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Department of Agriculture and Immi-
gration of Virginia

GEO. W. KOINER, Commissioner

In co-operation with the Forest Service United States

Department of Agriculture

HENRY S. Gravk&s, Forester

SHORTLEAF PINE IN VIRGINIA

The Increase in its Yield by Thinning

By W. W. ASHE

Forest Examiner, Forest Service

RICHMOND:
DAVIS BOTTOM, SUPERINTENDENT PURLIC PRINTING
1913

TE I.

PLA
Crowded small pole stand of shortleaf pine

about 30 years old in need of

stemmed

A large

gular in size.

but irre

’

The trees are slender and clean
num ber of the smaller trees should be removed.

thinning.

Department of Agriculture and Immi-
gration of Virginia
GEO. W. KOINER, Commissioner

In co-operation with the Forest Service United States
Department of Agriculture

HENRY S. GRAVES, Forester

SHORTLEAF PINE IN VIRGINIA

The Increase in its Yield by Thinning

By W. W. ASHE

Forest Examiner, Forest Service

RICHMOND:
DAVIS BOTLrOM, SUPERINTENDENT PUBLIC PRINTING
E 1913

By Tranefer
SEP do (gl

iz CONTENTS

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ILLUSTRATIONS

Plate I.—Crowded small pole stands of shortleaf pine about 30
years old in need of thinning. The trees are slender and clean
stemmed, but irregular in size. A large number of the smaller
trees should! she; removeds okie. 2% 2: ties eee ee es eee Frontispiece.

Plate IIA dense sapling stand of shortleaf pine 15 to 18 years
old, but too small to be profitably thinned. While the clean
condition of the floor is good, fire could do great damage to
such a stand

Plate IIJ.—Understocked large pole stand of shortleaf pine 30
years old. The trees are short-bodied and knotty and will yield
only low grade lumber. The best that can be done with such
a stand is to cut it, leaving the most slender, clean-bodied
trees for seed-trees

Plate IV.—Crowded, large pole stand of shortleaf pine 40 years
old, badly in need of thinning by removing the smaller pines
and many of the hardwoods. Condition of larger trees, with
long, smooth bodies, excellent.

Plate V.—Mature stand of shortleaf pine. Trees nearly uniform in
size and ready to be cut for lumber. Groups of slender, wind-
firm trees can be left: for seed trees.

Plate Vi.—Figure 1.—A typical case of sustained rapid diameter
growth, resulting from repeated thinnings, in a tree of short-
leaf pine which was overcrowded for many years. Wood of
ssuch a tree is free from large knots, and its stumpage is
-worth $8 a 1,000 board feet under a cost of operating of $12

Figure 2.—Stem of a small sprout sapling of shortleaf pine,
crooked and scarred at the neck as a result of the original
‘seedling having been killed to the ground by fire. Stump and
‘root rots gain entrance through such scars.

Shortleaf Pine in Virginia

The study upon which this report is based was undertaken by
the Forest Service in co-operation with the State of Virginia, the
work being done under the direction of the officer in charge
of State Co-operation in the Forest Service. By the terms of the
co-operative agreement, the State is authorized to publish the find-
ings of the investigation.

PURPOSES AND RESULTS.

At the request of Hon. C. A. Swanson, Governor of Virginia,
the Forest Service, United States Department of Agriculture, in
the autumn of 1909, made an examination of the second-growth
shortleaf pine in old fields in the middle portion of Virginia.
The cost of this work was borne jointly by the State of Virginia
and the Forest Service.

The examination included a detailed investigation of stands of
pine in old fields in Mecklenburg, Lunenburg, Brunswick, and
Hanover counties, which was supplemented by a general examina-
tion of the stands in other counties in the middle part of the State.
Its scope was:

(1) To ascertain the condition of the old-field stands and the
ralue of thei timber for lumber uses;

(2) To determine the effect of lumbering on the future yields
of the stands and to ascertain whether conservative methods of
cutting could be employed profitabLy ;

(3) To determine the yield of stands of different ages;

(4) To recommend methods of thinning and cutting to ac-
celerate growth;

(5) To devise methods of protection for young growth.

The conclusions reached as a result of the investigation can be
summarized as follows:

Shortleaf pine is the most important tree in twenty south-
central counties, but the yield from the pine lands is low because
there is neither protection nor a definite system of cutting. The
yield can be greatly increased and the quality of timber improved
by a regular system of management.

(1) Better protection against fires and insects is required in
most stands. Young stands, especially while in process of stocking,

6 SHORTLEAF PINE IN VIRGINIA

suffer most from fires. Older stands are most endangered by in-
sects. Protection against fire may be secured by means of fire
lanes, posted warnings, restriction of night hunting, and patrol
during dry seasons when neighboring lands are afire: The danger
of loss from insects may be reduced by making frequent thinnings
and by removing or by cutting infested trees.

(2) The average stand of pine is far too thinly stocked. ‘This
is due to insufficient natural seeding and to the thinning of young
stands by fire and of older stands by insects. The yield of such
thinly-stocked stands is considerably less, and the grade and value
of the timber is lower, than from thickly stocked stands.

(3) Crowded areas occur in nearly all stands, and some stands
are crowded throughout. Such crowded plots can be greatly im-
proved by thinnings. The effect of thinnings is to accelerate
growth, hasten maturity, and produce a superior quality of timber.
The beneficial results of thinnings decrease with the age of the
stand, but stands as old as forty-five years respond. to them well.

(4) Where natural seeding has not formed dense stands with-
in ten years, the stocking can be completed by the planting of
seed; and, where natural seeding does not take place, whole areas
may be seeded. Stands restocked in these ways can be expected to
yield fully as well as the best natural stands and to return a fair
rate of interest on their cost.

If management is applied, that is, if young stands are pro-
tected, full stocking secured, and the stands subsequently thinned,
the yield of saw timber from a 40-year-old stand can be more than
doubled and its value greatly increased. Shortleaf pine is already
one of the chief sources of building material on the farms. Fur-
thermore, the farms have more timber than is required for their
own support, so that as the general demand for coarse lumber 1n-
creases and its price rises, shortleaf pine in farm woodlots can be
made an important source of commercial timber and a means of -
permanent income.

DISTRIBUTION AND IMPORTANCE

Second-growth or old-field shortleaf pine is the most important
tree of middle Virginia and the Piedmont, south of the Rappa-
hannock, in which region it probably cccupies more than one-half
of the total forest area and more than three-fourths of the farm
forest area. It forms the dominant growth on more than 3,000,000
acres, on which it occurs either in. pure stands or, more commonly,

SHORTLEAF PINE IN VIRGINIA i

with a shght mixture of other pines and of seedling and sprout
hardwoods. It meets with least competition and forms the purest
second-growth stands in the tier of southern counties west of Lun-
enburg county. It is not common north of the Rappahannock
river, and is infrequent on the Blue Ridge mountains and in the
Great Valley, while in Tidewater Virginia it grows only on the
best drained clay soils, and in these sections, on account of the com-
petition of other species, its second growth seldom occurs in pure
stands.

NAMEs AND DisTINGUISHING CHARACTERISTICS

Shortleaf pine is also and more generally known as rosemary
pine, spruce pine, and yellow pine. The original growth is fre-
quently distinguished from the second growth in old fields under
the names of forest or woods pine.

This tree is not to be confused with scrub or jack pine,
which is also called spruce pine. Scrub pine is a smaller and in-
ferior tree with a limby stem and smooth, scaly bark. It is largely
replacing shortieaf pine in old fields in the northern portion of the
State and in the upper edge of the Piedmont in and near the
mountains, and is occasionally found mixed with shortleaf pine
southeastward as far as Brunswick county. Nor is it to be con-
fused with loblolly pine, which is known in extreme southern Vir-
ginia as shortleaf pine and, where it occurs near the coast, as long-
leaf, swamp, foxtail, or slash pine. Loblolly pine is the common
pine on sandy soils in Tidewater Virginia, but it extends westward
in association with shortleaf pine to Brunswick, Chesterfield and
Louisa counties. The northern pitch, bull, or black pine of the
mountains, which is yet another tree, seldom forms second growth
in old fields.

The cone and leaf differences of these trees will be a further
help in separating them:

Shortleaf pine has cones (burrs) seldom more than 1 1-2 inches
long, and slender, straight needles, two or three together, twice as
long as the cones.

Serub pine has cones of about the same length as those of
shortleaf pine (1 1-2 inches) but they are relatively broader. The
needles are stout and twisted, with never more than two together,
and are about the same length as the cones. Frequently the cones
of scrub pine and shortleaf pine remain on the trees for many years
after opening.

8 SHORTLEAF PINE IN VIRGINIA

Loblolly pine has large cones, from 3 to 4 inches long. Its
needles are borne in threes and are about twice as long as the cones.
The cones of this species usually fall during the second summer,
but sometimes they persist for several years.

Uses or Woop

The timber of second-growth shortleaf pine is largely sap-
wood. The formation of heartwood does not begin until the trees
are about twenty-five years old. For many years thereafter the
heartwood is limited to a small core, and more than two-thirds of
the volume of trees fifty years old is still sapwood. The most im-
portant uses for the wood of the shortleaf pine are for building
lumber, fuel, slack cooperage, box lumber, headings, and crates.
The wood contains too much resin to be a desirable material for
paper pulp stock without special treatment, although it is used to
some extent for this purpose. On account of its softness it is not
suited for railroad ties if the traffic is heavy, and, when used for
this purpose should be made more durable by preservative treat-
ment.

The large proportion of sapwood in the second-growth tim-
ber renders it undesirable for shingles, for which the durable heart-
wood of the old growth was extensively employed; and unfits it for
other uses requiring exposure to the weather, unless it is thoroughly
kiln-dried and painted. Logs more than fourteen inches in dia-
meter from trees with clear boles yield lumber suitable for ceiling
styles and panels of doors, sashes, window frames, interior wood-
work, and also for flooring if rift sawed. Timber suitable for such
uses must come not only from comparatively large trees, but from
trees which early cleaned their stems and formed wood in the lower
two-thirds of the trunk free of knots. That part of the tree which
can be converted into lumber of this kind should command, on the
basis of $25 for the finished lumber, a stumpage price of not less
than $10 a thousand board feet.

Unless the price of cordwood stumpage is proportionately
much higher than that of saw timber stumpage, the greatest profit
from a crowded stand will be secured by reserving the larger trees
for saw timber, and in the meantime thinning or culling the small-
est trees for cordwood, stave stock, box boards, bolts, and similar
purposes, for which small material is suited. If only selected trees
are retained for saw timber they should be allowed to attain a large
size in order to produce timber of high quality.

Leaner

“#

hic

hth

SPORE Ee

oe epee
bo

PLATE II.
dense sapling stand of shortleaf pine |

profitably thinned. While the clean condition of the

great damage in sucha stand.

but too small to be
floor is good, fire could do

’

5 to 18 years old

SHORTLEAF PINE IN VIRGINIA )

CONDITION AND COMPOSITION OF OLD-FIELD
STANDS

As early as 1735 it had become a fixed part of the farming
system of middle Virginia to clear new ground each year and to
abandon to tallow a parcel of the oldest and most worn farming
land. The land thus turned out was rapidly colonized with pines
through seed blown by the wind from old trees nearby. When
these pines had become large enough and the humus had been re-
stored to the soil through them, the land was usually cleared again.
Such a system of rotation of timber and cultivated crops was pos-
sible only in a region where land was abundant and cheap. It was
due in part to the lack of local markets, which made it necessary to
export a large portion of the crops and therefore to produce them
as cheaply as possible, regardless of the effect upon the soil; and
in part to the fact that these soils were not natural grazing lands,
and the depleted humus could be renewed naturally and cheaply
by the replacement of the native pines. Some of the existing
groves of old-teld pine thus originated before the Revolutionary
War. Most of them, however, are younger, having originated dur-
ing and just after the Civil War or in the subsequent periods of
agricultural depression about 1880 and 1892. These stands are
consequently of all ages; from the youngest, just in process of
stocking land which has been turned out during the past decade,
to those more than 100 years old. Stands between fifteen and
forty-five years old are, however, the most numerous.

Such old-field stands were thus established naturally, and no
efforts were made by the owners to increase their density when
they were too open or to protect them, while young, from fire.
They have seldom been thinned judiciously for improvement. As
a result, they vary widely in density. Small tracts are usually
well-stocked, since, if seed-bearing trees were nearby while stocking

ras taking place, seeds were in a few years scattered uniformly
over the entire tract and such small tracts were often protected
from fire by fences, or by adjacent cultivated fields. The trees in
such well-stocked stands are slender and clean-bodied, with small
crowns. The average tract, however, is poorly stocked. The trees
are isolated, individually, or in irregular groups, and consequently
short-bodied, knotty, and coarse-grained. This open condition of
many of the stands is due to the fact that seed trees were too
few or too distant while the stocking was in progress, or to the
fact that the fields became grassy and the seedlings were killed by

10 SHORTLEAF PINE IN VIRGINIA

fires that burned the grass. Scattered advance growth frequently
has borne seed and so stocked the gaps. Such stands are irregular
in age and size.

Many of the older stands have been irregularly and often heav-
ily cut for poles, cordwood, and even sawlogs. Most stands of sap-
ling or larger size are too open for the best growth of the trees
and for the highest financial returns.

The proportion of shortleaf pine in the old-field stands varies.
North of the Rappahannock river the proportion of scrub pine
mixed with the shortleaf increases, until in Fairfax county and the
lower end of Prince William county it largely replaces shortleaf
pine. It is also largely mixed with shortleaf pine in stands near
the mountains. In the shortleaf pine stands in the eastern ends of
Hanover, Chesterfield and Brunswick counties, there is a large
proportion of loblolly pine, which entirely supplants the shortleaf
farther eastward. South and southwest of Hanover county the
only pine in the field stands is the shortleaf, but species other than
pine form part of the mixture in a varying proportion, though
they seldom make up more than ten per cent. in stands younger
than thirty-five vears old. In young stands these associated species
vary with the kinds of seed-trees nearby. On lower slopes they
are usually maple, poplar, sweet gum, and the oaks; on hilltops
they are red cedar, oaks, hickory, black gum, persimmon, cherry,
thorn, sassafras, and dogwood.

PERMANENCY OF Otup-Fisnp Pine Stranps

As the field pine stands become older, especially after they
have passed the thirty-fifth year, their crown cover tends to thin,
and this favors the growth of the oaks and hickories, which come
in from seed dropped by squirrels, crows, jays, etc., and are better
able to grow beneath the cover than are young pines. Even after
the pine in the stand begins to seed the proportion of these broad-
leaf species continues to increase, since the young pines can come
in only when an extensive opening is made by the death of a large
pine. There is thus a tendency toward a gradual re-establishment
of the original forest tvpe which prevailed before the land was
cleared, namely, a mixture of oak, hickory, black gum, and pine,
with pine forming a small proportion on the best soil and a large
proportion—frequently more than half the number of trees—on
the poor, dry or sandy soils. The pure pine stands are, therefore, a
temporary type, which in time will be replaced by the permanent
mixed-growth type.

SHORTLEAF PINE IN VIRGINIA WE

It is not an invariable rule that “hardwoods follow pine” after
cutting or that “pine follows hardwoods” after cutting or clearmg.
But pure pine usually forms the second growth if there is no shade
or cover, as in old fields or on hardwood land which has been cut
clear in late summer or early autumn, when the sprouting power of
the hardwoods is low. If seed-bearing trees are near, such open
land, whether in field or forest, is captured in a few years by
pine, by means of its abundant, light seeds which are widely scat-
tered by the wind. The heavy seeds of oak, hickory and black
gum, which are carried largely by birds and squirrels, are dis-
seminated too slowly and irregularly to enable such species to
compete successfully with pine in stocking nearby open lands. Un-
der these conditions, pine usually follows oak.

On the other hand, pine is unable to establish itself beneath
dense shade, whether of pine or of hardwoods. For this reason
young pine growth is seldom found under the trees except in older
open pine stands. ‘The seeds of hardwoods, however, are dropped
from year to year in such stands and germinate; and the seedlings,
through their persistency and ability to endure shade, will survive
in shade in which a young pine can not live, although their growth
in this case is extremely slow. When the large pines are cut, these
stunted hardwoods, responding to improved conditions of ight and
root space, grow rapidly and if they are numerous they form the
larger part of the growth which follows the pine.

In those portions of the State in which it occurs, scrub pine
affects the permanence of the shortleaf pine stand on medium soils
even more than do the hardwoods. Scrub pine seeds prolifically,
when much younger and smaller than shortleaf pine, and the seed-
lings are tolerant of far more shade than those of the shortleaf.
For these reasons, it not only excludes the shortleaf from old *
fields which are in process of stocking, but it successfully competes
with the young hardwoods in occupying openings in stands of
shortleaf pine in which the cover is too heavy for shortleaf seed-
lings to exist, and thus in part succeeds the shortleaf in shortleaf
stands.

By reason of this aggressiveness, scrub pine is so completely
replacing shortleaf pine over large areas in the northeastern part
of the State and near the Blue Ridge that the economic range of
shortleaf pine is being restricted.

12 SHORTLEAF PINE IN VIRGINIA

MANAGEMENT

Forest management as applied to old-field stands may be sum-
marized as the use of any methods of restocking, cutting, or thin-
ning which will reduce the cost of growing timber or add to the
value of the timber grown.

Natural stands are usually either understocked, at least in
certain phases or during certain periods of growth, or else over-
crowded,

The maximum growth is obtained by maintaining such a num-
ber of trees to the acre as will utilize the full capacity of the soil
and at the same time secure the best development of the individual
trees. Understocked stands do not use the full capacity of the soil
and must be filled out to the required density by planting in the
thin places. In crowded stands, on the other hand, the indi-
vidual trees are retarded; they must be thinned in order to make
them grow at their best rate. These requirements of the stand
are discussed in connection with the subjects of thinnings and
planting.

Another phase of management is cutting at the period of ma-
turity as determined by either maximum yield or value. The rate
of growth or accretion of a stand is not the same at all ages. The
yearly growth rapidly increases from nearly nothing to a maxi-
mum, then slowly declines. When the rate of annual growth be-
gins to decline, a loss in yield is entailed if cutting is deferred.
The time at which the maximum of the average annual yield is
obtained varies with the size of the timber which is desired; it
would not be the same for lumber, which requires large timber, as
for cordwood, for which small timber can be used. But while it is
desirable to obtain the maximum annual yield from a stand, the
cost of production is a factor which cannot be neglected.

The cost of production embraces the interest on the investment,
the taxes, superintendence, protection, and the making of improve-
ment cuttings and thinnings. As far as the needs of owners and
the market conditions allow, a stand should be cut at financial
maturity, that is, when it yields the best returns on the investment.
‘These phases of management are considered in connection with
vields of stands at different ages, and with the cost of growing
timber. One of the most important considerations in manage-
ment is the method employed for obtaining a prompt renewal of
the stand in order to prevent the loss of interest on the investment
by the idleness of the land.

SHORTLEAF PINE IN VIRGINIA 13

Protection of stands from fire, from insects, and from fungus
diseases is necessary to insure fully stocked stands and sound
timber.

‘The figures relating to the growth and yield of shortleaf pine
are based on stands which are growing on soil formerly covered
with forests of shortleaf pine mixed with white oak, southern red
oak (Quercus digitata), black oak, and white hickory. The rate
of growth on such sites is regarded as the average or usual rate.
Where the pine now grows on soils which were formerly covered with
forests of shortleaf pine mixed with post oak, with black-jack oak,
or with Spanish oak (Quercus coccinea), or with a large propor-
tion of these oaks together with other oaks, the rate of growth and
the yield of the stands will be considerably lower than that given.

Fuity Srockep AND Crowpep, STANDS

A stand is fully stocked when it contains all the well-grown,
vigorous trees which the soil can support. This number decreases
with the age of the stand and the consequent increase in the size
of the trees. In a natural twenty-year-old stand of shortleaf pine
the number to the acre should exceed 1,500; at forty years it has
decreased to about 75U; at sixty years it has fallen to less than 450.
This reduction of the number of trees in a stand progresses nat-
urally. As the trees become older and larger, their crowns spread
and their roots extend in search of food and moisture. Competi-
tion for light, food and moisture ensues, and this in turn results in
the dying of the smaller and weaker trees, which are overtopped
and crowded out by the more vigorous ones.

A fully-stocked stand, in which natural thinning is taking place
rapidly, is crowded (plates I, IJ and IV). At any age the fact
that a stand is crowded is indicated by a close crown cover and the
presence of many dead trees and slender live trees with narrow
crowns. In a young stand of this character less than thirty-five
years old the crowding 1s so great that the crown of each tree al-
most touches the crowns of its neighbors and direct sunlight hardly
reaches the soil. The shade is sufficient to prevent the start of
young trees and most shrubs beneath the pines and the carpet of
pine needles is so thick as to exclude grass, while small dead trees
are numerous. In stands more than thirty-five or forty years old
there is a wider distance between adjacent crowns, due to the rapid
dying of the larger of the slender narrow-crowned trees. This
opening of the stand admits more sunlight, and young oaks, hick-

14 SHORTLEAF PINE IN VIRGINIA

ories, and other trees, as well as many shrubs, begin to grow be-
neath the pines. Dead trees and live trees with narrow crowns are
. not so numerous as in younger stands. The mat of pine needles is
thinner in the older stands and grass is able to spring up.

A fully-stecked young stand of shortleaf pine has, therefore,
a dense crown cover. In both young and old stands, if they are
fully stocked, there are slender trees with narrow, spry crowns and
dead trees which have been crowded out, though the latter are more
abundant in the young stands. Whether a stand is crowded and in
need of thinning may be determined by the greater or less abund-
ance of crowded and dead trees, considered in connection with the
age of the stand and the normal density of the crown canopy at a
given age.

UNDERSTOCKED STANDS

‘The average stand of shortleaf pine in middle and Piedmont
Virginia, however, instead of being too densely stocked, is too
thinly stocked. When the crowns do not interfere, or are round-
topped with practically horizontal lower branches, the stand is too
open for best growth.

Young and even middle-aged stands are frequently open, but
their wide-spreading crowns eventually close and form a dense
crown cover like that of a fully-stocked stand. But in this case
dead trees and slender overtopped trees are absent; the crowns of
the trees are too round and wide-spreading; the stems are too short
and limby; and the number of trees to the acre is much less than
in fully-stocked stands of the same height. (Table 9). Under-
stocked stands of this kind do not require thinning. Moderately
understocked young stands usually become crowded early enough
to reduce some of the evils of understocking, but the stems of
the trees are never so tall and free from limbs and knots as those
which develop when there is crowding all through the life of the
stand and their total yield is usually less than that of a fully-
stocked stand. (Plate III). Young understocked stands should
be filled out by planting.

In nearly every stand, however, there will be found at least
groups of trees which will be benefited by thinning. The presence
in the stand of numerous small dead trees and slender trees with
spiry crowns is a clear indication that thinning is needed.

SHORTLEAF PINE IN VIRGINIA 15

THINNINGS

The objects of thinnings are, first, to accelerate the growth and
shorten the time necessary to bring the stand to maturity, and,
second, by removing defective trees fo produce a mature stand
formed of perfect specimens and so increase the vield of lumber.
The elimination of the weaker specimens by natural process takes
place too slowly for the best development, because the growth of
the trees which are ultimately to survive is retarded by the pro-
Jongation of the struggle for light and food. Yet limited crowd-
ing is necessary at certain periods to force height growth and to
develop long, straight stems, reasonably free from limbs. More-
over, the number of trees to the acre largely determines the volume
of the yield and has an important bearing on the value of the
trees. Usuilly the crowded stands produce the greatest volume of
wood at all ages; but when the size or diameter of the individual
trees is of primary importance, as in the production of saw logs,
less crowding is desirable. By means of judicious periodic thin-
nings, it is possible both to favor competition and to relieve over-
crowding and in this way greatly to accelerate the growth of the
remaining trees. Such thinnings reduce the number of trees, but
they produce equally tall trees of much larger diameter, with
straight, clean stems and but little taper. It is commonly held
that if the larger trees are removed as they come to merchantable
size the smaller trees will make accelerated growth. This is un-
questionably true of many species and it is true also of short-
leaf pine under thirty years old, but in pure old stands of short-
leaf pine in Virginia the crowded and suppressed trees recuperate
so slowly that it is not profitabie to thin the stands in this way
after they have passed the age of thirty-five. years.

CLASSES OF TREES

Before thinnings can be intelligently made, the classes of
trees in a stand must be known and their relation to the growth
of the stand understood. The live trees in a second-growth pine
stand can be separated easily into three classes:

Dominant Trees—These are the tallest and thriftiest speci-
mens with the largest crowns. Their growth is rapid, both in
height and in diameter.

Intermediate Trees—These are the slender, clean-bodied trees,
with narrow, compressed erowns which are nearly as tall as the

16 SHORTLEAF PINE IN VIRGINIA

dominant trees. Their height growth is rapid, but, on account
of their small crowns, their diameter growth is slow. Besides be-
ing unable to make good volume growth themselves, they retard
the growth of the dominant trees.

Suppressed Trees.—These have fallen behind in height and
are so much lower than the other trees that direct sunhght is
largely excluded from them. They interfere very little with the
growth of the larger trees.

When overshadowing and suppression pass a certain point
the trees die. Three-fourths of the dead trees are in the sup-
pressed class, but intermediate trees also die trom overcrowding.
Dead trees exert no influence upon the growth of the stand. When
possible, however, they should be removed, since they contribute
to the danger of disease, insects, and fire.

HOW HEAVILY TO THIN

Thinnings must be heavy enough to provide more hght and
crown space, and more root space and soil moisture for the trees
that are left, yet they must never be heavy enough at one time to
admit too much sunlight and cause the crowns to spread unduly,
with a sacrifice in the rate of height growth. Too heavy a thin-
ning results in temporary understocking and produces the oppo-
site of the result desired.

To be most effective, thinnings should begin when a stand is
twenty years old, and should be hght and frequent. Early thin-
nings prevent the crowns from crowding before their, symmetry
is destroyed, and yet maintain sufficient crown rivalry to secure
continuous height growth and promote the rapid shedding of the
lower limbs. Before removing any tree, it 1s necessary to con-
sider how its removal will affect the remaining trees, not only un-
til the next thinning, but until the stand is mature and the trees
are merchantable.

Thinnings should be made not less often than once every ten
years. Even with ten-year intervals cuttings have to be too
heavy for the best interest of the stand and excessive crowding
takes place before a thinning is repeated. An interval of five
years is recommended as the most desirable. This develops the
full value of the stand, and also allows the cutting of enough
cordwood from the thinnings to pay for the work. A careful
observer will be able to lengthen the interval if the cost of thin-
nings requires it.

q% Tee

tis

ies :

eee

PLATE III.

-ge pole stand of

ied and knotty and w

The trees are

The best that can

shortleaf pine 80 years old

ield only low grade lumber

Understocked |ai

illy

bod
be done with such a stand is to cut it, leaving slender, clean-bodied trees for seed

trees.

short

SHORTLEAF PINE IN VIRGINIA M7,

WHAT TO REMOVE IN THINNING

Thinnings should remove such suppressed trees as are not
necessary to complete the crown cover, since they have made their
growth and exert little or no influence on the growth of the large
trees. Species of lower value, like gums, post oak, maple, sassa-
fras, and scrub pine, should also be cut, unless they are needed to
keep the crown cover complete. Punky or diseased trees should
be removed from stands of all ages. Short-bodied, crooked,
knotty, forked, or otherwise defective pine trees should be cut
from younger stands, but should be left in old stands when their
removal would make openings which would not be filled by the
spread of the surrounding crowns. Enough of the intermediate
class should be removed to provide growing space for the trees
that are left. The trees which are removed should be selected
evenly through the stand. If several adjoining trees are removed,
an opening is left which will be too long in closing. If trees are
left in groups, excessive crowding in the interior of the groups
will follow, and this will result in the loss by shading of the in-
terior branches and unsymmetrical development of the trees. When
there is a choice the trees which are left for permanent growth
should have well-developed and symmetrical crowns.

ACCELERATION IN GROWTH FROM THINNING

Until they are thirty or even thirty-five years old, the inter-
mediate as well as the dominant trees of shortleaf pine stands re-
spond vigorously and rapidly to thinnings by accelerated growth.
In colder stands, the recuperative power of the intermediate trees
declines and the recovery from the effects of overcrowding is slow.
The recuperative power of the dominant class, however, is main-
tained until the trees are sixty years old, when the period of rapid
height growth is well past and crown isolation has taken place.
The ability of the intermediate trees in young stands to recover
rapidly from the effects of close crowding, permits the cutting of
the largest trees in such stands and the leaving of the slender,
clear-stemmed intermediate trees to form the mature stand.

In Plate VI, fig. 1, which shows the cross section of a stem
of shortleaf pine, is to be seen the results of accelerated and sus-
tained growth which are due to repeated light thinnings. The
crowded condition of the inner rings of growth show that the tree
was a slender, intermediate tree before its crown was freed by the

18 SHORTLEAF PINE IN VIRGINIA

original thinning, made, as shown by the number of wide rings,
forty-seven years before the tree was cut. Several thinnings, made
since the original thinning, have prevented any marked decline in
the comparatively rapid rate of growth which took place after the
crown of the tree was originally freed of overcrowding. The rate
of growth is one inch of radius every eleven years, or about one
inch in diameter every five years ‘(the bark thickening as well as
the wood),—an excellent average rate of growth to seek to main-
tain in the trees of a stand. It produces timber suitable for the

highest classes of uses.

METHOD OF THINNING

The several thinnings are for the benefit of the final cutting
and unless the thinnings are made at a profit, the yield of the
final cutting must be far heavier as a result of the thinnings in
order to make them worth while. In young stands then, it 1s
possible to distribute a portion of the thinnings in the dominant
class; in old stands, thinnings must be largely restricted to the
suppressed and intermediate classes. Stands more than twenty
years old, which have never been thinned, require heavier thin-
nings than stands of the same age which have been thinned pre-
viously. ;
Sapling Stands (Younger than Tweny Years). —Thinnings ot
sapling stands are seldom possible on account of the expense of
making them and the small amount and poor character of the
wood obtained. Under average conditions of growth, the wood
which could be cut in a thinning in such a young stand would
be from two to four inches in diameter and would make only a
poor quality of fuel. Thinnings at this age are not recommended
unless the wood can be used. (Plate IT).

Small Pole Stands (From Twenty to Thirty Years Old) —A
crowded stand twenty-five years old contains a number of large
trees eight or nine inches in diameter breasthigh, and a few even
ten inches; many of which are in the advance growth, two or more
years older than the average age of the stand. Such trees are fre-
quently bushy and very limby, with wide-spreading crowns. Usu-
ally all of the nine and ten-inch trees in such a stand and many of
the eight-inch trees can be cut. These will furnish a small quan-
tity of saw timber. In addition to the large trees, all of the trees
below four inches, and usually about one-half of the five-inch trees
can bé removed. If no previous thinning has been made, about

SHORTLEAF PINE IN VIRGINIA 19

200 trees five inches and larger could be cut to the acre. These
should yield about ten cords of wood, of which the material above
nine inches might be sawed into about 500 board feet of lumber.
About 900 trees should be left to the acre. A thinning in a twenty-
year-old stand should yield much less, and one in a stand more
than twenty-five years old should yield more and leave fewer trees
per acre. At these ages trees are making very rapid growth, and
the branches of the crowns are sharpiy ascending, so that com-
paratively large openings are more quickly covered than in older
stands. For this reason thinnings at this period present no seri-
our difficulties, but it is desirable even in making a thinning at
this age to have in view the trees which are to form the final
stand and these should be the tree with very slender and clean
stems, that will yield several logs, and from which lumber can be
sawed free or nearly free from any except small knots. For the
relative value of these trees compared “vith the larger dominant
trees in a stand, see table 16. (Plate I).

Large Pole Stands (From Thirty to Forty Years Old) —A\
trees below six inches, most of the six-inch trees, and some of the
seven and eight-inch trees, should be removed from a normal
thirty-five-year-old stand. If no previous thinning has been made,
not less than 200 trees could be cut, many of which would, how-
ever, be five inches or less in diameter. If a thinning has previ-
ously been made, there would be fewer trees to come out. <A first
thinning at this time should yield from fourteen to seventeen
cords to the acre. Fewer trees are removed than in thinnings in
younger stands, and greater judgment must be used in making
selections. The method of cutting in strips can be economically
used only by farmers who either do their own logging or who can
personally superintend it. (Plate IV).

Mature Stands (From Forty to Fifty Years Old).—I# a stand
of this age has been previously thinned, about ninety trees to the
acre would be available for removal, comprising a few six-inch
trees which could not have been removed earlier without making
undue openings in the crown cover, many seven-inch and eight-
inch trees, and some nine-inch trees. If it were a crowded stand.
not previously thinned, from 100 to 200 trees to the acre might be
taken out, with a yield of not less than ten cords of wood per
acre. However, unless the stumpage value of trees from fourteen
to sixteen inches in diameter is greater than that of trees from
twelve to fourteen inches, a size which the trees reach when about

20 SHORTLEAF PINE IN VIRGINIA

forty-five years old, timber is produced at the lowest. cost by cut-
ting when the stand is about this age (see tables 12 and 17).
Under ordinary conditions, the stand would be cut for lumber, and
not thinned, at this period. (Plate V).

This method of thinning crowded stands is based on the
average crowded stand.

Lypical Stands.—Table I shows approximately the average
number of trees of each diameter from four inches up, which were
found in irregularly thinned stands growing under average condi-
tions. This table is approximately correct for the average of a
number of stands, but any individual stand at a given age will
probably show considerable variation from it, both in the total
number of trees per acre and in the number of trees in each class,
since slight differences in the quality of the soil affect the number
of trees to the acre at any age, and the degree of thinning in-
fluences both the number of trees and their size. It shows, how-
ever, the rapid elimination of the smaller trees, which are the ones
which should be chiefly removed in the thinnings, and it will serve
as a guide to indicate about the number of trees of each size which
should be taken out at each thinning. The stands which have been
grouped as thinned stands in some cases were undoubtedly natur-
ally thinly stocked and their density has been further affected by
artificial thinnings. sor this reason the favorable conditions of
these stands can not be entirely ascribed to thinnings.

TABLE 1.

Approximate number of trees four inches and over in diameter to the acre
in unsystematically thinned stands of shortleaf pine (ihe twenty-year-
old stand is unthinned).

Age of DIAMETHKR BREAST HIGH—INCHES

stand x 3

Years} 4 5 6 | 7 | 8 | 9 10 11 | 12 | 13 | M4 15 | 16 [a7 i Total

| { |

20 600, 400) 300} 50; 10). .|. a amt eee eae ene olla} ou aine
25 203 278) 228) 154) 92) 10 | ere coer rer Soe eti|teee " 97
80 70, 170) 176) 186) 106) 69) 25). 10 1 me 765
35 2) (6) U20) We ADS, 87) 46 2 oF PA re Wee be 615
40 8| 84; 91| 115} 83} 58} 37] 20] 8 1 505
45 fay 2 63) 97) 74). 64] 46) 30) 13 4 Age 420
BO | ss fey JE Bus VA Cet eRy) ei) sayy all i) 74) 355
55 sees Ir coal shee 12) 34) 48 53) 52) 41! 26) 15 if 1 289
602a|5—- 2) S18iees 42) 42). :42)-=33| 2M) 2 Blige 250
Odell aribiored (0) et Od Mies <0) fumes <0) rs da) fs 35) 0 Ko) 9) 3}. 218
TRUS Jeais iosay koe 3 SN 20 QT AS S32 ZR 20 Aer aL 195

-SHORTLEAF PINE IN VIRGINIA 21

Table 2 shows for two stands about forty-five years old the
effect of thinning in increased board yield and in the distribu-
tion of diameter classes. One is a crowded stand which has never
been thinned; the other has been thinned for fifteen years in a
desultory manner. Had the thinnings been systematically made,
better results would have followed. The large number of trees
between ten and fifteen inches in diameter in the thinned stand is
noteworthy. |

TABLE 2.

Effect of thinning on board-foot yield of shortleaf pine and the distribu-
tion of diameter classes (two stands about forty-five years old).

NUMBER OF TREES OF EACH
DIAMETER TO THE ACRE

DIAMETER OF TREES BREAST HIGH a

Unthinned Thinned

stand stand

4 16 8

5 52 10

6 168 32

ff 124 38

8 112 32

9 84 74

10-12 56 132

13-15 8 18

MOtalivercreesnstes ss «i as Se ceeds t bebeiestse 620 344

Dead trees (all diameters). ......... 176 16
Yield in board feet from trees 9 inches and

OVETAN GiAMelERy se) us a sles suromenicy 12,740 18,770

Cords of stem wood with bark to the acre. . . 61 50

Table 3 shows the average height of the trees in stands at
different ages, and the average diameter of all trees in unthinned
and irregularly thinned stands:

22 SHORTLEAF PINE IN VIRGINIA

TABLE 3.

Average height and average diameter of all trees in fully-stocked stands of
shortleaf nine.

AVERAGE DIAMETER OF ALL TREES
| Average Height of :
Age of stand Merchantable
stand Unthinned crowded Thinned stands
stands
Years Feet Inches Inches
20 32 4.0 4.0
25 Si 4.8 §.3
30 42 5.5 6.4
35 47 6.2 7.8
40 61 6.7 8.2
45 55 (Ce 8.9
50 58 ad 9.6
55 61 8.1 LOR
60 63 8.5 10.7

“ = . a .

Table 4 shows the number of trees nine inches and over in

diameter breast high in unthinned and irregularly thinned stands,
and the average diameter of such trees.

TABLE 4.

Average diameter and number of trees nine inches and over in fully-stocked
thinned and unthinned stands of shortleaf pine of different ages.

CROWDED UNTHINNED STANDS THINNED STANDS
Number of Average Number of Average

Age of Trees per Diameter of Trees per Diameter of
stand Acre Trees Acre Trees
Years | Inches Inches

20 are | és tees 3) aials ene

25 | 1 9.1 | 15 9.3

30 a 3 105 9.6

35 47 95 167 10.0

40 88 96 207 10.4

45 125 98 232 10.8

50 156 9.9 245 ey:

55 182 10.1 243 114

60 200 10.3 230 17

65 213 10.5 208 i 120

70 210 10.7 192 12.8

SHORTLEAF PINE IN VIRGINIA 23

PRODUCTION OF “CORDW OOD FROM ey AND
UNTHINNED STANDS

The yield of cordwood* is determined’ rather by the number
of trees than by the size of the individual trees. The most
crowded stands usually yield most heavily, and the yield appre-
clably declines as the stands become more open. This has a great
influence upon the yield of old stands, since after the thirty-fifth
year there is practically no increase in the yield in cords of un-
thinned stands, on account. cf the rapid dying of the smaller trees.
For this reason, thinnings are not so profitable for the production
of cordwood as for the production of saw timber; though the trees
which would die are saved, and some additional growth is secured.
If regular thinnings are made at intervals of five years, then at
the age of forty-five years the increased yield, including the thin-
nings, is only thirty-three per cent., as against an eighty per cent.

TABLE 5.

Yield of thinned and unthinned stands in cords—Trees three inches and
over in diameter.

ONGEANNED THINNED STANDS—YIELD OF THINNINGS
Number Ro proxtl | | votal ofall,
A Volume | Volume of f Trees mate | Volume of! previous | Total
te at stand be-| whichean|average,—_ Trees | Thinnings | Of Thin-
tana Different | fore each | be remcy -| diameter | removed | at any | Dings
epane | “Ages | Thinning} etineach| of Trees | in each Cutting Q Ee,
Thinning | removed Thinning period | Stand
| | | |
Years) Cords Cords | Inches | Cor | Cords Cords
(yy) (2) (3) | (4) (5) | (6) (7) (8)
| | | | |
20 47 | 47.0 | 93 3.3 6 | a 47.0
25 57 | 52.0 205. | 4.5 5.1 6.1 58.1
30 62 570 150 5.0 5.0 11.2 68.2
85 64 | 60.0. | 110 | 5.5 48 16 2 76.2
40 | 65 60.0 | 85 | 6.0 4.3 ita) 81.0
45 | 64 | 59.0 | 68 | 6.5 40 25.3 $4.3
50 | 63 | My/ (0) Pe 55 | 7.0 36 29.3 863
55 61 64.5 | 45 7.6 32.9 87.4
|

*Colomn 8 is the sum of columns 3 and 7.

*Unless otherwise stated, all references to cords are to standard
cords of 128 cubic feet, and the corded wood is measured with the bark
on. Standard cords can be converted into long cords of 160 cubic feet
by dividing by 1.25 or by multiplying by 4-5. Hither standard or long
cords with bark can be converted into cords without bark by multiplying

by .77, if the wood comes from trees which average less than 7 inches
in diameter, or multiplying by .82 if the trees average a larger diameter.

24 SHORTLEAF PINE IN VIRGINIA

increase obtained at the same age by the thinning for lumber.
Unless the value of cordwood increases with the diameter of the
wood (as it should if the wood is used for heading or stave bolts)
no added value per cord is secured by thinnings.

- The yield in standard cords, stem wood with bark, of thinned

and unthinned stands of shortleaf pine of different ages is shown .

in Table 5.

. Table 6 shows the approximate number of trees to the acre in
crowded stands of different ages, and in thinned stands. The dif-
ference between the number of trees in an unthinned stand and
in the same stand five years after it has been thinned indicates
approximately the number of trees which should be removed from
the unthinned stand. In practice, it probably would be best to
make two or more thinnings before reducing the number of trees
in an old, crowded sfand to the number in a normal, thinned stand.

TABLE 6.

Approximate number of trees of shortleaf pine to the acre in crowded and
thinned stands.

Maximum Yield of Cordwood—TYhe maximum yield in cords
is obtained earler than the maximum yield in board feet. The
best stands more than fifty years old give no heavier yield in cords
than younger stands, because they have few trees to the acre,
while neglected stands in which disintegregation is taking place
show even a decline in the volume.

PLATE IV.
A crowded, large pole stand of shortleaf pine 40 years old, badly in need of

Condition of

urdwoods.

«
€

and many of the h

removing the smaller pines

thinning by

Jarger trees, with long, smooth bodies, excellent.

Yearly increment of shortleaf pine in cords (stem-wood and bark)
trees three inches and over in diameter, breasthigh.

SHORTLEAF PINE IN

VIRGINIA

TABLE 7.

of all

UNTHINNED STANDS | THINNED STANDS

Age | Average Periodic Annual Average Annual Periodic Annual

of Annual Increment for each Increment in- Increment for each
stand Increment 5-year Period cluding Thinnings d-year Period
Years Cords Cords Cords Cords

20 Ze | 2.3 |

25 29 2. | 2.3 | op

30 Zell NG 2.3 2.0

35 1.9 5 a9 | 1.6

40 efi .4 | 2 | decrease

45 lee decrease | 1.8 a

50 12 of || iN 7 ne

55 Il es | 1.6 ss

60 8 ae Ih nr eres area eee || “

! t

In both thinned and unthinned stands on average sites the
maximum yield in cords per acre is obtained by cutting between
the ages of twenty and twenty-five years, at which time a yield of
fifty-seven cords per acre can be secured, or an averagé of 2.2
cords an acre a year. The size of the wood which is obtained at
that time is, however, much smaller than that from older stands,
and this fact affects its value.

26 SHORTLEAF PINE IN VIRGINIA

TABLE 8.

Cost per cord of growing shortleaf pine cordwood, stemwood with bark, in
unthinned and thinned stands; including thinnings, land value $5.00 an
acre, interest rate five per cent, and one per cent yearly in addition
for taxes and protection.

THINNED STANDS
UNTHINNED
Accumulated STANDS A
Cost of Land, THINNINGS Net
Age | at $5 per Acre, cost Cost
of | 65 per cent. in- Tae Rag of. per of
stand | terest, 1 per Cost of| Assumed] Accu-| Acre | Final] grow-
cent. added for | Final | grow- value |mula-| of | yield | ing
taxes. less val-| yieid jing per | Amount) — per ted pro- per
ue of land* cordt | cord | valuet| ducing cords
| Crops
Years Cords Cords | Cords
(1) (2) (3) (4) | (5) | | (7) (8) (9) (10)
20 $11.04 47 |$.28 6.1 $ .10 | ao $11.04) 47 |$.23
25 16 46 Zh .28 5.1 15 |$ .78 15 6 62 .30
30 23 72 62 .38 5.0 .20 1.97 PANTS) | 1397 .38
35 33.43 64 .o2 4.8 .20 ati 29.64| 60 49
40 46.43 65 81 4.3 25 6.37 | 40.06} 60 .66
45 63.82 64 .99 4.0 =) 9.60 | 54.33] 59 .92
50 87.10 GSH leas | meee ral 13.40 | 73.70) 57 | 1,30

* Column 2 i: obtained by calculating the interest at 6 per cent. plus 1 per cent, for taxes,
making a total of 6 per cent., compounded annually on a land value of $5 per acre.
Since tne land will remain after the timber is sold, its value is not included in the cost
oi growing.

* Column 4 is obtained by dividing column 2 by column 3.

| Column 7 is the product of: columns 5 and 6 compounded at 5 per cent every 5-year
period. Tho value of wood removed in thinnings (column 6) is only nominal on ac-
count of its small size and the difficulty of making thinnings-

§ Column 8 Is the remainder after deducting column7 from column 2.

§ Column 10 is obtained from dividing column 8 by column 9.

Cost of Growing Cordwood.—Table 8 shows the cost of
growing cordwood in both thinned and unthinned stands at a five

per cent. interest rate.
PRODUCTION OF SAW TIMBER

Influence of Density of Stand Upon Yield of Saw Timber at
Different Ages.

Maximum yield in lumber is obtained neither from stands
which are continuously very crowded nor from understocked stands.
but from stands which are periodically and lightly thinned after
having been crowded.

The most marked effect of thinnings in crowded stands is in
the amount and quality of the yield in board feet. The stands
which were measured to determine the effects of thinnings had
been thinned in no definite manner; in some cases only the smaller
trees, in other cases also some of the larger ones, had been cut out,

SHORTLEAF PINE IN VIRGINIA 27

as farm needs required. Some of these thinned stands were evi-
dently somewhat understocked; some were still too crowded ; «and
others, at the time the measurements were made, had not had time
to respond fully to the thinnings. It is probable that by sys-
tematic thinnings of the kind recommended the yield shown in the
tables could be further increased ten or even twenty per cent.

Vable 9 shows the yield of stands which have different
numbers of trees to the acre; in other words the yield is of under-
stocked, thinned, and crowded stands. The yield is based on cut-
ting to nine inches in diameter breasthigh, which is equivalent
to about eleven inches on the stump. In the understocked stands
the crown cover is practically as complete as in the thinned and
crowded ones, but all the trees are low and short-bodied and few
slender or dead trees are present. (Plate III).

TABLE 9.

Yield of stands of shortleaf pine having different numbers of trees per acre.
(influence of density of stands upon yield of saw timber).

AVERAGE UNDERSTOCKED || FULLY STOCKED STANDS CROWDED STANDS,
STANDS parce HAVE BEEN THINNED UNTHINNED
Age |Number of Yield Number of Yield Number of Yield
Trees to in Board Trees to in Board Trees to | in Board
Years! the Acre Feet the Acre Feet the Acre Feet
| |
30 350 3,800 | 765 | 8,400 | 1,235 200
40 300 5,700 | 505 16,400 860 6,000
50 150 6,900 — 355 | 20,400 5385 13,100
60 100 7,800 | 255 | —_ 28,000 395 16,800
| | ior eta

The yield of an understocked stand when more than thirty
years old is only about one-half of that obtainable from a fully
stocked stand of the same age, after thinning. Many of the trees
in open, understocked stands attain a diameter of nine or more
inches sooner than do trees in crowded stands, for in crowded
stands the continued competition retards the diameter growth of
the individual trees. This explains why crowded stands thirty
years old are not producing merchantable timber.

In the average understocked stand the cost of growing the
timber is far in excess of its present stumpage price. This is
largely due to the small yield. If sold at $2 per thousand board
feet, timber from understocked stands pays less than two per cent.
on the assumed investment of $5 an acre.

28 SHORTLEAF PINE IN VIRGINIA

‘able 10 shows the influence of density upon the cost per
1,000 board feet of growing shortleaf pine stumpage in old-field
stands, based on net returns at five per cent., taxes one per cent. in
addition, land value $5 an acre.

TABLE 10.

Influence of number of trees, or of density of stand on cost of growing
1,000 board feet in old-field stands ay on shortleaf pine.

2 < 7 THINNED STANDS, NEG-
AVERAGE UNDER-|CROWDED, UN- LECTING VALUE OF
Accumulated | SrOCKED STANDS | THINNED STANDS THINNINGS
Age Cost of the 3 4 eS Me aS eee
of Investment | |
stand per Acre Yield | Cost Yield Cost Yield Cost
less the per | per per per per per
Value of the Acre | Mft Acre M ft. | Acre M ft.
Land | |
Years | Bd. ft. | Bd. ft. Bd ft.
30 $ 23.72 3,800;| $6.80 cau treea ieee 8,400 | $ 2.82
40 46.43 | 5,700; 8.10 6,000 , $7,738 16,400 2.83
50 87.10 ;{ 6,900 12 60 | 13,100 6.65 20,400 4.27
60 159.90 7,800 20.51 | 15,000 10.66 23 000 6.82
|

At every age if thinnings are made without loss, the cost of
growing stumpage in fully stocked thinned stands is less than the
cost of growing it either in crowded or understocked stands. If
thinnings do not pay tor themselves the cost is higher, and if
they pay a profit, the cost is lower.

Age of Cutting for Maximum Yield—The maximum annual
vield in board feet from trees nine inches and over in diameter
breasthigh is obtained from thinned stands when they are cut at
forty-eight years of age. At that time in such a stand, the aver-
age annual yield per acre is about 410 board feet, and the diameter
of the average-sized tree is about 9.5 inches breasthigh, or 11.5
inches on the stump.

For unthinned stands, the maximum annual yield is obtained
by cutting when about fifty-seven years old. The-average dia-
meter of the trees in such a stand is about 8.2 inches at breast-
height or 9.8 inches on the stump. Table 11 shows the yearty
increment in board feet of trees nine inches and over in diameter
breasthigh.

cow arti

0 Nt ica Oe es

SHORTLEAF PINE IN VIRGINIA 29

TABLE 11.

Annual increment per acre in board feet of trees of shortleaf pine nine
inches and over in diameter breasthigh.

THINNNED STAND (THINNINGS net E ee
NEGLECTED) UNTHINNED STAND
Age We hl
of Average Periodic Annual Average Periodic Annual
stand | Annual Incremeut for Annual Increment for
Increment each Decade Increment each Decade
Years Board feet | Board feet Board feet Board feet
)
30 280 ls vats es coheed Olena ceme eae Wee less, Ae corte
40 410 | 800 150 eter iter
50 408 | 400 262 710
60 383 260 250 190
70 357 200 238 170

Cost of Growing Saw Timber—lf only the maximum annual
yield were to be considered in growing timber it would undoubt-
edly be advisable in all cases to hold timber until this could be
secured. The cost of carrying the investment, however, is a factor
which cannot be overlooked. The land has a sale value, and taxes
are paid upon it yearly. In addition, the cost of protection, such
“as maintaining fences, extinguishing fires, etc., must often be berne.

In making a calculation of the cost of growing timber it is
necessary to determine, from the time stocking took place to the
time when the timber is cut, the accumulated taxes paid on the
itand and the interest compounded annually on the investment
represented by the value of the land and the cost of stocking it.
In making this calculation, both the actual and tax assessment
value of the land has been assumed to be $5 an acre for the entire
period of growth. The tax rate and other expenses are assumed
to be one per cent. on this valuation. If the owner is content °
with a gross interest of six per cent. on his investment, then the
net rate, after deducting taxes and other expenses, will be five per
cent. a year.

In the old-field stands there is no cost of stocking to consider.
The profits of thinnings are supposed to be the same as those
given in column 7, Table 8, for cordwood.

In order to obtain a six per cent. investment which, after
allowing one per cent. per annum for taxes and protection, will
yield five per cent. net, the following yields and prices must be
secured. The value of the land is placed at $5 an acre. If stump-

30 SHORTLEAF PINE IN VIRGINIA

age is sold at less than the cost of growing 1,000 board feet, or if
the stands cut less than the amounts given at the different ages,
less than five per cent. net is obtained on the investment. If
stumpage is sold at a higher price and the value of the land is not
more than $5 an acre, then the investment will yield more than

five per cent.

TABLE 12.
Cost of growing shortleaf pine saw-timber in unthinned and thinned stands,
including thinnings. Land value $5 an acre; interest rate five per
cent; one per cent in addition allowed for tazes.

UNTHINNED STAND THINNED STAND
ae ; . Eb : ae
x bre}
stand pehrceers ett ie rd oa Cost of per acre Final Cost of
an acre, 5% interest, 1% Yield | growing of yield growing
added for taxes, less | per M producing per M
cost ot land , | Bd. ft. bd. ft. crop* bd. ft
Years | Ba. ft. |
| |
20 $11.04 Pears area eer hae io ar sow
25 16.46 | eiessoce Ma" | Bhat Mena atl Maem 900 $17.00 4
30 23.72 200G| (soar ween 21.75 8,400 2.59
35 33.48 1,400 | $23.80 29.64 13.400 2.21
40 46.43 6 000 7.64 | 40.06 16,400 2.44
45 63.82 10,200 6.25 54.33 18,700 2.90
50 87.10 13,106 6.70 73.70 20,400 3.61

* After deducting value of thinnings as shown in Table 8.

The cheapest cost of production, with interest at five per cent.
and t@&xes at one per cent., or six per cent. for both is $6.25 a
thousand board feet from unthinned stands and $2.21 from thinned
stands.

The period when the cost of growing the timber is the lowest
is known as the financial maturity. If timber’is held longer than
the period of financial maturity, there must be a considerable ad-
vance in its value to cover the cost of carrying it, that is, the
accumulated interest and taxes, and this is particularly true of
old stands the volume of which is increasing very slowly or per-
haps actually declining.

The owner of timberland is interested in knowing the rate of
interest he may expect from his investment when the product sells
at a give price. Tables 13 and 14 show the interest yielded
by stands of old-field pine at different ages, with the lend
worth $5 an acre and with stumpage selling at $2 a thousand
feet and cordwood at twenty-five cents a cord. In table 14

SHORTLEAF PINE IN VIRGINIA 9H |

for cordwood from a thinned stand, it is assumed that thinnings
produce the returns allowed in column 7, Table 8.

In the table for board feet from a thinned stand, thinnings
are supposed to be made without either profit or loss. The inter-
est yielded is gross, and includes taxes and the cost of protection—
items which would usually amount to about one per cent. of the
land value and would correspondingly reduce the returns.

TABLE 13.
SAW TIMBER STUMPAGE AT $2 A THOUSAND BOARD FEET.

Gross rate per cent yielded by stands of old-field pine on a land value of
$5 an acre.*

THINNED STAND > UNTHINNED STAND
A 5 5
ee @roua vate Gross rate
stand per cent. Yield ieler Gere
Yield per ES stand Vieidedvon per VERS paced
Acre neglectin - of
mininniniee ee ate cee stand Value
Years| Bi. ft. Per cent. Bd. ft. Per cent.
|
| | |
30 8,400 | - $16.80 | 4,3 rep lus
35 13,400 26.80 50 Pe caer
40 16,400 | 32.80 50 6,000 | $12.00 2.5
45 18,700 37.40 4.5 10,200 | 20.40 3.2
50 20,400 40.80 4.0 || 13,100 | 26.20 3.3

TABLE 14.
CORDWOOD STUMPAGE OF FINAL YIELD AT 24 CENTS A CORD.

4
Gross rate per cent yielded by stands of shortleaf pine in old-field with a
land value of $5 an acre.*

THINNED STAND —UNTHINNED STAND
Age i ie Arenas ee ee
ait Total Value, per eee Yiela | Gross rate
cand Final F eee per cent, ae | yer Cent.
vas yield aoe eS Yielded on per | value Yielded on
i umu t; A To
of Thinnings at 4¢ Land Value cre stand Land Value
Years Cords com pound interest Per cent. Cords | Per cent.
20 “it” SII kes Me gen raed | Seas ae 49 | $11:75 43
25 52 $13.74 4.0 57 14 25 4,2
30 57 16.08 4.0 62 15.50 3.8
35 60 | 18.44 3.8 64 16.00 3.5
40) 60 | 19.65 | 3.6 65. | 216525 3.0
45 59 23.94 3.5 | 64 16.00 28
50 57 26.43 ae 63 15.75 2.5

* Gross rate per cent. includes taxes and cost of protection as well as the interest on
the investment.

yA SHORTLEAF PINE IN VIRGINIA

VALUE OF TREES AND STANDS

The lumber from second-growth stands of shortleaf pine,
when .awed into boards one inch thick and graded according to
the rules of the North Carolina Pine Association, sells for a high-
er price than if it is sold ungraded, or than if it is sold in the
form of framing. The lumber which is sawed from young stands
less than 35 years old is as a rule too narrow, and that from stands
in which the trees have not been crowded, is too knotty to justify
grading. The older the stand the more valuable becomes the lum-
ber which can be cut from it not only on account of greater widths
but also a larger proportion of the high grade.. If the trees of
different diameters in a crowded stand which is about 50 years old
(the age of maturity) are carefully sawed into boards of even
width and uniform thickness, they will yield approximately the
amounts of the different grades of lumber which are given in
Table 15. The figures in this table are based on actual measure-

ments of grades which were made at a mill where trees of these

sizes and age were being cut.

TABLE 15.

Total volumes in board feet, and the amount of the grades of lumber in trees of different
diameters and heights in dense stands of short-leaf pine 45 lo 60 years old.

| AMOUNTS OF THE DIFFERENT

Diameter rota) | wumner |faungte”|__ GRADES Sawen From Trees | Zola

7 | 48 1} 5.0 ry eae) 6 22
8 53 14 6.0 2 6 14 Ges 28
Orne spree 6.5 4 133) 45 6 38
10 62 2h 6.5 4 8 igs) 4g 6 55
11 66-year ae 6.5 8 12). |. 25-5) 298 6 79
12 Wiig eens 7.0 18 | 93 | -87,.|_ 35 6 109
1B 4) 75. 3° A). 7:0 S286 2 Saas 6 142
14 78 See shee Wed 82 | 38 | 48 | 56 7 J81
15) =) 2} "280 34 7.5 AT | 06 1 eae eae 9 226
Wie ol bets a eee 8.0 70. | 4Ge.| > 7bo) rere attee 280
de SO 3h 8.0-- | 74-| 6051 108) Bre ae 338
18 81 3} 8.0 B36 l= 76.1 180") LOB" feette 398
19 81 3} 8.5 92-1 2) “dss Tasers ete 460
20 81 33 90 105; (115 fe67- 1.492 3 aie 527
21 81 34 9.0 120. |.188 {197 195°") 48 598
22 81 33 9.0 136 | 163 | 230 | 129 | 20 678

The smaller trees in stands of this age are long-bodied and
clear stemmed, have very little taper and thin bark, and, although

Vic
Trees nearly uniform in size and ready to

windfirm trees ¢

x
u

PLAT

and of shortleaf pine.

Mature st
be cut for lumber.

an be left for seed trees.

’

Groups of slender

a J pao tse

Dy)
0 Nhe

SHORTLEAF PINE IN VIRGINIA 318

the boards which can be sawed from such trees are narrow, they
are comparatively free from knots and will justify grading if
handled in connection with the wider boards from the larger trees.
Trees of the same size in younger stands are more tapering and
more knotty, and the lumber is of lower grade.
Air-dried lumber of the different grades, consisting of mix-
ed width, but less than 12 inches wide, is quoted (November, 1912)
at the following prices per 1,000 board feet, delivered at Norfolk,
* Richmond, Petersburg, Lynchburg, and Roanoke: No. 1, $26;
No. 2, $24; No. 3; $20; Box, $18; Red heart and cull, $16; Bark
strip, Nos. 1 & 2, $20; Bark strip, box $12. In Table 16 these
values have been applied to the amount of different diameters
delivered at Norfolk and the other points named above.

TABLE 16.

Value delivered at Norfolk, Richmond, Petersburg Roanoke, and Lynchburg, of the
graded lumber cut from trees of different diameters and heights* growing in crowded
second-growth stands 45 to 60 years old and the value of single trees and their stump-
age per 1,000 board feet under different costs of sawing and delivery at these points.

Value of lumber de- | Stumpage value per tree with ex penses

livered at Norfolk, Rich- | of sawing and delivery per
Diameter mond, ete. | 1,000 board ft. at
breast-high SesrS cde - | -
Frome | hoards |e a4
7 § .36 $15 95 Selon | $ .08 - $ .40
8 47% 16.40 .18 | 12 .06
i) .66 17.40 | 28 78H PA 13
10 1.01 18.35 | 46 | 85 24
11 1 53 19.80 74 .08 42
2 2.16 19.80 1.06 .85 638
13 2.86 20aee 1.44 | 1.16 .87
14 Bite 20.95 1.98 | 1.62 1.26
15 4.75 21.40 2.58 Pas 1.67
16 6.80 22.50 3.58 8.02 2.46
17 7.60 22.05 4.23 38.56 2.89
18 8.95 22 50 479 | 4.18 3.38
19 10.40 22.45 5.73 4.81 3,89
20 11.80 . 22.40 6.53 | 5 48 4.42 ,
21 13.40 22.40 7.41 | 6.22 5.02
22 15.17 22.39 8.37 | 6.01 5.65
\

*Heights which are given in table 15.

+Obtained by deducting thecost ofsawing and delivery per 1,000 board feet from the de-
livered value per 1,000 board feet, reducing the remaindér to the value of one board foot
and multiplying by the number of board feet per treeas shown in table 15; thus, $15.95
less $10.00 equal to $5.95—$5.95 divided by 100 and multiplied by 22 is equal to $.13.

In table 15 the expenses of sawing and delivery, $10; $12;
and $14 per 1,000 board feet are supposed to represent a low,

34 SHORTLEAF PINE IN VIRGINIA

a medium, and a high cost of operation, and are made up of the
cost of logging, felling, sawing, grading, interest on the investment
and carrying charges, cost of selling, delivery at market and load-
ing, drying, and profit of the operator. A profit of from $2 to $3
a thousand feet should be allowed in portable mill operations,
the. profit varying according to the size and length of the oper-
ation. It is noteworthy that while the value of the lumber per
1,000 board feet which is yielded by trees of different diameters
increases rapidly up to 16 inches in diameter, there is a decline
in the value per 1,000 feet of the lumber which is sawed from
trees of diameter above 17 inches. This is due to the fact that the
largest trees in these stands have larger and more numerous knots
in their stems and yield a lower proportion of the high grades
of lumber than do the slender, more clean stemmed, intermediate,
and suppressed trees.

If the number of trees of each diameter per acre in a 45-
year old stand (see Table 2) be multiplied by the value per tree
of each respective diameter, the sum of these amounts will give
the total value of the stand per acre, and from this the value per
1,000 feet of the stand. A similar set of values can be determined
for trees in younger and older stands. These are given in Table 17.

TABLE 17.

Value per 1,000 board fect of the lumber which can be sawed from dense unthinned stands
of short-leaf pine under different costs of manufaeture and delivery.

| Value per 1,000 board feet under a cost
| of operation and delivery of

years
$10 | $12 | $14
pias Kaweasce ek
3 | $ 5.40 | $ 3.40 | $ 140
40 | 6.00 | 4.00 2.00
50 7.05 | 5.05 3.05
60 | 8.60 | 6.60 4.40
70 | 10.05 | 8 05 6,05

If the values in Table 17 are compared with the cost per
1,000 board feet of growing timber, shown in Table 10, it will
be seen that the investment, if the stand is unthinned, dees not
yield five per cent. net, except under a logging cost of $10 and
when the stand is cut at the age of 50 years.

In a régularly thinned stand from which the very knotty trees
have been systematically removed when the stand was young,

SHORTLEAF PINE IN VIRGINIA aD

Jeaving only the longest-bodied and clearest stemmed trees at
each cutting and in which the trees have been forced to large
diameters by isolation after the clear stem-length is 50 feet in
length, it is believed that the stumpage value can be forced to a
ralue of $8 a 1,000 feet under a logging cost of $12 when 50
years old. This would yield about $250 per acre.

WASTE IN CUTTING SMALL TREES
The following table shows the actual volume in board feet of
trees of ciiferent diameters and heights when cut with a saw taking
a kerf of one-fourth inch; the volume in board feet when scaled
by Doyle-Scribner log rule; the volume of stem, wood only, in cubic
feet; the number of board feet, Doyle-Scribner rule, per cubie foot
of volume; and the percentage of waste.

TABLE 18..

Volume in board feet and in cubic feet and per cent of waste in sawing
trees of shortleaf pine of different diameters.

| Volume

| | \ |

The loss in scaling by Doyle-Seriber rule exceeds seventy-five
per cent. of the total cubic volume of the stem until the tree reaches
a diameter of thirteen inches, breasthigh. This large proportion
of waste is an excellent reason for not cutting young stands for
saw timber or for not cutting the small trees in old stands unless

they are suppressed trees.
LUMBERING AND RESTOCKING

Simultaneously with lumbering comes the subject of securing
a second stand of young pine to replace the one which is cut.

36 SHORTLEAF PINE IN VIRGINIA

After ordinary culling, such as is practiced for farm use, or in
clear-cutting stands of pine for lumber or for fuel, hardwoods
generally form the main part of the young stand. The reasons
for this are explained under the heading “Permanency of Old-
Field Pine Stands.” To obtain reproduction of pine, it is neces-
sary: (1) To cut nearly clean, that there may be abundant light:
(2) To leave seed-bearing pine trees scattered over the area or
standing nearby; (3) To cut out the large trees of such hard-
woods as dogwood, post oak, hickory, persimmon, ete., which have
sprung up beneath the pines, and which would suppress many
pine seedlings by their shade; (4) To bring as much of the min-
eral soil to the surface as possible. The hardwoods should be cut
in September, when their sprouting capacity is lowest.

Two methods of cutting are suggested. One method, leaving
isolated seed trees, is for use where the entire stand must be cut
at one time. The other, cutting in strips, or groups, can be applied
when there is a steady market for saw logs, as when there 1s a
nearby permanent sawmill, or logs can be shipped to such a mill,
and when it is possible to make two or more cuttings, not less.
than five years apart, in a stand, always having in view, however,
the development of the valuable long-bedied and clean-stemmed
trees (table 16) which are to form the mature stand.

Isolated Seed Trees —When the saw-timber must be removed
at one cutting it is advisable to prepare for the final cutting at the
time of the last thinning by developing seed trees. At forty-five
years of age, the production of seed by shortleaf pine is still ex-
tremely light, particularly in dense stands. If there are no old
forest pines which will serve for seed trees within 100 yards of
the tract, one object of the last thinning should be to select and
develop trees for seed trees.

Vigorous, large-crowned trees should be selected for this pur-
pose. They should be not less than four to the acre, and should
be evenly distributed or else located on the tops of hills or knolls.
Their crowns should be entirely freed by heavy thinnings on all
sides. This should lead to the production of a heavy crop of cones
and fertile seed within five years. If the crowns again crowd be-
fore lumbering, they should again be freed by further thinning.

When lumbering takes place, all merchantable trees should be
cut except these seed trees, which should be able to produce enough
seed in a few years to restock the land. (Plate V). If the seed
trees are windfirm they can go over until the next stand is cut;

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SHORTLEAF PINE IN VIRGINIA S7

if they fall, they can be used without breaking down too many of
the small trees in the young stand. Since the period of restock-
ing by this method would probably occupy from four to six years,
the soil would not be fully used during this time.

Cutting in Strips.—Complete and rapid stocking 1s better as-
sured by cutting in strips, but this method presupposes a continu-
ous market for saw logs. The area should be clear-cut over strips
not exceeding 200 feet in width, alternating with strips of equal
width which are only culled of the smaller trees. On level ground
these strips should be at right angles to the roads; on hilly land
they should lie up and down the slopes. The wooded strips should
be heavily thinned by the removal of all except the largest trees,
which should not exceed twenty to the acre, and should be left
well isolated. These trees will serve as seed trees, and on account
of their large number they should seed the entire area heavily
within five to ten years. As.soon as a thorough restocking 1s
assured they can be cut. Some of the young trees will be broken
down, but the loss will not be serious. The diameter growth of
the seed trees after the thinning will be large because of this isola-
tion. Blanks ten or more feet square left after the seed trees are
cut should be planted by seed spotting as described under the di-
rections for planting. The two loggings will increase the danger
from fire, requiring additional precautionary measures to be taken.

‘This methoa can be varied by leaving the seed trees in groups.

Cutting Unthinned Stands.—Both of the above methods pre-
suppose that the stand which is being cut has been thinned, and
consequently is formed entirely or largely of trees of merchantable
SIZe.

An understocked stand, similar to that shown in plate III,
and in which the trees are largely of merchantable size, can be
cut so as to secure a restocking, by leaving some of the more
slender but well crowned trees for seed trees.

The problem of cutting a crowded stand to the best advantage
and in a manner to secure a restocking is more difficult. The trees
in such a stand have a much ereater range of diameter than those
‘yp a thinned stand. There is a large number of small suppressed
and intermediate trees which may be too small to be cut. eco-
nomically for saw timber ‘(see “Waste in cutting small trees,” page
35). In such a case it may be desirable to remove the stand in
two or more cuttings, made at intervals of five or more years. At
the first cutting only the largest trees should be cut, particularly

38 BSHORTLEAF PINE IN VIRGINIA

those which have short and knotty stems. Such as have very
slender clean stems and good crowns should be left, but enough
of the largest trees should be taken to open the crown cover one-
third. Such a cutting might remove one-tenth of the total num-
ber of trees but more than one-half of the saw log volume of the
stand. At the second cutting not only should most of the trees
which have grown to merchantable size be removed, but also such
of the smaller stunted trees as have shown no indication of thrift
since the first cutting. The trees which are left should be choice
clean-stemmed specimens with medium sized, but thrifty crowns.
They can be left at the rate of ten to twenty to the acre. Such
trees as have weak stems which would be likely to be bowed or
broken by wind or sleet should not be left. Thickets of high
shrubs and broadleaf trees should be cut. It is probable that by
the time of the second cutting groups of young seedlings, about
one foot in height, will have appeared beneath the openings made
by the first cutting. Seed from the trees which are left after the
second cutting will complete the restocking. Two courses can be
followed in regard to the trees which are left after the second
cutting. Either they can be removed after thorough seedling es-
tablishment is assured, or they can be held over and cut at some
thinning period of the young stand. If trees with fifty feet of
clear length and diameters of from ten to twelve inches are left
after the second cutting and are held until they are twenty to
twenty-four inches in diameter their stumpage value will increase
from three to five times. This increase in value will be due en-
tirely to the greater size of the legs, which will yield a high grade
of lumber and can be sawn with small waste. (See Tables 16 and
18: and Plate Il, Fig’ 1). :

No method of cutting a crowded unthinned stand, however.
will give as great a yield in board feet per acre, or will produce
logs of as high a grade, as can be obtained from a well-thinned
stand.

PLANTING WASTE LAND

On many farms in middle Virginia there are tracts of gulhed,
or shallow soiled or rocky, or other poor or waste land which are
either without a growth of pine or are stocking extremely slowly
and irregularly. Shortleaf pine could be planted profitably on
such tracts. The sound seed of this pine sprout so freely, and the
growth of the young seedling is so rapid, that direct seeding can

SHORTLEAF PINE IN VIRGINIA. 39

be made in place of using young plants. Seed should be planted
in spots six feet apart in well loosened soil and lightly covered,
not deeper than one-half inch with earth. One of the two follow-
ing methods can be used. If the tract can be plowed. shallow
furrows can be laid off at intervals of six feet with a shovel plow
or small turning plow, and the seed dropped at six-foot intervals
in the furrows and lightly covered with a weeding hoe. If a plow
‘annot be used, the earth can be loosened with a ght grub hoe
over a spot six or eight inches square, and the seed planted and
lightly covered in the middle of this spot. If the soil is either
dry or light and sandy the planter should step on the spot after
covering to bring the earth in close contact with the seed and in-
sure germination. Set poles should be used to keep the rows
straight.

The seed of shortleaf pine has a low germinating percentage,
seldom more than forty-five per cent., and a number of seed,
twelve or fifteen, should therefore be dropped in a hole. As many
as can easily be held between the thumb, index finger and second
finger will insure a stand. ‘There are about 50,000 seed to a pound,
so that a pound, if carefully handled, will plant an acre. The
smallness of the seeds, however, makes them difficult to handle,
and an inexperienced planter will usually drop more than are
necessary for obtaining a stand. Planting should be done at any
time between the middle of February and the first of April,
whenever the soil is in suitable condition. Protection from fire
and cattle is absolutely necessary until the trees are three or four
inches in diameter and the bark thick enough to afford reasonable
protection, which will require from ten to fifteen years.

Returns from Plantations —Ilf such plantations are carefully
thinned their yield should greatly exceed that of natural stands.

The cost of planting an acre and of carrying the investment
is ealeulated on the basis of a land value of $10 an acre, with five
per cent. compound interest, which includes an allowance of one
per cent. an acre a year for taxes and protection. ‘This land value
is low for soils which will produce good shortleat pine. The prices
at which stumpage must be sold to net four per cent. on the in-
vestment are shown in Table 19.

CEOS Hanne MATE ee cad tcl ated at ees $10 00
Cost of seed one pound per acre......... 2-50
GOSt Obs planbine Der ACKC erste saree a 1 50

Total initial cost of investment........ $14 00

40 @HORTLEAF PINE IN VIRGINIA.

TABLE 19.

Cost of producing shortleaf pine stumpage in plantations with five per
cent gross interest on investment.

- Ni DQ « : Og h ;
Zz ne es moe we oD 333 oe suo as
s Ooms AS dohaee o8s ee, BS 5
) DO a0 =2 078 a8 OF Os OE
a Te sods Shek ie pe) mS. I as eye 3
9 pre ial Sheela Bb Sc 3%, BL a. as
FI See Abou s es aa, = BAM | es
Be arto Ot = 3 rs) - a6 = Sage a 2 BO
a sugdg7o0 “Ho. Ons oa Ok ORD cies D oo
oa Apo Soe amine Bene oS Sate a1]
° | gg edges mgtogss | ohn 8 SS a~Su 8 E
Rin coe & aaliey Cieyee aie | ie ie She ry ties ye 7
At fall Se 2So5 28a Sao Presi EA Bie | Bee 62
< | ae ao Ss rem Oo moOOm ous | Se on}
ae 7
20 § 27.10 Bai ieee eR RONG sot ee Fae es $ 1.28
30 40.20 $ 7.00 5,800 $555 || 51 .65
40 78.56 | 20.80 14 800 3.832 |i 60 96
50 150.58 40 28 19,3800 5.69 || 60 1 84
| |

* On account of the small amount of the thinnings and the short periods dwming which the
money from them would be invested, only 4 per cent. is allowed on them.

Thinnings made at middle of dtecades yield about eleven cords
at twenty-five years, fifteen cords at thirty-five years, and ten
cords at forty-five years per acre.

The minimum cost of producing lumber would be about $8.88
per 1,000 board feet, when a stand is about forty years old.

The minimum cost of producing cordwood would be about
sixty-five cents a cord at an age of thirty years.

These figures, which are conservative, indicate that planta-
tions can be expected to yield. at least five per cent. gross or four
per cent. net after allowing one per cent. or ten cents an acre a
year, for taxes and protection. With regularly made and care-
fully executed thinnings, the yield would probably exceed that of
the irregularly thinned stands on which the calculations are based
and the cost of production would be lowered; in other words a
higher interest rate would be obtained.

In order for a plantation to yield five per cent. net or Six per
cent. gross, allowing one per cent. an acre a year for taxes and fire
protection, the following returns, which are fair and reasonable,
must be obtained from stands of different ages.

SHORTLEAF PINE IN VIRGINIA. 41

z TABLE 20.

Cost of producing shortleaf pine stumpage in plantations with six per cent
gross interest on investment.

| ron | aia tee Sate Sad ler ei ao
Oo Oo ~ be °
eeees ro nsee eae og Bas S
s S) See Boose AsO =a O30 OE
Cea eee eele av cade aaa of Sore 5
vor BSoss as] S A: 3 De.
a | ORE Ss ss S Bp ie a| ou pee tile On
wm | #85° 24 SRL Y Sas o Qt 4 Bp ‘2 2) a0 °
° | SS fs ou Ee See (oo 7p | rs] iS pet 2}
o | B2ao70 [ho tae Sis sores, oa LF ers -
Zon | Om 2 Simin go8. ® AG ES) oan
oo | 3.0 DHS z o a
| Aeoais [Pe SONS Coe 5 Zi male) eine iS
< = Ma BOS e doe ohus Ss soHS =
BaSese Bae Ses | suse 2h Gute | #6
Year o ; z =~S Oe &
ears 2o<aePr RAR ae ES moon a5 zoom She
ee “
20 $ 34.80 : | 21 $ 1.66
5 ee | eters
30 70.36 $ 7.00 5,800 $ 10.91 51 1.23
40 184.06 20.10 14,800 7.70 60 1.88
50 247.88 40.28 19,300 10.77 60 3.30
| ’
}

*On account of the small amount of the thinnings and the short period during which tha
money from them would be invested only 4 per cent. net is allowed on them,

In neither of the foregoing calculations is any allowance made
for superintendence, and possible losses from insects, sleet and
snow breakage, and windstorm damage, but it must also be re-
membered that the constant increase in the price of timber is lke-
wise neglected.

THE PROTECTION OF STANDS

The two important dangers to pine stands, fire and insects,
are in a measure interrelated. Those trees which have been weak-
ened or injured by fires invite insects, while stands which are ht-
tered by the wood which has died from insect depredations, and
which have become grassy on account of openings made in the
crown cover where trees have been killed by insects are particularly
exposed to serious damage from fire. With both dangers, pre-
vention is the most effective means of control.

Fires —While the danger of fire is always present, it is far
more serious in connection with young stands and particularly
those in process of stocking, such as fields which have recently
been turned out, or newly cut or lumbered land. Fires injure
such young stands at any season of the year in which they may
occur. Although many individuals of shortleaf pine between one
and two feet high, when killed by an early spring fire, will sprout.
the sprouting capacity is irregular and unreliable (Plate VI, fig. 2).
Moreover, most of such sprouts die in a few years, while many of
the survivors are forked. After the tenth year, the heavy shade of

42 SHORTLEAF PINE IN VIRGINIA.

crowded stands and the thickened bark greatly reduce the danger
of fire, but even the heavy bark of old trees does not afford com-
plete protection from hot spring fires when these are driven by a
strong wind. ‘Thickly stocked shortleaf pine stands do not, as a
rule, become grassy or foul with shrubs and herbage, and conse-
quently do not require periodic winter burning for the purpose of
protection, such as may often be necessary for pole stands and
mature stands of loblotty and longleaf pines. Although no visible
damage may be done to older trees by such burnings, the rate of
growth is reduced by the destruction of the pine straw and the
humus, while even the shght scorching of trees may lead to the
entrance of insects or fungi.

Young stands and areas which are in process of stocking are
most effectively protected from fire by establishing and maintain-
ing open fire lanes, free from straw and litter, completely around
them or on the exposed sides. A shallow furrow can be plowed
every year on both sides of the lanes, and the intervening strip
can be raked clear, or it can be burned during damp, quiet weather.
In older stands the straw and litter can be raked off the lanes each
autumn and used for stable beddings. Well established lanes, if
they are free from stumps and shrubs, may conveniently be raked
with a side delivery rake. By locating lanes at intervals through
a large tract, as well as around it, it is separated into blocks which
are individually protected. Where possible, roads and paths
should be used for lanes. Since there is great danger of a serious
fire during and immediately after lumbering, extra protective pre-
caution should be taken at that time. A fire that occurs at that
time will frequently destroy the pine seedlings, but the replace-
ment of the hardwoods and shrubs takes place at once by sprout-
ing. Repeated fires eliminate the pines. When timber is sold or
when logging is done by contract, an enforceable fire penalty clause
should be inserted in the contract, in order to obtain the necessary
protection. :

The Federal Government under the terms of section 2 of
the Weeks Law extends its co-operation to States in assisting them
to protect the forested water-sheds of navigable streams from
fire. In order to secure assistance of this kind a State must have
provided by law for a system of forest fire protection and must
have appropriated funds for the purpose. Scarcely a more im-
portant step could be taken by the State of Virginia towards the
conservation of its forests than the establishment of a fire pro-

SHORTLEAF PINE IN VIRGINIA. 43

tective system. ‘The readiness of the Federal Government to co-
operate under the terms of this law as soon as the State itself
makes a start is an incentive to immediate action. In the short-
leaf pine area of Virginia the water-sheds of the Appomattox,
James, Roanoke and Rapidan rivers could be protected by such
co-operation.

Insects—The danger of fire is greatest to seedling stands, but
the possibility of insect damage, although it is always present,
mereases after the trees are twenty years old. One of the most
pernicious insects is the pine bark beetle, Dendroctonus frontalis,
Zimns which devastated the coniferous forest of middle and west-
ern Virginia between 1888 and 1892. ‘This species channels the
inner bark in the middle part of the stem and eventually girdles
the trees, thus killing them. Other beetles infest the wood of
the living tree, and yet others attack only dead or dying trees.
The fecundity of the pine bark beetle is so great that several large
broods are produced in a single summer, and when conditions are
favorable they propagate in enormous numbers and cause serious
depredations. Pure stands in old fields invite destructive attacks.
since in them the insects can readily spread from tree to tree.

The best way to hold this insect in check is to keep the trees
in thrifty condition by preventing overcrowding, by removing
wood which would serve as breeding places, and by cutting out in-
fested trees. It 1s particularly desirable to make these protective
cuttings before the spring and early summer broods of the insects
come out and spread. Infested trees should be promptly removed
as soon as noticed. The removal of weak trees in thinning elim1-
nates them as sources of breeding, while cutting low stumps and
close utilization, or the piling and burning ot tops—operations
which are sometimes advisable for other reasons—remove much
other wood. The cutting of live trees should be limited as far as
possible to the winter, but dead trees can be cut at any time.
Special care should be used in summer cutting not to leave freshly-
cut tops touching live trees, and to remove promptly trees that
have been killed by lightning. When cordwood or logs which are
spring or summer cut cannot be promptly removed, they should be
peeled or racked in the sun, that they may dry. Detailed infor-
mation in regard to protection against this beetle is contained in
Farmers’ Bulletin, No. 476.

Fungus Diseases—The most important known fungus which
attacks shortleaf pine is 7’rametes pini, the cause of redheart.

44 SHORTLEAF PINE IN VIRGINIA.

This is a dark brown snutt-colored “punk” which gains entrance
into the heartwood of the upper part of the stem through knot
holes, and into the lower part by wounds caused by falling trees,
fire scars, ‘(Plate VI, fig. 2), and insects. Trees which show the
“punk” should be promptly cut.

Pine stands are also exposed to damage from windstorms, and
from sleet and wet snow. The damage by wind cannot be pre-
vented. Fortunately, shortleaf pine, when it grows on deep soils,
is anchored by a long, strong taproot, and is very windfirm. On
shallow soils, particularly a hard-pan near the surface which
checks the descent of the taproot, it windfalls badly. Slender trees
are occasionally bent or even broken by wind. Frequent light thin-
nings render the trees in such stands more windfirm.

Sleet and wet snow are dangers against which there is no ade-
quate protection. The weight of sleet and wet snow frequently
breaks the leaders, and in crowded stands may bend many stems
beyond recovery, break them, or even uproot them. The only pre-
‘autionary measure is to strengthen the resisting power of limbs
and stems by thinning. Trees in young stands less than twenty
years old are the most likely to be broken and bent, while’ trees in
older stands, in which isolation is taking place, are the most apt
to be overturned. Frequently, insect depredations follow this kind
of damage.

PLATE VI.

apd hardwoods. The defective oak in the left
hrifty pine seedlings and should be

background serve as seed trees. The seediings

A culled stand of mixed pine
foreground is partially shading groups of t
removed. The large pines in the
are greatly exposed to fire.

pe
wits.

4
ea

rie eel

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