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OCCASIONAL PAPERS* - No. 46

April 15, 1935.

SOUTHERN FOREST EXPERIMENT STATION
E. L. Demmon, Director
New Orleans, La.

A DESTRUCTIVE FOREST FIRE AND SOME OF ITS IMPLICATIONS

By

C. A. Bickford, Junior Forester, and
Henry Bull, Assistant Silviculturist ,
Southern Forest Experiment Station.

* ' This series of publications releases data gathered in connection with in-
vestigations being carried on at the Southern Station. The information
contained in them is subject to correction or amplification following further
investigation. - Editor

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A DESTRUCTIVE FOREST FIRE AND SOME OF ITS IMPLICATIONS

By

C.A. Bickford, Junior Forester, and
Henry Bull, Assistant Silviculturist,
Southern Forest Experiment Station.

On the afternoon of September 17, 1932, between 12:30 and 3 o’clock, a
forest fire burned over 60 acres of timberland in an area known as the Elk Pasture,
3 miles north of Urania, in LaSalle Parish, northern Louisiana. This simple fact is
not, in itself, remarkable, but the forest stand in which the fire burned was not a
common class of stand. The fire was extraordinarily severe, and killed practically
every tree on the 60 acres. And the implications, conjectures, and controversies
raised by these circumstances are of interest and importance to all those in the South
who own or manage second -growth stands of longleaf pine.

The fire occurred on land belonging to the Urania Lumber Company, a com-
pany that has been outstandingly successful in its fire protection work. Indeed, so
successful has been the protection in Elk Pasture that up to September 1932 this
particular 60 acres had not previously burned since 1913, 19 years before. Mr. Henry
E. Hardtner, president of the company, has been actively interested in forest conser-
vation for many years, and several tracts of his property have now been completely
free from fire for periods of at least 15 or 20 years.

Elk Pasture, a tract of about 1,500 acres, was forested with virgin long-
leaf pine at the time of logging, about 1904. An average of 10 residual longleaf
pines and one residual loblolly pine per acre, trees that were too small to be util-
ized at the time of logging, were still standing in 1932. The first major longleaf
seed crop following logging occurred in or about 1906 but failed to establish a new
stand. The reasons for this failure are not definitely known. Hogs were undoubtedly
an important factor and fire was probably also of considerable importance. The major
longleaf seed crop of 1913 was largely successful in restocking the area. Fire pro-
tection was inaugurated in that year, and in 1916 the tract was fenced against hogs
and cattle. During the next 16 years, with nearly perfect protection from both hogs
and fire, a fine second-growth pine stand developed which in 1932 averaged about 900
saplings per acre.

In 1932, on about one fourth of Elk Pasture, longleaf saplings composed
about 90 percent of this young stand and loblolly saplings about 10 percent. On the
other three fourths of the tract, longleaf composed only about 20 percent of the young
stand and loblolly the remaining 80 percent. On the 60 acres burned in September
1932 the average ratio of longleaf to loblolly was approx im.ately 60 to 40, but indi-
vidual portions of the stand were either predominantly longleaf or predominantly lob-
lolly. The longleaf saplings ranged from 1 to 6 inches in diameter breast-high and
from 10 to 40 feet high. The loblolly saplings ranged from 1 to 10 inches in diameter
breast-high and from 15 to 50 feet high. In addition tc these well-established pine
saplings there were about 100 scrubby hardwoods, 1 to 4 inches in diameter breast-
high, on an average acre. Principally in the predominantly longleaf stands, there
were also hundreds of small, overtopped longleaf seedlings per acre, almost entirely
from the 1920 seed crop.

Thus the picture of the average acre in 1932 included some 11 pine seed
trees, ranging from 6 to 22 inches in diameter breast-high, 900 pine saplings, 100
hardwood saplings, and several hundred small, overtopped pine and hardwood seedlings.
To complete the picture as it actually appeared in 1932, we must also add numerous
brushy shrubs, intricate tangles of vines, and scattered tufts of grasses and sedges.
The most common and largest shrub was wax myrtle, which commonly reached a height
of 6 to 8 feet, and which became firmly and abundantly established in the period be-
tween logging and the establishment of a stand of young pines. As the young pines
overtopped them, many of these shrubs died but continued to stand for many years.
The final element in the picture is a mantle of dead pine needles or "straw" that
covered the ground to an average depth of 3 inches where unsupported by bushes or
tufts of grass. This mantle was spread generously over small bushes and tufts, creat-
ing highly inflammable domes from 6 inches to 2 feet high, and was draped abundantly
over the lower dead branches of the pine saplings and over the branches, both dead
and living, of the larger shrubs and small hardwoods. The irregular character of the
stand, the intricate intermingling of dead and living vegetation of all heights up to
50 and sometimes to 100 feet, and the curtain- like character and arrangement of the
pine straw and the leafy vines, all contributed to the development and maintenance
of a serious fire hazard that endangered the entire stand during periods of dry, windy
weather.

Such were the conditions on the morning of September 17, 1932. According
to Weather Bureau records, the spring and summer of 1932 had been relatively dry at
Urania. No rain had fallen during the 12-day period from September 5 to September
16, inclusive. The maximum daily temperature during this dry period had ranged from
86° to 97° F., and had averaged about 90° F. On September 17, 1932, the maximum
temperature was 98° F., the sky was partly cloudy, and there was a brisk but inter-
mittent northwest wind.

Thus was the stage set. About 12:30 p.m., a fire was discovered and re-
ported along the railroad right-of-way that bisects Elk Pasture, From then until 3
p. m., when the fire was definitely under control and almost out, undeniable facts
are difficult to establish. Honest differences of opinion exist as to whether or not
the fire could have been put out or controlled before it crowned and whether the fire
crew was sufficiently large, properly equipped, and thoroughly efficient in action.
Even eye-witness accounts of the fire are apt to be colored by the very rapidity of
the action and made unreliable by the impossibility of making calm, unhurried obser-
vations. Thus the actual fire will be passed over very briefly with mention only of
the highlights- -and even these are not entirely unassailable facts.

A former State fire warden, with 15 years’ local experience in fire fight-
ing, was first on the scene. He reached the fire while it was still burning in the
grass of the railroad right-of-way and before it reached the boundary fence, 100 feet
from the tracks, beyond which was the dense stand of pine. This man was unable to
stop or control the fire and it passed through the fence and almost immediately
crowned. About 35 men were at the fire by the time it reached the company’s fire-
line, 100 yards inside the fence. These men held the fire at this fireline for a short
time, but the fire soon crossed in so many places, aided by pine straw on the fireline
and by strong gusts of wind, that the line was lost and the firefighters were forced
to fall back. The fire raged fiercely through the crowns and it was said that the
wind carried sparks 100 yards ahead of the main fire and that the flames often reached
to the height of the larger pine seed trees. The fire was finally controlled by

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back-firing and direct attack by about 2 o’clock, after the head had advanced into a
stand composed principally of loblolly pine and hardwoods. By 3 o’clock only one
man was left to patrol the fire.

The results of the fire are a matter of factual record. The burned area
was carefully examined two weeks after the fire. The litter, ground cover, and
practically all the shrubs, vines, and smaller hardwoods had been completely consumed.
Scorched, blackened and partially or wholly defoliated pine and hardwood saplings
and pine seed trees remained standing. Of the pine saplings, only 13 percent of the
longleaf and 4 percent of the loblolly retained any green needles whatever. Of the
longleaf pine seed trees, ranging from 6 to 22 inches in diameter breast-high, 10
percent were completely defoliated, 32 percent retained scorched foliage but had no
green needles, and 58 percent had both scorched foliage and at least a few green
needles. The soil would have been completely bare but for a light mantle of ashes.

At the time of this first examination, foresters and others who viewed the
scene of the fire expressed widely differing opinions as to what the ultimate mortali-
ty of trees might be, but almost everyone present agreed that he had never seen a more
destructive fire in longleaf pine. A reexamination of the area one year later showed
a mortality in sapling pines of 100 percent and in longleaf pine seed trees of 95 per-
cent. Two years after the fire, 96 percent of the original longleaf pine seed trees
were dead. These figures apply to a sample area of 10 acres established at random
near the middle of the burn. Here and there outside the sample area a few scattered
pine saplings survived, particularly near the boundary of the burn. Near where the
fire started and where it final l3^ burned out, the mortality was considerably less than
on the sample area, but varied greatly from one locality to another. Almost all of
the hardwoods were killed back to the ground but sprouted during the 1933 growing
season. The extremely high mortal itj" was evidently not due to continued drought con-
ditions after the fire, since there was a rainfall of 1.6 inches only 2 days later and
a normal rainfall during the remainder of the fall and winter.

The facts concerning the Elk Pasture fire have now been related and a brief
discussion of some of the implications raised bj^ this fire seems pertinent. Because
the fire caused such appalling damage to a stand completely protected from fire for
19 years, during which time an extreme hazard had been built up, complete exclusion
of fire for long periods might well be considered unwise. In rebuttal it may be said
that the fire burned only 60 acres, which is only a drop in the bucket when consider-
ing the extensive holdings of the Urania Lumber Company, and that this is the only
very destructive fire of more than about 30 acres to have occurred in the long period
of protection. At least three other destructive fires occurred in 1930 and 1931 in
long-protected stands owned by the Urania Lumber Company, but these burned over only
14 to 33 acres each. Perhaps one can afford to take an occasional complete loss on a
few acres in order to reap, on the remainder of his holdings, the benefits of greater
growth and higher quality that are expected to accrue from complete protection.

A 60-acre fire is indeed so relatively small that some may consider it too
insignificant to warrant or justify serious consideration. It is not unreasonable, how-
ever, to believe that what can and did happen on only 60 acres might sometime occur
on more extensive areas, under more favorable fire conditions such as with a stronger,
steadier, or more prolonged wind, or with an earlier start, or in less accessible stands.
It is the threat, the strong possibility, that the 60-acre Elk Pasture fire may be re-
peated on a much larger scale that warrants serious consideration. Some will argue

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that the protective organization might be built up, without undue expense, to such a
point of efficiency that very destructive fires even as large as 60 acres could and
would be largely eliminated. Again there is a ready rebuttal --that there are occa-
sional fires that simply cannot be stopped or controlled within a reasonable time or
area by any methods now in use and that under complete fire protection the danger
and frequency of such fires will increase.

These are highly controversial subjects and strong arguments can be pre-
sented for each side. Before concluding the discussion, however, let us glance brief-
ly at the two obvious extremes of the fire question in the longleaf pine type and at
possible intermediate positions. At the one extreme is complete absence of fire pro-
tection, with annual or at least relatively frequent, entirely uncontrolled fires.
The results of this policy are amply demonstrated on millions of acres of forest lands
in the South. The stands of timber or of reproduction are generally very much under-
stocked and incomplete, occasionally absent altogether, and growth and quality are
generally lowered by severe or long -continued defoliation of the crowns and scarring
of the stems. At the other extreme is complete exclusion of fire, with the attendant
development under certain circumstances (as we have seen) of an extreme fire hazard
and the very real possibility of complete or almost complete loss when an accidental
fire occurs in very dry, windy weather.

Between these two extremes lies the practice of periodic controlled burning.
This practice consists of deliberate burning, under controlled, selected conditions
that preclude the possibility of serious damage, usually for the specific purpose of
destroying grass, underbrush, vines, pine straw, etc., that would otherwise accumulate
and constitute a high fire hazard. Other purposes, which will sometimes be primary
rather than secondary, may be to prepare the ground or improve the surface conditions
for desirable reproduction, to reduce the competition of associated vegetation such as
dense grasses, and to reduce the brown-spot needle disease which attacks longleaf
pine seedlings. Controlled, selected conditions will often mean burning at night,
during the winter, when the soil is moist, in limited areas bounded by natural or con-
structed firelines, and with a fire crew present. Such controlled burning might be
practical at, say, 3- to 5-year intervals, depending on the purpose and on the rate of
accumulation of the vegetation that constitutes the principal fire hazard.

Periodic controlled burning in the longleaf pine type seems a more logical
practice than either of the two extremes--especially the extreme of no protection at
all. But it is not as easy to apply in practice as it is to discuss on paper. The
stands and conditions must be carefully selected, and many different circumstances
must be taken into account. Above all, there is at present a lack of definite infor-
mation on the practice. Its ultimate results and effects are not known, and will not
be known until thorough, long -continued investigations have been completed. Until
then, periodic controlled burning may be considered a very promising and very logical
practice, but one that should not be used without full understanding of its appli-
cations and possible results.

The Elk Pasture fire raises questions that are not readily answered, and
implies problems that are not easily solved. These questions and problems, concerning
the proper use and relation of fire and protection in the longleaf pine type, consti-
tute a controversial subject of great importance to foresters and timberland owners
in the South. The Southern Forest Experiment Station is endeavoring to obtain and
interpret the basic facts.

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