of
tbreaks
these
78).
ce
able.
is
etles
fied
white
d by
ere
sease
tion
oms
color-
not
ording
prior
ten-12
and
type
te to
Both
umerous
964,
ein
eed to
inguish
Data Requirements
Two levels of data are required for decision making in forest insect and
disease management (Table 1).
The first level is a detailed in-place description and quantification of
insect or disease status on a management unit basis (i.e., stand, compartment,
etc). Purpose of these data is to serve as the basis for an "on-the-ground"
decision by the resource manager. Data may serve as a basis for instituting
cultural, biological, chemical, or integrated pest management strategies to
prevent or reduce losses or to take no action. Insect and disease data at
this level must be integrated with other resource data such as soil and
vegetation types, topography, access, and management constraints in order to
arrive at a sound decision.
The second level of forest insect and disease data is oriented toward the
Regional or national program administrator who is responsible for establishing
priorities for forest insect and disease research or action programs, allo-
cation of funds, adjustment of forest resource yield projections, or providing
data for accountability of funds expended and accomplishments achieved. Data
required at this level consist of quantitative summaries of area infested and
volume loss by pest species and land ownership class on a Regional or statewide
basis.
Statewide Loss Surveys
In 1976, the Forest Insect and Disease Management/Methods Application Group
was assigned the task of designing and implementing a survey system to estimate
annual bark beetle mortality on a statewide basis. Objective was to design a
practical inventory system utilizing existing technology. We were asked to
provide data on the number, diameter distribution, and volume in thousands of
cubic feet of timber killed annually.
Some major considerations in survey planning were that it be within the
technical and operational capabilities of the eventual user, repeatable on an
annual basis, and flexible and conducive to modification. This system would
be responsive primarily to the data requirements of the Regional or national
program manager but would have sufficient flexibility to provide a framework
to satisfy the needs of the local resource manager as well.
We selected mountain pine beetle, D. ponderosae, as the target. Mountain
pine beetle has historically been an important pest of several species of
pines in the western United States. Extensive areas of lodgepole pine, Pinus
contorta, and ponderosa pine, Pinus ponderosae, forests in the Rocky Mountains
and Pacific Northwest are currently suffering from epidemics, and there is an
urgent need for data on losses caused by this destructive pest.
Rather than begin on a statewide basis, we devoted the 1977 field season to
two pilot surveys to evaluate sampling methods and logistics. Two test sites
were selected, the Black Hills of western South Dakota and eastern Wyoming,
an area of extensive ponderosa pine forests; and the Targhee National Forest
in southeastern Idaho, an area which contains continuous forests of pure
lodgepole pine.