This file was created by scanning the printed publication.
Errors identified by the software have been corrected;
however, some errors may remain.
Problems In Snag Management Implementation
A Case Study 1
Edward W. Styskel
2
Abstract.--Providing suitable snags over time for dependent wildlife within intensively managed forests is an
extremely complex task. Problems encountered in achieving
this goal include: (1) moderate responsiveness by accountable personnel; (2) determining and following snag status;
(3) minimizing timber yield reductions; (4) imprecise
"longevity" data for standing snags; and (5) protecting
snags and live replacements from natural and man-caused loss.
Techniques used to overcome some of these obstacles are
discussed.
INTRODUCTION
efforts concentrated on protecting existing
snags. Then, additional attention was given to
reserving some live trees for future snag
replacements.
Now, systematic calculation of
the number and size of live trees for snag
replacements over a managed forest stand
rotation is undertaken, based upon growth predictions and estimated snag standing longevity.
Efforts to intensively manage commercial
forest land of National Forests in the wes·tern
United States on an "even-aged" basis have made
complex the task of providing sui table snags
over time for dependent wildlife. Specifically,
plans for the Deschutes National Forest in
central Oregon have scheduled lodgepole pine,
ponderosa pine, and mixed conifer forest stands
for conversion to intensive timber management
within 20, 40, and 50 years, respectively.
Furthermore, rotation ages for these stands will
be relatively short, at approximately 80, 135,
and 120 years.
Responsiveness
This transition has bridged several obstacles, the first of which has been moderate
responsiveness from personnel accountable for
getting the job done.
This problem is manifested at two hierarchal levels on a Forestthe line officers (Forest Supervisor and
District Rangers) who establish program direction, and the project work force who carry out
this direction.
Snag management goals for the Forest have
been established based on .the concept of "maximum potential population" offered by Thomas,
et al. (1979). Obstacles in achieving these
goals have been numerous and difficult. Some
have been
surmounted;
others
are
still
unresolved.
Exceptional are those line officers who can
place equal priority on providing snags for
wildlife and meeting annual timber sell targets,
when the--ratter is a performance appraisal
element upon which the agency measures their
managerial ability, and the former is not.
Until such time as performance appraisals relate
equally to all phases of National Forest management (i.e. meeting all targets of the Forest
Plan, instead of singling out specific ones such
as timber volume),
the barrier is still
potentially there.
This paper reports on what problems have
been encountered (thus, could be expected by
others implementing snag management), and how
some were concluded.
PROBLEMS
The transition from establishment of policy
concerning the management of snags, first set
forth on the Forest in 1973, to implementation
on-the-ground has been slow but steady. First
Project workers who perform the details of
project layout, whether it be timber sales,
timber stand improvement, forest fuels treatment, or other impacting activities, may view
snag management requirements as obstacles to
full achievement of their functional goals.
This is compounded by the volume of similar
functional "impediments", such as visual quality,
archeologic/historic protection, and others.
Often, field-goi~g project personnel are sea-
1
Paper presented at the Snag Habitat
Management Symposium, Flagstaff, Ariz., June 7-9,
1983.2
Edward W. Styske1 is Forest Wildlife
Biologist, Deschutes National Forest, Bend,
Oreg.
24
3
12 percent .
Timber volume loss for
me nded densities a nd sizes of snags
60 pe r cent of the maximum potential
of prima ry excavato r s account fo r a n
4
6 pe r cen t.
sonal employees with limited personal owne r s hip
i n determining the s e specific goals .
Pr oper emphasis from
the project work force is
l ating these personnel to
goals ,
including
those
management.
the line office r to
essen tial in stimuachieve all Forest
dealing
with
snag
the r ecomto s upport
population
addi tional
Often, live trees r ecommended by biologists
for f uture snag r e placements possess c ha r ac t e r is t ics of genetic i nfe rior ity fo r maximum grow th
potential.
Because a nticipa t ed t imbe r growth
a nd yield are usually predicated on g rowing
genet i cally
supe rior
trees,
t hese
goa ls
freq uen tly c ollide.
Snag Sta tus
Ano the r snag management problem is determining and following the status of snags pr oject
a r ea by project area .
This difficulty is
magnified as the area of pe r spective is enlarged
to an entire drainage, Ranger District, or
National Forest.
Red uci ng these conflicts was the initia tive
fo r utilizing the technique of "clumping",
whe r eby ~ ac r e parcels were r ese rved i nta ct
within every 8 to 12 ac r es of ~tting unit in
lodgepole pine forest (fig. 1).
The desi r ed
characteristics of these clumps are defined
ca r efully to assure that the prop e r density a nd
sizi ng of snags a nd live r e placements a re
availab l e .
Special snag inventories are time- consuming ,
a nd the r efore expensive .
Stand examination data, usually collected
by foreste r s for assessing forest stand conditions, offer a reasonable alternative . Owing to
regula rly low snag densities and small plot
size, sta nd exam plot frequen cy usually has to
be inc r eased to diminish exagge r ation of the
real-life situation .
Assump tio ns are made t hat the clumps : (1)
sa tisfy distribut ional r equi r ements based on
estimated te rritory sizes of most prima r y exca vators (Thomas, e t al. 1Y79);
(2) r e duce the
I t should be recognized that both techniques are a measurement of one point i n time
and
subject
to
rapid
change from natu ral
phenomena and human activities .
Tabulation for monitoring snags a nd live
replacements r eserved for wildlife can best be
accomplished during the timber marking stage in
timber sale pr epa r ation.
Tally records are
recorded in the field which document the number,
size,
species,
and
successional
condition
(Thomas,
et al .
1979)
of
snags
or
live
r eplacements r ese rved for wildlife.
Site specific storage and retrieval of this
data is necessary in o rde r to be able t o track
these a lloca t ions fo r future land manageme n t
decisions.
In the Pacif ic No rthwest Region of
the
U.S.
Department of Agriculture--Fo r es t
Ser vice , the TOTAL RESOURCE INFORMATION (TRI)
Sys t ern pr ovides an automated sys t ern capable of
handling this data by management "c e ll " .
Hinimizing Timber Yield Reduction
Minimizing timber yield falldown due to
wildlife tree requirements is still a nother
hurdle.
Two
concerns
have
developed-- the
r etardation of g r owth on crop trees from reserved
live
r eplacements,
a nd
the genetic
character of these reserved live trees.
Fig ure ! .--"Clumping" of r eser ved
live tree r ep l acements.
s nags
and
3
smith, Tony. 1982.
The effec t of the
proposed Deschutes National For e st's s nag policy
on the g rowth of manage d s t a nds.
Unpublished
r e por~.
Deschutes National Fo r est , Bend, Or eg .
Deschutes National Forest . 1982 . Managed
yie l d tables for the Deschutes National Forest
Land
Managemen t
Plan .
Unpublished process
r eco rgs . Deschutes National Fo r es t, Bend , Oreg.
McEwan , Linda. 1983.
Personal conversation .
Deschutes National Fo r est , Crescent,
Oreg .
McDonald (1976) reports in a Califo rnia
study that ponderosa pine seed trees had an
inhibitory effect on seedlings beneath them.
Live tree r eplacements could equally be expected, then, to negatively influence predicted
timber growth and subsequent yield.
Because of
this effect, estimated growth loss in managed
s t a nds on the Deschu tes National For est is
thought to be significant--pe r haps as high as
25
inhibitory eff~ct of evenly distributed live
tree r eplacem~nts; (3) diminish the widespr~ad
influence of gen~tically inf~rior or di seased
live r e placements on seedling crop trees; (4)
lessen blowdown loss experienced by single trees
exposed a fter forest canopy r emoval; (5) shrink
wildlife tree losses associated with othe r
forest activities; and (6) provide habitat
values for other wildlife. Monitoring over time
will determine the validity of these assumptions.
snag management goals, this loss, and that from
other causes, can often be mitigated with timber
sale generated Knutson-Vand~nberg funds to
artificially create or manipulate snags. Such
plans are underway on the Forest to accelerate
snag formation by various techniques , including
fire-scarring by piling and burning logging
debris at the base of live snag replacements,
and topping with explosives (Bull, et al. 1981)
or cutting.
Snag Standing Longevity
The latter technique was successfully
contracted this spring on snags and livg
replacements at a cost of $45 per tree.
Ponderosa pine with dimensions of 18 to
26 inches dbh averaging about 80 feet tall were
sawn off at a height of approximately 30 to
50 feet. The live r eplacements were topped to
r etain jus t enough live foliage for the tree to
stay alive, the assumption being that a diminished live crown would be more windfirm and less
influential on understory retardation and the
sp read of dwarf mistletoe.
Knowledge of the standing "life expectancy"
of snags is critically significant in determining how many liv~ tree replacements must be
reserved over a managed forest rotation to mee t
established goals.
Few studies have been
specifically designed to collect the kind of
data a biologist might desire.
Interpolation
from research conducted with other objectives in
mind is often necessary , and the more localized
the better.
Logging (or thinning) debris disposal and
vegetative manipulation accomplished by presc ribed burning may consume snags and down logs
without pre- planned safe-guards. Loss of snags
or live replacements due to post-sale activities
has occurred because attention to snags often
does not carry through to these stages of 'timber
management.
The land manager must learn to
think about snags in all types of management
activity befo r e this short-circuit can be
remedied.
Factors including soil type, site productivity, climate, heartwood/sapwood ratio, the
incidence of insects or disease, and others have
been identified by Keen (1955) as influencing
the rate of snag fall. To refine the longevity
estimates used on the Forest, these factors will
be measured in snag longevity monitoring efforts
beginning this year.
Wildlife Tree Protection
Physical protection of reserved snags and
live r eplacements is the final obstacle. Windthrow, and land management activities such as
logging , forest fuel treatment, timber stand
improvement, prescribed burning, and public
firewood cutting, are all known sources of
attrition.
Uncontrolled pub lic firewood cutting can
have significant consequences upon the retention
of snags for wildlife, especially where r elatively flat and open terrain or extensive road
systems allow easy vehicular access .
Land
managers can control this activity, though , to
lessen the influence on wildlife trees.
It has been established that snag attr ition
occurs from windthrow, and is influenced by bole
diameter--large diameter snags remaining upright
longer than smaller ones (Dahms 1949, Lyon
1977). Determination of this loss is pa ramount
to calculating snag and live r eplacement needs
for areas wh e r e snag retention is planned. For
example, some areas of the Forest have exhibited
r eductions in evenly distribut ed reserved snags
of 25 percent for 20- inch or greater dbh snags,
and 75 percent for less than 20-inch dbh snags,
immediately after canopy removal by clear-cut or
shelterwood.
First, a permit system, the provisions of
which are legally enforceable and require public
user contact with the manager, is r equisite .
Protection of wildlife trees must be considered
in specifying the requirements of the permit .
For example, specifications on permissible tree
species or diameter, areas open to cutting , or
snags with evidence of wildlife us e or pro tect ive signing may be necessa ry.
Public education of the potential for
cohflict between firewood cutting and maintaining snag habitat for wildlife can occur at
the time of permit acquisition, and wi th Public
Service Announcements during the woodcutting
season.
Snag hazards to worker safety and fire
protection in woods operations have prompted
State Laws and Administrative Rules which
require snag felling for reasonabl e hazard
control. The consequences of these requirements
can be moderated with careful attention to
project design and wildlife tree position . For
example, wildlife trees would not be positioned
where obvious hazard to log landings or proposed
road locations would jeopardize their retention.
Violation of permit provisions on the
Deschutes National Forest is punishable through
criminal citation and fine . In addition, mitigative damages can be assessed against violators
for the cost of replacing the felled snag. When
6
While the felling of hazardous snags in
timber harvest is a step backwards in terms of
Corn , Don. 1983. Personal conversation .
Deschutes
National
Forest ,
Sisters,
Oreg.
26
available,
a suitabl~ live tree of similar
would be killed, with the damage
assessment b~ing
th~
cost of a rti ficially
inducing mortality, plus th~ comme rc ial valu~ of
the t ree .
Whe r e live t r ee r epl ac~ments a re
unavailable, the damage ass~ssm~nt would be the
cost of constructing, installing, a nd maint a ining s uitable n ~sti ng and p~rching s tructu r es.
a short distance , making this t~chn ique suitable
even in visually s~nsitiv~ areas.
dim~nsions
CONCLUDING IDIARKS
While t he obs tacl~s to providing sui table
snag habitat for d~pe nd e nt wildlife a r ~ both
diverse and substan tial, it is p rematur~ t o say
th~y
are insurmountable .
Successful effo rts
must r~cogniz~ these probl~ms, r ~ceiv~ full
commitment to their resolution , be in novative
and aggressive in dealing with pot~ntia l
solutions, and c losely monitor the results.
In
areas of ~x cessiv e vuln~rability to
cutte r s , "armoring " of wildlif~ tr ees
is a productive t~chnique. Twisted- wire fence
stays nailed on the snag (fig . 2) have effect lvely protected assailab le snags at a cos t of
about $3.50 per snag for ma teria l s and labor.
The na rrow stays b~corne virtually invisible from
fir~wood
LITERATURE CITED
Bull ,
Evelyn L., Arthur D. Partridge, and
Wayne G. Wi ll iams . 1981. C r~ating snags
with explosives. USDA For . Serv. Res. Note
PNiv- 393, 4 p . Pac . Northwes t For . and Range
Exp . Stn . , Po rtland, Or eg.
Dahms , Walter G. 1949. How long do ponderosa
pine snags stand? USDA For . Serv . Pac.
Northw~st
For. and Range Exp . Stn. R~s .
Not~ 57 , 3 p.
Portla nd, Or eg.
Ke~n , F. P.
1955. The rat~ of natural falling
of beetle- killed pond~ rosa pine snags . J .
For . 53( 10) : 720-723.
Lyon, L. Jack.
19 77. Attrition of lodg~pole
pine snags on the Sle~ping Child burn,
Montana. USDA For . Serv. Res. Not~ INT- 219 ,
4 p.
Intermt . For. and Range Exp . Stn. ,
Ogd~n . Utah .
McDonald , Philip M.
1976.
Inhibiting eff~ct
of ponderosa pine seed trees on seedling
growth. J . For. 74(4):220- 224.
Thomas, Jack W., Ralph G. fu1de r son, Chris Maser,
and Evelyn L. Bull.
1979 .
5 . Snags .
p . 60-77. In Wildlif~ habitats i n managed
forests : The Blue Houn tains of Oregon and
Washington.
Jack Wa rd Thomas, t~ch. ed.
USDA For . Serv . Agric . Handb. 553, 512 p.
Figure 2. --"Armoring" of tre~ trunk. Three o r
four s t ays, offset to ~xtend height of bole
protection, a r e secured by bent-over nails
in sound wood.
27