Little Arnot Photograph Series
A long wait with a slow modem, but a great 60-year photo record!
In 1927, scientists of the United States Forest Service Allegheny Experiment
Station formed a partnership with managers to collect data in stands scheduled
to be harvested as part of the first timber sale on the 4-year-old Allegheny
National Forest. The data would be used to help managers decide which kinds
of silviculture to use. The stands chosen for this timber sale, near the
Little Arnot Creek in Warren County, were photographed as well. Scientists
continued to collect data and take photographs at about ten year intervals
since that timber sale. Inventories consisted of tallies of all trees 1.0
inches in diameter at breast height (dbh) on a 1.0 acre plot within the harvest
areas. Some stands were only partially cut, and have since received final
harvests. But the stand that grew up after the clearcut in 1928 still stands,
and the photographs that follow show the development of this stand, a typical
even-age, second-growth stand.
||This photograph shows the stand prior to harvest in 1927. This
stand had a basal area of 128 square feet, with 335 trees per acre.
The medial diameter of the merchantable trees was 14.9 inches, and
almost 64 square feet, or about half the basal area, consisted of
American beech. Ten species were measured in this stand, with sugar
maple and black cherry representing the second and third most basal
||The timber sale was conducted in two parts. This was typical of
harvests at that time. First, the merchantable sawtimber was removed
during the winter of 1927. Although sawmills and chemical wood factories
often shared railroad facilities their harvests were conducted separately.
The sawmill harvest left the residual shown in this photograph.While
it is difficult to imagine that it was economical to harvest the
widely spaced, small residual trees apparent in this photograph,
such double harvests were not unusual where railroad access was available
to chemical wood companies.
||Then, most of the remaining trees were harvested for use as chemical
wood. The chemical wood industry flourished in the Allegheny region
from the early 1900's until the early 1940's. Destructive distillation
of small hardwood trees was made economical by the ready availability
of natural gas and by cooperation with booming sawmill and tanning
industries in the same region. In the case of the Little Arnot clearcut,
however, some trees were left, representing 3.1 square feet of basal
area, or about 24 trees per acre. The trees that were left had a
merchantable medial diameter of 8.4 inches, and were consisted of
8 basswood trees per acre, 12 sugar maples, 3 American beeches, and
1 blue beech.
||By 1937, some trees that had regenerated in the wake of the harvest
disturbance had grown large enough to be tallied (1.0 inches and
larger). There were 8.1 square feet of basal area per acre, and the
new stand was dominated by the shade-intolerant and fast growing
black cherry, which represented 2.6 square feet per acre. Residual
trees still dominated the merchantable portion of the stand, holding
the merchantable medial diameter at 8.8 inches, and basswood and
sugar maple, each with several residual trees, joined black cherry
as the species with the most basal area in the new stand. There was
apparently no regeneration of American beech in the wake of the 1927-28
harvest, for although beech continues to be tallied, it is as one
small stem per acre.
||By 1947, the stand had begun to differentiate into crown classes,
and the differences in growth rates between the species begin to
be apparent. The large trees in the left foreground are 20-year-old
black cherry, while a 20-year old sugar maple sprout clump in the
center background are much smaller. The basal area per acre in 1947
was 34.4 square feet, consisting of 497 trees per acre. about one-third
of this basal area , or 11.5 square feet, was black cherry, with
sugar maple and the short-lived pin cherry representing the second
and third most basal area, respectively. The medial merchantable
diameter persisted at 8.9 inches, and there were 12 tree species
detected in this tally.
||By 1958, species became quite distinct. The black cherries in the
left foreground had the characteristic flaky bark. The stand was
fully stocked, with a relative density of 102%, and a basal area
of 107.6 square feet , consisting of 1610 trees per acre! Black cherry
continued to dominate, representing 43.6 square feet per acre, followed
in order by sugar maple and ostrya. Fourteen tree species were tallied
in 1958, including one-time appearances by short-lived species like
devil's walking stick and serviceberry.
||No tally was made in 1968, but in 1972, the stand had 120.4 square
feet of basal area per acre. Self-thinning had reduced the number
of trees per acre to 997. Relative density stood at 99%, and the
medial diameter of merchantable trees had reached 9.1 inches. Black
cherry, sugar maple, and ostrya, in that order, dominated the stand's
basal area, with black cherry now representing 56.7 square feet per
acre. Twelve tree species were detected during this inventory.
||In 1978, basal area per acre had reached 125.8 square feet, in
661 trees per acre. Relative density was 94%, and merchantable medial
diameter was 9.7 inches. Black cherry, sugar maple, and basswood,
respectively, dominated the stand's basal area, with black cherry
representing 65.3 square feet of basal area per acre. Pin cherry
was completely absent from the stand by this tally, fifty years after
disturbance. The faster growth of black cherry is apparent by this
time, with the medial diameter of merchantable black cherry at 9.4
inches, while sugar maple, still heavily influenced by the residual
stems left after the chemical wood harvest, had a medial merchantable
diameter of 8.7 inches.
||In 1989, basal area had reached 149.8 square feet per acre, of
which 82.4, or 55%, was black cherry. There were 461 trees per acre,
of which only 140 were black cherry. Sugar maple, with 282 trees
and 32% of the basal area, and basswood, with only 11 trees but 8
% of the basal area, are still the second the third most common species,
by basal area. The medial diameter of merchantable cherry trees was
11.5 inches, while sugar maple's was 9.6 inches. Sawtimber volume
had begun to accumulate in this stand, which had a net sawtimber
volume of 5300 board feet per acre, of which 3400 were black cherry.
Eleven tree species were detected in this tally, with the addition
being a single hickory sapling. A different camera was used for this
photo which has caused the trees to look larger than they should
in the series.
||The most recent tally was made in 1998 when total basal area was
158.0 square feet per acre, with total number of trees being 346
per acre. Black cherry accounted for 87.3 square feet of the basal
area and 106 of the trees. Sugar maple added 206 trees per acre,
and 49.0 square feet of basal area per acre. Eight basswood trees
per acre contributing 9.8 square feet of basal area was the third
most common species once again, by basal area. Medial diameters for
merchantable cherry and sugar maple were 13.2 and 10.2 respectively.
The net sawtimeber volume increased in the last ten years to 8032
board feet per acre, of which 5390 board feet were black cherry.
The hickory sapling found in the previous tally didn't survive the
last ten years, the total number of species found in 1998 was 10.