In 1948 when the extensive open parts of the Reservation were grazed
and cultivated, small trees were inconspicuous and few. Mature trees,
with trunk diameters of 9 inches to more than two feet, were
distributed over the pastured areas, however, with groves of American
elm, honey locust, and walnut near the edges of the woods, and
occasional scattered trees of these species and of osage orange,
coffee-tree, red haw, hackberry, and ash.
Table 2.--Percentages of Different Kinds of Small Trees (Six
Inches to a Foot in Trunk Diameter) on Different Slope Exposures.
---------------------------+--------+----------+--------+---------
| North | Hilltops | West | South
| slopes | | slopes | slopes
---------------------------+--------+----------+--------+---------
| | | |
Elm | 29.6 | 29.9 | 34.6 | 57.9
Chestnut oak | 29.6 | 17.5 | 15.5 | .4
Hickory | 11.1 | 25.4 | 28.4 | .8
Walnut | 5.6 | .7 | 7.4 | 5.3
Hackberry | 13.0 | 1.0 | 3.7 | 26.4
Black oak | 1.9 | 16.3 | |
Red oak | 1.9 | | 6.8 |
Locust | | 3.3 | | 3.0
Osage orange | | 2.0 | | 1.5
Coffee-tree | 1.9 | .7 | | 1.1
Cherry | | | | .4
Red haw | | 2.4 | |
Mulberry | | .7 | |
Redbud | 9.3 | | 3.7 | .8
Boxelder | | | | 2.6
| | | |
Total trees in sample | 54 | 295 | 162 | 266
---------------------------+--------+----------+--------+---------
In 1949 soon after the discontinuance of grazing and cultivation, a
large crop of tree seedlings became established. Each year thereafter
the numbers were augmented by new crops of seedlings, but conditions
rapidly became less favorable for their establishment, as the ground
cover of herbaceous vegetation became thicker. The numbers and kinds
of young trees that became established differed markedly in different
situations. The seedlings present in large numbers were those of elm,
honey locust, boxelder, dogwood, walnut, osage orange and crab-apple.
There was none of the climax species--oaks or hickories--in the
sample.
Table 3.--Numbers of Young Trees Per Acre in Fields of the
Reservation, June, 1952.
---------------------+----------+-------+----------+--------+-------
| | |Bottomland|Hilltop |
|Bottomland|Hilltop| fallow |fallow |Prairie
| pasture |pasture| field | field |
---------------------+----------+-------+----------+--------+-------
No. of 1/100 acre | 250 | 80 | 70 | 80 | 50
plots sampled | | | | |
| | | | |
Honey locust | 83.0 | 58.8 | | 5.6 |
Elm | 80.0 | 72.5 | 138.8 | 230.0 | 150.0
Boxelder | 1.6 | 1.2 | 22.9 | | 200.0
Dogwood | 18.8 | 18.8 | 11.4 | 51.2 | 44.0
Walnut | 2.0 | 50.0 | 7.15 | |
Osage orange | 16.0 | 48.7 | | |
Crab-apple | 7.2 | 93.8 | | 1.2 |
Red haw | 5.2 | 17.5 | 2.8 | 2.5 | 4.0
Coffee-tree | 4.8 | 1.2 | | |
Hackberry | 2.8 | | | | 2.0
Cottonwood | .2 | | | |
Ash | | 8.8 | | 3.7 |
Plum | .8 | | | |
Peach | .2 | | | |
Cockspur thorn | .8 | 21.3 | | |
Sycamore | .4 | | | 1.2 |
Cherry | | 1.2 | | | 2.0
| | | | |
Total number counted | 236 | 393 | 279 | 296 | 402
---------------------+----------+-------+----------+--------+-------
Table 3 shows the numbers of young trees counted in a total of 530
plots of 1/100 acre each, in June, 1952. The trees counted included
all those approximately one foot high or larger. A few were up to 12
feet tall, but most were between one foot and five feet in height. Not
included were the many smaller seedlings, which were mostly concealed
beneath the dense layer of low herbaceous vegetation.
Of young trees there were most on the bluestem prairie area, less on
the former pastures and least on the fallow fields. In both the
pasture areas and the fallow fields, the bottomlands had fewer trees
than the hilltops--60 per cent and 94.3 per cent, respectively. In
every instance the abundance of young trees seemed to be inversely
proportional to the amount of competing herbaceous vegetation. The
bottomland fallow fields, which had the fewest tree seedlings, were
dominated by a rank growth of giant ragweed and sunflower, often as
much as ten feet tall, effectively shutting most of the light from the
tree seedlings. By 1954, however, the sunflower was nearly eliminated,
and the giant ragweed, though still abundant, was much stunted.
The bluestem prairie on an area of hilltop and upper slope had not
been burned over or otherwise disturbed for some years prior to 1948,
and probably trees began to invade this area years before they invaded
the fallow fields and pastures accounting, in part, for their greater
abundance in 1952. Approximately half of the young trees on this
prairie area were boxelders, which were relatively scarce on the other
four areas. Elm was either first or second in abundance on each area.
On both types of pasture areas honey locusts were appearing in
abundance and osage orange seedlings were present in somewhat smaller
numbers. However, these two kinds of trees were almost entirely absent
from the other areas sampled, except that a few locusts were recorded
on a hilltop fallow field. In 1948 honey locust seeds were noticed in
great abundance in the droppings of cattle; their dispersal in this
manner probably is in large part responsible for the abundance of
young honey locusts throughout the former pastures. Osage orange may
have been distributed in the same manner. Seedlings of dogwood were
moderately numerous on each one of the areas sampled, and those of red
haw were somewhat less abundant on each area. Crab-apple was the most
abundant species invading the hilltop pastures but was scarce or
absent in the other situations. The remaining species of trees,
including coffee-tree, hackberry, cottonwood, ash, plum, peach,
cherry, cockspur thorn, sycamore, and redbud, each made up only a
small percentage of the tree crop in the situations where they
occurred.
In late July and early August, 1954, counts of young trees were made
again on the upland pasture area, with a total of 200 1/100-acre plot
samples. This sample was taken at the end of one of the longest and
most severe droughts in the history of the area. Both 1952 and 1953
had drought summers, and up to the end of July the summer of 1954 was
exceptionally dry also. The conditions of the young trees at this
time, in the relatively dry and shallow hilltop soil, was especially
significant. As might have been anticipated, in this 1954 count, young
trees were more numerous than they had been on any of the areas
sampled in 1952. However, the data for 1952 and 1954 are not entirely
comparable, because in 1952 none of the plots sampled was nearer than
50 feet to the edge of the woods, whereas in 1954, the sample was
arranged to be representative of the entire field, including the parts
adjacent to the woods. The numbers per acre of each kind of tree, and
the percentages that were dead or dying, were as follows: crab-apple
167 (33.5 per cent dead); locust 98 (3 per cent dead); elm 69.5 (2.9
per cent dead); osage orange 63.5 (none dead); walnut 36.5 (4.1 per
cent dead); red haw 25.5 (none dead); ash 19.5 (none dead); cockspur
thorn 17 (17.6 per cent dead); wild plum 14 (3.6 per cent dead);
dogwood 9.5 (none dead); prickly ash 2 (25 per cent dead); black oak
1.5 (none dead); boxelder .5 (none dead). Thus, of the species that
were prominent invaders of the field, only crab-apple showed heavy
mortality. In many instances the mortality in crab-apple was due
wholly or in part to attack by cottontails (_Sylvilagus floridanus_),
which had completely girdled many of the stems. In general, mortality
in the young trees was light in this grassland area compared with the
mortality in any part of the woodland.