/85 55/80 55/80 50/75
Well
55/75 55/85 55/80 55/75 55/75 50/70
Excessively Well
50/70 50/75 50/75 45/75 45/75 45/70
Green – strong candidates , Yellow – possible candidates, Red – not appropriate (too wet), Purple – strong caution
(severe nutrient limitations and seasonal water deficits). Base and target estimates of site index (25 year).

32. Deployment
Is there G X E?
Do certain species/families/clones
perform better on different sites?

33. UPLAND P DEFICIENT SITE - 25 YEARS
80
Loblolly Slash Longleaf
70
feet
60
AVERAGE HEIGHT
50
40
30
20
10
0
Control Cult+100N22P42K Cult+400N86P166K
Clark and Saucier (1991)

34. Deployment
Is there G X E?
Do certain species perform better on
different sites?
YES!

35. LOBLOLLY PINE FAMILY PERFORMANCE ACROSS SITES
8-YEAR GROWTH
ft 3/acre 1600
1400
07056
1200
Family Mean Volume
1000
08059
800
600
01064
400
200
0
Poor Average Good
McKeand et al. 1996

36. Deployment
Is there G X E?
Do certain families perform better on
different sites?
For all practical purposes - NO!

37. Potential for Using Varieties
– Outstanding growth
– Stack multiple traits in addition to growth
• Extremely low rust incidence
• Small branch size, narrow crowns
• High percentage of sawtimber quality trees
– Greater uniformity in non growth traits
– Potential for greater stand uniformity in tree size

38. Increase in the percentage of trees
with sawtimber potential

39. Using Varieties
• Opportunities within existing silvicultural systems
– Reduce planting density
• No need to plant extra trees to offset losses due to
mortality, poor stem quality, and suppression
• No need to plant extra trees to maintain stem quality
• Better diameter growth
– More thinning options
• Greater percentage of sawtimber quality crop trees
• Greater flexibility in terms of timing and intensity
– Synergy with other silvicultural investments
• More sawtimber quality trees = greater profitability

40. Using Varieties
• Opportunities to develop new silvicultural systems
– Planting take rows with lower quality genetic
material
• Reduced planting costs with a varietal component at
conventional planting densities
• Additional volume at first thinning
• Some lost flexibility - Must thin early so as not to
reduce growth potential of varietal crop trees

41. Using Varieties
• Opportunities to develop new silvicultural systems
– Plant fewer trees per acre
• Lower seedling and planting costs
– Wider row spacing becomes an option
• Lower per acre costs for row related
treatments (bedding, machine planting,
banded weed control, banded fertilization)
• Possibly eliminate the need to remove entire
rows and their crop trees during thinning
– No thin sawtimber regime a possibility – optimum
planting density

42. No Thin Sawtimber Regime - LOBDSS
Sawtimber = 13” or greater dbh to 8” top, $35/ton, Everything else = $7/ton,
discounted present value of all costs (except seedlings) = $450/acre, seedlings $.35 each

43. Silviculture for Loblolly Pine in Arkansas
Prescription Guidelines
• Planting Considerations
– Select best family or variety
– Morphologically improved seeding
– Density and spacing based on product goals
• Ameliorate Soil Physical Limitations
– Bed wet soils
– Rip shallow mountain soils
• Manage Non-Crop Tree Vegetation
– Prior to planting - hardwood and woody shrubs
– Grass and weed control for at least the first year
– Thin - timing and intensity based on product goals
– Understory vegetation in conjunction with thinning and/or fertilization
• Ameliorate Nutrient Limitations
– 18N+20P lbs/acre banded (36N+40P broadcast) DAP at age 0 - 1 if P deficient
– 150N lbs/acre (Urea) broadcast at age 6 to 8 years
– 200N+25P lbs/acre broadcast every 6 years starting at first thinning
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