The Black Hills, Bear Lodge Mountains, and Devils Tower - Mountains and Plains: The Ecology of Wyoming Landscapes - page 275

the Black Hills have been subjected in the past to
extensive forest fires, which have destroyed the
timber over considerable area. Around custer Peak
and along the limestone divide, in the central por-
tion of the Hills, on the headwaters of the Box elder
and Rapid creeks, scarcely a living tree is to be seen
for miles. . . . Some portions of the parks and val-
leys, now destitute of trees, show by the presence
of charred trees and decaying stumps that they
were once covered by forest, but generally the pine
springs up again as soon as it is burnt off, though
sometimes it is succeeded for a time by thickets of
small aspens . 30

neous and have fewer large trees. their results support
the work of William Baker and his associates. 36
the apparent effects of fire suppression are various
and wide ranging. to illustrate, tree density has clearly
increased, with trees often invading adjacent grasslands
and causing a concomitant reduction in the amount of
forage for livestock, deer, and elk (fig 16.9) . 37 After long
periods with high tree density, many understory plants
die. in contrast, and predictably, thinning by timber
harvesting leads to an increase in understory plant
growth. notably, a large number of tree seedlings often
become established if thinning or some other kind of
disturbance is followed by relatively wet weather the
following spring. tree density increases quickly if there
is no surface fire to kill the young trees (fig. 16.10). 38

Similarly, R. i. Dodge observed in 1876 that “through-
out the Hills the number of trees which bear the marks
of the thunderbolt is very remarkable. . . . the woods are
frequently set on fire. . . . there are many broad belts of
country covered with tall straight trunks of what was
only a short time before a splendid forest of trees.” early
photographs also suggest a more open forest with many
dead standing trees. 31
Lightning strikes are still a major cause of grassland
and forest fires in the regio n. 32 S ome areas might have
experienced a comparatively long fire-free period in
the 1800s, which would have enabled fuel accumula-
tion sufficient for the extensive crown fires observed
by early explorers. Douglas Shinneman and William
Baker concluded in 1997 that frequent surface fires
maintained open savannas on drier sites, such as in the
southern Hills, but that forests at higher elevations and
in the northern Hills had less frequent, more dramatic
stand-replacing crown fires over areas of 20,000 acres
or more. thus, it's likely that the Black Hills and Bear
Lodge Mountains as a whole have a mixed fire-intensity
regime, with both kinds of fires possible, depending on
climatic and fuel conditions at the time. 33 n ative Ameri-
cans surely had an effect on the fire regime as well (see
chapter 11). 34
Fires have been suppressed for such a long time—
and timber harvesting has removed so much of the tree-
ring evidence—that reconstructing the original forest
structure and fire history using dendrochronology has
been difficult. However, ecologist Peter Brown and his
associates found evidence for a diversity of forests, with
savannas interspersed with high-density forests. 35 they
concluded that the forests of today are more homoge-

Fig. 16.9. Young ponderosa pine are invading this meadow,
located to the south of the castle creek meadow shown in
fig. 16.8. Above the meadow, mountain pine beetles are killing
many of the ponderosa pines, opening up the forest after a
long period of increasing tree density.