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FORESTRY

RESEARCH

WHA T'S NEW IN THE WEST FEB. 1975
U.S. Department of Agriculture Forest Service

a note to you

On the cover — a portion of the Idaho Batholith, drained by the
South Fork of the Salmon River (see story, page 3).

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 Sta¬
tions in the West. These research centers 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 and Washington); Pacific
Northwest (Alaska, Oregon, and part of Washington); and Pacific Southwest
(California, Hawaii, Guam and American Samoa).

some credits

Writers for this issue are: Delpha Noble and Martin Onishuk, Inter¬
mountain Station; Louise Parker, Pacific Northwest Station; Marcia Wood,
Pacific Southwest Station; and Phil Johnson, Rocky Mountain Statiom

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

our addresses

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

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

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.

Logging the Idaho Batholith

If you want to learn how to harvest and
how not to harvest timber over much of
the mountainous West, the Idaho Batholith pro¬
vides an excellent laboratory. Covering about
16,000 square miles in central Idaho where it spans
portions of six National Forests, the Idaho Batho¬
lith is larger than New Hampshire, Delaware, and
Connecticut combined. The climate can be desert¬
like in summer, Arctic in winter. Much of the Bath¬
olith is A-frame-steep, granitic rock covered by
shallow soil that slides, washes, or blows when man
or nature strips away the trees, shrubs, and grasses
that have become adapted to this harsh environ¬
ment.

Over much of the Batholith the protective
blanket of vegetation is kept thin and threadbare
by too much sun and wind. A soaking rain, or a
hunter’s Jeep, can inflict wounds that eventually
start the mountain sliding down. Some of the log¬
ging done here more than a decade ago, for exam¬
ple, started massive landslides. Although the de¬
structive logging practices were stopped, protests
about the damage done to the Batholith continue
today.

Many of the slopes still offer Douglas-fir and
ponderosa pine ripe for the mill. So, a team of
scientists from the Intermountain Forest and
Range Experiment Station (INT) is currently prob¬
ing the effects of various logging practices on this
fragile forest environment. Team leader is Dr. Wal¬
ter E. Megahan; his group is from Intermountain’s
Forestry Sciences Laboratory in Boise.

◄ Well-fractured, slightly weathered rock, Idaho Batholith

3

Because erosion and stream sedimentation are
two major hazards on the Batholith, these were the
first targets of INT scientists. In 1972, Dr. Mega-
han and Walter J. Kidd reported in the Journal of
Forestry that skidding logs from stump to truck
increased stream sedimentation only slightly over
the natural level. The authors also compared the
amount of sedimentation caused by two different
skidding methods — the skyline system, a port¬
able aerial tramway that keeps logs off the ground
much of the time; and the jammer, a mobile winch
that drags logs along the ground. The authors con¬
cluded that there was no difference in the amount
of sedimentation created by the two systems.

Sediment increase

The main increase in sedimentation, reported
the scientists, came not from skidding logs, but
from building the network of roads required to
move the jammer within reach of felled trees.
Roadbuilding increased sediment production an av¬
erage of 750 times over the natural rate for the
6-year period following construction. Among the
remedial measures recommended were planning
timber sales to keep roadbuilding to a minimum
and avoiding erosion-prone areas.

In a following research paper (INT-123-FR3),
Megahan and Kidd explored in greater detail the
relationship between roadbuilding and erosion.
Surface erosion, they reported, was very high im¬
mediately following road construction, but de¬
creased very rapidly thereafter. More than 90 per¬
cent of the erosion measured for the 6-year study
period occurred during the first 2 years. Similar
trends have been found elsewhere in the Batholith.
The scientists believe that road erosion can be re¬
duced by applying control measures immediately
after the road is constructed and protecting the soil
surface until vegetation becomes established.

Studies have shown that excessive erosion
need not be an inevitable consequence of road con¬
struction. Mulching, coupled with reseeding or
transplanting, can reduce surface erosion rates by
more than 95 percent. Transplanting deep-rooted
shrubs and trees offers the additional benefit of
reducing the landslide hazard on roadfills. Survival
of ponderosa pine planted on roadfills has averaged
97 percent 4 years after planting.

Working with what they have discovered so
far, Dr. Megahan and his scientists are looking
deeper into the erosion and sedimentation phe¬
nomena in the Batholith. They have learned that
from June through September, the period of most
intense rainfall, erosion rates on roadfills are three
times greater than at any other time of year. Ero¬
sion occurs during the drier months as well. Over a
4-year study period, about 20 percent of the road-
fill erosion that occurred during the summer and
early fall happened when there was no rainfall.
During 2 of the years sampled, more than 50 per¬
cent of the total erosion occurred during periods
when it did not rain. The soil was carried away by
“dry creep,” a form of wind erosion usually
thought to be a serious problem on the Great
Plains, not the forested mountains of Idaho.

Also in progress is a cooperative study be¬
tween INT scientists and Dr. Delon Hampton,
Howard University, Washington, D.C., aimed at
identifying the basic physical, chemical, and hydro-
logical properties of both soil and bedrock. From
data gathered thus far, James L. Clayton and John
F. Arnold have developed a method for classifying
the weathering and fracturing properties of granitic
rocks. The technique, described in General Techni¬
cal Report INT-2-FR3, can help identify areas
where massive landslides might occur after road¬
building or logging.

Silver Creek study

What about effects of logging other than ero¬
sion? In cooperation with forest managers on the
Boise National Forest, a 2,200-acre study area has
been set up in the Silver Creek drainage, north of
Boise. Here Dr. Megahan and his scientists will try
to find out how logging and the attendant road
construction affect cycling of soil nutrients, wild¬
life (including birds and small mammals), reforesta¬
tion, streamflow and water chemistry, productivity
of the residual timber stand, patterns of vegetative
succession, aquatic insect populations, and many
other facets of forest communities. Specialists in
forestry, range and wildlife ecology, hydrology,
soil science, and silviculture will do the study. Sci¬
entists stationed at Forestry Sciences Laboratories
in Missoula, Montana, Bozeman, Montana, and
Moscow, Idaho, will also participate (see p. 15).

4

Tools for land-use planning

Can the dollar value of resource com¬
modities such as wood, water, and forage
be determined? Is it possible to assign meaningful
values to non-market products and amenities such
as wildlife habitat and scenery? How can the as¬
signment of values to your resources help you with
your multiple-use land planning?

Economists of the Rocky Mountain Forest
and Range Experiment Station watershed evalua¬
tion project at Tucson, Arizona, believe there are
answers to these questions — answers that can be
shaped into planning tools.

A number of multiple-use planning tools are
being developed in the western United States. Sev¬
eral of these are models designed to predict the
ability of land to generate desired levels of re¬
sources at minimal management expense.

The economists at Tucson are adding to the
utility of these models by .devising ways and means
to ascertain the worth of forest resources to the
public. Their objective is to incorporate public de¬
mands, impacts, and concerns, as well as the pro¬
ductive capabilities of the land, into the planning
process. (seep. 10)

Planners look ahead with VIE WIT

▼ Foresters Bob Addison (left) and Gary Morrison (right) used VIEWIT for the Big Sur Unit, Los Padres National Forest

Sometimes it’s difficult to predict how a
new road, timber sale, or other proposed
use will affect the way a forest landscape looks.
Some planners are finding that a computer pro¬
gram known as VIEWIT is useful to them when
they need to know what sort of visual impact a
project will have.

VIEWIT, first put together 8 years ago, has
since that time been refined and tested on more
than 2 million acres of forest land in the Western
U.S. The VIEWIT package was developed by re¬
searchers at the Pacific Southwest Station and by
the people in the National Forest System who have
used the program and have suggested many of the
options VIEWIT now incorporates.

Most popular of the VIEWIT offerings is the
seen-area analysis. Here’s how it works. Let’s say
the VIEWIT user wants to know exactly what (and
how much) forest terrain can be seen by someone
standing at an observation point. The vantage point
the user selects could be a fire tower, or a proposed
location for a highway turn-out, or some similar
outlook. Once the user gives the computer the re¬
quired information about the forest terrain, and a
set of instructions, the computer can perform the
analysis, and display the results, in a few seconds.

Using only one observer point is seen-area
analysis at its simplest. It’s possible for the user to
submit requests for much more complicated analy¬
ses because the VIEWIT program can accommo¬
date a lot more observer points. For example, let’s
say the VIEWIT user has drawn up three alterna¬
tive routes for a proposed forest road. By stringing
observer points along each route, the user can de¬
fine the alternative roads for the computer. Then,
the user can instruct the computer to display the
location and the amount of forest terrain that
could be seen by visitors traveling along each of the
proposed routes.

Two of the scientists who have helped devel¬
op the VIEWIT program are Gary Eisner and Elliot
Amidon of the Pacific Southwest Station. They say

the VIEWIT seen-area analyses are somewhat like
the line-of-sight surveys that the military uses.

In order to run a seen-area analysis, or to use
any of the other VIEWIT options, the planner
needs to:

• divide the study area up into small, uni¬
form units called “terrain cells” and to

• digitize each cell’s elevation, so the eleva¬
tion will be in a format that can be read by com¬
puter.

It’s up to the user to decide how much actual
terrain each cell represents. One group that wanted
a very detailed VIEWIT analysis used cells that rep¬
resented less than one acre pef cell. Another team
used cells that took in more than 1 0 acres per cell.

There are a lot of different ways to get
elevation data digitized. Some people
have done the work themselves, using a digitizer
and 7'/2-minute topographical maps prepared by
the U.S. Geological Survey. Others have arranged
for someone outside their organization to provide
magnetic tapes of terrain data.

Each of the VIEWIT printouts is based upon
the terrain cell format. The types of printouts
available to the user are: the grey-scale map, in
which different shades of grey indicate the infor¬
mation the user requested; the numeric map, or
tables.

VIEWIT currently includes about 14 different
options. A planner, for example, can use VIEWIT
to determine how many times (or what percentage
of times) observers will see each cell. Or, the user
can get a VIEWIT printout that indicates the as¬
pect of each cell in relation to the prospective ob¬
server. In this analysis, the computer assigns from
zero to 10 points to each cell: a cell facing an
observer head-on, for example, is going to have
more visual impact — and thus more points —
than a cell which is oriented away from the viewer.
Using other instructions, the planner can get a
printout of the slope class of each cell, (see p. 15)

7

What makes deer choosy eaters?

In the woods foresters try to prevent exces¬
sive animal damage to young trees. But at a
research site in Olympia, Washington, forest scien¬
tists step out of the laboratory to watch deer
browsing on young trees in nearby pens.

The deer are confined in large experimental
areas as part of a research effort to find solutions
to the problems of animal damage to trees in
Northwest forests.

One of the scientists in the three-man research
team at Olympia is M. A. Radwan, a plant physiol¬
ogist and chemist. Radwan’s colleagues are Glenn
Crouch, project leader, and Ned Dimock, silvi¬
culturist.

Radwan originally worked in the broad area
of animal damage — including that caused by rab¬
bits, bear, deer, and mice. In recent years, however,
he has concentrated on the problem of black-tailed
deer browsing on Douglas-flr trees. One objective is
to find out if it is possible to breed Douglas-fir
trees that are resistant to nibbling by deer. Even if
complete resistance is not accomplished, the scien¬
tists should learn enough to help foresters get
young seedlings beyond the deer browsing years
more quickly.

The researchers think the answer to resistance
lies in chemistry. For years, it has been observed
that deer like some species more than others.
Glenn Crouch, for example, has found that deer
prefer Douglas-fir to red alder, and red alder to
vine maple in winter. Even within a species, some
trees are browsed more often than others.

8

“The trees within a species all look pretty
much the same,” Radwan says, “so there must be
some chemical variation that causes the difference
in animal preference.” His job is to find out what
the variation is. Right now, he’s looking for “chem¬
ical indicators of resistance,” or those compounds
which occur in larger quantities in resistant trees.

Scientists begin their study of a problem with
the literature already published on the subject.
Some of the current studies of deer browsing indi¬
cate that plants high in protein and sugar (there¬
fore more nutritious) are more likely to be
browsed heavily. Radwan pooh-poohs this “theory
of nutritional wisdom.”

▼ PNW chemist and plant physiologist M. A. Radwan

This chromatograph printout indicates the amount of terpene compounds in the mixture

He cites studies which show that deer fre¬
quently avoid red alder and other species that are
very high in nutritive value. Some of Radwan’s
early papers have attempted to resolve the litera¬
ture on this point. For a summary, see especially
an article entitled, “Plant Characteristics Related
to Feeding Preference by Black-Tailed Deer,
Journal of Wildlife Management (38( 1): 32-4 1 ).

Radwan is concerned primarily with two large
group of chemicals — the phenols and terpenes.
Both appear to affect preference, but it is not clear
yet which is more important.

Phenols are the second largest group of plant
compounds. For years, scientists have suspected
that phenols affect disease and insect resistance.
But these compounds have never before been
studied in Douglas- fir foliage.

Phenols are detected by a simple laboratory
technique in which the foliage is put into a solvent,
concentrated, purified to eliminate chlorophyll,
sugars, and other unneeded compounds, and ap¬
plied to a filter paper. The compounds that sepa¬
rate out — at different spots on the paper — can
then be analyzed by various techniques, including
study under fluorescent light.

Radwan is especially excited about one of the
phenolic compounds. “Imagine my delight,” he
says, “when we began to look at the filter paper
under fluorescent light, and a bright blue color
kept showing up from foliage that was susceptible
to browsing.” It turned out to be chlorogenic acid,
a combination of caffeic and quinic acids.

Not only do deer more consistently browse
trees that are high in chlorogenic acid, but they
also prefer mature Douglas-fir which is even higher
in chlorogenic acid than young trees. (Deer browse
young trees more frequently simply because they
can reach them more easily.)

Browsing preference tests have been con¬
ducted by Ned Dimock, using trees from the Sole-
duck Ranger District in the Olympic National For¬
est. This has provided a specific, but very localized
sample with which to work. Radwan believes that
somewhere in the vast gene pool of nature there
are Douglas-fir trees that have more variation —
some that have more chlorogenic acid, others that
have less. One of the next items on the research
agenda is to take a larger sample of trees and try
them out on deer in the pens.

Once Radwan finds the compounds which af¬
fect resistance, if these exist, there are at least

9

three ways to use the chemicals to solve deer
browsing problems. The first is to breed trees that
are resistant, and use them in planting programs
which favor those trees. The second technique is to
use chemicals from the resistant trees as natural
repellents, which could be sprayed on the trees at
critical times of the year. The third is to identify
an attractant which could be sprayed on nearby
vegetation to encourage browsing there.

Radwan’s search for factors affecting animal
preference for plants is one of several studies
underway at Olympia. Others of major importance
involve accurately assessing the impact of damage
to young trees, and investigating the opportunities
for modifying silvicultural practices to reduce ani¬
mal damage. □

Value tools continued

Paul F. O’Connell is working on a method to
determine current and future dollar values for tim¬
ber, forage, and water resources. He has successful¬
ly tested his approach in a trial estimation of the
worth of these resources in Arizona’s Salt-Verde
Basin. O’Connell is also investigating ways to pre¬
dict the impact of land management decisions on
the economy and social structure of surrounding
communities. The Mogollon Rim of Arizona is his
test site for this research.

▼ Radwan (right) and Dale Ellis (left) use a

James M. Turner is seeking ways to predict
the expense of different types and intensities of
land management. His current study encompasses
five different treatments to increase water yield
from ponderosa pine forests on Arizona’s Beaver
Creek watersheds. Turner’s research reveals that
man and equipment hours, and total treatment
costs, can be forecast from data on the basal area
and other characteristics of timber planned for re¬
moval.

Ron S. Boster is concentrating on a system
for measuring the importance of esthetic features
on wildlands. Boster and his colleagues say a modi¬
fication of the psychologists’ “theory of signal de¬
tection” holds promise as a reliable technique for
doing this job. It provides a means for unbiased
measurement of perceptual reactions to scenic
views of managed and unmanaged landscapes. The
technique has been successfully tested on water¬
sheds in the Beaver Creek drainage.

The Tucson crew is moving steadily toward
refinement of the value, cost, and esthetic meas¬
ures described. These value tools are of little use to
land planners, however, without means to predict
the productivity of the land under alternative types
of management. So, other Rocky Mountain Station
projects at Tempe and Flagstaff, Arizona, are pro¬
viding facts on land capability. Researchers in these
projects are discovering how wildlife habitat, recre-

chromatograph to analyze the content of browse species

\4 I t. i

ation opportunities, soil productivity, fire hazard
conditions, and timber, water, and forage values
vary in response to an array of land treatments.

How can these production capabilities and
their associated values be combined into a work¬
able tool that will help resource administrators
make land management decisions? O’Connell, lead¬
er of the economics project, says they can be orga¬
nized into models — mathematical computer
models that will yield a variety of management
approaches to achieve desired resource production
goals. Accompanying these alternatives are costs as¬
sociated with each, plus the values to society of the
products produced. From these figures, cost-bene¬
fit ratios may be readily calculated.

Model tests

So far, a partial model test has been run on
the Woods Canyon Management Unit of the Beaver
Creek watershed, Coconino National Forest. In this
test, dollar values and production capabilities were
assigned to timber, water, and forage. Esthetic
quality and wildlife habitat values were expressed
by index scales. Results of the model run are cur¬
rently being analyzed. A similar experiment is
planned for the Thomas Creek watersheds on the
Apache National Forest.

O’Connell points out that the model his team
is designing is not intended to produce “the one
ultimate scheme” for managing the natural re¬
sources on any land unit. That final decision will
always rest with the responsible manager. What the
model will do is display alternative combinations
of products the land is capable of producing, and
the estimated cost of management necessary to
produce each product combination. It will also
provide a measure of the social and economic con¬
sequences of each management alternative. For
areas where resource production is free to fluctuate
with changing demands (as opposed to agency-
established production goals), the model will show
which of the alternative treatment patterns would
result in maximum return for public dollars in¬
vested (most favorable cost/benefit ratio).

If you would like to know more about the
economic decisionmaking aids being developed by
the Tucson project, write to the Rocky Mountain

Station for some of the following publications:

Boster, Ron S., and Terry C. Daniel. 1972. Measur¬
ing Public Responses to Vegetative Management. In
Proc. 16th Annu. Ariz. Watershed Symp. (Phoenix,
Ariz., Sept. 1972.) Ariz. Water Comm. Rep. 2,
p. 38-43.

Brown, Thomas C., and Ron S. Boster. 1974. Ef¬
fects of Chaparral-to-Grass Conversion on Wildfire
Suppression Costs. USDA Forest Serv. Res. Pap.
RM-1 19-FR3. 11 p.

Brown, Thomas C., Paul F. O’Connell and Alden
R. Hibbert. 1974. Chaparral Conversion Potential
in Arizona. Part 2: An Economic Analysis. USDA
Forest Serv. Res. Pap. RM-127-FR3. 28 p.

O’Connell, Paul F, 1970. Economic Modeling in
Natural Resource Planning. In Proc. 14th Annu.
Ariz. Watershed Symp. (Phoenix, Ariz., Sept.
1970.) Ariz. State Land Dep. Ariz. Landmarks
1(2): 3 1-38.

O’Connell, Paul F. 1972. Economics of Chaparral
Management in the Southwest. In Watersheds in
Transition. (Proc. Symp. Amer. Water Resour.
Assoc., Fort Collins, Colo., June 1972.) Am. Water
Resour. Assoc. Proc. Ser. 14, p. 260-266.

O’Connell, Paul F. 1972. Valuation of Timber,
Forage, and Water From National Forest Lands.
Ann. Reg. Sci. 6(2): 1-14.

O’Connell, Paul F., and Ron S. Boster. 1974. De¬
mands on National Forests Require Coordinated
Planning. Anz. Rev. 23(2): 1-7.

O’Connell, Paul F., Ron S. Boster, and James
Thompson. 1974. Recreation Uses Change Mogol-
lon Rim Economy. Am. Rev. 23(8-9): 1-7.

Turner, James M. 1974. Allocation of Forest Man¬
agement Practices on Public Lands. Ann. Reg. Sci.
8(2):72-88.

Turner, James M., and Frederic R. Larson. 1974.
Cost Analysis of Experimental Treatments on Pon-
derosa Pine Watersheds. USDA Forest Serv. Res.
Pap. RM-1 16-FR3. 12 p. □

11

Publications

Shelterwood harvesting

It has been 12 years since the Forest
Service began experimenting with shelter-
wood harvests in old-growth Douglas-fir in the
Pacific Northwest. Originally, the system was
tried in an effort to get regeneration on diffi¬
cult sites (too hot, dry, or cold) where clear-
cutting was not satisfactory.

Now, Dick Williamson, a research forest¬
er with the PNW Station in Olympia, Washing¬
ton, has taken a close look at 21 shelterwood
units in western Oregon, logged between 1962
and 1968. All were at elevations between
3,000 and 5,200 feet. In addition to checking
for regeneration, the researchers took a look
at the survival and condition of the overstory
trees left from the first logging.

Results of the study seem to support the
opinion stated years ago by the noted forest
scientist Leo A. Isaac — that shelterwood
harvesting is a viable alternative to clearcut-
ting. Williamson recommends that foresters

leave the most vigorous, dominant trees in the
stand. This helps prevent windthrow and im¬
proves the genetic constitution of the new
forest. Where protection from rather severe
environmental conditions is necessary, a shel¬
terwood stand of about 100 to 180 square
feet of basal area per acre is recommended. If
conditions are more favorable, a more open
shelterwood or seed tree treatment may be
possible.

See “Results of Shelterwood Harvesting
of Douglas-fir in the Cascades of Western
Oregon,” Research Paper PNW-161-FR3 by
Richard L. Williamson.

Fir engraver studied

Site class, crown class, and logging his^
tory may each influence the degree to which
white fir are — or are not — susceptible to
attack by fir engravers. This is what George
Ferrell, a Berkeley entomologist, reports in
“Stand and Tree Characteristics Influencing
Density of Fir Engraver Beetle Attack Scars in
White Fir.” The report (Research Paper
PSW-97-FR3) is available from the PSW Sta¬
tion.

In this California study, Ferrell looked at
cross-sections from 603 trees. His unit of mea¬
sure was “mean scar density” — the number
of scars he found in each bole cross-section
divided by the volume and the age of the
cross-section.

He found that:

• tree age by itself is not an accurate
indicator of a tree’s susceptibility to fir en¬
graver attack;

• trees growing on high-quality sites
had lower mean scar densities than those
growing on poorer sites;

• trees of the dominant crown class
had lower mean scar densities than suppressed
and intermediate trees;

• logging and site quality apparently

12

interact: trees in a heavily logged stand, grow¬
ing on the poorest quality site studied, had
higher scar densities than the trees of the oth¬
er study plots.

Ferrell also did an earlier study on the
same subject, which he wrote up in “Weather,
Logging, and Tree Growth Associated with
Fir Engraver Attack Scars in White Fir” (Re¬
search Paper PSW-92-FR3: contact PSW for
copies).

He found that increases in both scar
abundance and fir mortality usually coincided
with periods in which the tree’s growth
slowed down, and were usually preceded by
one or more years of below-normal precipita¬
tion.

Ferrell thinks the following might reduce
the amount of damage fir engravers inflict on
the white fir in cutover sites:

• if possible, avoid logging during peri¬
ods of drought and subnormal tree growth;

• avoid silvicultural systems that re¬
quire repeated logging, with rapid removal of
a high percentage of the mature stand;

• dispose of slash.

Avalanche guidebook

People are traveling mountain highways
and flocking to winter sports areas in increas¬
ing numbers. Developers are buying up moun¬
tain lands for vacation home subdivisions.
Mining and other resource-using industries are
building facilities in the mountains. Commu¬
nications networks and energy transport lines
criss-cross our mountain ranges. All are threat¬
ened by destructive avalanches unless the haz¬
ard is considered in the process of planning
for mountain land use and development.

Mario Martin elli, Jr., has recently com¬
pleted a guide that mountain planners will
find useful in helping them locate and assess
avalanche problem areas. Martinelli is princi¬
pal meteorologist and leader of avalanche re¬

search at the Rocky Mountain Station’s Fort
Collins laboratory. The guide is “Snow Ava¬
lanche Sites: Their Identification and Evalua¬
tion,” USDA Forest Service Agriculture Infor¬
mation Bulletin 360-FR3.

In his guide, Martinelli stresses the need
for identifying and evaluating avalanche po¬
tential. He describes evidence planners may
use, both winter and summer, to identify ava¬
lanche paths. He then goes on to suggest ways
to estimate the size and frequency of ava¬
lanches when formal observation records are
not available. Numerous photographs illus¬
trate described conditions. He concludes with
a sample of a form planners can use for ava¬
lanche site evaluation, and a reference list of
additional publications on the subject.

For a copy of Bulletin 360-FR3, write to
the Rocky Mountain Station.

Budworm damage

The western spruce budworm inflicts a
peculiar type of damage on western larch, one
of the most important conifers in the north¬
ern Rockies. The budworm larvae not only
feed on the foliage, in much the same way as
they do on other species, but they also sever
the stems of new shoots. This often results in
deformed and forked trees as lateral shoots
turn up to replace the severed leader. Net
height growth on trees that have their termi¬
nal leaders cut by budworm larvae is also re¬
duced by 25 to 30 percent.

David G. Fellin and Wyman C. Schmidt
of the Intermountain Station have made stud¬
ies of how budworm damage affects form and
height growth. A report on the quantitative
aspects of their studies is in the Canadian
Journal of Forest Research (3(1): 17-26).

In a later report, “How Does Western
Spruce Budworm Feeding Affect Western
Larch?” (General Technical Report INT-7-
FR3), Fellin and Schmidt use photos to illus-

13

trate how the larvae damage the trees. These
examples should help the reader predict how
western larch will be affected by repeated at¬
tack. Copies of the Technical Report are avail¬
able from the Intermountain Station.

Sagebrush control

Under certain conditions, cattle ranchers
might find that sheep could be just what the
ranchers need to sustain and improve the graz¬
ing capacity of cattle ranges. Here’s why:

During the past 30 years, range managers
have tried to rehabilitate depleted, overgrazed
areas. One of the most commonly used meas¬
ures for restoring rangeland is removal of
woody species that compete for moisture. No
species in the Western U.S. competes more
vigorously than big sagebrush {Artemisia tri-
dentata). After removal of the sagebrush,
managers often reseed with a good forage
grass — crested wheatgrass {Agropyron des-
ertorum ) has been one of the most successful
grasses for reseeding throughout the sagebrush
zone. However, the wheatgrass stands are very
vulnerable to reinvasion of the sagebrush. Un¬
less control measures are maintained, the big
brush again becomes dominant to the extent
that the ranchers are right back where they
started — the range again needs rehabilita¬
tion.

This is where sheep come in. If turned
onto the range in late fall, before the sage¬
brush becomes too dense, sheep can do an
excellent job of controlling sagebrush.

Density of the sagebrush is a vital factor
in the success of this control program. Results
of a 6-year study conducted at the Benmore
Experimental Range in Tooele County, Utah,
showed that when sagebrush density was
about Wi plants per 100 square feet of area,
the seeded grass did well. However, if there
were 13 plants per 100 square feet, the sage¬
brush won. Sheep maintained their weight on

an area where sagebrush density was light, but
lost weight where the sagebrush was domi¬
nant.

The researchers doing the study also
evaluated spring grazing by cattle as a control
measure. Under the conditions at the Ben-
more Range, cattle failed miserably in con¬
trolling sagebrush. These animals ate only a
few flower stalks of sagebrush — they sim¬
ply didn’t like the menu!

Using sheep to control sagebrush is a rel¬
atively simple means of biological control. It
is cheaper than chemical or mechanical sage¬
brush control treatments of seeded ranges.
And, the shrub provides forage for the sheep.

By using “woolies” in range manage¬
ment, cattle ranchers will not only improve
their ranges, but may also realize a profit in
the wool produced by their “brush control¬
lers.”

Write to Intermountain Forest and
Range Experiment Station for a copy of
“Sheep Can Control Sagebrush on Seeded
Range If ... ” RP-299-FR3, by Neil C.
Frischknecht and Lorin E. Harris.

▼ In a Utah test, sheep controlled sagebrush growth

14

VIEW IT continued

Some of the VIEWIT options are a
combination of different types of analyses.
Most of these combinations involve “weight¬
ing,” a mathematical process that was not
intended to — and won’t — make the com¬
puter the decisionmaker.

One such combination is the “times seen
and distance weighting analysis.” In another
option, the user can combine times seen with
relative aspect and distance weighting.

More information on the VIEWIT op¬
tions is in a user’s guide written by Wayne
Iverson and Christine Johnson of the Forest
Service’s California Region and by Mike
Travis and Gary Eisner of the PSW Station.
The guide will be published by the PSW
Station.

Right now, the Station has three papers
with background information on the program.
“Computing Visible Areas from Proposed
Recreation Developments ... A Case Study”
is a Research Note (PSW-246-FR3) in which
Gary Eisner describes how he and members of
the Black Hills National Forest staff used
VIEWIT to find out what areas of the Forest
could be seen from 12 different recreation
areas and from three routes proposed for a
scenic tramway. “Delineating Landscape View
Areas ... A Computer Approach” (Research
Note PSW-180-FR3) is an earlier report by
Eisner and colleague Elliot Amidon. Burt
Litton explains how VIEWIT was used in a
case study on the Teton National Forest in
“Landscape Control Points: a Procedure for
Predicting and Monitoring Visual Impacts”
(Research Paper PSW-9 1-FR3).

Other sources of information on VIEW¬
IT are the recreation or engineering units of
some of the USD A Forest Service Regions
in the West, and Gary Eisner of the PSW Sta¬
tion in Berkeley.

Prospective users of the VIEWIT pro¬
gram might be interested in the Forest Serv¬
ice’s new series on landscape architecture in
wildland management. The first of these pub¬
lications are “National Forest Landscape
Management Volume 1” (Agriculture Hand¬
book No. 434, $1.50, catalog number Al.
76:434 Vol. 1) and “National Forest Land¬
scape Management Volume 2, Chapter 1 —
The Visual Management System” (Agriculture
Handbook No. 462, $1.80, catalog number
Al. 76:462). Both are basic texts and are
available from the Superintendent of Docu¬
ments, U.S. Government Printing Office,
Washington, D.C. 20402.

A comprehensive research report on
how to classify forest landscapes is Burt
Litton’s “Forest Landscape Description and
Inventories — a Basis for Land Planning
and Design” (Forest Service Research Paper
PSW-49-FR3). Contact PSW for copies. □

B at ho / it h continued

If you would like copies of the cited
reports, contact the Intermountain Forest and
Range Experiment Station, Ogden.

Megahan, Walter F., and Walter J. Kidd. 1972.
Effects of Logging and Logging Roads on
Erosion and Sediment Deposition for Steep
Terrain./. For. 70(3): 136-141.

Megahan, Walter F., and Walter J. Kidd. 1972.
Effect of Logging Roads on Sediment Produc¬
tion Rates in the Idaho Batholith. USDA
Forest Serv. Res. Pap. INT-123-FR3. 14 p.

Clayton, James L., and John F. Arnold. 1972.
Practical Grain Size, Fracturing Density, and
Weathering Classification of Intensive Rocks
of the Idaho Batholith. USDA Forest Ser.
Gen. Tech. Rep. INT-2-FR3. 17 p. D

15