ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

There are at least three interesting and significant residue management imp1 ica-
tions related to this Engelmann spruce beetle outbreak; the first involved the
util ization of these wind- and beetl e-created residues, While foresters were strug-
gling to remove the standing and downed residual trees before they deteriorated too
badly, several species of woodpeckers--known to increase their numbers in such
outbreaks (Yeager 1955)--were feeding on the beetles in the infested standing trees.
However, to reach the beetles in the cambium, the woodpeckers removed large quantities
of the scaly bark. This accelerated checking and substantially reduced the period
of time that residue trees could be salvaged for sawtimber (Fellin 1955). A similar
instance was reported from the Gasps Penninsula in eastern Canada, where beetle-
killed spruce dried more rapidly when woodpeckers removed the bark in search of
beetl e 1 arvae ( R i 1 ey 1 940).
The second residue management implication was both biological and socio-political;
at issue was whether the removal of beetle-infested trees from the forest would
effect some control--assuming that the beetles were still present in the trees--or
would the removal be strictly a residue-salvage situation. This was an exceedingly
volatile issue because forest pest "control " funds were available for access and
removal of trees that were still beetle-infested, but not to remove the residue or
salvage the trees.
One of the most controversial Engelmann spruce stands was in Bunker Creek, a
roadless area about 15-20 miles from the Spotted Bear Ranger Station and contiguous
to the western edge of the Bob Marshall Wilderness. Proponents argued that a road
must be built to remove the beetle-infested trees; opponents argued that whether the
trees were infested or not, a road in that area would jeopardize the wilderness. I
personally spent 15 days in that forest in 1956 with a bark beetle survey crew. We
determined that, in fact, the standing trees, though they had been infested, were
now residue; and the beetles were gone. As a result of our survey findings, pest
"control" funds, though requested, were not authorized to access those beetle-kil led
spruce. In 1971, 15 years later, a road was built and Bunker Creek was made accessi-
ble. The Engelmann spruce beetle residues were salvaged and ended up at the Hoerner-
Waldorf pulp mill in Missoula, Montana. Payne (l969), in discussing the role of
politics in the coniferous forests, cited the Bunker Creek controversy as a classic
example of how pressure and political groups are involved in the management decisions
in northern Rocky Mountain forests.
The Engelmann spruce windthrow illustrates a third implication of residue
management: how our forest insect and disease problems change as old-growth forests
are converted to stands of young trees. As the Engelmann spruce beetle problem
diminished with the logging of progressively more mature and over-mature s ruce
during the past two decades, an increasing number of clearcuts have been p 1 anted to,
or have naturally regenerated with, young Engelmann spruce. Damage to these ywn
trees by the Engelmann spruce weevil, Pissodes strobi (Peck) (=engelmanni Hopkins
has steadily increased. These small weevils attack and kill or seriously injure 7
terminal shoots of young trees, causing crooks in the trunk or a stunted, forked,
and worthless tree (Keen 1952). By 1966, terminals destroyed by weevils were noticea-
ble in most stands of spruce reproduction in the Northern Rockies; some were recur-
rently damaged (Tunnock 1966). By 1971, the weevil was distributed throughout young
spruce stands in this region (McGregor and Quarles 1971) and terminal killing w w
prevalent in many areas. In some young trees, repeated attacks to live portions of
the main bole killed the trees outright, or predisposed them to death by secondary
insects. "In some areas," according to McGregor and Quarles (1971), "large blocks'
of young even-aged spruce offer ideal conditions for buildup and maintenance of
weevil populations." No doubt this weevil will continue to be a serious problem in
the management of young Engelmann spruce in the Northern Rockies,