Historic, Archive Document

Do not assume content reflects current
scientific knowledge, policies, or practices.

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a note to you

Forestry Research: What’s New in the West , is a report on the work of
the USDA Forest Service’s four Forest and Range Experiment Stations in
the West. These research centers, and the states included in their areas of
study are: Rocky Mountain (North Dakota, South Dakota, Nebraska,
Kansas, Colorado, Arizona, New Mexico, and part of Wyoming, Oklahoma,
and Texas); Intermountain (Montana, Idaho, Utah, Nevada, and part of
Wyoming); Pacific Northwest (Alaska, Oregon, and Washington); and Pacific
Southwest (California, Hawaii, and the Pacific Basin).

on the cover

Dr. Richard “Skeeter” Werner of the Institute of Northern Forestry
checks an insect trap near Fairbanks, Alaska (see story, page 1). Inside: page
6 photo courtesy John Schomaker; page 7 photo, upper right, (citizens’
community planning group) courtesy Fort Collins Coloradoan.

our addresses

Single copies of most of the publications mentioned in this issue are
available free of charge. When writing to research Stations, please include
your complete mailing address (with ZIP) and request publications by
author, title, and number (if one is given).

For PSW publications write:

Pacific Southwest Forest and Range
Experiment Station
Post Office Box 245
Berkeley, California 94701

For RM publications write:

Rocky Mountain Forest and Range
Experiment Station
240 West Prospect Street
Fort Collins, Colorado 80521

If you are planning to move, please notify us as much in advance as
possible. Send your old address, your new address, and the address label
from the back cover to Forestry Research: What’s New in the West, 240
West Prospect Street, Fort Collins, Colorado 80521.

When reprinting articles, please credit USDA Forest Service. Mention of
commercial products in this issue is for information only— no endorsement
by the U.S. Department of Agriculture is implied.

For INT publications write:

Intermountain Forest and Range
Experiment Station
507 25th Street
Ogden, Utah 84401

For PNW publications write:

Pacific Northwest Forest and Range
Experiment Station
Post Office Box 3141
Portland, Oregon 97208

Alaska — filling in the gaps

Two men, working more than a thousand
miles apart, are involved in some of the
most exciting forestry research in Alaska. Richard
“Skeeter” Werner of the Pacific Northwest Sta¬
tion’s Institute of Northern Forestry in Fairbanks,
and John Hard of the Station’s Forestry Sciences
Laboratory in Juneau, are research entomologists.
Their work involves millions of acres of forests,
populated with all of the unknowns that a scientist
could want.

In many ways the world of the Alaskan
forests remains an enigma. For example, Werner

points out that in 1975, thousands of acres of larch
were defoliated in Alaska’s interior region, south of
Fairbanks. The insect which caused the defoliation
has not been identified.

Werner and his coworkers at the Institute of
Northern Forestry are in a unique position to make
significant contributions to knowledge of the
forest ecosystem of interior Alaska. They are cur¬
rently working on a series of studies about epi¬
demics of the spear-marked black moth. During the
past 2 years, this moth has raged throughout the
interior, defoliating millions of acres of birch. The

T Forest Service researchers in Juneau are working on the insect problems of southeast Alaska.

damage has been so extensive that the brown and
golden colors of the hard-hit trees make it appear
that fall exists year round.

Werner points out that there have been peri¬
odic outbreaks of defoliators for as long as records
have been kept and that these insects usually hit
millions of acres because of the homogeneous
nature of interior timber stands.

Research on the spear-marked black moth is
progressing. So far, life history studies have identi¬
fied four larval stages. The pupae develop in the
forest duff and emerge as adults during June. A
virus, two fungi, and a bacterium have been found
to kill 80 to 90 percent of the third and fourth
instar larval stages and parasites have killed up to
95 percent of the pupae. The identification of
these agents holds promise for natural control
methods. Werner and his colleagues at the Institute
of Northern Forestry assume that birch and other
hardwoods will become economically important in
the future in interior Alaska, and for this reason
are accelerating their research on the spear-marked
black moth and other insects that attack hardwood
trees.

Natural role of insects

Werner emphasizes the important natural role
insects play in maintaining forest ecosystems. For
instance, insects add to nutrient cycles. As they
feed, leaf parts and waste drop to the forest floor
by the ton, contributing to the slowly decompos¬
ing mass of the forest duff and the nutrient cycle.
In addition, birds, yellow jackets, and hornets feed
on the moths and act as natural controls.

Until recently the spruce bark beetle had re¬
ceived the most study in interior Alaska. Entomol¬
ogists now feel that proper management of forests
will reduce the destructive effects of this forest
pest. They have found that the beetle populations
expand in areas where untreated slash remains on
the ground. Improving treatments of slash and
other residues will significantly reduce the beetle
problem.

The situation is different in southeast Alaska.
There, the research emphasis is on the black¬
headed budworm and the hemlock sawfly. Be¬
tween 1950 and 1955, the budworm was respon¬
sible for the defoliation of 9 to 10 million acres of
Sitka spruce forest in southeast Alaska.

John Hard, entomologist with the Forestry
Sciences Laboratory in Juneau, says that the focus
of the budworm and sawfly research has been on
the biology and population ecology of the two
species. The most significant effect of both defolia¬
tors is reduction in the growth of affected trees,
and some top kill. In several cases, all parts of the
trees are killed.

Weather data analyzed

Hard points to several factors that help to
control these forest pests. For example, the sawfly
and budworm in southeast Alaska are living near
the northern limit of their range, where conditions
are less than ideal. Hard feels there may be a
relationship between weather and insect outbreaks.
He and Bill Farr, a research forester, are analyzing
weather data from 50 to 60 stations in coastal
Alaska. The weather data will be used to establish
climatic zones to see how these zones compare
with the areas where risk of insect attack is high.

The main research effort in southeast Alaska
involves identification of natural controls and their
interaction. Hard says that parasites and fungi,
acting together with the cool, moist climate, usu¬
ally control outbreaks naturally before damage
becomes extensive in virgin stands.

Most Alaskan timber is harvested from the
hemlock and Sitka spruce forests of the south¬
eastern panhandle. The rate of timber harvest has
increased since the 1950’s. Any time an environ¬
ment is modified, the risk of problems, such as
insect outbreaks, is increased. Hard feels it is highly
probable that chemical control will become more
necessary as young, managed forests replace the
old growth. Environmentally safe chemicals such as
Orthene, Dylox, and Lannate have been tested and
look promising.

The work of Werner, Hard, and other ento¬
mologists is filling the gaps in man’s knowledge of
the forest ecosystem of Alaska. These research
results are helping to insure productive resource
management for the Land of the Midnight Sun.

— By Thomas M. Baugh, Pacific Northwest Station

John Hard is now with the Pacific Southwest
Station’s Field Evaluation of Chemical Insecticides
Unit in Davis, California.

2

Those beetles in the trees

The mountain pine beetle has probably al¬
ways been present in the millions of acres
of lodgepole pine forests in the West. One of the
earliest infestations existed in the Horse Creek
Drainage of Utah Territory more than 180 years
ago, long before white men began to explore the
Wasatch Mountains.

Infestations may not always be troublesome:
when beetle numbers are relatively small, the
quarter-inch long, black insect and the lodgepole
trees coexist rather peacefully. But during a beetle
population explosion, which can occur every 20 to
40 years in a given area, hordes of beetles can
destroy entire forests.

Scientists at the Intermountain Forest and
Range Experiment Station, along with cooperators,
have conducted extensive research to better under¬
stand the mountain pine beetle’s life cycle and
relationship to lodgepole pine. Now thbir emphasis
is shifting to application of the research results to
promote effective control of the beetle.

A major step in the control work is the devel¬
opment of a model that demonstrates the inter¬
action of beetle populations with lodgepole stands.
“We based our model on 14 years of data on
population dynamics of bark beetles,” explains Dr.
Walter E. Cole, project leader in charge of the
research. “Use of the model has already helped us
prepare some preliminary management strategies to
deal more effectively with the insect.”

Attacking beetles leave telltale boring dust in
bark crevices and on the ground at the base of a
tree. A few weeks after entry, fungi carried by the
beetles stain the wood blue just beneath the bark.
This is a certain indication that the tree has been

attacked and killed. When the tree is attacked, the
color of the needles changes from healthy green to
deep reddish-brown. The change is so gradual that
it is usually not noticeable until the spring follow¬
ing attack. Needles drop off the tree within 2 or 3
years after the attack.

▼ Cage used for pine beetle study, Wasatch National Forest.

T Adult mountain pine beetle (enlarged).

Mountain pine beetles may attack individual,
scattered trees, but more often they attack entire
groups of trees. These group infestations can ex¬
pand with each new beetle generation, and even¬
tually, large areas may suffer extreme losses of
forest cover.

Intermountain Station studies indicate that
few lodgepole pine stands in the Intermountain
and Northern Rocky Mountain areas are safe from
the beetle. Depending upon the characteristics of
sites, from 44 to 90 percent of lodgepole stands
have experienced or will experience an epidemic.
Usually, an epidemic lasts from 6 to 8 years. Once
an infestation has reached epidemic proportions
there’s nothing anyone can do to stop it, Cole says.

The beetle at work

Natural enemies of the beetle — woodpeckers
and several insects— become more numerous when
beetle populations are high. However, these natural
predators do not provide effective control by
themselves.

Unfortunately, the beetles attack the most
healthy, vigorous trees in a lodgepole stand. Be¬
cause beetles prefer larger diameter trees, losses
range from 1 percent of 4-inch diameter lodgepole
to 87 percent of trees with 16-inch or larger diame¬
ters. In some stands, all trees over 12 inches in
diameter are killed.

When adult beetles seek new, green trees to
infest, they seem to search for large, dark objects
against a light background. This searching behavior
helps beetle populations expand, simply because
the larger trees provide the greatest food supply.

The flight period lasts from late summer to
early fall. Mating occurs after the female bores into
the trees. Small grubs hatch from eggs and begin to
feed on the tree’s phloem tissue before hibernating
for the winter. Phloem is a complex layer of living
tissue just beneath the bark through which ingre¬
dients of a tree’s food supply are transmitted.

In spring, the grubs resume feeding and grow
into pupae. By midsummer, new adults emerge
from the now-dead tree and fly to living trees to
launch a new 12-month beetle life cycle.

The Intermountain Station researchers have
found that, in addition to the number and distribu¬
tion of large diameter lodgepole, thickness of
phloem tissue is very important to beetles. If the
phloem is thicker than one-tenth inch, beetles can
produce large numbers of eggs, and populations
can expand to epidemic proportions. In thinner
phloem, they do not thrive, and populations may
decrease. In general, large diameter trees contain
thick phloem; small diameter trees contain thin
phloem.

No blanket prescription

The site and elevation of a stand of trees also
are important. Beetle survival is much greater at
lower elevation sites — beetles are less able to with¬
stand the harsh environments of high elevations.
Other factors — temperature, population density,
and rate of phloem drying — also influence the
amount of loss caused by a mountain pine beetle
infestation.

According to Cole, there is no blanket pre¬
scription for management of infested lodgepole
pine stands. “Clearcutting might be the best
method of control in some areas, but is taboo
where recreation or watershed values are high.”

Cole recommends removing trees before they
reach vulnerable sizes, thus eliminating or reducing
the potential for beetle epidemics. Because beetle
behavior is so closely tied to food supply — large
diameter trees with thick phloem tissue — logging
the proper trees in a stand would reduce the food
supply before the beetle becomes excessively active
within the stand.

An estimated 69 percent of all emerging adult
beetles come from infested trees 12 inches or larger
in diameter, and 89 percent of emerging adults
come from trees with 10-inch or larger diameters.

4

Dr. Cole says, “We will have to be satisfied
with harvesting smaller diameter trees. This will
mean a 60-year rotation period instead of an 80- to
100-year rotation. If the food isn’t there, the
beetles won’t be there. If we keep 5 years ahead of
the beetle, by managing stands to limit the food
supply, we have a good chance of winning.”

Managing lodgepole pine in this manner also
should provide a continuous supply of timber,
forest cover for recreation and watershed purposes,
and sound wildlife habitat.

Meeting the challenge

Although scientists have developed basic
knowledge of beetle biology and several control
techniques, there is a great need to integrate beetle
control strategies into forest management prac¬
tices. Existing techniques and knowledge must be
perfected through experimental testing.

More scientific knowledge is needed of the
relation between mountain pine beetle populations
and forest stand dynamics to refine trend predic¬
tions and to more fully understand mechanisms
that trigger epidemics. This research should empha¬
size study of diseases — root rot and dwarf mistle¬
toe — and other insects that may set the stage for
beetle attacks.

Additional research also is needed to evaluate
alternative methods of beetle control. Possibilities
include chemical attractants, repellants, and pro¬
tective substances, and effective methods to apply
them to tree stands without impairing forest
values.

Expanding knowledge of the mountain pine
beetle, plus expanding markets for lodgepole pine
harvested in prevention programs, will help contain
the tiny black beetles and assure a continuing
supply of green trees in the Rocky Mountains.

If you would like to know more about Inter¬
mountain Station studies of the mountain pine
beetle, Dr. Cole recommends the following publica¬
tions: “Mountain Pine Beetle Brood Production in
Relation to Thickness of Lodgepole Pine Phloem,”
by Gene D. Amman, Journal of Economic Ento¬
mology 65(1): 138-1 40; “Mountain Pine Beetle In¬
fluence on Lodgepole Pine Stand Structure,” by
Gene D. Amman and Bruce H. Baker, Journal of
Forestry 70(4): 204-209; “Population Changes of
the Mountain Pine Beetle in Relation to Eleva¬

tion,” by Gene D. Amman, Environmental Ento¬
mology 2(4): 54 1-547; “Interaction Between
Mountain Pine Beetle and Dynamics of Lodgepole
Pine Stands,” by Walter E. Cole, Research Note
INT-170-FR7; “Competing Risks Analysis in
Mountain Pine Beetle Dynamics,” by Walter E.
Cole, Researches on Population Ecology
1 5(2): 183-192; “Interpreting Some Mortality Fac¬
tor Interactions Within Mountain Pine Beetle
Broods,” by Walter E. Cole, Environmental Ento¬
mology 4(1): 97- 102; “Flight and Attack Behavior
of Mountain Pine Beetles in Lodgepole Pine of
Northern Utah and Southern Idaho,” by Lynn A.
Rasmussen, Research Note INT-180-FR7; and
“Mathematical Models for the Mountain Pine
Beetle-Lodgepole Pine Interaction,” by Walter E.
Cole, Gene D. Amman, and Chester E. Jensen,
Environmental Entomology 5(1): 1 1-19.

— By Dick Klade, Intermountain Station

▼ Lodgepole pine devastated by the mountain pine beetle.

▲ What experiences and benefits do recreationists gain from specific activities?

Recreation — for what benefits?

Why do people engage in various outdoor
recreation activities? What benefits do
they gain? How can knowledge of these benefits
help land managers decide what or what not to do?
Dr. B. L. Driver, project leader for recreation re¬
search at the Rocky Mountain Station, Fort Col¬
lins, Colorado, is seeking answers to these ques¬
tions. The objective of the program Driver directs
is to identify and measure the benefits recreation¬
ists receive from specific types of outdoor activities
and environments. He believes this information will
help land managers compare recreation values with
other resource values in an efficient and equitable
manner.

The research at Rocky Mountain Station is
part of a much broader recreation program involv¬
ing most Forest Service Experiment Stations. In
the West, Driver coordinates his work with that of

Gary Eisner, Pacific Southwest Station; John
Hendee, Pacific Northwest Station; and Bob Lucas,
Intermountain Station. Eisner and his associates
are developing computerized systems for process¬
ing recreation planning information, particularly in
the field of visual landscape management (see
Forestry Research, February 1975, p. 6). John
Hendee and his colleagues are obtaining informa¬
tion on dispersed recreation in areas other than
wilderness, particularly recreation associated with
consumptive (hunting) and non-consumptive uses
of wildlife. They are also looking for ways to
reduce vandalism, littering (see Forestry Research,
December 1975, p. 7), and other types of undesir¬
able behavior. Bob Lucas is directing studies on
wilderness management (see Forestry Research,
April 1976, p. 11). These scientists are seeking
ways to improve the recreation environment.

6

Driver wants to know how the recreationist “prof¬
its” from these improvements and from other
conditions and circumstances surrounding recrea¬
tion pursuits.

In most areas of resource management —
timber, watershed, wildlife, or range — it is not too
difficult to identify and quantify products in
specific terms. Recreation, however, is an excep¬
tion — it is quite difficult to define the social goods
and services produced. What are the benefits real¬
ized from a forest campground, for example? Are
they camping opportunities, such as 90 sites per
day for 120 days per year? Are they “X” number
of visitors or “Y” number of visitor days? Are they
“Z” units of user satisfaction? Are they human
beings who are better able to cope with personal
and social problems as a result of their outdoor
experiences? Are the goods and services produced
all of these, and more? How can these products be
compared with benefits resulting from alternative
resource uses, such as the production of “X” board
feet of lumber?

In the past, many management decisions re¬
lated to recreation have been based on intuition.
However, untested intuition can lead to biased
appraisals of the products we suppose result from
outdoor recreation activities. For this reason,
Driver is working to develop objective measures of
the goods and services resulting from outdoor rec¬
reation. His first task has been to separate the

A Is a person a better citizen after outdoor recreation?

demands of recreationists into four categories:

1. Demands for recreation activity opportuni¬
ties, such as the opportunity to hunt elk, to camp
in a wilderness area, or to canoe whitewater.

2. Demands for specific resource attributes,
social settings, or management actions that help
users have specific satisfying experiences. These
“attribute demands” include such things as trophy
elk, untrammeled wilderness, fast whitewater, low
levels of congestion and noise, or reasonable en¬
trance prices.

3. Demands for specific basic experiences
that give satisfaction. Examples are skill testing,
exploration, esthetic enjoyment, family together¬
ness, mental relaxation, privacy, social recognition,
exercise, or nature learning.

4. Demands for the physiological, psychologi¬
cal, and sociological benefits resulting from basic
experiences. These benefits, defined in terms of
improved performances when the recreationists go
back home, include improved physical and mental
health, enhanced self-confidence, improved job
performance, increased family solidarity, or greater
commitment to resource conservation.

Can city recreation substitute for other activities?

7

i

Recreationists are more aware of their de¬
mands for specific activities and the conditions
surrounding those activities ( 1 and 2 above) than
they are of the basic experiences or benefits (3 and
4). However, Driver sees categories 3 and 4 — those
satisfying experiences and positive personal and
social changes resulting from participation in out¬
door recreation activities — as the ultimate goods
and services produced.

The research Driver supervises is based on this
demand scheme and is proceeding in two phases. In
phase one, questionnaires are being designed to
quantify the relative importance of more than 40
types of desired and expected recreation experi¬
ences. Using these questionnaires, researchers are
identifying experiences which are in most demand
and the importance of each experience to partici¬
pants in specific activities.

Second phase studies

Results so far show that users engage in par¬
ticular activities to realize several satisfying experi¬
ences. Some of these experiences are more highly
valued than others. For this reason, a particular
activity is chosen so that the user might gain the
most valued types of experiences afforded by that
activity. The results also show that some experi¬
ences, such as solitude, risk-taking, skill develop¬
ment, and family togetherness, are highly depen¬
dent on specific characteristics of the physical and
social setting where the activity takes place. Condi¬
tions at home and work seem to influence the
types of experiences expected, too.

Information gained on user preferences will
by itself be useful to management. Also, it will be
the basis of the second phase studies. In this phase,
the “experience demands” of clearly defined user
groups will be used to formulate hypotheses about
possible benefits for various types of users. These
hypotheses will then be tested to identify and
quantify specific benefits.

Cooperators such as Dr. Perry Brown of
Colorado State University and Dr. George Peterson
of Northwestern University, member institutions
of the Eisenhower Consortium for Western En¬
vironmental Forestry Research, and other Forest
Service research units are making major contribu¬
tions to the Rocky Mountain Station recreation
research program. The results of this work should

give planners, managers, and policymakers better
information to answer such questions as: What
types of recreation opportunities should be pro¬
vided? Where? When? By whom? For whom? At
what price? What substitute opportunities can be
provided and still produce desired experiences and
benefits? How willing are recreationists to pay, or
to commit other personal resources, to achieve
desired experiences? Can the needed natural re¬
sources be committed to make possible the experi¬
ences and benefits unique to a given environment?

For more information about this research,
write or call Dr. Driver at the Rocky Mountain
Station (303) 482-7332; on FTS phone 323-521 1.
Several recent publications on this type of research
are listed below. Copies may be obtained from the
sources named in the citations:

Driver, B. L. 1976. Quantification of Outdoor
Recreationists’ Preferences. In Research, Camping
and Environmental Education, p. 165-187. Betty
van der Smissen and Judy Myers, eds. Penn State
Univ., HPER Series No. 1 1.

Driver, B. L. 1976. Toward a Better Under¬
standing of the Social Benefits of Outdoor Recrea¬
tion Participation. In Proceedings Southern States
Recreation Research Applications Workshop, p.
163-189. USDA Forest Serv. Gen. Tech. Rep.
SE-9. Southeastern Forest Exp. Stn., Asheville,
N.C.

Driver, B. L., and John R. Bassett. 1975.
Defining Conflicts Among River Users: A Case
Study of Michigan’s AuSable River. Naturalist
26(1): 19-23.

Driver, B. L., and Perry J. Brown. 1975. A
Social-psychological Definition of Recreation De¬
mand, with Implications for Recreation Resource
Planning. In Assessing Demand for Outdoor Recre¬
ation. Appendix A, p. 63-88. Natl. Acad. Sci.,
Wash., D.C.

Driver, B. L., and S. R. Tocher. 1970. Toward
a Behavioral Interpretation of Recreation, With
Implications for Planning. In Elements of Outdoor
Recreation Planning, p. 9-31. B. L. Driver, ed.
Univ. Mich. Press, Ann Arbor.

Knopf, Richard C., B. L. Driver, and John R.
Bassett. 1973. Motivations for Fishing. In Trans¬
actions of the 38th North American Wildlife and
Natural Resources Conference, p. 191-204. Wildlife
Manage. Inst., Wash., D.C.

— By Phil Johnson, Rocky Mountain Station

8

Pheromones for insect control

The Douglas-fir tussock moth is still making
history in the Pacific Northwest, but more
quietly now than during the most recent — and
most severe — of its periodic outbreaks. Between
1970 and 1974 the population of this permanent
resident of Northwest forests increased so rapidly
that it severely defoliated portions of forests in
Oregon, Washington, and Idaho.

In 1976, the search continues for better ways
to cope with future outbreaks. One of the most
promising new control techniques may be the
pheromone or sex attractant of the tussock moth,
produced artificially in the laboratory in 1974.
Development of the artificial sex attractant, which
duplicates the natural attractant of the moth, may
soon make it possible to determine the location

and size of local populations. Eventually the attrac¬
tant may also be developed as a control technique.

The scientific team that identified and synthe¬
sized the pheromone is headed by Dr. Gary Dater-
man, an entomologist at the Pacific Northwest
Station’s Forestry Sciences Laboratory in Corvallis,
and Dr. Doyle Daves and Dr. Ronald Smith, chem¬
ists at the Oregon Graduate Center, Beaverton.
Supporting and assisting them are technicians who
perform highly specialized tasks. Dr. Lonne Sower,
a recent transfer from the Agricultural Research
Service, is an experienced pheromone scientist who
has joined this team to assist in development of
pheromones of tussock moths and other insects.

In 1973, the same team identified the sex
attractant of the pine shoot moth. Using similar

▼ Female Douglas-fir tussock moth pupae contain eggs and are larger than the male pupae.

laboratory and field procedures, they are now
working to identify the attractants of the western
tussock moth and the rusty tussock moth. Though
these insects are far less destructive to Northwest
conifers than the Douglas-fir tussock moth, scien¬
tists are interested in their attractants because
these moths are closely related. In the woods they
may even be attracted by the same pheromone.

In their collaboration, which began in 1970,
Daterman, Daves, and Smith have developed their
own investigative methods for tuning in on insect
communication. It is a process that requires perse¬
verance, and, most of all, cooperation between the
chemist and the entomologist.

The first step is to find out whether the insect
has an attractant and. if so, which sex produces it.
To start with, the entomologist grinds up the ab¬
domens of female insects and mixes them in a
solution, which is filtered and tested on male
moths. The solution will contain hundreds of com¬
pounds, such as fats, waxes, and sugars, but if the
male responds, it also contains an attractant. The
problem now becomes the task of identifying this
seductive pheromone so that it can be isolated
from the other chemicals.

Separating the compounds

The purification process is a sort of labora¬
tory do-si-do in which the entomological and
chemical teams take turns performing their special¬
ized procedures. The chemist’s job is to eliminate
all compounds except the pheromone. The ento¬
mologist’s job is to test the material on male moths
to verify attractiveness of test samples.

The chemists use column and gas chromatog¬
raphy and mass spectrometry to separate the vari¬
ous compounds and to divide the solution into
small fractions. The entomologist tests each frac¬
tion on male moths in a laboratory cage. The
fractions that attract moths are separated further;
these fractions are again tested on male moths.
This process may be repeated dozens of times until
only the attractive chemical remains.

Finally, the chemists are able to make a sub¬
stance identical to the one female moths produce
so effortlessly. The chemical that attracts the
Douglas-fir tussock moth is cis-6-heneicosen-l 1-
one. It is highly attractive to male moths regardless
of whether it comes from a female moth or a

chemical laboratory. A one-anogram sample — 35
trillionths of an ounce— is enough to attract male
moths in laboratory tests.

In 1975, field studies to develop new control
methods for the Douglas-fir tussock moth were
carried out by Forest Service and cooperating re¬
searchers under an accelerated research program of
the U.S. Department of Agriculture. Nine Western
States and British Columbia were involved. All co-
operators reported captures of moths in areas
where they could not be detected by other meth¬
ods. In addition to Douglas-fir tussock moth, three
other species were attracted by the chemical.
Methods have been worked out to distinguish the
different species captured in the cages.

A trapping procedure

In addition to conducting the pheromone
studies, researchers are trying to develop an effec¬
tive trapping procedure. The scientists have tested
trap design, trap placement, the number of traps
needed in an area, and the attractant dosage
needed. The goal is to determine the relationship
between the number of moths trapped and the
total number of moths in a given area. When
applied over a wide area, a trapping system could
pinpoint areas where populations are increasing
and require intensive surveillance. This information
would help land managers forecast potential epi¬
demics and make decisions about the need, timing,
and methods for control.

The possibility that the sex attractant may be
used for direct control is also under study. One
way to do this may be to disrupt the reproductive
behavior of the moth by permeating the atmo¬
sphere with the attractant so male moths cannot
find the females. This approach has already been
used successfully in field experiments against the
gypsy moth and some agricultural pests.

Like most insects, the Douglas-fir tussock
moth operates by instinct and reacts to behavioral
stimuli. Once a stimulus such as the pheromone has
been duplicated it can be used to manipulate or
disrupt the normal life processes of an insect. The
use of pheromones is particularly promising be¬
cause only small quantities are needed, and because
apparently there is no hazard to other parts of the
environment.

— By Dorothy Bergstrom, Pacific Northwest Station

10

Imagery may aid wildland inventory

The cameras and scanners that were carried
high above the earth in the ERTS-1 mission
of 1972 and the Skylab maneuvers of 1973 pro¬
vided photos and photo-like imagery of the earth’s
surface. Among the people who were anxious to
get a look at this new imagery were scientists in the
remote sensing research unit at the Pacific South¬
west Station, Berkeley, California, and members of
the range inventory staff at the Rocky Mountain
Station, Fort Collins, Colorado. Both groups
wanted to see if the imagery — taken from an alti¬
tude of 570 miles in the case of ERTS-1 and from
260 miles in Skylab — could provide faster and
more accurate inventories of the nation’s forests
and rangelands — inventories that are vital if wild¬
land managers are to have the up-to-date informa¬
tion they need in order to make resource decisions.

The scientists were concerned not only with
exploring the uses of the imagery they had at hand,
but also with reporting back to the National Aero¬
nautics and Space Administration on possible ways
to modify future flights, to produce better imagery
for foresters and range managers.

The researchers found that although there are
problems with the space data, and some limits to
its use, much of it contains needed information on
the location, size, and composition of forests and
rangelands.

In the ERTS experiments, results indicate
that, for now, the best use of this imagery is in
distinguishing only the most general land-use
classes. The ERTS data were gathered by multi-
spectral scanner, a device that operates on the
principle that each feature in the natural landscape
absorbs, transmits, emits, and reflects a certain
amount of radiation. These spectral properties give
natural features distinctive, multispectral signa¬
tures. The ERTS multispectral scanner looks at
approximately 1 acre of land at a time, measuring
reflected energy in four spectral bands of the vis¬

ible and near infrared portions of the electro¬
magnetic spectrum. This radiance information was
transmitted to ground stations, and recorded on
magnetic tapes. The data were analyzed later to
determine the location and components of all the
scenes that were noted by the scanner. The analysis
can be performed by computers that are specially
programmed to translate the information. Or, the
data can be reconstituted into photo-like, black-
and-white or color composite imagery, which lacks
the resolution of conventional aerial photography

▼ R. C. Aldrich was coordinator of the Skylab report.

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but covers a much larger area than that shown in
the standard aerial photo.

Test sites in the ERTS experiment included
some of the countryside near Atlanta, Georgia,
where forests — which comprise 60 percent of the
study area — occur in a challenging checkerboard of
small ownerships, interspersed with fields of crops
and bodies of water. Other test sites included the
Manitou Experimental Range in central Colorado,
a mountainous area with a complex vegetational
mosaic of forest and grassland types. Also included
was a study area in the Black Hills of South
Dakota, where the intent was to see if ERTS
imagery could be used to detect infestations of the
mountain pine beetle in ponderosa pine forests.

Data from the Atlanta site were useful only to
the extent of classifying what was or was not
forest. Neither the computer-assisted analyses of
the magnetic tapes nor examinations of the photo-
like imagery by skilled photointerpreters could
detect, with the 95 percent accuracy required,
whether areas identified as forests were pine or
hardwood.

Imagery from other sites

In the Colorado study, examination of ERTS
data by computer-assisted analysis of the magnetic
tapes, by microdensitometer (an instrument that
measures the density of the photo-like imagery for
later separation, by computer, into different cover
types), and by photointerpreters, were accurate
enough in distinguishing deciduous forests from
coniferous forests and grassland. But all approaches
had too many errors in the next refinement — that
of identifying the specific type of forest or grass¬
land. The same was true with the Black Hills exper¬
iments — the space imagery could not be used
beyond broad, general classifications. The attempt
to identify forest trees under stress from mountain
pine beetle attack was unsuccessful. Part of the
problem was that the photointerpreters only had
ERTS imagery from August and September of
1972, and needed — but didn’t have — ERTS
imagery for the same period for the following year,
to use as an aid in detecting changes in the vegeta¬
tion. Instead, the 1973 imagery was from June,
“the worst possible time of the year to detect
insect stress,” because recent kills were barely
beginning to show foliage discoloration.

A more detailed explanation of each of these
studies and of related tests is included in “Evalua¬
tion of ERTS-1 Data for Forest and Rangeland
Surveys,” issued as Research Paper PSW-112-FR7.
Copies are available from the Pacific Southwest
Station, Berkeley.

Sky lab results

The study of Skylab imagery was based on
data obtained by a multispectral camera, a 13-
channel multispectral scanner, and a terrain mapping
camera carried on board the spacecraft. As with the
ERTS study, the analyses of Skylab data — by
photointerpreters, or by microdensitometer or
computer — all met the accepted standard of accu¬
racy in distinguishing forest from non-forest, and
for identifying general rangeland classes, but could
not be extended further into more detailed classifi¬
cations. The Skylab and ERTS results did differ,
however, in the mountain pine beetle study. Color
photos from the Skylab mapping camera showed
trees under stress, if they occurred in clusters that
were at least 85 feet in length.

Some problems were similar to those that
occurred in the ERTS study. One mistake in the
interpretation of these photos, for example, was in
incorrectly labeling wet meadows as mountain
bunchgrass, an error that the researchers thought
could probably be explained by the fact that the
two types of vegetation intermingle as the
meadows give way to mountain slopes. More infor¬
mation on the Skylab experiments is presented in
“Evaluation of Skylab (EREP) Data for Forest and
Rangeland Surveys,” Research Paper PSW-113-
FR7, which will be issued later this year by the
Pacific Southwest Station.

— By Marcia Wood, Pacific Southwest Station

The Rocky Mountain and PSW Station units
involved in the satellite experiments are now part
of the new Resources Evaluation Techniques
Research and Development Program. The group is
responsible for developing a system for inven¬
torying timber supplies, rangelands, recreation
resources, and fish and wildlife habitat. These
inventories are needed for estimating both current
and future supplies. The Program is headquartered
at the Rocky Mountain Station, Fort Collins.

Publications

A A productive range that once was chaparral land.

Rocky Mountain ranges

Grazing by domestic livestock or by wild
game converts forage — a resource that could
not otherwise be used — into needed food and
fiber. In recent years, rangelands have been
recognized for other resource values, such as
water yield, esthetics, and recreation opportu¬
nities. Production of range-fed livestock once
played a major role in the development of our
nation. Continued use of range resources may
well be important to our future welfare, be¬
cause the amount of energy used to produce
food via range grazing is well below the levels
needed to grow food on cultivated lands.

Range scientists at the Rocky Mountain
Station have published “status of knowledge”
papers for seven range ecosystems in the cen¬
tral and southern Rockies. These papers syn¬
thesize 70 years of research and management
experience. Each carries a description of
(l)the resource, (2) effective range manage¬

ment techniques for the ecosystem, (3) ways
to improve the forage resource, and (4) needs
for additional information to cope with
emerging problems.

Shrub and woodland ecosystems

S. Clark Martin of Tucson, Arizona,
authored “Ecology and Management of
Southwestern Semidesert Grass-Shrub
Ranges” (Research Paper RM-156-FR7). This
ecosystem encompasses a discontinuous belt
50 to 100 miles wide across valleys and lower
mountain slopes between 3,000 and 5,000
feet elevation in southern Arizona, New Mex¬
ico, and west Texas. Livestock management
systems here are designed to take advantage
of forage growth following summer rains.
Overgrazing encourages shrub invasion, partic¬
ularly mesquite, which is difficult to get rid
of. Yearlong grazing is common, but varia¬
tions of rest, deferred, and rotation systems
are proving effective. Martin notes the need
for ways to integrate grazing with demands
for desert recreation, wildlife habitat, and
subdivision development.

Dwight R. Cable, also of Tucson, com¬
piled “Range Management in the Chaparral
Type and Its Ecological Basis” (Research
Paper RM-155-FR7). This Southwest ecosys¬
tem is confined primarily to a narrow band of
rugged country 3,000 to 6,000 feet in eleva¬
tion south of Arizona’s Mogollon Rim. Over-
grazing near the turn of the century resulted
in the dense brush stands that are present
today. However, combinations of prescribed
fire, mechanical removal, chemical reduction,
and planned grazing can hold the chaparral in
check while improving range conditions, wild¬
life habitat, water yield, and esthetics. Infor¬
mation is needed on grazing systems that
incorporate chaparral control, improve grass
production, and utilize nutritious shrub
sprouts.

“Characteristics and Management of
Southwestern Pinyon-Juniper Ranges” (Re-

13

search Paper RM-160-FR7) was authored by
H. W. Springfield (now retired) of Albu¬
querque, New Mexico. Springfield notes this
ecosystem occurs under diverse soils and
climates between 4,500 and 7,500 feet eleva¬
tion throughout the Southwest. Overgrazing,
dating back 200 years in some cases, favored
the dense woodlands found today in many
grassland areas. Control of the piny on-juniper,
primarily by mechanical means, can restore
grazing capacity, and can improve wildlife
habitat and esthetics, if properly planned.
Various forms of rotation and deferred graz¬
ing systems are proving more successful than
season or yearlong systems. Seeding of de¬
pleted areas following control of the woody
species can also yield excellent results if seed¬
beds are properly prepared and if steps are
taken to conserve soil moisture.

Pine-bunchgrass ecosystems

Pat O. Currie, stationed at Fort Collins,
Colorado, wrote “Grazing Management of
Ponderosa Pine-Bunchgrass Ranges of the
Central Rockies” (Research Paper RM-159-
FR7). The ecosystem described occupies a
band along either side of the Continental
Divide from central Wyoming to central New
Mexico at elevations of 5,000 to 9,500 feet.
Forage is found in parks and meadows as well
as in open pine stands. Overgrazing and aban¬
doned farmsteads created severe watershed
problems following World War I. Today, graz¬
ing management has restored range productiv¬
ity, and reseeding has been highly successful,
with the proper mix of species. Grazing sea¬
sons may be extended to 10 months, using
the right combinations of seeded and native
ranges. Intense pressures for recreation experi¬
ences and mountain home developments are
being imposed on the ecosystem by nearby
metropolitan areas. Current research is focus¬
ing on ways to integrate grazing and other
resource demands into a complementary land
management system.

“Range Management and Its Ecological
Basis in the Ponderosa Pine Type of Arizona”
(Research Paper RM-158-FR7) by Warren P.
Clary, formerly of Flagstaff, Arizona, de¬
scribes pine-bunchgrass lands between 6,000
and 9,000 feet elevation in the central part of
that State. Since the early 1900’s changes —
from open forests to dense thickets of young
trees — have been in part the result of protec¬
tion from fire. Forage for livestock and big
game has declined. Research has shown inten¬
sive silviculture can improve timber produc¬
tion and water yield from these forests, while
enhancing forage for livestock and big game
animals. Reseeding can also improve forage
production. But, where reforestation is de¬
sired, reseeding should be limited to short¬
lived grasses and forbs. As with the pine type
in the central Rockies, research here is focus¬
ing on ways to integrate rapidly growing rec¬
reation uses with other demands on range and
associated resources.

▼ Cattle thrive on a seeded range in Colorado.

14

High mountain ecosystems

George C. Turner (now retired) of Fort
Collins compiled information on “Manage¬
ment of Mountain Grassland” (Research
Paper RM-161-FR7). Mountain grassland
ranges comprise about 10 percent of the sub-
alpine forest area between 8,000 and 11,500
feet elevation in Wyoming, Colorado, New
Mexico, and Arizona. Though small in acre¬
age, this range can be very productive. Local
livestock producers rely on it for summer
forage. Depending on the size of the ranching
operation, season-long grazing at light stock¬
ing levels, or some form of deferred, rotation,
or rest grazing system at more intense stock¬
ing levels, can be successfully applied. Over-
grazing results in takeover by unpalatable
weed species. More needs to be learned about
basic vegetation-soil-site relationships and
about integration of grazing with emerging
recreation activities.

“Alpine Range Management in the West¬
ern United States — Principles, Practices, and
Problems” (Research Paper RM-157-FR7) by
John F. Thilenius of Laramie, Wyoming, sum¬
marizes the “status-of-our-knowledge” for the
high ranges, from timberline to mountain top,
stretching from northern Montana to north¬
ern New Mexico. Sheep are the primary
domestic livestock users of these ranges. A
variety of grazing techniques can be success¬
fully applied under the direction of compe¬
tent herders. However, under certain condi¬
tions, grazing with unherded bands of sheep
may be as successful as herded management.

Because of the severity of the environment,
reseeding and other improved practices have
been only partially successful in rehabilitating
damaged ranges. More precise ecological
classification for alpine ranges is needed to
improve the ability of managers to accommo¬
date sheep and wildlife grazing, as well as
back country recreation in this fragile en¬
vironment.

Range ecosystems summary

Specialists in range management and re¬
lated fields will find the detailed information
and literature sources of these individual re¬
ports helpful to them as they seek solutions
to range problems. Key facts from each
“status-of-our-knowledge” paper are included
in “Range Management in the Central and
Southern Rocky Mountains — A Summary of
the Status of Our Knowledge by Range Eco¬
systems” (Research Paper RM-154-FR7).
Author Harold A. Paulsen, Jr., designed this
document to give administrators a quick ref¬
erence to range ecosystems of the Rockies as
well as to the problems that need more study.
This summary report, and the individual re¬
ports, are available from the Rocky Mountain
Station.

C/earcutting and wildlife

Large-scale clearcutting in ponderosa
pine can inhibit use of the forest by wildlife,
research indicates. Some studies by J. Edward
Dealy of the Pacific Northwest Station have
shed light on this problem. Dealy found that
clearcutting increased forage as expected, but
that wildlife did not use the areas as much as
they had before, probably because most feed¬
ing sites were too far from suitable cover.

Dealy indicates that timber management
practices might be improved if foresters first
determine how far an animal must go into a
timber stand to be hidden from view. This
distance can then be used as the radius in
designing cover patches.

If timber harvesting is done in strips,
care should also be taken to prevent the devel¬
opment of “shooting lanes” — continuous
strips of leave timber — by interrupting the
strips at reasonable distances with openings.

Other recommendations include mini¬
mizing the open areas that can be seen from
any one point in block-shaped clearcuts, and

15

using cattle to remove cured grass. This last
recommendation will produce new grass
growth for wildlife during the fall, spring, and
summer months.

“Management of Lodgepole Pine Eco¬
systems for Range and Wildlife,” by J. Ed¬
ward Dealy, is reprinted from the proceedings
of the Management of Lodgepole Pine Sym¬
posium. For copies write the PNW Station.

Quiet campgrounds

Recreational use of roadless areas is in¬
creasing. Resource managers are faced with
the problem of designing campgrounds for
larger numbers of people while maintaining a
quality backcountry experience.

A Pacific Northwest Station study pro¬
poses guidelines for placement of campsites in
roadless areas. According to the authors, their
suggestions will help minimize the impact of
noise from campers. Their research was based
on four assumptions: (T) visitors to roadless
areas seek solitude and isolation from those
outside of their immediate group; (2) the im¬
pact of auditory and visual encounters be¬
tween parties is especially great at campsites;
(3) the distance that campground noise travels
indicates the campsite spacing necessary to
minimize impacts between groups; and (4) the
spacing between campsites is most critical in
the interior (as opposed to peripheral) por¬
tions of a roadless area.

The researchers recommend placing
campsites laterally along streams and as close
to swift water as is ecologically acceptable.
Lakeshores and meadows are unacceptable
campsite locations because they do not
dampen sound. The authors recommend tak¬
ing advantage of any natural features that
deaden noise.

“Guidelines for Roadless Area Campsite
Spacing to Minimize Impact of Human-
Related Noises,” General Technical Report
PNW-35-FR7, by Tom Dailey and Dave
Redman, is available from the PNW Station.

Analyzing logging systems

Working in cooperation with Forest
Service researchers, two industrial engineers
have developed a system to collect time and
motion study data on logging operations.

David F. Gibson, professor, Montana
State University; and John H. Rodenberg,
now with Weyerhaeuser Company; describe
the system in “Time Study Techniques for
Logging Systems Analysis,” a report pub¬
lished by the Intermountain Forest and Range
Experiment Station.

The authors describe how standardized
time study techniques can be used for analyz¬
ing the steps in a typical logging operation —
mechanized felling, skidding with a rubber-
tired tractor, and loading. They also include
samples of the forms, flow process charts, and
other materials necessary for a time and
motion study.

For copies of the publication, General
Technical Report INT-25-FR7, write the In¬
termountain Station, Ogden.

Thinning Douglas-fir

When do you precommercially thin
Douglas-fir? How do you space the trees?
These questions and others are answered in
“Guidelines for Precommercial Thinning of
Douglas-fir” by Donald L. Reukema. Reu-
kema says that precommercial thinning is a
practical means of substantially increasing
wood production. His research has shown that
stands should be thinned when crop trees are
about 10 to 15 feet tall and 10 to 15 years
old. At this age, Douglas-fir is generally ad¬
vanced enough to show potential growth rate,
stem and branching characteristics, and sus¬
ceptibility to various types of damage. If thin¬
ning is delayed after competition begins, crop
trees may never realize their full growth
potential.

The number of trees left after precom¬
mercial thinning should depend upon the tree

16

size desired at the first commercial thinning.
The report provides a guide to the desired
number or spacing of trees, in terms of stand
average d.b.h., number of trees, and basal
area. Reukema warns that foresters should
not maintain an overdense stand in one spot
to offset a lack of trees in another. Also,
foresters should strive for uniformity in tree
size. As a general rule, it is best to remove all
unwanted trees.

Reukema’s paper, General Technical
Report PNW-30-FR7, is available from the
PNW Station, Portland.

Pollution from slash fires

Are EPA regulations about the smoke
from slash fires bugging you? Do people
complain about ash-covered laundry? If the
answers are yes, you might want to get a copy
of the publication, “Emissions from Slash
Burning and the Influence of Flame Retard¬
ant Chemicals.” The paper is based on the
research of D. V. Sandberg and S. G. Pickford
of the Pacific Northwest Station, and E. F.
Darley of the University of California,
Riverside.

First — the bad news. In tests conducted
at UC Riverside, scientists applied the fire
retardant DAP to fuel beds composed of
ponderosa pine slash. They were interested in
the distribution of the emissions of hydro¬
carbon gases, carbon dioxide, and total
particulate matter during the course of the
burning. Did DAP reduce pollution? Accord¬
ing to the scientists, “The use of DAP to
reduce the pollution potential was largely
disappointing. This retardant increased all
pollutants, especially the particulate faction,
even though less fuel actually burned in
treated fuel beds.”

Now for the good news! Results indi¬
cated that the elimination of the fine fuels —
those that constitute a wildfire risk— takes
place during the initial stages of fire. Most
gaseous emissions (potential pollutants) occur

later, after the dangerous fine fuels have been
consumed. Sandberg, Pickford, and Darley
conclude that “Methods of burning which
increase the proportion of high intensity
burning or the rapid extinguishment of slash
fires after burning the fine fuels should result
in a pronounced decrease in amounts of
gaseous pollutants.”

Their report, which is a reprint from the
Journal of the Air Pollution Control Associa¬
tion 25(3) : 27 8-28 1, is available from the
Pacific Northwest Station, Portland.

You have now received seven issues of
Forestry Research: What’s New in the West,
either at the mailing address indicated on the
back cover label, or as part of a bulk mailing.
If you have friends who would be interested
in this publication, you may wish to let them
know they can be added to the mailing list by
filling out the coupon below and mailing it to
us.

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i _ J

17

NATIONAL AGRICULTURAL LIBRARY

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