2017 Western Gulf
April 26 – 27, 2017 Pineville Convention Center Pineville, LA
Michael Blazier and Philip Dougherty Forest Insight Conference April 26, 2017
Climate trends Silviculture decisions for establishment Silviculture decisions for mid-rotation
Average annual precipitation expected to stay similar or slightly increase Biggest change expected is increase in summer temperatures, which will make droughts more common as soil more rapidly dries Tree ring studies in Southeast covering 1000 – 2006 show 20th century had fewer droughts than the long-term average Climate resembles 1920’s – birth of seedling orchards to replant wildfire losses Seager et al. 2009
Reduced growth rates Reduced regeneration success
Changes in wood properties
Summerwood percentage could decline
Increased fire and insect disturbances
Example: 2011 Texas drought killed 66% of seedlings in one-year-old loblolly pine plantations
Example: Potential northward expansion of southern pine beetle
Increased risk of invasive species Spittlehouse and Stewart 2003, McNulty et al. 2012
Stronger localized thunderstorms
Tornados
Trees blown down, broken tops, loss of foliage (especially with hail) Trees blown down, reduced stem quality, tree vigor reduction
Hurricanes
Massive areas of damage Occur with 4 to 15 year frequency along coasts Total forest losses, severe stem quality reduction, reduced forest vigor
Resilient forests: Tolerate normal climate trends Tolerate gradual climate shifts Return to prior condition after disturbance naturally or with management
Forest establishment phase:
Most sensitive to climate extremes Highest amount of silvicultural tools to foster resilient forests
Millar et al. 2007
Forest species diversity of upper Coastal Plain expected to decline Loblolly pine, southern red oak, Shumard oak expected to be dominant species Drought-tolerant species like oaks and longleaf pine may thrive
McNulty et al. 2012
Match species to site conditions Areas of concern:
Long rotations at edges of species range Productivity gains expected at northern edges Productivity losses expected at southern edges Conservative “hedge”: bias selection toward drought-hardy
species
Longleaf pine – well- and excessively well-drained soils Longleaf more drought, fire, and hurricane tolerant Southern red oak, Shumard oak, hickories – relatively droughtand fire-tolerant McNulty et al. 2012, Guldin 2013


Longer rotation length = longer exposure to climate trends Shorter rotations especially helpful near coasts to reduce hurricane damage
Industry and large non-industrial private landowners: Loblolly pine on 25-30 year rotations Lowest exposure to climate extremes More frequent opportunities to alter management to adjust to climate
USDA Forest Service Shortleaf and longleaf pine restoration Longest rotations: 80+ years Highest exposure to climate extremes Shortleaf and longleaf most drought-hardy southern pines Burning regimes reduce wildfire risks
Small non-industrial private landowners: Mixed pine-hardwood Medium rotation length: 30-40 years Largest landowner type in Southeast Vague or non-defined management objective Low capital to invest in silviculture Thinnings offer opportunities to alter stand conditions
Within species there is genetic variability in numerous growth characteristics Adaptations to regions in which they’re grown Some characteristics (small crown, fast growth) enhanced with breeding
Commercially significant species been in breeding programs for decades Loblolly pine: NC State Tree Improvement Cooperative Western Gulf Tree Improvement Cooperative Many seed sources commercially developed
Breeding programs for numerous tree species

Can move seed sources east-west widely and northsouth slightly
Grow longer into season since region has higher summer precipitation Generally smaller crowns and greater height growth Less prone to wind damage


Typically stop growth more readily in droughty conditions Larger crowns and more branches than east coast seed sources
East coast seed sources moved into Western Gulf since 1970’s due to growth and form advantages Trade-off in survivability and faster growth Conservative seed source selection: Local seed sources Constrain east coast genotypes to sites with better moisture-holding capacity
Lambeth et al. 1984
8-103
LA OP
9
7-56
93
100 a
a
a ab
b
Survival (%)
80
60
40
20
0 7-56
 
8-103
Clone 9
Clone 93
7-56 had lowest survival All genotypes >80% survival
LA OP

Clones had best height growth 7-56 intermediate
60
50
40
Tree height (ft.)

a
7-56 8-103 Clone 9 Clone 93 LA OP
a b c c a
30
a a a b a ab b b b a
20
a b
a b
10
0
2006
2008 2009 2010 2011 2012
2015
Clone 93 has greatest site index All genotypes except 8-103 outperform local genetics Difference between 93 vs LA OP = extra log per tree
Exhibtied Site Index, 25-year base age (ft)
85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0
ab
b
a
c
7-56 OP
8-103 OP
c
Clone 9
Clone 93
LA OP
Foliage:Branch:
Branch:Stem:
7-56 & 9 > 93
Avg. Branch Diameter:
93 & 9 > 7-56
7-56 > 93
Avg. # of whorls:
9 > 7-56, 8-103 & 93
Family/ Variety
Foliage : Branch
Branch : Stem
Avg. Branch Dia.
Avg. # of Whorls
7-56
1.18 c
0.78 a
0.56 a
14.5 b
8-103
1.23 bc
0.55 bc
0.49 ab
14.1 b
9
1.56 ab
0.59 ab
0.48 ab
16.8 a
93
1.66 a
0.33 c
0.40 b
12.6 b
Scores:
1 – pole quality 2 – minor-defect sawtimber 3 – low-grade sawtimber 4 – Butt log only 5 – Pulpwood only 6 – Cull tree
Tree 93 has most trees in top-grade timber LA OP has most trees in lowergrade timber
100%
Whole Tree Grade (WTG) Proportions by Genetics
90%
Proportion of Genetic in Each Grade Class
80% 70% Whole Tree Grade %6 60%
Whole Tree Grade %5 Whole Tree Grade %4
50%
Whole Tree Grade %3 Whole Tree Grade %2
40%
Whole Tree Grade %1 30% 20% 10% 0% 9
93
756 Genetics
8103
state
Top concern for stand establishment is fostering good root system development Excessively-well and well-drained sites enhance drought effects Longleaf and shortleaf pine more adapted to such sites Loblolly pine planted due to its faster growth
Bareroot
5 – 14 cents/seedling Most commonly planted November-February planting window
Container
16-24 cents/seedling Gained popularity within past 10 years September-April planting window
105
100
Survival (%)
80
a
b
a b
a b
60
40
Bareroot Container
100
Survival (%)
Bareroot Container
95 90 85 80
20
75 70
0 2003
2004
2005
1993 1994
Year
East Texas Container survival 18% greater than bareroot
1998
2001
2003
Year
North Central Louisiana Container survival 16% greater than bareroot
Can capitalize on wider planting window of container seedlings to plant in fall Fall planting – longer time for root establishment before stressful summer months
-1
5
3
Stand volume (m ha )
6
4
Bare-Oct Bare-March Cont-Oct Cont-March
a
3
b b
b
2
1
a a b
0
b
b b a a 2003
2004
2005
Year
Containers had greater volume in year one By year 3 October-planted seedlings had greater volume than all others 2003 & 2004 average temp and precip; 2005 droughty
Seedling type & planting date
Root system length (cm)
Taproot length (cm)
Root System Diameter
Bareroot, March
85.3
30.5
38.6
Bareroot, October
83.8
25.1
43.0
Container, March
86.0
30.2
32.2
Container, October
98.1
34.8
28.0
Roots at age 3 in east Texas Fall-planted container seedlings had greatest total root and taproot depth Bareroot seedlings had greater diameter
21-year study in NW LA Best returns from 300 and 600 TPA
Best mix of pulp, CNS, sawtimber
Planting nearer to 300 TPA can promote wind and drought resilience
4000 Wood volume (ft3/acre)
Volume of wood products in a 21-year-old loblolly pine plantation in northwest Louisiana in response to five planting spacings.
Total Pulpwood Chip-n-saw Sawtimber
3000
2000
1000
0 1000
600
300
200
100
Planting density (trees/acre)


Herbicides important for promoting survival and fast dominance of crop trees Re-allocate nutrients and water to crop trees
Soil moisture increased by Accord
30 CONT BC
25
Volumetric soil moisture (%)

Soil moisture in response to untreated control (CONT) and brush control with Accord (BC) to a 6-inch depth. Haworth, OK 2002
20
15
10
5
0 0
50
100
150
200
Julian day
250
300
350
Some herbicides need to be applied to actively growing vegetation to be effective at control Droughty conditions: use high end of labeled rates for control Triclopyr (Garlon) Sulfosulfuron (Outrider) Clopyralid (Transline) Glyphosate (Accord, Roundup, Razor)
Some herbicides need water to facilitate activity & should be avoided in drought
Sulfometuron methyl (Oust)
Herbicides applied post-planting during drought can damage or kill crop trees Imazapyr (Arsenal, Chopper) Sulfometuron methyl (Oust) Metsulfuron methyl (Escort) Hexazinone (Velpar) Triclopyr (Garlon) Pendimethalin (Pendulum)
Apply at low rates during modest drought Do not use during severe drought
Subsoiling
Breaks up soil Traps water near seedling Hardpan, retired ag fields require subsoiling

Facilitates deeper rooting
Reallocates nutrients and moisture to crop trees
Example: 2011 Texas drought plantation mortality Unthinned: 1.4 to 6.4% Thinned: 0.3 to 0.5%
Keeps trees vigorously growing = reduces pest risks Thinning earlier, lighter, and more frequently than conventional (one thinning within rotation) can confer wind damage resistance Billings and Edgar 2011
Reduces understory and midstory
Fosters reallocation of water and nutrients to crop trees Reduces fire damage risks Promotes wildlife habitat
Fire or herbicides
Herbicide effects last longer Crown scorch can reduce tree growth
Release + Burn
No Treatment
Mid-rotation herbicide improved tree growth when applied year after thinning No response to herbicide applied 3 years postthinning Growth benefit lasted nearly 13 years after treatment
6
5
Diameter growth (in.)
ab
NO HERB HERB 1YAT HERB 3YAT
a b
4 a b
b
3
2 b
a b
1
0 99-04
99-06
Growth period (years)
99-13


Characterized by low loblolly pine stocking and hardwoods with crowns equal to or overtopping loblolly pine crowns Common situation in small NIPF forests
Herbicide options for release: Aerial Hack and squirt Pellets
Stands with 20-30% stocking (10-15 ft2 per acre basal area) can reach 60% stocking (45 ft2 per acre basal area) within 15 years or less
Baker and Shelton 1998
Growing body of evidence that fertilization can ameliorate lost loblolly pine forest productivity under reduced soil moisture expected in southeastern US Fertilization offsets lost growth more on sites with lower water-holding capacity Results of Southeast-wide study (PINEMAP) led by University of Florida
pinemap.org
Climate trends indicate hotter summers in our region Promoting good root systems to overcome dry summers is key to successful establishment Silviculture adjustments possible:
Match species and seed source to site, extra caution at southern edge of species range Plant container seedlings in fall to promote best possible root growth prior to first summer on well-drained sites Herbicides and fertilizer promote vigorous mid-rotation stand growth
Billings, R., Edgar, C. 2013. Impact of the 2011 drought on thinned and unthinned pine plantations. Texas Forestry. 53:1-4. Blazier, M.A., Dunn, M. 2008. Stock type, subsoiling, and density impact productivity and land value of a droughty site. South. J. Appl. For. 32:154-162. Guldin, J. 2013. Adapting silviculture to a changing climate in the southern United States. P. 173-192 In: Vose, J.M., Klepzig, K.D. (eds.) Climate Change Adaptation and Mitigation Management Options. A guide for natural resource managers in Southern forest ecosystems. CRC Press, Inc. Lambeth, C.C., Dougherty, P.M., Gladstone, W.T., McCullough, R.B., Wells, O.O. 1984. Large-scale planting of North Carolina loblolly pine in Arkansas and Oklahoma: a case of gain versus risk. Journal of Forestry. 82:736-741. McLachlan, J.S., Clark, J.S., Manos, P.S. 2005. Molecular indicators of tree migration capacity under rapid climate change. Ecology. 86:2088-2098 McNulty, S., Sun, G., Mohan, J., Caldwell, P., Prestemon, J., Doyle, T.W., Johnsen, K., Liu, Y. 2012. Forests and climate change in the Southeast. NCA Southeast Technical Report. Millar, C.I., Stephenson, N.L., Stephens, S.L. 2007. Climate change and forests of the future: managing in the face of uncertainty. 17(8):2145-2151. NOAA. 2013. Southern climate impacts planning program. www.southernclimate.org Prasad, A.M., Iverson, R., Matthews, S., Peters, M. 2007-ongoing. A climate change atlas for 134 forest tree species of the eastern United States [database]. http://www.nrs.fs.fed.us/atlas/tree, Northern Research Station, USDA Forest Service, Delaware, OH Seager, R., Tzanova, A., Nakamura, J. 2009. Drought in the southeastern United States: Causes, variability over the last millennium, and the potential for future hydroclimate change. Journal of Climate. doi: 10.1175/2009JCLI2683.1 Spittlehouse, D.L., Stewart, R.B. 2003. Adaptation to climate change in forest management. BC Journal of Ecosystems and Management. 4(1):1-11. Stovall, J. 2013. New stressors new strategies. TFLC workshop presentation. Available online: http://forestry.sfasu.edu/faculty/stovall/home/documents/stovall_tflc_2013.pdf USDA Agricultural Research Service. 1990, 2012. Plant hardiness zone map. www.planthardiness.ars.usda.gov Williams, M.I., Dumroese, R.K. 2013. Climatic change and assisted migration: strategic options for forest and nurseries. Forest Nursery Notes. Summer 2013. P. 33-35 Zhu, K., Woodall, C.W., Clark, J.S. 2011. Failure to migrate: lack of tree range explosion in response to climate change. Global Climate Change. doi: 10.1111/1365-2486.2011.02571.x