I
Southeastern Forest Experiment Station

P. 0. Box 2680

Ashevi 11 e, North Carolina 28802
Contents

Introduction . . . . . . . . . . . .

PI ant Suscepti bi 1 i ty

Root Damage. . . . . - . . - l l

Bole Damage. . . . . . . . . - .

Crown Damage . - . - . - . - . l

Growth Effects . . . . . . . . . l l

&ii ni mi zi ng Tree Damage

Tree and Stand Factors - . . - l

Burning Weather. . . . . - . - -

Season of Burn . . . . . . . . .

Conclusions . . . . . . . . . . . .

1

8

8

9

10

Literature Cited . . . . . . . . . . 11

Effects of Fire on Southern Pine:

Observations and Recommendations

Dale D. Wade, Project Leader

R.W. Johansen, Research Forester

Sou tbern Forest Fi re Labora tory

Dry Branch, Georgia

ABSTRACT

This overview systematically discusses fire

damage as it relates to al I parts of tbe tree:

avai Zabl e 1 i terature is cri ti qued, apparent contradictions resolved, and some cormonly beld dsconcepti ons dispel 1 ed. Suggestions for avoiding fire damage

during prescribed burns are gi veu.

Keywords: Fire damage, fire injury, crown scorch,

fire mortality, bark char.

Introduction

In tbe Southern hi ted States the

intenti onal use of fire bas evolved over

the past three centuries into a highly

sopbi sti ca ted tool, currently used on

more than 4 mi 11 ion acres of southern

pine forest 1 and each year. The tradi ti onal means of treating tbi s acreage

has been wi tb backfires. Tbese fires,

if properly conducted, are of rel ati vely

low intensity and cause Ii ttle if any

need1 e scorch once tbe pines reach 20 to

25 feet in height. Backfires are slow

movi ug, however, generally spreading

1 ess than 150 feet per hour, wbi cb

necessi ta tes numerous i n teri or pl owl i nes

or lengthy burnout times. This slow

rate of spread coup1 ed wi tb tbe 1 imi ted

occurrence of days wi tb acceptable

prescri bed burning condi ti ons means tba t

tbe number of acres actually treated

during a given year frequently fall s far

short of the number planned. Many

resource managers attempt to reach tbei r

acreage goals by burning under marginal

wea tber condi ti ous, extending the winter

burning season to encompass early fall

and 1 ate spring, or resorting to 1 i ne

beadfi res, wbi cb take much 1 ess time to

complete but wbi cb burn wi tb increased

i n tensi ty. Inherent in al 1 tbese practi ces is tbe greatly increased potenti al

for fire damage. The addi ti onal acreage

burned by uti 1 izing these more risky

practices is small, however, compared

to the gains realized from emerging

aerial igni ti on tecbni ques. Now

thousands of acres can be burned during

a given day under close to ideal condi ti ons tba t, incidentally, occur when

litter moisture is slightly damper tban

desi rabl e for 1 i ne backfi res.

Aeri ally igni ted spotfi res sol ve

many of tbe problems associated wi tb

backi ng fires, but tbey bave one potenti al ly maj or drawback: al though tbi s

tecbni que resul ts in fires tba t burn in

al 1 di recti ous, most of tbe area is

exposed to beading or flanking flames;

and the bigber fire intensi ties produced

increase tbe potential for crown scorch.

Intensi ti es are al so magni fi ed along

the merging zones as the spots burn

togetber. Tbus the resource manager

needs to use care in se1 ecti ng burning

condi ti ons to prevent excessi ve beat

from developing under the stand. If a

mistake i s made and i ntensi ties are

bigber than desired, what del-eterious

effects might a forest manager expect?

and bow can they be assessed? Tbi s

Report attempts to answer these questi ons and, in so doing, dispel some

commonly be1 d mi sconcepti ons. Al -

though the ye1 1 ow or bard pines are

empbasi zed- - in particular, the four

major southern pines- -much of the i nformati on presented pertains to other pine

species as we1 1.
PI ant Suscepti bi 1 i ty

PI ant suscepti bi li ty to fire vari es

among species as well as among indi vidual s wi thin a species. Di fferences

between speci es are generally attributed

to bark thickness, rooting depth, crown

cbaracteri s ti cs, and the rel ati ve densi ty of tbe stand (Brown and Davis

1973). R’i thin a species, the age of the

tree, season of the year, prefire and

post f i re soi 1 moisture condi ti ons, and

ambi ent temperature at the time of the

fire are addi ti onal factors thought to

be important. Rnowledge of these and

other envi ronmen tal , physi 01 ogi Cal, and

phenological factors can be used by a

resource manager to more accurately predict the fate of fire-damaged trees.

Li terature reviews describing some of

these factors and their effects include

Bare (19611, Langdon( 1971)) McArthur

( 1980) , Ryan ( 1982) ; and Spa1 t and

Rei fsnyder (1962). Ku1 man (1971) presents an excel 1 ent review of the effects

of insect defoliation which, like fireinduced crown damage, resul ts in at

least a temporary reduction in photosyn the ti c capaci ty.

The thresh01 d temperature at whi ch

plant tissue death is instantaneous

vari es slightly by speci es but is

generally considered to be 141 OF.

Lower temperatures can also be lethal

if sustained 1 ong enough. For example,

Rel son (1952) found that the time needed

to kill the need1 es of four southern

pine speci es averaged 1 ess than 1 minute

at 138 “F, almost 5 lninutes at 131 OF,

and over 11 minutes at 124 OF. Ursic

(1961) found that tissue death occurred

in 2 hours at 118 OF and Eare (1961)

found it did not occur below 113 "F in

the 20 species he reviewed. Gentile and

Johansen (1956) reported 100 percent

mortality of sand pine (Pinus clausa)

and slash Dine j__P. elliotti var.

c?lliottii) seedlings after immersion of

their root systems in a 125 "F water

bath for 17 minutes, whereas i mmersi on

in 116 OF water for 25 minutes had no

effect on survi val . @hen measured by

heating indi vi dual plant ccl 1 s, death

has been shown to occur at 108 “F in

eastern whi te pine (P. strobus) (Thimann

and Kaufman 1958) an'ii- between 118 and

122 "F in longleaf pine (P. palustris)

(Hare 1965b). -- ---- Death of a-few ccl 1 s IS

of 1 i ttl e consequence, but as addi ti onal

amounts of 1 i ve tissue are kill ed, the

fate of a tree becomes increasingly

dependent (up to a point) upon postfire

environmental condi ti ons and is much

more difficult to predict correctly.

Fire can damage the roots, bole, or

crown of a tree; a sing1 e fire can, and

often does, impact al 1 three zones.

Root Damage

Hare (1961) stated that roots are

most susceptible to heat injury because

they have no specialized exterior protecti on. Rut root damage i s generally

assumed not to be a problem during

prescri bed burning, provi ded the roots

are be1 ow the soi 1 surface and the soil

is moist. As the humus and upper soil

dry out during periods of drought,

however, 1 ess protection is provided

(Bead1 e 1940) , and shall ow- rooted plants

can be killed. Heywa rd (1934) reported

that a “very hot ” spring wi 1 dfi re on the

Georgia Coastal Plain killed all long1 eaf pine feeder roots w=i thin the top

inch of soil, but he thought they would

be qui ckly rep1 aced. Gei szl er and

others (1984) examined the suscepti bili ty of Sierra 1 odgepol e pine (P. contorta var. murrayana) roots to'"

Kintensi ty wildfires by comparing

root mortal i ty wi thin a meter radi us of

each stem to the amount of charred bark

on the stem. Retween 14 and 33 percent

of the trees wi th no evidence of bark

char and no burned fuels at tbeir base

nonethel ess had fire- ki 11 ed roots. When

char was observed on more than 66 percent of a tree ’ s basal circumference,

the probabi 1 i ty of associated root- ki 11

approached 100 percent. McConkey and

Gedney (1951) found the number of fi reki 11 ed or severely inj ured vi si bl e roots

was a better indicator of future mortal i ty in eastern whi te pine stands than

was crown scorch.

The senior author has been involved

wi th seemingly i nnocuous prescri bed

fires in south Fl ori da dry prairie ecosys terns. Fine fuel 1 oads were 1 ess than

2 tons/acre and, except under the scattered cl umps of South Fl ori da slash pine

2
(P* elliottii var. densa), fuel contin? ty was such that backfires would not

carry we1 1, residence times were short,

and no scorch was observed. Yet the

01 der pines were dead 4 months 1 ater,

wi th no outward evi dence of i nj ury or

i ofes ta ti on. Furthermore, i n termi xed

younger trees showed no vi si bl e signs

of stress. Al though the root systems

were not excavated, a plausible explanati on is that the fire kill ed the upper

feeder roots of al 1 trees, and only the

younger ones were able to put out

new rootlets in a timely fashion.

The reintroduction of fire into

stands after 1 ong periods of exclusion

can al so result in root and 1 ower bole

damage. Low- in tensi ty fi res may smol der

in the domelike accumulations of sloughed

bark and deep needle accumulations beneath the trees, resul ting in their

death months 1 a ter. This phenomenon

has been noted in loblolly (P. taeda)

and short1 eaf (P. echina ta) ;i;;' nz---

(Ferguson and o~he~-li%%i, in ponderosa

pine (p. ponderos& (Herman 1954)) and

in sugar pine (P. &mberti ana) (Wagener

1955). Although fi’re can damaqe

existing roots, i t al so sti mu1 ates new

root growth as evidenced by increased

fine root densi ty the year foll owing

fire, apparently in response to recycled

nutrients (Kummerow and Lantz 1983).

Some i nves ti ga tors, for exampl e

Swaine and Craighead (1924)) have

reported consi derabl e root mortal i ty

associ ated wi th crown defol i ati on from

insect attack. We speculate that thi s

same association would resul t from a

heat- induced 1 oss of foliage. Redmond

(1959) found that wi th 1 ess than 70

percent defoliation by spruce budworm

(Chori stoneura fumi ferana) , young balsam

firs (Abies bal samea) were able to DUOduce n=otlets and survive but tbat

mature and overmature trees coul d not

do so.

Bole Damage

If the cambi urn tissue is ki 11 ed

completely around the bole at any height

be1 OR the 1 i ve crown, the stem will die

back to this gird1 e unless i t can be

bridged wi th new tissue. Al though pi tcb

(P. rigida) and shortleaf pines can

sprout basal 1 y when young, and pond pine

(P. serotina) can stem- sprout as we1 1, -- .__-

most other North American pines are

unable to do so and thus girdling be1 ow

tbe 1 i ve crown invariably resul ts in

their death. Death, however, may take

some time to manifest i tsel f. Al though

the phi oem is heat- kill ed, the xylem may

not be affected, thereby al 1 owing water

to continue to reach the tree crown. It

can take 1 to 2 years for the we1 1-

developed root systems of 1 arge,

vigorous trees to exhaust their food

reserves and di e. Wyant and others

(1986) state that most long-term studies

show fire-related mortali ty peaks the

second growing season foll owing fire,

but the 1 i terature does not support this

con ten ti on. Instead, i t shows the preponderance of fire- caused mortal i ty

occurs wi thin the first full post f i re

growing season unl ess secondary factors

such as insects are involved.

The aboveground cambi um depends

upon. the bark for protection, and the

insulating abi li ty of thi s outer skin

varies considerably wi thin and between

speci es (Ryan 1982; Spa1 t and Rei fsnyder

1962) . Of the many bark characteristics

studied in the efforts to determine and

rank fire resistance by tree speci es,

two of the most important are thought

to be thickness (Reifsnyder and others

1967) and the presence of an outer 1 ayer

of dead bark (Vines 1968) , especially in

pines whose bark tends to be more corky

(Stickel 1941).

Fahnestock and Rare (1964) found

that bark thi cker than 0.5 i rich protected longleaf pine cambium during

prescribed fires. Al though we have not

measured the relationship between bark

thickness and survival in the field, we

have a fairly 1 arge data base (over

1,000 trees) relating basal diameter

to survi val . When combined wi th pub1 i shed bark thi ckness to stem diameter

ra ti 0s (e. g. , Pederick 1970)) our data

show that bark considerably thinner than

0.5 inch wi 11 protect young 1 obl olly and

slash pines during 1 ow- i ntensi ty dormant -

season fires. Dare (1965c) subjected 14

southern tree species to an external

heat pulse. He was able to divide the

3
sped es in to fi ve fi re- resi stance

cl asses based on bark thickness and i ts

i nsul a ti ng effi ci ency. Longleaf pine

and slash pine formed the most resistant

cl ass; 1 obloll y pine and bal dcypress

(Taxodium -di stjchum) , the second most

resistant cl ass.

The bark of longleaf and slash

(Martin 1963), and loblolly (kfinor 1953)

pines thi ckens wi tb age and diameter,

the latter being the more important.

But at a gi ven age or diameter, thi ckness can vary considerably, depending

upon such factors as seed source (McMinn

1967) and crown posi ti on. Pederi ck

(1970) showed that bark thi ckness of

1 oblol ly pine is a strongly i nheri ted

characteristic; as a result, bark

thi ckness vari es widely between trees of

comparable size and age. He also

concl uded that the bark of Piedmont

populations is inherently thicker than

that of Coastal Plain populations.

McNab (1977) found that 85 percent of

the variation in survi val foll owing

1 ow- intensi ty wi 1 dfire in a dense

1 oblol ly pine stand was explained by

di fferences in bark thi ckness.

Wabl enberg (1960) found that suppressed

1 obl 01 ly pines were much slower to devel op thi ck, i nsul a ti ng bark. Thi s fact

has direct imp1 ications when using fire

as a thinning tool. Because bark

thickens with age, the bark at the base

of a pine is much thicker than that

farther up the stem. Phi 11 ips and

Schroeder (1972) found that tbe bark

thickness of lo- inch d. b. h. slash and

1 obl 01 ly pines at the height representi ng 25 percent of merchantabl e

height (about 15 feet) was 50 percent

1 ess than that at ground I eve1 . Prom

this point upward the decreases continued, but at a much more gradual

rate. In their study, s,I ash pine had

sl igbtly thi cker bark ( x = 0.95 i rich

at tree base) tban 1 obl oily pine

(7 = 0.85 i rich at tree base). Pederi ck

(1970) measured the bark thickness at

vari ous stem heights on young 1 obl 011 y

pines averaging 6 inches d. h. h. The

bark at 1.5 feet was more than twice as

thick as i t was at 15 feet. Ee found

the ratio of double- bark thickness to

insi de bark stem diameter decreased from

0.202 at 1.5 feet to 0.144 at 10 feet

and then 1 ess rapidly to 0.112 at 20

feet. From a theoretical s tandpoi n t,

doubling the bark thickness will

increase the 1 etbal exposure time by a

factor of 4.

In tui ti vel y, i t would seem that tree

girth should be an important factor in

determining fi re suscepti bi 1 i ty. Because wood acts as a heat sink, the

greater the vol ume of a secti on of stem,

the greater i ts abil i ty should be to

retard temperature bui 1 dup in the cambi um. Moreover, live wood has a much

higher moisture content than the dead

outer bark, which means these live

tissues have a much higher thermal conducti vi ty and can thus more rapidly

di ssi pate a fi re- genera ted heat pul se.

The fact that the cross-sectional area

of the stem increases as the square of

the diameter means that as a tree gets

1 arger, i t becomes increasingly more

difficult to girdle in a single fire.

The importance of tree girth as a factor

in determining cambi al temperature responses i s currently a topi c of debate

among fire researchers. Both Robert E.

Martin’ and Ralph M. Nelson, Jr. ,2 have

deri ved equations whi ch show stem di ameter exerts a pronounced influence, but

these equations have yet to be field

veri fi ed.

It is often assumed that the more

rapid passage of a heading fire wi 11

cause 1 ess heating of the 1 ower stem

than a slower moving backing fire. Even

though peak temperatures are not as

high, the 1 onger duration of elevated

temperatures along the 1 ower stem during

passage of the backing fire are thought

to be more 1 i kely to produce 1 ethal

temperatures at the cambi urn. However,

the actual situation is not so clear

cut. Headfi res al ways spread faster

than backfires under the same burning

condi ti ons, but they al so have a deeper

(hori zon tal ) fl ame zone; tbus, resi dence

‘Martin, Robert E. 1985. Personal conmuaication.

Uoiversi ty of California, Department of Forestry and

Resource Management, 145 Mu1 ford Ball, Berkeley, CA

94720.

'Nelson, Ralph M., Jr. 1986. Unpublished data on file,

Southern Forest Fire Laboratory, Route 1, Box 182A,

Dry Branch, M 31020.

4
times are often about equal. Also,

during backfires most of tbe 1 i tter

fuels are consumed in tbe flame front,

whereas residual flaming and smoldering

combustion continue after passage of

headfire flame fronts. The net result,

according to measurements by Fahnes tack

and Dare ( 1964) , is that the very base

of a tree is subjected to about the same

total amount of beat energy in both

backfires and headfires. But this does

not mean the total beat energy released

is equi val ent for both beading and

backing fi res. Assuming tbe caloric

contents of the fuel beds are COMparable, the total amount of beat energy

released i s simply a functi on of tbe

total amount of fuel consumed. In the

above study, beadfires consumed 8.7 tons

of fuel/acre, 2 tons/acre more than

backfires. Tbi s addi ti onal released

heat was distributed fartber up the tree

stems primarily because of the higher

flames associated wi tb beadfi res.

However, i t is widely accepted and supported by both laboratory (Beaufai t

1965; Del son 1982) and field (Eougb

1968, 1978) studi es that backfires

usually consume more forest floor fuels.

In these cases, backfires sboul d do a

better job of “cooking” tbe stem because

tbei r heat is concentrated at tbe base

of a tree, as demonstrated by tbe results of Bruce (1951) and Liudeumuth

and Byram (1948) in longleaf pine.

Again, contrasting resul ts have been

reported (e. g. , Davis and Martin 1960))

and many questions al so remain re

the net resul t of differences in

ard i ng

fark

mechanical and thermal properties related to tree height and diameter.

Several methods of assessing camb i al

damage in tree boles have been used.

These i ncl ude the physi cal exami na ti on

of the cambi urn (Mann and Gunter 1960;

Dill er and others 1961) , sometimes with

the help of viabil i ty test stains (Hare

1965a; Kay1 1 1963) ; the use of a moi sture meter (Hare 1960); the amount of

pi tch bleeding (Fabnestock and Hare

1964; D&nn and Gunter 1960) ; and the

presence of bark beet1 es (Mann and

Gunter 1960). Ferguson (1955) found

basal damage as indicated by cupping

of the bark, combined wi tb crown scorch,

to be useful in assessing damage to 1 oblo? ly and shortleaf pines.

Al tbougb bark char height is an

i ndi ca tor of fi re i ntensi ty, Bourgeoi s

(1985) was unable to correlate it wi tb

the growtb of young 1 obl 01 ly pines, nor

has i t been found to be highly corre1 ated wi tb pine mortal i ty (Eerman 1954:

Vi 11 arrubia and Chambers 1978) unless i t

was noted wi thin the crown (Dixon and

otbers 1984; Storey and Derkel 1960).

These resul ts strongly imply that any

carrel ati on between high bol e char

rati OS and mortal i ty i s simply an analog

of heavy crown damage. Cooper and

Al tobell i s (1969) conducted a study in

1 oblol ly pines 1 ess than 6 inches d. b. b.

to determine whether they are kill ed by

bole damage, crown damage, or botb.

Resul ts indicated a fire intense enougb

to kill tbe stem cambium al so killed the

tree crown. Van Wagner (1970) stated he

bad yet to find large red (P. resi nosa)

or eastern whi te pines that- died of stem

cambi al damage alone, al though young

trees do. Wade (1985) found that al 1

1 oblol ly pines a$ 1 east 4 years 01 d with

1 ess than 75 percent crown scorch were

still alive the fall after dormantseason wi 1 dfi res. Data in Cain (1985)

show al 1 pines more than 5 feet tall

wi th 1 ess than 95 percent crown scorch

survi ved the first growing season fol1 owing a planned headf i re in an overcrowded g-year- 01 d 1 oblol ly stand. Live

crown consumpti on, if i t occurred, was

not speci fi ed. At tbe other end of tbe

seal e are pines such as 1 odgepol e (P.

contorta var. latifolia) that retain ----

rel a ti vely tbi n bark tbroughout tbei r

lives and are thus susceptible to cambi al damage even in 01 d age (Peterson

1984). Gara and others (1986) found

cambi al tissue was kill ed whenever tbe

bark of 1 odgepol e pine was charred.

Qown Damage

Once soutbern pines reach 2 to 3

inches d. b. b. , mortal i ty resul ti ng from

fire will generally be caused by damage

to the tree crown. But this does not

mean, in spi te of the commonly be1 d mi sconcepti on to t-he contrary, that need1 e

scorch is the principal cause of pine

5
mortal i ty. Dormant- season fires can- -

and often do- -completely defoliate a

tree wi thout ki 11 i ng i t as 1 ong as

enough buds and branch cambium survive.

What consti tutes “enough” depends upon

such factors as prefire tree vigor,

postfi re weather, and tree species.

Need1 e kill is a prerequisi te to bud

ki 11 in those species whose buds are

equal to or 1 arger than the need1 es in

cross secti on because in this case buds

have a higher heat capaci ty (By ram

1958). Thus the larger the bud, the

more heat resistant it is. Dare (1961)

states that the bud seal es, 1 i ke bark,

are insulating tissues.

But how can au observer on the

ground determine whether the buds or

branch cambi um have been thermally

ki 11 ed? Perhaps the easi es t method

is to use need1 e consumption as an

i ndi cator of bud and cambi urn death.

Temperatures of about 400 OF are required to ignite the foliage, and these

are high enough to ki 11 surrounding

meri s tema ti c ti ssue. In fact, the data

presented by many authors show 1 i ttl e

mortal i ty in southern pine unti 1 crown

scorch approaches 100 percent (Allen

1960; Ferguson 1955; Mann and Gunter

1960; Van Loon 1967; Villarrubia and

Chambers 1978; Wade and Ward 1975;

Wal drop and Van Lear 1984). But as

crown consumpti on begins, drama ti c

increases in mortal i ty take place

(McCull ey 1950; Storey and Merkel 1960;

Wade 1985). This same phenomenon has

been noted in the West wi th Jeffrey

pine (P. . j effre.yi) and ponderosa pine

(Dieteach 1979; Derman 1954; Lynch

1959; Pearson and others 1972; Wagener

1955; Wyant and others 1986) and wi th

red pine and eastern whi te pine in the

Lake States and Ontario (Dochinger 1963;

Methven 1971: Sucoff and Allison 1968;

Van Wagner 1963).

Postfire damage surveys should be

conducted within 2 to 3 weeks after a

fire, before the scorched foliage fall s.

Otherwise, neither consumption nor prefire 1 imb death and foliage 1 oss (e. g. ,

from insect activity) can be accurately

assessed wi thout close i ndi vi dual branch

inspection, such as done in the study

described by Wyan t and others (1986).

Dead foliage retained for much longer

periods indicates that the branches

themselves have al so been kill ed, precl uding development of an absci ssi on

layer at the needle base.

Growth Effects

As might be expected, even when

parti al defoliation does not resul t in

tree death, i t can adversely affect

growth. McCulley (1948, 1950) presented

data showing that height growth of slash

pine 1 ess than 7 inches in diameter was

suppressed for 3 years foll owing fire

even when the tree crowns were not

scorched. Two years after a winter

prescribed burn, Johansen and Wade3

found that the growth of 7- to 9-i rich

diameter slash pines wi th 1 ess than

10 percent crown scorch was only 85 percent of that of adjacent unburned trees.

Eowever, many of the trees on these

spotfire burn plots were subjected to

much higher scorch levels: perhaps

some root mortality took place even

under the slightly scorched trees.

Landsberg and others (1984) documented

reduced growth of prescribed burned

45-year- 01 d ponderosa pine compared wi th

adjacent unburned control trees four

growing seasons after treatment. They

attributed this reduced growth in part

to measured reductions in crown need1 e

mass on the burned areas, which in turn

resul ted in 1 ess total fol i ar ni trogen

(al thougb no differences in fol iar N

concen tra ti on were found between

treatments) .

Where both radial and height growth

have been studied after heavy scorch,

height growth has generally been found

to be more severely depressed (McCulley

1948, 1950; Wahl enberg and others 1939)

although Bourgeois (1985) and Johansen

(1975) found the opposi te to be true.

It should be noted that al though radial

growth is traditionally measured at

d. b. h. , the 1 ower stem is the zone of

slowest growth and thus the 1 east responsi ve to defol i a ti on (Ku1 man 1971).

'Effects of crown scorch on survival and growth of

pines. (Illanuscript in process, Dry Branch, GA. )
Though growth 1 osses can he substanti al (Barrett 1928: Mann and Bhame 1955;

Morrell 1932; Wakeley 1931; Wyman 1922))

predi sturbance growth rates are usually

achieved again wi thin a few years (Sick -

ford and Curry 1943; McCull ey 1948,

1950; Stone 1942) even after nearcomplete need1 e 1 oss (Cary 1932; Wade

and Ward 1975). Exceptions, however,

can be found (e.g., Evenden 1940).

Some early investigators recorded a

continued depressi on of growth in

southern pine wi th annual fires

(Mackinney 1931, 1934; Paul 1926))

whereas later workers (e.g., Sackett

1975) have not. Trees surveyed by these

workers were of comparable age, so the

difference in results is likely due to

differences in behavior or timing of the

fires- -neither of which were described

in the earlier reports. The authors

note wi thout comment that most resul ts

of de1 eteri ous growth effects due to

fire were pub1 i shed during the time when

a sharply focused Federal effort was

underway to ha1 t the centuries- 01 d southern tradi tion of “burning off the

woods. ” The resul ts of a fully rep1 i -

cated study described by Bayer ( 1982) ,

however, cannot be as easily dismissed.

He found that the growth of 19-year-old

1 ongl ea f pines was retarded by bi enni al

burning treatments begun when the stand

was 12 years of age.

On the other hand, many studi es have

documented increased growth rates after

light- to-moderate crown scorch (up to

60 percent in one study) when compared

wi th unscorched controls. Early workers

(e.g., McCulley 1948, 1950) often ignored such increases or attri buted them

to experimental error. Wyant and others

(1983) gi ve an excel 1 ent discussion of

the effects of a dormant-season fire on

ponderosa pine shoot growth the foll owing

growing season. Because shoot 1 ength

and the number of fasci cl es and needles

(fat tors determi ned during bud forma ti on)

did not differ between treatments, the

authors concl uded that the physi 01 ogi cal

processes wi thin the dormant buds were

not affected by the fire. In contrast,

fascicle growth and the size of buds

formed the season following fire were

both significantly greater on trees in

the burn. Johansen (1975) documented a

first-year postfire increase in radial

growth of 1 o-year- 01 d slash pine if

crown scorch was 1 ess than 15 percent.

Height growth increased for al 1 scorch

cl asses be1 ow 85 percent. Even those

trees wi th 100 percent defol i ati on but

no consumpti on had shown signi fi cant

(0.05 1 evel) radial and height growth

increases over the check trees wi thin

four growing seasons. Cruschow (1951,

1952) reported that the 5-year average

diameter and height growth of “lightly”

scorched slash pine exceeded that of the

unburned control s. Morris and Mowat

(1958)found a like response in ponderosa pine 6 years postfi re. Somes and

Moorhead (1954) noted increased diameter

growth of prescribed burned shortleaf

pine (they did not measure height growth)

compared wi th trees on unburned control

plots 8 years after fire.

Mechaai cal pruning of 1 oblol ly

(Wahlenberg 1960)) longleaf (Wahlenberg

1946)) ponderosa (Barrett 1968)) shortleaf (Walker and Wi ant 1966) and slash

pines (Bennett 1955) has not shown

these same posi ti ve growth responses.

They have, in fact, demonstrated the

increased retardation of both radial

and height growth wi th increasing

increments of croun removal. Thus,

tree growth increases after fire- caused

1 ower branch mortal i ty are not just a

response to the removal of 01 der, 1 ess -

productive branches. Reduced understory

competi ti on and recycl ed nutri ents are

undoubtedly factors. Stark and Cook

(1957) showed that 40 percent defoliation by insects (which was distributed

throughout the whole crown rather than

progressing from the bottom up) was the

threshold for both height and radial

growth 1 osses in mature 1 odgepol e pine,

whereas young trees coul d wi thstand up

to 50 percent defoliation wi thout radial

i ncremen t 1 oss. Cook (1961) found that

the amount of increment 1 oss was posi -

ti vely carrel ated to the 1 ength of time

defol i ati on (from i nsects) exceeded 40

percent. Ryan (1982)pointed out that

young, rapidly growing trees on good

si tes can wi thstand a much greater

reducti on in the ra ti o of 1 i ve crown to

total height than can older, slower
growing trees. Foll owing a January fire

in 1 o-year- old slash pine, Grisson

(1985) charted monthly radial growth

throughout the remainder of the year.

Radial growth of the severely scorched

( >40 percent) trees was much 1 ess than

that of their unscorched companions

during the spring hut had compl etely

recovered by fall. Midday xyl en potenti al (sap pressure) in the scorched

trees was higher al though sti 11 negati ve, suggesting these trees were under

1 ess water stress. He postulated thi s

reduction was due at least in part to

small er live crowns and thus reduced

transpi ra ti on and subsequent water

denand.

Craighead (1927) reported fire defo1 i ati on of short1 eaf pine resul ted in

growth abnormal i ties such as missing

rings on the 1 ower stem the year after a

burn. Mssing rings after defoliation

have al so been reported for other pines

(Ri e teri ch and Swetnam 1984; Ku1 man

1965; Kulman and Hodson 1963; O'Neil

1963). -Other investigators (.Tenison

1943; Van Loon 1967; Wal drop and Van

Lear 1984) found no reduction in postfire growth even wi th complete defo1 i a ti on. However, when analyzing radial

growth from increment cores as done by

some of the above authors, missing rings

will he over1 ooked if the cambi um is

used as the reference point. This oversight not only leads to erroneous

results but can al so lead to a compl acent atti tude regarding fire intensi ty

and attendant crown scorch. Johansen

and Wade4 descri be the dramati c 1 -year

growth 1 oss that occurred over two

growing seasons foll owing a fire that

severely scorched much of a i?5-year-old

slash pine pl antati on; 60 percent of the

trees wi th over 95 percent crown scorch

did not put on a growth ring at d.b.h.

the first postburn growing season.

hii ni ni zing Tree Damage

Tree and Stand Factors -

Bark thickness and twig size, as

we1 1 as bud si ze and the amount of

‘See footnote 3.

foliage protecting the growing tips,

influence the probabil i ty of f i reinduced crown damage and provide a

method to rank fire resistance.

Longleaf pine with its stout terminal

branches (0.5 inch or 1 arger) and 1 arge

buds, which are further protected by

enconpassing clusters of lo- to

l&inch-long needles, is the most fireresistant of all pines. Chapman (1936)

wrapped tissue paper around the buds of

l- to S-foot-high longleaf pine seed1 ings and found i t was not even scorched

during the ensuing “hot” fire. The

three other major southern pines have

twigs that are more sl ender, generally

between 0.125 to 0.25 i rich i n di ame ter,

and much smaller buds. Reed1 e 1 ength

al so differs, wi th short1 eaf pine having

the shortest, 1 oh1 01 ly next, and slash

pine approaching that of longleaf pine.

That bark thi ckness i s posi ti vely corre1 ated wi th diameter means branch cambi um

i s not as we1 1 insulated as stem cambi um

and is therefore more responsive to

changes in ambient air temperature.

Thus during the day, the preburn temperature of the branch cambi urn wi 11

general ly he cl oser to the 1 ethal plant

ccl 1 temperature than wi 11 be the stem

cambi urn, especially when the tree crown

is in direct sunlight.

The higher the base of the 1 i ve

crown, the safer i t is from 1 ethal temperatures generated by a burning understory. As the crown becomes denser

and 1 onger, more heat is intercepted,

thereby shielding the upper crown.

There is 1 i ttl e doubt that vertical

flow is impeded by dense canopies, but

whether this results in higher scorch

heights as suggested by Ryan (1982) is

deba tab1 e. Openings in dense canopies

will invariably result in increased

crown scorch, of the peripheral trees as

the hot gasses are vented upward through

these gaps.

Burni ng Weather --. -.---

The greater the windspeed wi thin the

stand, the faster the gaseous conbus ti on

products wi 11 be mixed wi th cool er air

and di ssipated horizontally ahead of the

fire instead of rising directly up into

the overhead tree crowns. The greater
the windspeed, the farther the flames

will be bent over, thereby increasing

the distance radiant beat (which cools

as the square of the distance) must

travel to reach the crowns. The advantage of greater windspeed, however, has

to be tempered with the fact that flame

length and depth, and thus fireline

intensity, also increase with increasing

windspeed.

According to Ryram (1948, 1958), the

most important parameter determining

crown damage is the preburn vegetation

temperature which is dependent upon the

ambient air temperature. Vegetation

temperature can, in fact, sometimes

exceed amhient temperature by more than

40 OF because of solar radiation. For

example, assuming a lethal temperature

of 140 OF and a straight-line relationship, it follows that about twice the

amount of heat will be needed to kill

foliage with an initial temperature of

50 OF than is needed at 90 "F. When

weather conditions are favorable for

underburning, temperature differences in

a tree crown will not approach this

magnitude because of the cooling action

of the wind. Kyram (1948) described a

substantial increase in fire tolerance

when ambient temperature dropped to

29 OF, Below this temperature, water in

the foliage freezes and large quantities

of heat are needed to convert it hack to

a liquid.

___-__.--.-- Season of Burn

The remaining factor that resource

managers can control is the time when

burning takes place in relation to the

physiological state of the trees (dormant or active). Meristematic tissue

appears to be more heat resistant during

the dormant season (Rare 1961; JameSOn

1961; Kay11 1968). When a bud breaks

dormancy in the spring, it pushes

through the protecting bud scales and

elongates beyond the protective needles,

temporarily beconu'ng much more vulnerable to heat injury. Alexandrov (1964)

presented data showing the process of

hardening off during the fall increased

tissue heat resistance of several species of grass 5 to 6 "F during the

winter. Whether this phenomenon occurs

in pine and, if so, to what extent, has

yet to be determined. Levitt (1972)

described the mechanics of this increased thermotolerance but failed to

recognize its potential significance.

Although perhaps not much of a problem

in the Deep South, Kulman (1971) cites

several authors who show that late

summer defoliation leaves twigs MIlignified and thus subject to winter

damage.

If the literature relating crown

scorch to mortality is separated by

season of burn, the results are striki ng. Trees with near-total foliage

scorch but no crown consumption resulting from fires between October

through h%rch had a much higher likelihood of survival than those with

similar damage caused by fires from

April through Septemher. Craighead

(1940) demonstrated that complete defoliation of lo- to 25-foot-tall jack

pine (P. hanksiana) and Scotch pine (5

~ves~ris)-&i%i~ the growing season .----

wiil cause 100 percent mortality. He

mechanically removed all foliage at

different times of the year for up to

3 years. He found that removal of all

foliage during the growing season

(either about a month after new growth

started in the spring or at the end of

the growing season) caused tree death.

On the other hand, Wilson (1966) completely defoliated Scotch pine prior

to new foliage development in the spring

for 3 consecutive years without any

mortality.

Kramer and 'rletmore (1943) found that

spring defoliation of six species of

evergreen shrubs in North Carolina resulted in increment loss but August defoliation resulted in death. Wilkinson

and others (1966) reported 75 percent

mortality in jack pine defoliated by

second-generation redheaded jack pine

sawflies (Neodiprion rugifrons). O'Neil ---- - ----.-- (1962) found complete mechanTca1 defoliation of jack pine in early August

invariably resulted in death of the individual. Beal (1942) reported the

same result in loblolly and shortleaf

pines with complete late-summer defoliation by redheaded pine sawflies @

__- lecontei). He further noted that trees

9
partially to completely overtopped by

hardwoods were much more susceptible to

mortal i ty (33 percent of the shaded

pines in the 26 to 50 percent defol i ation cl ass died, whereas none of the unshaded pines succumbed). Di fferences i ?

survi val after defol i a ti on, especi al 1 y

when early in the growing season, may

be primarily due to tbe fact that some

pines--notably loblolly, longleaf,

shortleaf, and slash- -do not bave fully

preformed buds and thus undergo several

successi ve need1 e flushes during the

growing season. Species such as red

pine, eastern whi te pine, and ponderosa

pine wi th fully preformed buds are, on

the other hand, 1 id ted to a sing1 e

growth flush per year (Kramer and

Kozl owski 1979). Thus, species wi th

preformed buds that are defoliated after

the spring need1 e flush have to wai t

until the foil owing spring to refol Late.

A study is currently underway at the

Southern Forest Fire Laboratory to quanti fy the abi 1 i ty of the mu1 tinodal

southern pines to refol i ate after

growing- season defol i a ti on.

Concl usi offs

There are times when prescribed

burns are conducted at higher fire intensi ties than planned, resul ting in

total scorch of al 1 need1 es in a tree

crown. But the effects may not be as

cal ami tous as they at first appear.

Southern ye1 1 ow pines wi 11 usually not

die from even total crown scorch provi ded tbat the buds are not ki 11 ed and

the fire occurs wben the trees are dormant. The manager must, however, be

ready to accept the loss of approxi -

mately 1 year’s diameter growth over the

next 2 years when maximum crown scorch

i s incurred. If, however, severe crown

scorch occurs when conifers with preformed buds are physi 01 ogi call y ac ti ve,

the likelihood of mortal i ty is high.

Al 1 pines are more vu1 nerabl e during

this period because elevated preburn

ambi ent temperatures mean the buds are

more 1 i kel y to recei ve a 1 ethal heat

dose from the fire.

Three instances where special care

should be exercised when prescribed

burning under a pine overstory are:

(1) during the growing season, (2) during ini ti al burns after 1 ong fire- free

periods because of the potential for

root and 1 ower bol e damage beneath the

smol deri ng dome1 i ke duff accumul a ti ons,

and (3) when using 1 ine beadfires or

the flying driptorch (which rapidly

creates 1 ine headfi res as the spots

merge) because of the potential for

unacceptably high fire intensi ties.

Nonethel ess, prescri bed burning,

i ncl udi ng aeri al i gni ti on techni ques,

can be used without fear of undue damage

during the dormant season by adhering to

es tab1 i shed gui del i nes: Burn when the 1

ambi ent air temperature is be1 ow 60 “F,

rel ati ve humi di ty exceeds 35 percent,

wind direction i s steady, wi ndspeed i s

between 1 and 3 mi/h at midfl ame height,

and 1 i tter moisture content exceeds

moisture of extinction (35 percent) at

the soil-litter interface. On a given

day, fire intensi ty can be regulated by

the choice of igni tion tecbni que.

10
Literature Cited

Alexanokov. V. YA. Cystophysiological aad cytoecologi -

cal investigations of heat resistance of plant cells

toward the action of high and low temperature.

Quarterly Review of Biology 39:X-77; 1964.

Allen. Peter 8. Scorch and mortality after a summer

burn in loblolly piae. Res. Notes 144. Asbeville,

NC: U. S. Department of Agriculture, Forest Service,

Southeastern Forest Experiaent Station; 1960. 2 pp.

Barrett, James W. Pruning of ponderosa pine. Res. Pap.

PNH-68. Portland. OR: U.S. Reoartneat of Aariculture, Forest Service, Pacific’ Northwest Forest and

Range Experiment Station: 1968. 9 pp.

Barrett, 1. I. Fire damage done to a mature 1 oblol ly

pine stand. Naval Stores Review 3B(lB):11; 1928.

Beadle, N. C. IF. Soil temperatures during forest fires

and their effect on the survival of vegetation.

Ecology 28:180-192;1940.

Beal, J. A. Mortality of reproduction defoliated by

tbe red-beaded pine satiy (.l@odl rlon recootei

Fi tcb). Journal of Forestry 34563; 1942.

Beaufai t, W . R. Characteristics of backfires and headfires -in a pine need1 e fuel bed. Res. Note INT- 39.

0,edeu. UT: II. S. Department of Agriculture, Forest

&vice, Iutermoum~ain Forest aid Range Experiment

Station; 1965. 7 pp.

Bennett, Frank A. Tbe effect of pruning ou the beigbt

and diameter growtb of planted slash pine. Journal

of Forestry 53( 9) :636-638; 1955.

61 ckford, C. A. ; Curry, Jobn 8. The use of fire in the

protection of longleaf and slash pine forests.

Occas. Pap. 105. Askevil 1 e. NC: II. S. Deoartnent of

Agri cul ture, Forest Service, Southeastern Forest

Experiment Station; 1943. 22 pp.

Bourgeois, 0. dl. Growth and mortality of dominant and

co- dominant trees ia prescribed burned pine plaotations--first-year results. Rep. 6-85. Suuuerville.

SC: Westvaco, Southern Woodlands; Hay 1985.5 pp.

Bayer, Yilliam 0. Growth of young longleaf pine as

affected by biennial burns plus chemical or mecbanical treatments for comueti tion control. In: Soutbem si 1 vi cul tural researib conference; 1982 November

4-5: Atlanta, GA. New Orleans, LA: Il. S. Department

of Agri cul tare, Forest Service, Soutbern Forest

Experiment Station; 1982:62-64. [Available fma

George U. Andrews Forestry Sciences Laboratory,

Auburn, AL]

Brown, Autbur A.; Davis, Kenmeth P. Forest fire

control and use. llew York: McGraw-Rill; 1973:46-78.

Bruce, David. Ffre, site, and longleaf belgkt growtb.

Journal of Forestry 49( 1) :25-28; 1951.

By ram, George H. Some basic thermal processes cant rolling the effects of fire on living vegetation. Bes.

Notes 114. Asbeville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station; 1958. 2 pp.

Byram, 6eorge M. Vegetation temperature and fire

damage in tbe southern pines. Fire Control Notes

9( 4) :34-36; Uasbingtoo, DC: U.S. Department of

Agriculture, Forest Service; 1948.

Cain. Mcbael D. Prescribed winter burns can reducp

tbi growth of nine-year-old loblolly pines. Res.

Note SO-312. New Orleans, LA: U.S. Department of

Agriculture, Forest &r&e, Southern- Forest

Experiment Station; 1985. 4 pp.

Gary, Austin. Some relations of fire to longleaf pine.

Journal of Forestry 30: ( 5) 594-601; 1932.

Chapmam, 8.8. Effect of fire in preparation of seedbed

for longleaf pine seedlings. Journal of Forestry

34(g) :852-854; 1936.

Cook, J. A. Growth reduction in 1 odoguol e pine defo-

:;;;;d k$s. n;$&~;~~&$&$g6~.

Cooper, Robert IF.; Al tobell is, Anthony T. Fire kill in

youmg loblolly pine. Fire Control Notes x)(4) :14-15;

Washington, DC: II. S. Department of Agriculture,

Forest Servi ce; 1969.

Crai@ead, F.C. Abnormalities in annual rin s msulting from fires. Journal of Forestry 25(7 f

:840-842;

1927.

Craigbead. F.C. Some effects of artificial defoliation on pine and larch. Journal of Forestry

38( 11) :885-888; 1940.

Oavis, Lawrence S. ; Martin, Robert E. Time- temoerature

relationships of test bead fires and backfires. Res.

Notes 148. Asbevill e, NC: U. S. Department of Agriculture, Forest Service, Southeastern Forest

Experiment Stati on; 1960. 2 pp.

Dieteri cb, Jobn 8. Recovery potential of fire- damaged

southwestern ponderosa pine. Res. Note m-379. Fort

Co1 11 ns, CO: U. S. Department of Agriculture, Forest

Service, Rocky Mountain Forest and Range Experiment

Station; 1979. 8 pp.

Dietericb. Jokn If.; Swetnam, I71oras X. Dendrochronology of a fire- scarred ponderosa pine. Forest

Science 3D( 1) : 238-247 ; 1984.

Dixon, Wayne N. ; Corneil, Jeffrey A. ; Wilkinson,

Robert C.; Fol tz, John L. Using stem char to predict

mortality and insect infestation of fire-damaged

slasb pines. Southern Jourual of Applied Forestry

8(2):85-88; 1984.

Oocbinger, L. S. Artificial defoliation of eastern

wki te pine duplicated some effects of cbl erotic

dwarf disease. Res. Note CS- 16. Columbus, 08:

II. S. Bepartaeot of Agriculture, Forest Service,

Central States Experiment Station; 1963. 6 pp.

[Avai 1 able from Northeastern Forest Experinent

Stati on, Broomal 1, PA]

Evenden, James C. Effects of defoliation by tke pine

butterfly upon ponderosa pine. Journal of Forestry

38( 12) :949-955; 1940.

Faknestock, George R. ; Bare, Robert C. Beating of tree

trunks in surface fires. Journal of Forestry

62( 11) : 799-805; 1964.

11
Ferguson, E. R. ; Ci bbs. C. B. ; Thatcher, R. C. “Cool

burns” and pine mortality. Fire Control Notes

21(l) :27-29. WasbJngton, DC: U.S. Department of

Agri cul ture, Forest Servi ce; 1960.

Ferguson, EdwJn R. Fire-scorched trees- - will they 1 ive

or die? In: Proceedings, 4th annual forestry sywposiuw; 1955 April 16- 17; Baton Rouge, LA: Louisiana

State UnJversity; J955. (pp.102-113).

Gara, R. I. ; Agee, J. K. ; Li ttke, Y .R . ; Geiszier, D. R.

Fire wounds and beetle scars. Journal of Forestry

84( 4) :47-50; 1986.

Ceiszler, D.R.; Cara, R.1.; Littke, A!& Bark beet?e

infestations of lodgepole pine following a fire in

south central Oregon. Zei tscbrift fib Angewandte

Entonmlogie 98( 4) : 389-394 ; 1984.

Centi 1 e, A. C. ; Jobaosen. R. W. Eeat tolerance of sl asb

and sand pine seed1 ings. Res. Notes 95. Ashevil Je,

NC: U.S. Department of Agriculture, Forest Service,

Southeastern Forest Experiment Station; 1956.1~.

Crissom, Janes EdwJn. Effect of crown scorch oo water

status and growtb of slasb pine trees. Gainesville:

hi versi ty of Florida; 1985. 50 pp. Thesis.

Gruscbow, George F. Effect of winter burning on growtb

of slash pine In the flatwoods. Journal of Forestry

50( 7) :515-517; 1952.

Gruscbow, George F. Effect of dnter burning on slash

pine growth. Southern Lumberman 183( 2297) :260. 262,

264; 1951.

Bare, R. C. Cbemi cal test for fire damage. Journal of

Forestry 63( 12) :939; J965a.

Bare, R. C. Siwpl e hot stage for studying critical ccl 1

temperatures. Canadian Journal of Botany 43(6) :

777- 779; 1965b.

Bare, Robert C. Contribution of bark to ftre resistance. Journal of Forestry 63( 4) :248-251: 196%.

Rare, Robert C. Detecting dead carbiur wJ tb a moisture

meter. Journal of Forestry 58( 10) :815-817; 1960.

Bare, Robert C. Beat effects on living plants. Occas.

Pap. 183. New Orleans, LA: U. S. Department of

Agriculture, Forest Service, Southern Forest

Experiment Station; 1961. 33 pp.

Berman, F. R. A guide for marking fire- damaged POnderosa pine in the Soutbwest. -Res. Note 13. Fort

Collins. CO: 6. S. Department of Agriculture, Forest

Service; Rocky Mountain Forest and Range Experinent

Station; 1954. 4 pp.

Heyward, Frank. Cormnents on tbe effect of fire on

feeding roots of pine. Savannak Weekly Naval Stores

Review and Journal of Trade 44( 19) :4; 1934.

Jameson, Donald A. Meat anddesiccation resistance of

important trees and grasses of tbe pinyon-juniper

type. Botany Gazette 122:174-179; 1961.

Jewison. George I4. Effect of sing1 e fires on the

diameter growth of sbortleaf pine in tbe Southern

Appalaclrians. Journal of Forestry 41( 8) :574-576;

1943.

Jobansen. R. W. Prescribed burninR way edance Rrowtb

of young slasb pine. Journal of Forestry -

73( 3) :148-149;1975.

Kavll. A.J. Beat tolerance of Scats pine seedling cam-

&&a using tetrazolium chloride to.test viability.

Publ. 1006. Ottawa. Canada: Department of Forestry,

Forest Research Branch; 1963. -12 pp.

Kayll, A. J. Beat to1 erance of tree seed1 ings. lo:

Proceedings, 8th annual Tall Tinbers fire ecology

conference; 1968 R&cb 14- 15; Tal lakassee, FL:

Tall Timbers Research Station; 1968; 8:89-105.

Kramer, P. J. ; Wetmore, T.E. Effects of defoliation on

01 d resistance and diameter growtb of broad- 1 eaved

evergreens. American Journal of Botany 30:428-431;

1943.

Kramer, Paul J. ; Kozl owsk i , T. J. Pbysiol ogy of wuody

plants. New York: Acadeni’c Press; 1979. 811 pp.

Kulran, B. R. Effects of artificial defoliation of pine

on subsequent shoot aad needle growth. Forest

Science 11:90-98; 1965.

Kulwan, 8. R. Effects of insect defoliation on growth

and wortal i ty of trees. Annual Review of Entomology

16:289-324; 1971.

llulatau, KM.: Hodson. A.C. DJstribution and effects

o f ack- iae budwon defoliation. Forest Scieoce

9:lile-15{ 1963.

Kumnerou. J.; Lantz, R.K. Effect of fire on fine root

density in red sbaok (Adenosscoma s arSI'Ydflum Torr.)

chaparral. Plaat and Soil 70( 3) :3h.

Landsberg, J.D.; Cocbmn, P.B.; Finck, M.M.; kIartin,

R. E. Foliar ni troeen content and tree growth after

prescribed fire i; ponderosa pine. Resr Note

PM-412. Portland, Ofi U.S. Department of

Agri cul ture, Forest Servi ce, faci fi c Northwest

Forest and Range Experiment Station; 1984. 16 pp.

Lanadon. 0. Cordon. Bffmts of vrescribed burnina on

timbe> species in the soutbeahern coastal plain.

In: Proceedi rigs, Prescribed burn@ >vmooslum: 197l

Avril 14-16: Charleston. SC: 1971134-44: IAvailable

horn Southesstem Forest Rxieriment Station,

Asbevi I1 e, NC]

Levitt, J. Responses of plants to environmental

stresses. New York: Academic Press; 1972. 697 pp.

Bough, W.A. Estimating available fuel weight consuwed

by prescribed fires in the So&b. Res. Pap. SE- 187.

Ashevil 1 e, NC: II. S. Departaent of Agriculture,

Forest Service, Southeastern Forest Experiment

Station; 1978. 12 pp.

Houoh. WA. Fuel consumption and fire bebavior of

hazard reduction burns. Res. Pap. SE- 36. Asbevi 11 e,

NC: [I. S. Department of Agriculture, Forest Service,

Southeastern Forest Experiment Station; 1968. 7 pp.

Lindenwuth, A. W., Jr.; 5yram. George H. Beadfires are

cooler near the ground than backfires. Ffre Control

Notes 9(4):4-g. Washington, DC: U.S. Department of

Agri cul ture, Forest Service; 1948.

Lynch, Donald W. Effects of a til dfire on mortality

and growthof young ponderosa pine trees. Res. Note

66. Ogden, UT: II. S. Department of Agriculture,

Forest Servi ce, Intermountain Forest and Range

Experiment Stati on; 1959.8 pp.

1 2
Mackiaoey, A.L. Some effects of three annual fires on Minor, CbarJ es 0. LobJol Jy pine bark tbickaess. LSU

growth of longleaf pine. Journal of Forestry For. Notes 1. Baton Rouge, LA: Agricultural Experi32(8) :879-881; 1934. ment Station; 1953. 2 pp.

Mackimey, A.Z. !J%irteea annual fires in tbe longleaf

pine type. Bull. 15(37). AsbeviJJe, NC: U.S. Department of Agriculture, Forest Service, AppaJ acbi an

Forest Expr?riment Station; 1931. 3 pp. [Available

from Soutbeastem Forest Experiment Station,

AsbeviJJe, NC]

MorreJl, Fred. Effmts of fJre on longleaf pine. Serv.

Bull. 16(22):5-6. WasbJngtoa, DC: U.S. Department of

Agriculture, Forest Service; 1932.

Mann, W. I;., Jr. ; Gunter, Eria Jt. The odds for a firedamaged pine to die. Soutb. For. Notes 126. New

Orleans, LA: U.S. Department of Agriculture, Forest

Service, Southern Forest Experiment Station: 1960.

2 PP.

illorris, Willian 6.; Howat, k&Jo L. Some effects of

tbinaiag aponderosa pine tbi cket wJtb a prescribed

fire. JoumaJ of Forestry 56(3):203-209; 1958.

Nelson, JlaJpb M. Observation on beat tolerance of

soutbera pine needles. Sta. Pap. 14. AsbeviJJe, NC:

U.S. Department of Agriculture, Forest Service.

Soutbeastera Forest Experiment Station; 1952. 6 pp.

Mann, Y.F., Jr.; aann?. Tomw. Prescribe-burning

planted slash pine. Soutb..For. Notes 96. NewOrJeans. LA: U.S. Deoartrent of Aqrfculture. Forest

Service; Soutbero Forest J?xperiment Station: 1955.

2 PP.

Martin, Robert E. A basic approach to fire injury of

tree stems. IO: Proceedings, 2d anaual Tall Timbers

fire ecology conference: 1963 Barcb 14-15;

TaJJabassee, FL: Tall Tiabers Research Station;

1963; 2: 151-162.

Nelson, RaJpb JL, Jr. An evaluation of tbe carbon

balance technique for estimating enJssion factors

and fuel consumption ia forest fires. Res. Pap.

SE-231. AsbeviJJe, NC: U.S. Department of Agriculture, Forest Service, Soutbeas tern Forest Experiment Station, 1982.9pp.

O'Neil,. L.C. Some effects of artificial defoliation on

HcArthur, 6.M. Prediction of cmwn scor& in Pacific

Northwest underbums. Seattle: University of

Washington, Co1 1 ege of Forest Resources: 1980.

176 pp. Tbesis.

O'NeiJ, L.C. Tire suppression of growth rings in jack

pine in relation to defoliation by tbe Swaine jackpine sawfJy. Canadian Journal of Botany

41( 2) :227-235; 1963.

McConkev. moatas W.: Gednev, Donald JL A guide for Paul, Benson Jl. Influence of fires oa growtb of pine.

Soutbem Lunbeman 122(1582) :41: 1926. sal va"ging wJd te pine iaj &ed by forest TJ res.

Res. Notes ll.BmomaJl. PA: U.S. Jlepartmeat of

Agriculture, Forest Service, Nortbea%tem Forest

Experiment Station; 1951. 4 pp.

McCulley, &O. knagemeat of natural slash pine stands

in tbe natwoods of soutb Georgia and north Florida.

Circular No. 845. Washington, DC: U.S. Department

of Agriculture, Forest Service; 1950. 57 pp.

McCuJJey, R.O. Progress report on astudy of tbe significant factors affecting fire injury and tbe

effect of such iniurv on tbe mortality aad growth

of slash pine oa"tb; Osceola NationaJ- Fores:.

AskeviJJe, NC: U.S. Department of Agriculture,

Forest Service, Soutbeistem Forest-Experi m?at

Station; 1948. 27 pp.

P

McMinn, James Ii. Comparative fire resistance of trio

seed sources of South Florida slash pine. Res. Note

SE-68. AsbeviJ Je, NC: U.S. Departnent of

AgricuJ ture, Forest ServJce, Soutbeastera Forest

Experiaeat Station; 1967. 3 pp.

McNab, W.B. An overcrowded pine stand tlrianed dtb

fire. Soutbern Journal of Applied Forestry

l( 1) :24-26; 1977.

Metbven, Ian JL Prescribed fire, crown scorch and

mortality: Field aad Jaboratory studies on red

aud tiite piue. Zof. Rep. PS-X-31. CbaJk River,

Ontario: Canadian Forest Service, Petawawa Forest

Experiment Station; l!XXlOpp.

MJl Jer, Sharon JL; Malac, Barry F.; Johsoa; John w. A

case bistory of slash aad longleaf pine survival

following a tinter wJJdfire. Modland Res. Notes 11.

Savaunah, GA:Unioa Bag- Camp Paper Corporation;

1961. 3 pp.

Pearson, JLA.; Davis, J.E.; Schubert; 6.8. Effects of

wildfire oa tinber and forage production in Arizona.

Journal of Jhge Nanagement 25(4):250-253; 1972.

Pederick, Leon A. Variation and inheritance of ster

fom and bark thickness in young JobJoJJy pine.

Tech. Rep. 41. Raletgh, NC: No& Carolina State

UaiversJty; 1970:8-35.

Peterson, David L. Predicting fire-caused mortality in

four aortbern Rocky Mountain conifers. In: Convention

of Tbe Society of Aaerican Foresters proceedings;

1983 October 16-20; Portland, OR: U.S. Departaeat

of Agriculture, Forest Service, Pacific Soutbwest

Forest and Jlange Jhperiateat Station; 1984:276-280.

PbJJJJps, D.R.: Schroeder, Janes G. Soae pbysi caJ

characteristics of bark from plantation-grown

slash and JobJoJJy pine. Forest Products Journal

22( 10) :30-33; 1972.

Rednwnd, D.B. Mortality of rootlets in balsam fir

defoliated by tbe spruce budworm. Forest Science

5(1):64-69; 1959.

Reifsnyder. William E.: Jlerriagton, Lee P.; Spalt,

Karl W. Thermopbyssical properties of bark of shortleaf, Jongleaf, and red pine. Bull. 70. New JJaven,

CT: Yale University ScbooJ of Forestry: 1967. 41 pp.

Ryan, Kevin C. Evaluating potential tree nortali ty

fron prescribed burning. In: Baungartaer, David H.,

ed. Proceedinqs. symposium site preparation aad

fuels aaaageaent ou steep terrain; 1982 February

15-17; Pullman, WA: Wasbiagton State University

Cooperative Extension: 1982167-179.

1 3
Sackett, Stephen S. ScbeduJiaB prescribed burns for

hazard reduction in the So&beast. Journal of Forestry 73( 3) : 143-147 ; 1975.

Somes. 8. A. ; Roorhead, 6. R. JJo thinning and prescribed

burning affect tbe growth of shortleaf pine? Res.

Notes 34, groomal 1. PA: II. S. Department of Agriculture, porest Service, Wortbeastern Forest Experiment Station; 1954. 2 pp.

Spat t , RarJ W . ; Reifsayder, WiJ liar E. Bark cbaracteristics aad fire resistance: a Ji terature survey.

New Orleaas, LA: U. S. Departneat of AgricuJ ture,

Forest Service, Southern Forest Experiment Station,

1962. 19 pp.

Stark, R .Y . ; Cook, J.A. The effects of defoliation

by the Jodgepole needle wioer. Forest Science

3( 4) : 376-396; 1957.

Stickel, Paul W. O n tbe relation between bark cbacacter aud resistance to fire. Tech. Note 39. Broomal 1.

PA: II. S. Departwent of AgricuJ ture, Forest Service,

Nortbeasteru Forest Experiwent Station; 1941. 2 pp.

Stone, E. L. Effect of fire on radial growth of longleaf pine. Soutb. For. Notes 43. New Orleans, LA:

U. S. Departwent of Agriculture, Forest Service,

Southern Forest Experiweat Station; 1942 (p. 3).

4 PP.

Storey, Theodore 6. ; Nerkel , JkJward P. JkutaJi ty in a

Jougleaf-slasb pine stand following a dater wildfire. JournaJ of Forestry 58(3) :206-210; 1960.

Sucoff , Fdward I. ; Allison, J.R. Fire defoliation and

survival in a 47-year-old red pine plautation. Res.

Notes 187. St. Paul, HN: University of Jbuuesota;

1968. 2pp.

Swaiae, J. M. ; Craigbead, F. C. Studies on tbe spruce

budwof'm (Cacoecia fum’ferana Qen.) Part 1. A

general account of tbe outbreaks, injury and associated insects. Ted. Bull. 37. Jhminion of Canada,

Department of AgricuJ ture; 1924. 91 pp.

Tbiwaan, R. V. ; Raufwaa, 0. Cytoplasaic streawing iu

the cawbiuw of rsbi te pine. IO: Tbiwana, K. V., ed.

Tbe physiology of forest trees. Mew York: Ronald

Press; 1958:479-492.

Ursic, S.J. J+JtaJ root temperatures of 1-O JobJoJJy

‘;‘5”6”11 seedJlngs. Tree PJauters’ Notes 47(12) :25-28;

Van Loon, A. P. Some effects of a wild fire oa a

southern pine plantation. Res. Note 21. Taree, New

Soutb Wales, Australia: Forestry Conn~ission o f

New Soutb Wales; 1967. 38 pp.

Van Wagner, C.E. Fire aad red pine. In: Proceedings,

10th annual Tall Timbers fire ecology conference;

1970 August 20-21; Frederictoa. New Brunswick.

Tallahassee, FL: Tall Timbers- Research Stati on;

1970;10:211-219.

Vaa Wagner, C. E. Prescribed burning experiments: red

and wbite pine. PubJ. JOZO, Ottawa, Canada: Wepartweut of Forestry, Forest Research Branch; 1963.

27 P P.

Vi J Jarrubia, CbarJes R. ; Chambers, Jir L. Fire: J ts

effect on growth and survival of JobJoJJy pine

(Pi nus taeda L. ). Louisiaaa Acadenly of Science

4l,3?F933Tton Rouge, LA: Louisiana State

Uni versi ty; 1978.

Vines, R. 6. Beat transfer tbrough bark, and tbe

resistance of trees to fire. Australian Journal of

Botany 16: 499-514; 1968.

Wade, Dale D. SurvivaJ in youag JobJoJJy pine pIantations followJag wildfire. In: Proceediugs, 8th

national coufereuce on fire and forest meteorology:

1985 ApriJ 29-Bay 2; Detroit, HI. 1985:52-57.

[Available from Society of Awerican Foresters,

Washington, DC]

Bade, Dale D.; Ward, DaroJd E. Maoagewent decisions in

severely dawaged stands. Journal of Forestry

73( 9) :573-577; 1975.

Wageuer, WiJJis W. Preliwinary guidelines for estimating tbe survival of fire- dawaged trees. For. Res.

Notes 98. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range

Experiwent Station; 1955. 9 pp. [Available frow

Pacific Soutbwest Forest aad Range Experiwent

Station. Berkeley, CA]

WaJ~Jenberg, W. 6. LobJoJJy pine: its use, regeneration, protection, growtb and wawagewent. JJurbaw,

NC: ScbooJ of Forestry, Duke Uni versi ty; 1960.

603 pp.

WaJ~Jenberg, LG. Longleaf pine: its use, regeneratiou,

protection, growtb and wanagewent. Washington, D. C. :

CbarJes Latbrop Pack Forestry Foundation: 1946.

429 pp.

W&J enberg. W. 6. : Greene, S. W. ; Reed, JLR. Effects of

fire and cattle grazing on longleaf pine lands as

studied at UcNeill, Bississippi. Tech. Bull. 683.

Wasbington, OC: U. S. Department of Agriculture,

Forest Service: 1939. 52 pp.

Wakeley, Philip C. Effect of a single ainter fire on

planted slash pine. Forest Worker 7( 2):ll; 1931.

WaJdrop, Tbowas A. ; Van Lear, David 8. Effect of crowa

scorch on survi vaJ and growth of young JobJoJ Jy

pine. Southern JouruaJ of Applied Forestry

8( 1) :35-40; 1984.

WaJ Per, Laurence C. : Wiant, JJarry V. , Jr. Si J vicul ture

of sbortleaf pine. Bull. 9. Nacogdocbes, TX: Stepben

F. Austin State College, ScbooJ of Forestry: 1966.

60 P P .

Wilkinson, R. C.; Becker, 6. C.; Benjadn, D.H. Tlre

biology of Neodl rfon PTU ifrons, a sawfJy infesting

jack pine 4&ii%i8?-of the EntomJogicaJ

Society of knerica 59:786-792; 1966.

Wilson, L.F. Effects of different population levels of

tbe Europeaa pine sawfJy on young scotch pine trees.

Journal of Econoric JJntowoJogy 59:1043-1049: 1966.

Wyant, Jawes 6.; Laven, Richard D. ; &ni , Phi lip N.

Fire effects on shoot growth characteristics of

ponderosa pine in Colorado. Canadiau Journal of

Forest Research 13(4) :620-625; 1963.

Wyant, Jawes G.; hi, PJriJip N.; Javen, Ricbard D.

Fire induced tree aortali ty in a Colorado onderosa

pine/Douglas-fir stand. Forest Science 32 P 1) ~49-59;

1986.

Wyuan, Lenthall. ResuJ ts fron sample plots fn

southern pines experinents. Journal of Forestry

20( 7) : 700-787 ; 1922.

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