Presentation by Dr. Steve Jack to support the Adaptive Silviculture for Climate Change (ASCC) J.W. Jones Ecological Research Center Workshop held January 12-14, 2016

1. Disturbance & Ecology of
Coastal Plain Forests
with a focus on
Longleaf Pine
Dr. Steve Jack
Conservation Ecologist and Applied Forest Scientist
Joseph W. Jones Ecological Research Center

2. Disturbance Ecology
• Develop understanding of what is “natural”
for a given location and forest type

3. Disturbance Ecology
• Develop understanding of what is “natural”
for a given location and forest type
• For disturbance should consider:
– Frequency
– Scale
– What is left after disturbance

4. EXAMPLE: Natural Variation in Disturbances
(based on ca. 20 studies; Seymour et al 2002)
1
Interval between Disturbances (at the same point on the landscape) - years
ContiguousAreaDisturbedandRegenerated-ha
Severe
Fire
and
Wind
100 1000 10000
0.0001
0.001
0.01
0.1
1
10
100
1000
10000
Natural
Canopy
Gaps
100-year return
interval
Range =
.001 - .1 ha

5. Natural Disturbance Agents
In southeast many
things can cause
disturbance:
– Wind
– Lightning
– Insects
– Disease
– Water
– Fire

6. Natural Overstory Disturbance
More common sources in longleaf forest result
in small scale disturbance
– Lightning (more prevalent on xeric sites)
– Competition (more prevalent on hydric
sites)
– Wind (more prevalent on hydric sites)
– Beetles/root rot
– Fire
From Palik and
Pederson (1996)
Suppression
DBH class (cm)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70
Percentageoftotalpopulation
0
10
20
30
40
Unknown
0
4
8
12
16
Lightning
0
2
4
6
8
10
12
14
16
Wind
0
4
8
12
16
Live
0
2
4
6
8
10
Mortality
(trees ha-1
5 yr-1
)
0 2 4 6 8 10 12
Numberofplots
0
4
8
12
16
20
24
28
Mortality
(m2
ha-1
5 yr-1
)
0.0 0.2 0.4 0.6 0.8 1.0

7. Conceptual Longleaf Model
from Michener et al. 1996

8. Natural Disturbances
In longleaf forests result in:
• Perpetual forests with multiple age classes
• Continuous fuels through time and across
space – supports fire
• Variable density and spacing (heterogeneity)
• Advance regeneration seedling pools in
more open areas

9. Fire in Coastal Plain Forests

10. Role of Fire
• Maintain early successional state
• Reduce fuel accumulations
• Affects structure and function
– Reduced or absent midstory
– Species rich ground cover
– Nutrient cycling
Day 1
3 months
1 year
3 years
10 years
30 years

11. Fire and Biodiversity
Fire is the
overriding feature
that sustains the
biodiversity of the
longleaf pine
ecosystem
– Frequent
– Continuous over
time

12. Diverse Ground Cover Community

13. Diverse Faunal Community

14. Longleaf Pine Prior to European
Settlement

15. Longleaf Communities - Montane

16. Longleaf Communities - Sandhills

17. Longleaf Communities - Mesic

18. Longleaf Communities - Flatwoods

19. Longleaf – Wide Ecological Amplitude
• High water use efficiency – tolerates droughts,
extensive root system
• Overstory trees can survive short-duration
flooding
• Unique regeneration habit – tolerates fire,
drought-tolerant once established
• Associated understory species have similar
characteristics
• Resistant to pests, disease, physical damage
• FIRE adapted (required?) species

20. Management at Ichauway

21. With Predicted Climate Change …
• What factors will change, and how will the
changes affect the forest?
– Altered precipitation patterns?
– Elevated average temperatures?
– More severe weather events?
– More wildfires? Reduced use of Rx-fire?
• What forest types will be best adapted to the
“new” (and changing?) conditions?

22. Disturbance Frequency & Extent with
Climate Change
from Michener et al. 1996
Catastrophic
flooding
Droughts
Hurricanes & Tropical
Storms

23. Heard from Experts

24. Hurricanes & Tropical Storms

25. Hurricanes & Tropical Storms

26. Hurricane Damage

27. Hurricane Damage

28. Hurricane Damage
• Southern MS Katrina Damage
• Two 20 year old plantations, each with stands of
loblolly, slash and longleaf
Species Type of Hurricane Damage (%)
None Snapped Leaning Blown Over
Loblolly 16.3 75.9 5.7 2
Slash 52.4 38.1 7.8 1.7
Longleaf 64 8.9 16.9 10.2
Source: MS Forestry Commission

29. Flooding Events

30. Drought Response
• Large effects on regeneration
– Seedling survival
– Seed production
• Cumulative effects on overstory
– Decreased vigor
– Increased susceptibility to pests
• Ability to burn, mortality following fires

31. Changes in Fire Regimes

32. Changes in Fire Regimes

33. Forest Responses to These Changes?
• Fire-maintained longleaf forests may be in
best position to continue under altered
climate
• But what about other forest types that are
more common on the landscape?

34. Mixed Pine – Hardwood Forests