1 Dendroecological Techniques for Reconstructing the History of Wildfires in the Southern...

1

Dendroecological Techniques for Reconstructing the History of Wildfires in the

Southern Appalachian Mountains

Dendroecological Techniques for Reconstructing the History of Wildfires in the

Southern Appalachian Mountains

Henri D. Grissino-Mayer 1

Charles W. Lafon 2

Georgina G. DeWeese 1

Lisa B. LaForest 1

Serena R. Aldrich 2

Henri D. Grissino-Mayer 1

Charles W. Lafon 2

Georgina G. DeWeese 1

Lisa B. LaForest 1

Serena R. Aldrich 2

11 22

1700 1750 1800 1850 1900 1950 2000....

Fire

Regi

meLow Fuel LoadingsFew Ladder FuelsSurface FiresLow IntensityStand Main tenance

1700 1750 1800 1850 1900 1950 2000....

Fire

Regi

me

High Fuel LoadingsIncreased Ladder FuelsCrown FiresHigh IntensityStand Rep lacement"Doghair" Thickets

Low Fuel LoadingsFew Ladder FuelsSurface Fire RegimeLow Severity FiresStand Maintenance Fires

High Fuel LoadingsIncreased Ladder FuelsIncreased Stem DensityCrown Fire RegimeHigh Severity FiresStand Replacement Fires

© USDA Forest Service

1700 1750 1800 1850 1900 1950 2000…

1700 1750 1800 1850 1900 1950 2000…

The “Western Model” where fire exclusion = increased fuels and

increased fire danger

But, in the eastern U.S., 20th century fire exclusion could decrease potential for future wildfires.

Mill MountainMill Mountain

Mill

Mou

ntai

n

FS R

oad

TMP stands on SW-

facing slopes

Fire History:

Four subsites per larger site

Between 15-40 samples at each subsite

Complete inventory regardless of the number of scars on the sample

Concentration on logs, snags, remnants

Over 600 trees sampled for fire history

Fire History:

Four subsites per larger site

Between 15-40 samples at each subsite

Complete inventory regardless of the number of scars on the sample

Concentration on logs, snags, remnants

Over 600 trees sampled for fire history

Stand History:

Three 50 x 20 m “macroplots” per site

Inventoried all tree species, measured dbh

Cored, crossdated/aged all trees ≥ 5 cm dbh

Inventoried all saplings < 5 cm dbh,> 50 cm ht

Inventoried seedlings in 10 x 20 msubplot

Collected sections from 20 mountainlaurel stems

Measured depth to mineral soil at20 random locations

Stand History:

Three 50 x 20 m “macroplots” per site

Inventoried all tree species, measured dbh

Cored, crossdated/aged all trees ≥ 5 cm dbh

Inventoried all saplings < 5 cm dbh,> 50 cm ht

Inventoried seedlings in 10 x 20 msubplot

Collected sections from 20 mountainlaurel stems

Measured depth to mineral soil at20 random locations

Pines Oaks

Mountain Otherlaurel hardwoods

20 m

50 m

A section from a fire-scarred Table Mountain pine snag.

How many fire scars can you see here?

Initial in-field visual inspection most often underestimates true amount of fire history info per sample.

Note that TMP is a very slow-growing tree species (xeric sites, lithic/poor soils, time in understory).

Note issues we face when attempting to date the tree rings on each sample.

TMP can be very young and very small in size when first scarred. At Mill Mountain, median age at first scarring = 16 years, median diameter at first scarring = 6.7 cm.

TMP sampled at Kelly Mountain in 2005 near

Blue Ridge Parkway, displaying an incredible sequence of fire scars.

Initial in-field inspection estimated 6 or 7 possible

fire scars.

Final tally: 11 scars

Interpreting Fire History Charts

Years on x-axis

Period of Reliability: 1896 to 1944

Each line = 1 tree Sample IDs

Composite axis

Solid lines = recorder years

Each tic = fire scar

Dash lines = non-recorder years

Begin/end symbology

Interpreting Fire Regimes

Central Tendency –Weibull Median Probability Interval (MEI)

Variability – are intervals even?UEI, LEI = range

Seasonality – season is very importantEarly Season = DELate Season = MLA

Severity – are cohorts visible?

All scarred and10% scarred classes

Brush Mountain Fire History

Period of Reliability: 1758–1934

All-scarred class:

MEI: 3 yrs; LEI: 1 yr; UEI: 8 yrs

10%-scarred class:

MEI: 8 yrs; LEI: 2 yrs; UEI: 19 yrs

90% DE fires, 10% MLA fires

Brush Mountain Fire History


All-scarred class:

MEI: 3 yrs; LEI: 1 yr; UEI: 8 yrs

10%-scarred class:



0

5

10

15

20

25

30

35

40

45

50

1800 1825 1850 1875 1900 1925 1950 1975 2000

Establishment Year

DB

H (cm

)

PineOakOther Hardwoods

North Mountain Fire HistoryPeriod of Reliability: 1779–1934All-scarred class:MEI: 3 yrs; LEI: 1 yr; UEI: 6 yrs10%-scarred class:MEI: 7 yrs; LEI: 2 yrs; UEI: 15 yrs84% DE fires, 16% MLA fires

North Mountain Fire HistoryPeriod of Reliability: 1779–1934All-scarred class:MEI: 3 yrs; LEI: 1 yr; UEI: 6 yrs10%-scarred class:MEI: 7 yrs; LEI: 2 yrs; UEI: 15 yrs84% DE fires, 16% MLA fires

0

5

10

15

20

25

30

35

40

45

50

1800 1825 1850 1875 1900 1925 1950 1975 2000

Establishment Year

DB

H (cm

)


Griffith Knob Fire HistoryPeriod of Reliability: 1810–1934All-scarred class: MEI: 2 yrs; LEI: 1 yr; UEI: 4 yrs10%-scarred class:MEI: 4 yrs; LEI: 1 yr; UEI: 12 yrs72% DE fires, 28% MLA fires

Griffith Knob Fire HistoryPeriod of Reliability: 1810–1934All-scarred class: MEI: 2 yrs; LEI: 1 yr; UEI: 4 yrs10%-scarred class:MEI: 4 yrs; LEI: 1 yr; UEI: 12 yrs72% DE fires, 28% MLA fires

0

5

10

15

20

25

30

35

40

45

50

1800 1825 1850 1875 1900 1925 1950 1975 2000

Establishment Year

DB

H (cm

)


Little Walker Fire HistoryPeriod of Reliability: 1789–1934All-scarred class: MEI: 3 yrs; LEI: 1 yr; UEI: 5 yrs10%-scarred class:MEI: 4 yrs; LEI: 2 yrs; UEI: 8 yrs79% DE fires, 21% MLA fires

Little Walker Fire HistoryPeriod of Reliability: 1789–1934All-scarred class: MEI: 3 yrs; LEI: 1 yr; UEI: 5 yrs10%-scarred class:MEI: 4 yrs; LEI: 2 yrs; UEI: 8 yrs79% DE fires, 21% MLA fires

Mill Mountain Fire History


All-scarred class:


10% scarred class:



Mill Mountain Fire History


All-scarred class:


10% scarred class:



SpeciesBasalArea

(stems/ha)Frequency Density Dominance

Relative Frequency

(%)

Relative Density

(%)

Relative Dominance

(%)

Importance Value(%)

Acerrubrum

99.70 2.33 23.33 83.08 2.55 2.67 0.81 1.51

Castanea dentata

< 0.001 0.17 1.70 < 0.001 0.74 0.19 0.001 0.23

Nyssa sylvatica

252.01 16.33 163.33 210.00 17.22 17.78 7.75 14.25

Pinus pungens

1599.50 37.33 373.33 1332.92 38.63 37.71 55.75 44.03

Pinusrigida

< 0.001 0.08 0.83 < 0.001 0.09 0.09 0.002 0.047

Pinusstrobus

277.80 2.58 25.83 231.50 3.53 3.54 2.21 2.32

Pinus virginiana

0.003 0.83 8.33 0.003 0.86 0.88 0.04 0.45

Robinia pseudoacacia

< 0.001 0.08 0.83 < 0.001 0.36 0.09 < 0.001 0.11

Quercusalba

< 0.001 0.58 5.83 < 0.001 0.65 0.65 0.02 0.33

Quercus coccinea

118.40 7.92 79.17 98.67 8.10 7.54 2.21 5.95

Quercus montana

653.38 24.58 245.83 544.49 24.59 26.02 29.57 26.73

Quercus rubra

144.30 2.50 25.00 120.25 2.98 2.07 1.63 2.22

Quercus velutina

0.003 0.50 5.00 0.003 0.70 0.54 0.02 0.31

Saplings

Species

BrushMountain

GriffithKnob

Little Walker Mountain

NorthMountain Total Percent

Acer rubrum 12 8 13 46 79 7.14

Carya glabra 0 2 0 0 2 0.18

Castanea dentata 1 2 5 1 9 0.81

Fagus grandifolia 0 0 0 0 0 0.00

Nyssa sylvatica 95 5 35 338 473 42.77

Pinus pungens 5 131 92 9 237 21.43

Pinus rigida 0 2 0 0 2 0.18

Pinus strobus 1 18 43 0 62 5.61

Pinus virginiana 0 16 0 0 16 1.45

Quercus alba 1 7 1 10 19 1.72

Quercus coccinea 0 99 1 0 100 9.04

Quercus montana 4 4 0 39 47 4.25

Quercus rubra 3 11 6 1 21 1.90

Quercus velutina 0 0 15 1 16 1.45

Robinia pseudoacacia 0 4 15 0 19 1.72

Tsuga canadensis 0 3 1 0 4 0.36

SpeciesBrush

MountainGriffith Knob

Little Walker Mountain

NorthMountain Total Percent

Acer rubrum 44 26 50 73 193 23.74

Carya glabra 0 22 0 0 22 2.71

Castanea dentata 0 1 7 2 10 1.23

Fagus grandifolia 0 1 0 0 1 0.12

Nyssa sylvatica 7 0 4 36 47 5.78

Pinus pungens 0 8 5 0 13 1.60

Pinus rigida 0 3 0 0 3 0.40

Pinus strobus 0 1 1 0 2 0.25

Pinus virginiana 0 5 0 0 5 0.62

Quercus alba 0 17 0 1 18 2.21

Quercus coccinea 8 39 0 51 98 12.05

Quercus montana 150 35 36 10 231 28.41

Quercus rubra 7 94 8 8 117 14.39

Quercus velutina 5 45 0 0 50 6.15

Robinia pseudoacacia 0 0 3 0 3 0.37

Tsuga canadensis 0 0 0 0 0 0.00

Seedlings

Brush Mt. Mountain Laurel

0

2

4

6

8

10

12

14

16

18

1945-1949 1950-1954 1955-1959 1960-1964 1965-1969 1970-1974 1975-1979 1980-1984

Establishment Date

North Mt. Mountain Laurel

0

2

4

6

8

10

12

14

16

18

1945-1949 1950-1954 1955-1959 1960-1964 1965-1969 1970-1974 1975-1979 1980-1984

Establishment Date

Mountain Laurel: Brush Mountain

Mountain Laurel: North Mountain

Previous studies found that a duff layer of 1.5 to 3 inches is sufficient for successful Table Mountain pine regeneration.

Surprisingly, we found average duff (+litter) depths to be about 3 to 3.5 inches at all sites, with maximum values between 6 and 7.5 inches.

What about hardwoods?

We found many fire-scarred hardwoods, but these proved very difficult to analyze.

Advanced decay

Erratic ring patterns

Difficult to crossdate

ConclusionsConclusions

Past fire regimes:

Fires were very frequent, once every 2 to 3 yrsRange: shortest interval = 1 yr, longest = 8 yrs

Potentially widespread fires, once every 4 to 8 yrsRange: shortest interval = 1 yr, longest = 18 yrs

In general, these fires were low severity fires.

Cohorts evident in age structure and fire history analyses, indicating moderate severity fires.

Dominated by dormant season and early growing season fires.

Stand composition:

Current overstory dominated by chestnut oak, Table Mountain pine, and black gum

Sapling composition dominated by black gum and Table Mountain pine

Seedling composition dominated by oaks and red maple, with very few Table Mountain pines

Future stands likely will be dominated by black gum, oaks, and red maple, with very few Table Mountain pines

ConclusionsConclusions

Moving to the south:Great SmokyMountains National Park

Builds upon the work of Mark Harmon, Tom Waldrop, andPat Brose

Gold Mine Trail, Cooper Road Trail, and Rabbit Creek Trail, all on west side of park

Dominated by shortleaf andVirginia pines, many with fire scars.

Moving to the south:Great SmokyMountains National Park

Builds upon the work of Mark Harmon, Tom Waldrop, andPat Brose

Gold Mine Trail, Cooper Road Trail, and Rabbit Creek Trail, all on west side of park

Dominated by shortleaf andVirginia pines, many with fire scars.

A truly surprising find: actually locating in the field two of Harmon’s original samples taken in 1981.

With a hand saw, no less.

A truly surprising find: actually locating in the field two of Harmon’s original samples taken in 1981.

With a hand saw, no less.

fire, fire, fire, firefire, fire, fire, fire

And the lack thereof =

the 20th century “curl”

And the lack thereof =

the 20th century “curl”

1804

19001900

Preliminary fire history for Gold Mine Trail

Very patchy fire regime

Only one major widespreadfire in 1929

This 1929 event was also thelast major fire event as seenin the fire chart.

Older samples will pushthe fire inventory backto the late 1700s.

University of TennesseeHenri Grissino-MayerGeorgina DeWeeseLisa LaForest David MannAlison MillerEvan LarsonDaniel LewisSaskia van de GevelChris UnderwoodBeth AtchleyMichelle PfefferNathaniel MorganAnna ComptonAshley HeatonPreston RobertsPamela DalalJessica BrodgenWayne ClatterbuckTim Green

University of TennesseeHenri Grissino-MayerGeorgina DeWeeseLisa LaForest David MannAlison MillerEvan LarsonDaniel LewisSaskia van de GevelChris UnderwoodBeth AtchleyMichelle PfefferNathaniel MorganAnna ComptonAshley HeatonPreston RobertsPamela DalalJessica BrodgenWayne ClatterbuckTim Green

Texas A&M UniversityCharles LafonSerena AldrichAdam KrustchinskyPaul RindfleischAlexis GreenJennifer HossJohn AldrichKirk StueveLauren SpencerJeremiah WagstaffJames Dalton

The Nature ConservancyJudy DunscombWanda SanJuleJennifer Allen

Virginia Department ofGame & Inland FisheriesNelson Lafon

Texas A&M UniversityCharles LafonSerena AldrichAdam KrustchinskyPaul RindfleischAlexis GreenJennifer HossJohn AldrichKirk StueveLauren SpencerJeremiah WagstaffJames Dalton

The Nature ConservancyJudy DunscombWanda SanJuleJennifer Allen

Virginia Department ofGame & Inland FisheriesNelson Lafon

USDA Forest ServiceSteven CroyElaine Kennedy SutherlandBeth BuchananJesse OvercashCarol Hardy CroyGeorge AnnisDanny WrightButch ShawHerbie HuffmanKenneth HickmanJason HattersleyZack PenningtonMitch Kerr

West Virginia UniversityStockton Maxwell

USDA Forest ServiceSteven CroyElaine Kennedy SutherlandBeth BuchananJesse OvercashCarol Hardy CroyGeorge AnnisDanny WrightButch ShawHerbie HuffmanKenneth HickmanJason HattersleyZack PenningtonMitch Kerr

West Virginia UniversityStockton Maxwell

PersonnelPersonnel

A Very Special Thank You toA Very Special Thank You to

Michelle Pfeffer

1981–2006

Michelle Pfeffer

1981–2006

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