Historic, Archive Document

Do not assume content reflects current
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Forestry

Research

West

Forest Service

U.S. Department of Agriculture

November 1980

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cr

Forestry

Research

West

Forest Service
U.S. Department of
Agriculture

November 1980

In This Issue

Page

Managing big sagebrush lands
-what’s best? 1

Silver Creek - field laboratory

in the Idaho Batholith 4

Logging injuries increase decay
in true fir 8

Risk-rating systems developed
for firs 12

New publications 15

Cover

Research Entomologist George
Ferrell of the Pacific Southwest Sta¬
tion has developed a system for
estimating the longevity of California
red fir, Shasta red fir, and white fir.
Read about it on page 12. (Photo by
Dennis Galloway)

To Order Publications

Single copies of publications referred
to in this magazine are available
without charge from the issuing
station unless another source is
indicated. When requesting a
publication, give author, title and
number.

Each station compiles periodic lists
of new publications. To get on the
mailing list write to the director at
each station.

Subscriptions

Subscriptions to this magazine will
be sent at no charge. Write To:

Forestry Research West
240 West Prospect Street
Fort Collins, Colorado 80526

To change address, notify the
magazine as early as possible. Send
mailing label from this magazine and
new address. Don't forget to include
your Zip Code.

Permission to reprint articles is not
required, but credit should be given
to the Forest Service, U.S.D.A.

Mention of commercial products is
for information only. No endorsement
by the U.S.D.A. is implied.

A report for land managers on
recent developments in forestry
research at the four western
Experiment Stations of the Forest
Service, U.S. Department of
Agriculture

Western Forest
Experiment Stations

Pacific Northwest Forest and Range
Experiment Station (PNW)

809 N.E. 6th Ave.

Portland, Oregon 97232

Pacific Southwest Forest and Range
Experiment Station (PSW)

P.O. Box 245
Berkeley, California 94701

Intermountain Forest and Range
Experiment Station (INT)

507 25th Street
Ogden, Utah 84401

Rocky Mountain Forest and Range
Experiment Station (RM)

240 West Prospect Street
Fort Collins, Colorado 80526

Managing big
sagebrush c. o
lands - what’s

best? r ^

j

by Rick Fletcher
Rocky Mountain Station

The sagebrush ecosystem is one of
the largest irangeland ecosystemsjin
\ the westerrrDnited States. Of the'*
y* several species, big sagebrush
(] 'Artemisia tridental is the most
< vtflciespread, covering approximately
145 million acres.

Such an abundant species has
important environmental and
economic implications. Sagebrush
lands provide habitat for a variety of
wildlife; are an important grazing
resource for the livestock industry;
are irrigated for agricultural crops,
are strip-mined for coal, uranium,
and other minerals; are used for
fishing, hunting, and other
recreational activities; and provide
runoff water for local ranchers to
help fill tanks and watering ponds
for livestock, and even as a
municipal water source.

Despite the multiple values,
sagebrush management concepts
have often been geared toward
< removal of the shrubs in favor of
grasses and forbs for livestock
grazing. While this practice
increases usable forage production,
it triggers changes in other
resources as well.

In 1967, researchers at the Rocky
Mountain Station, in cooperation

"v. with the Bureau of Land Manage-
ment, began studies at the
7,000-acre Stratton Sagebrush
Hydrology Study Area in south-
central Wyoming to determine how
various sagebrush management
practices affect the hydrology of
sagebrush lands, their grazing value,
and the impact on other resources.
Dave Sturges, research forester at
the Station’s Forest, Range, and
Watershed Laboratory at Laramie,
Wyoming, says, “These other
ecologic and hydrologic changes
have received little attention
compared to the well-documented
response in usable forage
production. But, they are changes
that need serious consideration
before a sagebrush management
program is defined.’’

Hydrologic relations

“Sagebrush lands are not noted
water producers," Sturges explains,
“but there is speculation that
decreased evapotranspiration
subsequent to sagebrush control
can increase streamflow since less
water from melting snow is needed
to rewet soil." Plot studies were
initiated at Stratton in 1968 to
isolate various hydrologic responses
to sagebrush control and thus
provide insights into how an entire
watershed might respond. Root and

1

The volume of soil utilized by individual big
sagebrush plants as a moisture reservoir was
identified in a study that used a neutron
probe to measure soil water content.

water-use characteristics of
individual big sagebrush plants
were investigated in addition to
learning how spraying stands of
sagebrush with 2,4-D affects snow
accumulation and melt, soil water
use, and vegetation production.
Scientists have found 2,4-D,
registered with the Environmental
Protection Agency, to be one of the
most effective and efficient means
of controlling sagebrush. Millions of
acres of sagebrush lands have been
sprayed in the west over the last 25
years.

Soil moisture

Seven plots were sprayed with 2,4-D
in 1970 killing over 95 percent of the
plants; study records now extend
over a 10-year period. Soil water
depletion was reduced 22 percent
the first 8 days after spraying and
by fall the soil water recharge
requirement was 31 percent less
compared to unsprayed plots. The
size of treatment effect declined the
first 5 years after spraying, but then
stabilized in the fifth to tenth years

at about a 10 percent difference. All
of the reduction in soil water use
was located in soil 3 to 6 feet deep
beginning the second year after
spraying. Thus, Sturges indicates
sagebrush control on lands with
soils less than 3 feet deep merely
shifts the moisture draft from
sagebrush to replacement grass
species and treatment will have no
effect on water yield. On sites with
soils deeper than 3 feet which are
fully charged each spring,
controlling sagebrush does have a
potential for slightly increasing
water yield.

Snow accumulation and
melt

Records indicate spraying slowed
the rate of snow accumulation on
treated plots during the early part of
the winter even though sagebrush
skeletons remained intact. Once
snow depth reached the height of
the sagebrush stand, about 45 cm,
vegetation exerted less and less
influence on accumulation. By
spring, all vegetation was covered
by snow and snow depths on treated
and untreated plots were similar to
those before spraying. “What we
learned,’’ said Sturges, “is that
sagebrush control can reduce the
rate of snow accumulation if
replacement vegetation is shorter
than the brush, but once snow
covers vegetation, the interaction
between topography and wind then
controls snow buildup."

Researchers also looked at post¬
treatment snowmelt characteristics
and could detect no difference in
the rate of melt on sprayed and
unsprayed plots. That is, any
difference in snow depth at
maximum accumulation on sprayed
and unsprayed plots persisted
throughout the melt season.

Vegetation response

A typical response by vegetation to
sagebrush control was observed.

One year after spraying,
researchers found that grass
production had doubled and it was
2.6 times that of untreated plots 3
years after spraying. However, total
above-ground biomass growth was
less on sprayed plots. The increase
in grass production did not
compensate for lost biomass growth
by sagebrush and forbs. Above¬
ground biomass production on
sprayed plots was 29 percent less
than on untreated plots the year
after treatment, and was still 23
percent less in the third posttreat¬
ment year.

Stream contamination
by 2,4-D

The herbicide 2,4-D is usually
applied to sagebrush as an aerial
spray, and therefore, is subject to
wind drift. This can result in
contamination of surface waters
with possible adverse effects on fish
and other aquatic organisms if
concentrations reach 1,000 ppb
(parts per billion).

A watershed 587 acres in size was
sprayed at the Stratton site in 1976
observing standard Bureau of Land
Management spraying guidelines.
The maximum level of 2,4-D in water
samples taken from the creek was 5
ppb which occurred immediately
after spraying. Herbicide levels
decreased to 3 ppb, between 3 and
12 hours after treatment, and 2 ppb
were detected 1 , 2, and 3 days after
spraying.

Sturges explains, “The primary
reason 2,4-D concentrations were
so low was because a 100-foot wide
unsprayed buffer zone was left on
each side of the stream. In addition
snow still covered the stream
channel which further reduced
herbicide entry. We believe spraying
guidelines established by the Forest
Service or Bureau of Land Manage¬
ment will keep contamination of
water to a minimum and thus
spraying presents no danger to
aquatic organisms.”

Wildlife studies

The U.S. Fish and Wildlife Service’s
Denver Wildlife Research Center
has recently completed studies at
Stratton on the effects of sagebrush
control on several wildlife species.
As yet, results from those studies
are not available. However,
intensive investigations on how the
Brewer’s sparrow, one of the most
abundant non-game birds occurring
in the big sagebrush ecosystem,
responds to spraying have been
conducted.

Brewer’s nests were first located
and then sagebrush around half of
the nests was sprayed with 2,4-D to
indicate how the birds are affected
the year of treatment. Production of
eggs and young were similar for
both treatments. The dried leaves
that remained on sprayed sagebrush
plants apparently provided sufficient
shade and protection from
predators.

A different picture emerged,
however, when Brewer’s use of
sprayed vegetation for nesting
habitat was compared with use in
undisturbed vegetation. Bird
densities in an area sprayed with
2,4-D the preceding year was 67
percent lower than in untreated
sagebrush vegetation, and 99
percent lower 2 years after
treatment. The few birds seen in the
sprayed area were near small areas
of live sagebrush that had survived
treatment.

A continuing effort

Scientists have learned a lot at
Stratton, but their work in evaluating
changes that result from sagebrush
control is far from over. Currently,
John Schmid, entomologist at the
Station’s headquarters in Fort
Collins, is analyzing insects
collected on treated and untreated
watersheds to determine what
species inhabit these ecosystems.

Max Schroeder of the U.S. Fish and
Wildlife Service is also compiling
data from studies on nesting birds
and small mammals. Results from
his work should shed light on what
effects spraying with 2,4-D have on
these animals.

In addition, researchers at the
Laramie lab are continuing to
assess changes that occur in water
yield characteristics such as total
annual yield, snowmelt and ground-
water runoff, changes in sediment
transport, snow accumulation, and
soil water use. Traditional range
management information about
vegetative production and compo¬
sition, and changes in ground cover
are also being evaluated.

For more information on hydrologic
aspects of the Stratton study, contact
Dave Sturges, Forest, Range, and
Watershed Laboratory, 222 South
22nd Street, Laramie, Wyoming
82070. Phone (307) 742-6621,

FTS operator 328-1 110.

Suggested reading includes the
following, all available from the
Rocky Mountain Station:

Hydrologic Relations of Sagebrush
Lands, a reprint from the
Proceedings of the Sagebrush
Ecosystem Symposium held in
Logan, Utah, April 27-28, 1978, by
David L. Sturges.

Soil Moisture Response to Spraying
Big Sagebrush: A Seven-Year Study
and Literature Interpretation,
Research Paper RM-188, by David
L. Sturges.

Snow Accumulation and Melt in
Sprayed and Undisturbed Big
Sagebrush Vegetation, Research
Note RM-348, by David L. Sturges.

The Effect on the Brewer’s Sparrow
of Spraying Big Sagebrush, a reprint
from the Journal of Range Manage¬
ment, Volume 28, Number 4, by Max
H. Schroeder and David L. Sturges.

Sagebrush bordering the stream channel was
left untreated for wildlife habitat and to
reduce entry of 2,4-D into the waterway.
Snow still covered the stream channel at the
time of spraying which further reduced
herbicide entry into the stream.

3

Silver Creek
- field laboratory
in the Idaho
Batholith t

by Delpha^sloble
Intermountain Station

The Silver Creek Experimental Area
within the Boise National Forest is a
thriving field laboratory located in
one of the most difficult places in
the West to harvest timber — the
Idaho Batholith.

But timber is being harvested — as
Forest Service researchers and land
managers engage in a joint venture
to harvest old-growth timber from
Silver Creek's steep slopes. Boise
Forest personnel are managing the
timber sales for maximum protection
of the forest ecosystem as
researchers of the Intermountain
Station conduct studies to obtain
information on the environmental
impacts of the logging activities and
associated road construction.

Covering about 16,000 square miles
in central Idaho, the Idaho Batholith
spans large portions of eight
National Forests, extending into
Montana. About 80 percent of the
area is forested — more than 90
sawmills draw timber from Batholith
lands. Thousands of sheep and
cattle graze in the area every
summer, and the lands support
many kinds of wildlife. The
recreation potential of this area
attracts several million visitors each
year. About 50 percent of the total
water yield for the State of Idaho
originates from the Idaho Batholith.

Administrators responsible for
managing Batholith lands are faced
with a dilemma: on one hand they
receive constant pressure from
various interest groups to use the
valuable resources. On the other
hand, they are well aware of the
impacts of logging and road con¬
struction, and of the consequences
that can result from improper land
use practices.

AH

PL

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4

Batholiths are characterized by
coarse, granitic soil that can slide or
wash away when man or nature
removes or disturbs the native
vegetation that has become adapted
to the harsh environment. The Idaho
Bathoiith can be desertlike in
summer, arctic in winter. Logging
and road construction on slopes can
lead to erosion and sedimentation
unless logging and transport
systems are selected carefully.

Other environmental consequences
include flood hazards, effects on
wildlife and fisheries, regeneration
of forest stands, and timber
production.

Walter Megahan, project leader and
research hydrologist on the staff of
the Intermountain Station, has been
involved with the Silver Creek
Experimental Area since the earliest
planning activities. He says, “It has
been impossible to accurately
predict the onsite and offsite effects
of these environmental conse¬
quences, posing a crucial problem
for the land manager. He is unable
to define limitations to use, if and
how management practices might
be applied, and possible tradeoffs in
the various uses and values, even
though he is required to do so for
environmental analysis reports.”

The research being conducted at
Silver Creek is designed to provide
many of these capabilities. The
studies are multi-disciplinary, an
approach that is particularly
appropriate because of the many
interactions that exist. In addition to
being able to predict the
environmental effects of selected
land uses, the research is designed
to devise ways to minimize adverse
effects on areas where disturbance
is unavoidable.

The study area

The experimental area is located
within the Emmett Ranger District of
the Boise Forest in the headwaters
of the Silver Creek drainage, a
tributary of the Middle Fork of the
Payette River.

The 2,300-acre site is representative
of much of the range conditions
found in the Idaho Bathoiith. Soils
range in depth from about 50 inches
in the lower portions of the study
watersheds to less than 10 inches in
the drainage heads. Side slopes also
vary greatly — they range from a
gentle 10 to 20 percent to nearly
vertical 80 percent. Elevations range
from 4,500 to 6,700 feet. All
drainages flow in a southeast
direction except one creek that
flows northwest. Ponderosa pine,
Douglas-fir, and white fir are the
dominant tree species.

Research data collected over the
past 15 years provide a storehouse
of information unparalleled
anywhere in the Idaho Bathoiith.

This, and data from past inventories
of soil, timber, vegetation habitat,
and hydrologic characteristics,
supply baseline knowledge adequate
to evaluate the impacts of timber
harvesting and road construction
activities.

Recording precipitation at a climatic station
on Silver Creek.

Seventeen different studies are
being conducted on eight small
watersheds ranging in size from 64
to 500 acres. Major areas of
investigation are:

SILVICULTURE — size of cut
opening; site preparation;
regeneration; timber productivity;
residual stand responses.

ENGINEERING — forest road
design, construction, and
revegetation; harvesting systems
and techniques.

WILDLIFE — responses; changes in
habitat.

SOILS — nutrients; surface
conditions.

HYDROLOGY — streamflow rates;
water chemistry; sediment yields;
stream channel characteristics.

5

Researcher analyzes the chemical content of
stream water samples.

ENTOMOLOGY — aquatic insect
activity and habitat.

ECOLOGY — plant succession;
biomass.

ESTHETICS — impacts of road
construction and timber harvest
practices.

will be clearcut in units up to 5
acres. Another will be clearcut in
units up to 1 acre, and two of the
watersheds will be cut by selection.
One watershed will be left
undisturbed as a basis to compare
and evaluate the effects of
silvicultural practices on the others.
The study results will tell
researchers which method and what
intensity of logging produces the
least ill effects.

Silvicultural practices

The timber sales at Silver Creek
form a logging mosaic on eight
small watersheds ranging in size
from 64 to 500 acres. Cutting is
designed to remove about 35
percent of the total stand on each
watershed. In 1976, helicopters
were used to remove portions of the
timber stands from two of the
watersheds. Logs from three of the
watersheds will be removed with a
skyline — similar to a short ski
tow powered by a crane. All
merchantable trees in units up to 25
acres will be clearcut on two of the
watersheds. Two other drainages

Road construction

Previous research on steep, granitic
slopes has shown that roading has
great potential for accelerating
erosion. Megahan says, “We know
that erosion hazards can be reduced
considerably by modifying road
design and construction practices.’’
He adds that additional research is
needed, however, to measure the
cost versus erosion reduction
relationships for these practices.
Another serious question with
respect to road erosion is, “How
much and when do eroded materials
reach downstream locations, and
what are the biological impacts as
the sediments move through the
channel system?’’ Megahan says,
“Although we presently have some
knowledge of the effects of roads on
sedimentation, we know almost
nothing about effects on water
chemistry and streamflow rates."
The road-related studies at Silver
Creek are designed to help answer
some of these questions.

Construction of roads on three of
the watersheds began this past
summer. Road construction is
limited to three drainages, using
three standards of construction and
two levels of erosion control
practices.

In each drainage, the roads are 14
feet wide, but there the similarity
ends. The surface varies from
nothing but dirt to gravel and a
gravel-asphalt mix. A variety of road
design practices are being used in
the construction. Field instruments
will record data telling researchers
which combination produces the
least erosion.

The roads will be allowed to sit for
at least 3 years before logging
begins. That will allow researchers
to measure the impact of the
construction without mixing the
sediment from logging in with the
results.

6

Researchers are confident that
there are many valuable uses of the
knowledge being gained from the
Silver Creek studies. Much of the
information can be directly applied
on granitic soils of the Idaho
Batholith and on other batholiths of
the western United States. Land
managers can use the information
to evaluate possible effects of
planned activities on water quality,
streamflow, and aquatic systems.
The information will also allow them
to develop and evaluate alternatives
and timing strategies. Engineers will
be able to predict impacts that will
result from planned road locations
and designs. And as they consider
tested design techniques and
treatments, they will have cost-
effective information on which to
evaluate alternative choices.

Researchers will have further insight
into the basic erosion processes
occurring on disturbed soils, and will
be able to provide basic data for
developing and using watershed
response models.

Transferring the
technology

Technology transfer, which has been
defined as a “continuous process
with live circuits,’’ is an integral part
of the Silver Creek program. As
various studies are completed, the
results are published for immediate
application by land managers. Other
applications of results occur through
presentations at meetings of forest
engineers, hydrologists, and soil
scientists; during field training
sessions; and presentations to
professional organizations.

Publications relating to the Silver
Creek studies, now available from
the Intermountain Station, include:

Clayton, James L., “Nutrient gains to
adjacent ecosystems during a forest
fire: an evaluation,’’ For. Sci. 22(2),
INT-R-455.

Clayton, James L., “Soil disturbance
following clearcutting and helicopter
yarding in the Idaho Batholith,”
(available after January 1, 1981).

I

ii # I

>>wlKn|[Hl,

..

Clayton, James L., and C. E. Jensen,
“Water retention of granitic soils in
the Idaho Batholith,” INT-RP-143.

Clayton, James L., and Debora A.
Kennedy, “A comparison of the
nutrient content of Rocky Mountain
Douglas-fir and ponderosa pine
trees,” INT-RN-281 .

Fausset, Neal E., James K. Apple-
gate, Paul R. Donaldson, and Lane
D. Eggers, “Geophysical investi¬
gation of rock properties near Silver
Creek, Boise National Forest, Idaho,”
In Proceedings of the 16th Annual
Engineering Geology and Soils
Engineering Symposium, Boise,

Idaho, April 5-7, 1979. p. 201-218.

Hart, Donald S., and Merlyn A.
Brusven, “Comparison of benthic
insect communities in six small Idaho
Batholith streams,” Melanderia, Vol.
23, 1976.

Megahan, Walter F., “Channel
sediment storage behind obstruction
in forested watersheds draining the
granitic bedrock of the Idaho
Batholith,” In Proceedings of the
workshop on sediment budgets and
sediment routing, Corvallis, Oreg.,
May 30 - June 2, 1979.

Megahan, Walter F., “Volume weight
of reservoir sediment in forested
areas,” J. Hydraul. Div., ASCE, Vol.
98, INT-R-252.

Megahan, Walter F., and Roy A.
Nowlin, “Sediment storage in
channels draining small forested
watersheds in the mountains of
central Idaho,” 3rd Fed. Interagency
Sedimentation Conf. Proc., 1976,
INT-R-438.

Servicing a water level recorder at a stream
gage.

Logging injuries
increase decay
in true fir c j

by Dorothy Bergstrom
Pacific Northwest Station

Basal wounds, like this one, are more serious
than other wounds because moisture from
the ground hastens fungal entry.

If intensive management of second-
growth true fir is to produce more
timber on a reduced land base as
foresters anticipate, logging wounds
must be reduced. Wounds to trees
that occur during repeated stand
entries are often infected by decay
fungi, resulting in unnecessary loss
of wood. Losses as high as 14
percent of the board-foot volume
were measured in one study in
northern California.

This is the urgent message from
Paul Aho, forest pathologist with the
Pacific Northwest Station’s Forestry
Sciences Laboratory in Corvallis,
Oregon. His assessment is based on
recent studies of decay in young,
managed stands of true firs in
Oregon, Washington, and California.

“We used to think that when the
highly defective old-growth true fir
was cut, losses from decay would
drop drastically because the
younger managed stands would be
healthier and rotations shorter,"
says Aho. “Although losses to decay
in advance regeneration are less
than in old growth, they are much
greater than anticipated and incom¬
patible with goals to increase wood
production,” he said.

Aho began his studies because
forest managers in eastern Oregon
and Washington had become con¬
cerned about future yields from
second-growth fir stands. The large
amount of decay present in old-
growth true fir raised questions
about how much decay might
already be present in the second-
growth stands that were expected
to provide the next timber crop.

As a result of past management
practices, including fire control,
advance true fir regeneration now
covers thousands of acres formerly
dominated by pine stands. Although
these young stands have been sup¬
pressed for decades, they grow fast
when released and appear ideal for
future intensive management.

In his studies, Aho had the benefit
of discoveries made in 1975 by
Canadian forest pathologists about
the Indian paint fungus ( Echino -
dontium tinctorium ) — one of four
species that cause most decay in
true fir and hemlock. The scientists
found that this fungus can invade
wounds as small as a pinhead — or
where a shade-killed twig breaks off.
It had been assumed previously that
only large dead branches and stubs
were infected. The scientists also
discovered that the fungus invades
suppressed trees that are unable to
grow new wood fast enough to close
the small wounds. Once in the bole
of the tree, the fungus can remain
semidormant for decades, then
become active when another wound
occurs near the infection site.

Aho already knew that Indian paint
fungus was causing almost 80 per¬
cent of the decay in old-growth
grand and white fir in eastern
Oregon and Washington. Now he
became concerned about the ability
of the fungus to invade suppressed
regeneration. He suspected that if
trees already infected by the fungus
were wounded later during selection
cutting, the result might be sub¬
stantial decay at rotation age and
reduced wood production.

Logging damage studied

To learn more about the extent of
the problem, Paul Aho and Greg
Filip, a forest pathologist with the
Forest Service’s Pacific Northwest
Region, began a study in the
Fremont National Forest in southern
Oregon, in 1977. They surveyed four
stands of advance white fir regener¬
ation. One stand still had an
overstory of mature white fir and
ponderosa pine. The overstory had
been removed from the other three
stands.

8

These cross sections from an old-growth
white fir tree show extensive decay caused
by Indian paint fungus.

More than 50 percent of the trees
sampled had at least one wound.
Decay was negligible because
the wounds were so young. But
laboratory studies later indicated
that 22 percent of the trees were
infected by the Indian paint fungus.
Most of the infections were
dormant. The three other important
decay fungi — Pholiota sp., Hericium
abietis , and Fomes annosus — were
also present.

Because of these findings, Aho and
Filip began a more extensive study
in 10 National Forests in eastern
Oregon and Washington. They
sampled 20 trees in each of 25
stands of suppressed grand and
white fir that had been precommer-
cially thinned after removal of the
overstory. More than half the trees
had one or more injuries, and 53
percent of the wounds had associ¬
ated decay. The amount of decay
was small — 2.5 percent of the cubic
volume and 4.0 percent of the
board-foot volume. But since the
trees were small, averaging only 5.9
inches in diameter and 31 feet in
height, and would take decades to
reach merchantable size, decay
could be expected to increase
significantly by harvest time.

Indian paint fungus was found in
almost a quarter of the trees
sampled. Slightly more than half the
infections were already causing
decay. Of the infections that were
still dormant and had not begun to
cause decay, 70 percent were in
trees that had not been wounded.

In 1979, another study of logging
damage was begun at the request of
managers in the Lassen National
Forest in northern California. The
managers were concerned about
possible decay losses from injuries
caused during commercial thinning
of white and red fir. Cooperating
with Aho in the study were two
scientists with the Forest Service’s
Pacific Southwest Region: Mike
Srago, a forest pathologist
with Forest Insect and Disease
Management, and Gary Fiddler, a
silviculturist at the Silvicultural
Development Unit at Burney,
California. They felled and dissected
225 wounded true firs from 11
stands that had been thinned 4 to 25
years earlier. They found 275
wounds averaging 13 years in age;
all were infected by decay fungi.

The decay had caused a loss of 4.5
percent of the merchantable cubic
volume and 14 percent of the board-
foot volume. The fungi causing the
decay were the wound invaders
Pholiota sp., Hericium abietis, and
Fomes annosus. The Indian paint
fungus was found only in limited
areas and did not account for much
decay.

“These losses are serious,” says
Aho, “because decay will increase
substantially during the 40 to 60
years before trees grow to harvest
size.”

To find out whether more careful
logging reduces injury to crop
trees, Fiddler and others at the
Silvicultural Unit surveyed the
damage to white and red fir stands
in northern California. These stands,
less than 100 years old, had been
commercially thinned. In some
stands, conventional logging
methods were used; in others,
techniques designed to reduce
injury were used. In stands logged
by conventional methods, wounds
were found on 22 to 50 percent of
the crop trees; three-quarters of the
wounds were in contact with the
ground. In three stands, 8 to 18
percent of the crop trees were so
badly damaged they were not worth
growing to harvest age. In stands
thinned by methods designed to
reduce injuries, however, only 5 to
14 percent of the crop trees were
wounded and none were worthless.

Ways to reduce injury

Aho strongly recommends that
forest managers follow the practices
that sharply reduced tree injury in
the California study:

Presale Preparation

1. Timing is important. Do not log
during the spring and early summer
when the sap is flowing and the bark
is loose. Trees are more easily
wounded then, and injuries tend to
be larger.

2. Select the size and type of
logging equipment appropriate to
the topography, tree size, soil type,
and soil conditions. For example,
cable yarding systems should be
used on slopes steeper than 35
percent. On more gentle terrain, use
track-laying or rubber-tired skidding
vehicles. Equipment should be no
larger than needed for the size of
logs to be removed. On clay soils, or
soils saturated with moisture, use
skidding equipment that produces
low pressure to reduce soil com¬
paction. In stands that will tolerate
little damage, consider using horses
to skid logs.

9

3. Mark leave trees, instead of those
to be cut. This calls attention to the
crop trees; as a result loggers are
more likely to avoid hitting them.

4. Lay out skid trails in advance.
They should be only slightly wider
than the skidding vehicle and
preferably no wider than 8 feet.
Trails should follow straight lines to
minimize skidding distances, and
there should be no sharp turns.
Some trees along the edges of skid
trails can be designated “bump
trees” and removed last.

5. Cut logs short enough to minimize
scarring of the residual stand.

6. Do not thin stands of young, thin-
barked species, such as hemlock,
too heavily. The leave trees may
suffer from release shock or
sunscald wounds. These wounds
nearly always become infected,
and associated decay is usually
extensive.

Logging techniques

1 . The first step in logging is to cut
and remove trees in skid trails so
fallers can locate the trails easily.
Cut stumps low— as low as 3 inches
above the ground — to prevent the
skidder from being shunted
sideways and bumping residual
trees.

2. Fell trees either toward or away
from skid trails. This will reduce
maneuvering of the skidder that is
likely to result in damage to leave
trees.

3. Use end-line skidding; that is,
skidders should remain on skid trails
and the cable pulled out to the logs.

If a wound is large, it is more readily
infected and decay is more likely.
Deep, gouged wounds are more
frequently infected and likely to
have more decay. Also, if the
surface of a wound is rough, it takes
longer for new wood to grow over it,
leaving more time for decay fungi to
enter.

Wounds in contact with the ground
nearly always become infected, and
decay progresses faster than in
wounds above the ground line.

Basal wounds also mean greater
losses of timber, since much of the
value of a tree is in the butt log.

Trees with nonresinous wood, such
as true fir and hemlock, are more
likely to be infected following injury
and to have more extensive decay
than species with resinous wood,
such as Douglas-fir and pines. Sitka
spruce is an exception; it has resin
ducts but is also very susceptible to
invasion by fungi when wounded.

Environmental conditions — rainfall,
aspect of slope, topographic
position, elevation, and site —
probably influence the amount of
infection, but Aho says information
on these factors is scant and often
contradictory.

Frost cracks, shake, and wet wood
are other complications often
associated with wounds in true fir
and hemlock. In old-growth forests,
these defects were mainly initiated
by fire wounds and caused signif¬
icant losses of volume. In second-
growth forests, logging wounds are
replacing fire as the major cause of
these defects.

This large sunscald wound was caused by too
heavy thinning in white fir.

Factors affecting decay

Whether decay results from
wounding depends on the size of
wounds, the time they take to heal,
their location on the tree, and
the species of tree wounded. The
likelihood of decay increases with
the number of wounds to the same
tree.

4. Before skidding, trees should be
limbed flush to the bole, topped, and
cut into logs.

“If these procedures are followed,”
says Aho, “logging damage will be
minimal, decay will be reduced, and
the residual stand will be capable of
responding to thinning.”

10

Outlook for the future

What is the outlook for second-
growth true fir forests? Can the
growth expected with intensive
management make up for the
current losses to decay? No one
knows for sure, but Aho feels the
prognosis is not good unless
wounding of residual trees is
reduced. He is convinced that the
logical, cost-effective way to do this
is to adopt logging practices
designed to protect crop trees
during entries to stands.

“Once an injury is made,’’ Aho
says, “there are no chemical or
biological methods for protecting
trees from decay fungi. The best
control is prevention — by using
improved, easily adapted logging
techniques.’’

Additional information

Aho has written about his findings in
“Decay of Grand Fir in the Blue
Mountains of Oregon and
Washington," Research Paper
PNW-229, available from the Pacific
Northwest Station, and in
“Incidence of Wounding and
Associated Stain and Decay in
Advanced White Fir Regeneration on
the Fremont National Forest,
Oregon" by Gregory M. Filip and
Paul Aho, available from State and
Private Forestry, Pacific Northwest
Region, USDA Forest Service,

P. O. Box 3623, Portland, Oregon
97208.

As a basic text on the process of
decay, Aho recommends a publica¬
tion based on the research of Alex
Shigo at the Northeastern Station.
“Compartmentalization of Decay in
Trees,’’ by Alex L. Shigo and Harold
G. Marx, Agriculture Information
Bulletin No. 405, is available from
the Superintendent of Documents,
U.S. Government Printing Office
Washington, D.C. 20402, (Stock No.
001-000-03671-8; price $1.85).

This cross section of white fir shows decay
associated with a wound.

1 1

example, could determine that
mature red firs with a 70 percent or
higher probability of dying within the
next 5 years should be cut at the
earliest planned harvest; firs with
lower risk ratings could be left in the
stand until later.

The systems — one for white fir and
one for both California red fir and
Shasta red fir — are based on two
summers of field observations of
characteristics of several thousand
living or recently killed firs. The
systems are easy to use and
statistically sound. They are best
applied to northern California sites
similar to those at which they were
developed. This area of applicability
includes the Sierra Nevada north of
Lake Tahoe, the southern Cascades,
the eastern Siskiyou Mountains, the
Salmon-Trinity Mountains, the
Warner Mountains and nearby
ranges, and the Marble Mountains.
About 40 percent of the commercial
red fir and white fir forest land in
California is in this region.

The systems are designed to give
managers of fir stands the same
kind of aid that the Ponderosa Pine
Risk Rating System, developed in
the 1930’s, has provided managers
of ponderosa pine and Jeffrey pine
stands. The Pine System, developed
by K.A. Salman and J.W. Bongberg,
along with the tree classification
systems developed by F.P. Keen
and Duncan Dunning, all of the
Pacific Southwest Station, started
Ferrell on the fir rating systems.
“The earlier work with pines
suggested that a system for risk
rating firs would be feasible and
practical to develop,” Ferreil says.
The need for a fir system was
obvious — for lack of information on
how to assess risk in firs, many
foresters were using the pine
systems to get some idea of how to
evaluate questionable-looking firs.

Crown raggedness made a difference in the
risk-ratings of the two mature red firs
(adjacent each other) here. The tree at left
has only 5 percent risk of death; the one at
right has a risk-rating of 19 percent.

Risk-rating
systems
developed for
firs t o

by Marcia Wood
Pacific Southwest Station

A new technique for “risk-rating” fir
trees in northern California has been
developed by Research Ento¬
mologist George Ferrell of the
Pacific Southwest Station. Ferrell's
risk-rating systems are based on
easily assessed characteristics of
mature California red fir, Shasta red
fir, and white fir. The systems
present a rapid and reliable method
for determining the probability that a
given fir will die within the next 5
years. Although this information can
be used in a variety of ways, Ferrell
expects that one of the most
common uses will be in deciding
which trees might be best to remove
from stands. A silviculturist, for

Much support for the risk-rating
project came from the National
Forest System’s Pacific Southwest
(California and Hawaii) Region.
Regional Silviculturist John
Tappeiner says, “In many cases, we
could pick out the better firs from
the poorer ones. But, we had no
way of estimating how long the
poorer ones would live. The systems
give us a way to make these
estimates.”

Rating a tree

The systems focus on easily
distinguished features of mature firs
that are at least 10 inches in
diameter and are growing either in
virgin old-growth stands or old-
growth stands that have been cut
over but still have some mature
overstory. In each system, four tree
characteristics are evaluated. A tree
that is being risk-rated is given
“award” points for positive
characteristics and “penalty” points
for negative features. Total points
are computed and matched to a
percent rating, to indicate the
probability that the rated tree will
die sometime within the next 5
years. The system is described in
detail in General Technical Report
PSW-39, “Risk-Rating Systems for
Mature Red Fir and White Fir in
Northern California.” This Report is
available from the Pacific Southwest
Station.

For California red fir and Shasta red
fir, award points are given for crown
class; possible scores range from 6
points for a dominant tree to no
points for a suppressed tree. Points
are also awarded for the percentage
of the tree’s height that is made up
of living crown — 5 points for each
10 percent of the tree height that is
living foliage. Penalty points are
given for a recent topkill, and for the
percentage of the total crown that
looks ragged. A ragged crown could
be one that is missing branches
along one side, or has dead or dying
branches here and there.

A ward-Penalty Risk System for mature red fir

Crown Class Award

Suppressed . 0

Intermediate . 2

Codominant . 4

Dominant . 6

Live Crown Percent (to nearest 10 percent of tree height)

5 points for each 1 0 percent .

Total Award .

Top Condition Penalty

Recent topkill . 1

Ragged Percent (of crown missing, dead, and dying
to nearest 10 percent)

4 points for each 10 percent .

Total Penalty .

Risk Point Total

a. Enter Total Award or Penalty

(whichever larger) .

b. Subtract smaller Total .

c. Risk Point Total .

Percent Mortality (within 5 years)

a. Award equals or exceeds Penalty . 0 to 20 percent

b. Penalty exceeds Award

Points

Percent

Points

Percent

1 to 4

21 to 30

15 to 17

60 to 70

5 to 8

30 to 40

18 to 21

70 to 80

9 to 1 1

40 to 50

22 to 25

80 to 90

12 to 14

50 to 60

26 +

90+

J

The white fir system uses a few
different criteria. Healthy trees are
given award points for each 10
percent of crown length that is
composed of upswept or horizontal
branches. White fir penalty points
are based on both the crown density
(3 penalty points for a thin crown, no
penalty for a dense crown) and on
the percent of the crown that is
ragged. Bark fissures are also used
as risk predictors — if living inner
bark doesn’t show up between the
outer bark plates, the tree receives
28 penalty points; if live inner bark
is apparent, there’s no penalty.

Red fir can be risk-rated with this scorecard.

Ferrell says that using these
predictors is a straightforward
procedure that can, after some
practice, be completed in “just a
few minutes.” He emphasizes,
however, that the systems do not
determine how a stand should be
managed. “The systems give
percent probabilities — it’s up to
the manager to determine what
percentages are 'high' or ‘low’ risk
for each stand.”

13

Although about 60 percent of the crown of
this white fir is ragged , the risk-rating system
indicates that there is only a 4 percent
chance that the tree will die within the next
5 years.

The four predictors used in each
system were the best in the field of
22 different characteristics that
Ferrell analyzed and monitored
during two summers of data
collection. Fie used a computer
program developed by David
Flamilton and others at the Inter¬
mountain Station to determine which
predictors would be the most
reliable. Those selected have an
accuracy of 95 percent or better.
(Characteristics that had a high
accuracy rating, but were eliminated
to keep the systems simpler,
included crown class and diameter
class, which were eliminated as
predictors for white fir, and crown
width and crown density, which
were not used for the red firs.) After
narrowing the field of candidate
characteristics, he used another of
Flamilton’s computer programs to
determine probabilities for each of
the selected predictors.

Applications

The systems should be useful in
making many types of stand
management decisions. In a
sanitation salvage, for example, the
systems could be used to identify
trees that are the most likely to be
lost to destructive insects and
diseases. These trees can be
removed from the stand (salvaged)
before they become both a loss and
a center of insect and disease
activity. In a shelterwood harvest,
the systems could be used to
indicate which overstory trees will
survive long enough to provide seed
and shelter.

Ferrell expects the systems to be
helpful not only to people who are
just starting out in forestry but also
to those who have been in the field
for a long time. For newcomers,
such as summer or part-time
employees who are learning how to
mark timber, the systems provide “a
common basis for training,” Ferrell
says, and “allow markers to come
to consistent estimates of risk.” For
those who already have a lot of
experience estimating risk, the
systems may help refine their
judgement. Silviculturist Dick
Castaldini of the Plumas National
Forest says the systems have some¬
times changed his mind about which
trees to cut. “I was surprised to find
that some of the white firs I
normally would have cut were not
that badly off, after all,” he explains.
“In our own marking, we may have
taken these trees, but the risk
systems indicate we didn't have to.”

Limitations

Prospective users of the systems
should be aware of some limitations.

Probably the most important is the
geographical restriction — the
systems can’t provide reliable
results if they are used outside of
the northern California areas for
which they are intended. (Ferrell is
currently working on a special risk¬
rating system for the central Sierra
Nevada.) A second important
limitation is that the systems should
not be used as the sole criterion for
a stand management decision. As
Regional Silviculturist Tappeiner
explains, “The risk-rating systems
are a guide — they can help people
write a stand management
prescription. But, if people use just
the risk-rating approach without
looking at other parts of the stand
environment — the microclimate,
the stocking level, and other
factors — the systems won’t work.
The systems alone won’t help
determine what a stand is doing;
they have to be used with
judgement and care.”

A final limitation of the systems is
that there may be some northern
California sites to which they do not
apply. Tappeiner explains, “Firs
occur on so many different site
conditions that it would have been
impossible for George to test the
systems on them all.”

Although the systems are limited to
a 5-year prediction span, this is one
limitation that is not now seen as
important, by some prospective
users, even though most cutting
plans involve cutting intervals of at
least 10 years. Dean Angelides,
forester with Southern Pacific Land
Company’s Tahoe District, says,
“Even though the systems only go
up to 5 years, they are better than
our best guess, right now. If we look
more critically at the characteristics
Ferrell calls important, we should be
able to make 10-year estimations.”

Ferrell himself predicts that the risk¬
rating systems will have “an
important financial impact on forest
management in California” and will
“affect the harvesting of many
thousands of mature, sawtimber¬
sized trees over the coming years.”

14

New

publications

A new report on
ponderosa pine

Managing the 6.7 million acres of
commercial forestland dominated by
ponderosa pine in the Pacific
Northwest represents the ultimate
challenge to the silviculturist,
according to researcher Jim Barrett
of the Pacific Northwest Station.
Ponderosa pine forests can be
prime examples of how multiple-use
management works. They produce
wood for a wide variety of products,
abundant grazing for livestock,
cover for wildlife, and a variety of
recreation opportunities for people.

Barrett has pulled together
information that has been
accumulating for 60 years about all
aspects of managing ponderosa
pine, and organized it in a report
that should be particularly useful to
practicing foresters. A bibliography
of more than 100 references is
included.

In the report, Barrett discusses
reasons for the marked drop in the
amount of commercial forestland
dominated by the species. Barrett
says it is the result of cutting
practices and the exclusion of
periodic ground fires that once
helped maintain the fire-resistant

pine stands. As the mature pine
overstory has been cut, the land
type has shifted to other single
species types or the mixed conifer
type. Even though this shift has
taken place on about 5 million acres
in Oregon and Washington in the
last 25 years, lumber products
valued at $569 million were
produced in 1976 from the
ponderosa pine forests that remain
in the two States.

Barrett also makes recommenda¬
tions for future research, which he
feels should include replicated trials
of silvicultural systems in the major
habitats of the ponderosa pine type.

Copies of “Silviculture of Ponderosa
Pine in the Pacific Northwest: The
State of Our Knowledge,” General
Technical Report PNW-97, by James
W. Barrett, are available from the
Pacific Northwest Station.

All about the
tussock moth

A major tool for transferring
knowledge about the Douglas-fir
tussock moth and its place in
ecosystems of the Western United
States is a report recently
completed at the Pacific Northwest
Station. The report covers the entire
spectrum of knowledge about the
insect, from its biology to computer
models for simulating behavior in
future outbreaks.

Much of the information came from
work supported by the USDA
Expanded Douglas-fir Tussock Moth
Research and Development
Program, which was established in
1974 to coordinate and accelerate
work on the insect after a severe
outbreak in eastern Oregon and
Washington in 1971-74. The
program was headquartered at the
Pacific Northwest Station.

The book was written by 45 scientist
authors and was organized and
edited by a technical editor and two
entomologists. The publication was
planned early in the program as an
important, final product. While
scientists were conducting studies
they were also planning how they
would report their findings and
synthesize them with previous
research on the insect, and do this
in a form useful to managers.

Copies have been distributed to
universities and libraries. Additional
copies can be ordered from the
Superintendent of Documents, U.S.
Government Printing Office,
Washington, D.C. 20402. “The
Douglas-fir Tussock moth, A
Synthesis,” edited by Martha
H. Brookes, R. W. Stark, and
Robert W. Campbell (Stock No.
001-000-03924-5) sells for $16.75.

15

Eucalyptus studied

Two new reports on growth of
eucalyptus trees are now available
from the Pacific Southwest Station.

In one report, Research Forester
Jerry Walters of Honolulu, Hawaii,
analyzes spacing intervals used in
sawtimber plantations of saligna
eucalyptus. The plantations were
located on the north slope of Mt.
Haleakala on the Island of Maui, and
were planted at spacings of either 8
by 8 feet, 10 by 10 feet, 12 by 12
feet, or 14 by 14 feet. At periodic
intervals during the 15-year study,
Walters measured diameter, height,
height to a 4-inch and a 9-inch top,
and height to live crown; he also
calculated board foot and cubic foot
volumes.

He found that the total amount of
wood produced in 15 years was
about 29,000 board feet per acre,
regardless of the spacing interval.
However, he recommends the 14 by
14 foot spacing as “probably the
most economical for a sawtimber
operation.’’ He explains that the
14-foot spacing required fewer trees
to harvest: 100 trees per acre at the
14-foot spacing produced the same
volume as 162 trees per acre at the
8-foot spacing. He says that trees in
the 14 by 14 foot spacing should be
harvested at 15 years, in order to
avoid some of the growth stresses
that occur in older eucalyptus.

Details about the study, and
Walters’ comments on possible
spacings for pulpwood plantations
and combined pulpwood-sawtimber
plantations, are in the report,
“Saligna Eucalyptus Growth in a
15-year-old Spacing Study in
Hawaii,’’ Research Paper PSW-151.

In the second report, researcher
James P. King of the Pacific
Southwest Station, Honolulu, and
former PSW scientist Stanley L.
Krugman, now with the Forest
Service’s Washington, D.C., office,
describe a northern California test of
36 different species of eucalyptus.
The purpose of the test was to
determine which species would
grow well at low-elevation sites in
central California.

The species used in the study were
recommended by Australian
scientists, and were selected from
among 500 species of eucalyptus on
the basis of their cold-hardiness,
good form, and potential usefulness
for landscaping or for providing
wood products or wildlife habitat.

For the test, small stands of each
species were planted on a test site
about 20 miles northeast of San
Francisco. The study area was
similar to inland areas where the
best-performing eucalyptus might be
used in future plantings. On the
basis of observations made over a
period of about 12 years, King and
Krugman recommend only seven
species for further testing. These
are: red-gum eucalyptus (Eucalyptus
camaldulensis ), mountain-gum (£.
dalrympleana ), tingiringi-gum (E.
glaucescens ), rose-gum (E. grandis),
shining-gum (E. nitens), swamp-gum
(E. ovata), and manna eucalyptus (E.
viminalis). These species had “high
survival, made good growth, and
readily recovered from a record-
breaking freeze that occurred during
the study.’’ Further recom¬
mendations about planting
eucalyptus in California are in the
report, “Tests of 36 Eucalyptus
Species in Northern California,”
Research Paper PSW-152.

16

Calculator help for
field foresters

The popularity of hand-held
programmable calculators for field
use is increasing. They are small,
inexpensive, easy to use, and
rugged enough for outdoor use.
Some models can store and execute
programs containing over 2,000
steps.

A new report is now available that
describes various programs
designed to help foresters use hand¬
held, programmable calculators to
gather and analyze data in field
situations. Programs are presented
which perform: slope to horizontal
distance conversions; basal area
computation; tree height deter¬
minations; adequacy of sample test;
multispecies board foot volumes;
basal area factor gauge calibration;
limiting distance; scaling of aerial
photos; calculations for variable plot
cruising; and variable plot cruising
summaries.

Programs described are written in
outline form and are not specific to
any particular brand of calculator.
However, a calculator with 200 or
more program steps is desirable.

The programs are presented in
order of complexity, so the user is
gradually introduced to the more
advanced programming techniques.

Managing spruce-fir

Engelmann spruce-subalpine fir
forests are not only the largest and
most productive timber resource in
the central Rocky Mountains, but
they provide habitat for a wide
variety of wildlife, forage for
livestock, recreational opportunities,
scenic beauty, and the majority of
water for this region.

Researchers at the Rocky Mountain
Station have used RMYLD, a field
and computer simulation program,
to predict the potential production of
this forest type in the central
Rockies under various combinations
of stand density, site quality,
rotation age and thinning schedule.
These estimates are useful to land
managers to project future develop¬
ment of stands managed in different
ways for various uses.

If you would like a copy of the paper
describing the use of this simulation
program, write the Rocky Mountain
Station and ask for “Management of
Spruce-Fir in Even-Aged Stands in
the Central Rocky Mountains,”
Research Paper RM-217-FR24, by
Robert R. Alexander and Carleton B.
Edminster.

The Rocky Mountain Station has
copies of this report. Request
“Hand-Held-Calculator Programs for
the Field Forester,” General
Technical Report RM-76-FR24, by
Wayne D. Sheppard.

17

Ponderosa pine
growth analyzed

The first results from studies of the
effects of thinning, spacing, and
brush competition on planted
ponderosa pine in northern
California are presented in two new
reports by Research Forester
William W. Oliver of the Pacific
Southwest Station.

In “Growth of Planted Ponderosa
Pine Thinned to Different Stocking
Levels in Northern California,”

Oliver describes the effects of
thinning pole-sized ponderosa pine
to growing stock levels of 40, 70,
100, 130, and 160 square feet of
basal area per acre. His study site,
a 20-year-old plantation on the west
slope of the northern Sierra Nevada,
is comparable to other highly
productive sites in the west-side
Sierra Nevada and the Cascade
Range.

Oliver monitored the plots for five
years after thinning, measuring
growth in diameter, basal area,
height, volume, and crown width. He
reports, “Surprisingly, only trees in
plots that were heavily thinned to 40
square feet of basal area per acre
grew faster in diameter after
thinning than before thinning. At all
of the higher stand densities, the
rate of diameter growth was
substantially less after thinning.”

He explains that this response to
thinning was probably influenced by
the initial spacing of the stand.
“Before thinning, the trees were
uniformly spaced (at 6 by 8 feet) and
were healthy and vigorous. Their
periodic annual growth — in both
diameter and volume — was at its
peak. After thinning, diameter
growth of trees at all the higher
growing stock levels continued the
decline that normally follows the
culmination of periodic annual
growth.”

Oliver contends that even though
thinning contributed to a potential
loss in stemwood volume on a per
acre basis, thinning should pay off in
the long run, through the shortened
period of time needed for trees to
reach sawlog size and through the
improved health of the stand. He
contends that the thinned stand
“could be ready for commercial
harvest 15 years sooner than an
unthinned stand. The growth of trees

18

in the plots that were thinned to 160
square feet of basal area per acre
may seem adequate now, but
thinning to a growing stock level of
100 would bring the plantation to
merchantable size 15 years
sooner — at age 35 for growing stock
level 100 against age 50 for growing
stock level 160.” In regard to the
health of the stand, Oliver says,

‘‘An unthinned stand, similar in
productivity to the one I studied, is
likely to have a density of 300
square feet of basal area per acre
at age 50. Growth losses, including
mortality from intertree competition,
and possibly from bark beetles,
could be substantial. In contrast,
stands thinned to growing stock
level 100 could reach 200 square
feet of basal area per acre at age
35 years. This density is sufficient to
support a commercial thinning, yet
is probably not dense enough to
jeopardize the health of the stand.”
Further details are in his report,
Research Paper PSW-147.

In a second study of ponderosa pine
in northern California, Oliver found
that spacing and brush competition
“strongly influence stem diameter at
breast height, as well as crown
width, live crown ratio, and average
branch diameter 12 years after
planting.” His results came from
tests of five different spacings,
ranging from 6 by 6 feet to 18 by 18
feet, used on study plots located at
2,650 feet elevation on the west
side of the Sierra Nevada. At the
outset of the study, ponderosa pine
seedlings were planted in brush-free
plots. During the next 12 years,
Oliver monitored tree growth on
study plots where brush was
allowed to reinvade, and on sites
where brush was killed by hand or
with an herbicide.

On several plots, Oliver found that
competition from such brush
species as whiteleaf or Indian
manzanita, deerbrush, and Sierra
gooseberry, or from the sprouts of
California black oak or tanoak,
resulted in a loss equivalent to
3 years growth in tree diameter.
Within each spacing, trees in the
brushy plots tended to be smaller
and more variable in size than trees
in the brush-free plots. Competition
between trees in brush-free plots
began during the 8th year for trees
spaced at 6 by 6 feet, and during
the 10th year for trees spaced 9 by
9 feet. By the 12th year, however,
intertree competition had not yet
begun for trees spaced 12 feet
apart, or wider.

More information on the study is in
Research Note PSW-341, "Early
Response of Ponderosa Pine to
Spacing and Brush: Observations on
a 12-year-old Plantation.” Copies of
both of Oliver’s reports are available
from the Pacific Southwest Station.

19

Timber bidding
methods examined

Does selling federal timber by
sealed bids in the Western United
States bring more revenue to the
federal purse than selling by oral
bidding? Apparently it did during
1977 when sealed bidding was the
usual sale method. In a new report
from the Pacific Northwest Station,
Economist Richard Haynes says
that, in general, sealed bidding
increased competition in the regions
studied. The increase was substan¬
tial in the prime forests west of the
Cascades in Oregon and Washing¬
ton, where sealed bidding brought in
an extra $54.2 million on sales of
$653.8 million. In Montana and
Idaho sealed bidding increased
revenue by $6.2 million on sales of
$50.3 million.

Hayes arrived at this conclusion
after measuring the amount by
which sealed and oral bids
exceeded the minimum price the
Forest Service set on timber in three
areas: Idaho and Montana, Oregon
and Washington, and California. He
compared sales for fiscal years
1975 and 1976 with calendar year
1977, when sealed bidding was
common.

The report brings some hard facts to
the longstanding controversy about
the respective advantage of sealed
and oral bidding for federal timber.
One aspect of the controversy that
has not been studied previously is
the effect of outside bidders.

Haynes found that outside bidding
had been going on before the
adoption of sealed bidding. He
concluded that other factors, such
as a decline in timber availability
and concern about maintaining
control of particular markets
provided a better explanation of
outside bidding than bidding method.

The controversy about bidding
method is currently dormant
because competition is setting new
records for stumpage prices and
because the law making sealed
bidding the primary sales method
was changed by Congress in 1978
to restore the bidding methods
traditional for each area.

The report also contains an
examination of the Small Business
Set-Aside program. Haynes found
that in some areas the program had
led to lower prices for those firms
winning set-aside sales.

Copies of “Competiton for National
Forest Timber in the Northern,
Pacific Southwest, and Pacific
Northwest Regions,” Research
Paper PNW-266, by Richard W.
Haynes, are available from the
Pacific Northwest Station.

20

Stream dynamics
for land managers

Streams are important components
in any ecosystem, and land
managers need to understand the
general concepts of stream behavior
to learn how management actions
affect these waterways.

A new report is out that presents a
general outline of water flow,
sediment transport, and other major
processes of stream dynamics. It
shows how the complexity of stream
behavior forces the land manager to
consider the individual components
of each case. The report empha¬
sizes that stream restraining
measures must be applied with
great caution so that treatment of
one critical location will not simply
lead to the formation of another
problem, or that the side effects of
treatment will not be more
detrimental to stream improvement
than no treatment at all.

The report covers: the basic fluvial
process, equilibrium condition and
adjustment processes, monitoring
stream behavior, and a listing of
literature citations on stream
dynamics.

For your copy, write the Rocky
Mountain Station and request
“Stream dynamics: An Overview for
Land Managers,” General Technical
Report RM-72-FR24, by Burchard FI.
Fteede.

Brushland
management
symposium planned

A symposium on management of
brushlands in southern California,
the Southwestern U.S., and other
regions of the world that have a
Mediterranean-type climate, will be
held June 22-26, 1981, in San Diego,
California. The conference is
designed for researchers, land
managers, and others interested in
current brushland management
practices and recent advances in
brushland management research.
Topics will include the effects of
brushland management on vegeta¬
tion, wildlife, soils, and hydrology;
the use of prescribed fire as a
management tool; and new ways to
make better use of brushlands.

The conference, which is titled
“Dynamics and Management of
Mediterranean-type Ecosystems: An
International Symposium,” is
sponsored by the Pacific Southwest
Forest and Range Experiment
Station and by San Diego State
University. Co-sponsors include the
Sierra Club, National Park Service,
and several other State, Federal,
and international organizations.

More information is available by
writing to: Chairman, Dynamics and
Management of Mediterranean-type
Ecosystems: An International
Symposium, Pacific Southwest
Forest and Range Experiment
Station, 4955 Canyon Crest Drive,
Riverside, California 92507 U.S.A.

Plant a tree! Mark the 75th birthday
of the Forest Service by giving a
living gift to future generations.

In the next issue of Forestry
Research West, we’ll look at the
role of tree roots in stabilizing forest
slopes, examine the habitat needs of
anadromous fish, review several
new research publications, plus
touch on other areas of important
research. Watch for it!

If you know of someone who would
be interested in this publication, he
or she can be added to the mailing
list by filling out the coupon below
and mailing it to us.

Please add my name to the
mailing list for Forestry
Research West.

Mail to: Forestry

Research West

U.S. Department of Agriculture
Forest Service
240 West Prospect Street
Fort Collins, Colorado 80526

☆ GPO 1980—777-067/2

21

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