Forest Soils, the Key Factor of Crop Productivity timber harvesting and site preparation.
By RICHARD E. MILLER
Forest t1oor depth indicates the balance
F
between the rate at which organic
amily forest owners and gardeners
share a common goal: To protect
debris is deposited and decomposed.
and maintain their productive soils
Some forest floor is always desirable.
and to improve their less productive or
However, deep accumulation of forest
degraded ones. Most know that produc­
floor (exceeding about five inches)
tive soil supports plant growth through a
usually indicates slow rates of organic
vigorous community of soil organisms,
matter decomposition and nutrient
physical structure and favorable mois­
cycling, which restrict growth or diver­
ture, nutrition. temperature and aeration.
sity of soil organisms and plants.
A wide variety of life forms reside
Protecting
and interact in forest soils. Mycorrhizae
Soil Productivity
::rre important for water uptake, storage
Natural and human-caused distur­
and transport: they release compounds
bances affect soil structure, nutrient sta­
that enhance absorption of certain nutri­
tus, moisture, temperature. pH and
ents. Some species of bacteria in nodu­
organic matter. litterfall. forest-floor
lated plant roots and in decaying wood
"Pumice" soils can produce large trees
fix (convert) nitrogen
despite absence offine textured layers.
(N) from the air
into N-forms that are available for
plants and other organisms. Certain
fungi and bacteria protect particular tree
species from pathogens. Various
microbes secrete organic glues that bind
Thinking about Certification? soil particles into water-stable aggre­
gates that ensure movement and storage
of air and water in the soil.
Above the forest soil are leaf litter
and woody debris that help protect
structure of the mineral soil from the
direct impact of rain, heavy equipment
--we've got
the facts.
or logs. This forest t1oor (duff) also
contributes to soil humus and nutrient
cycling, when fallen plant and woody
tissues are decomposed by the resident
composition and plant-species composi­
tion can also be changed. For example,
tire frequency, and especially intensity,
int1uence losses of organic matter and
nutrients. Conservation and addition of
nitrogen is particularly important
because this nutrient element usually
limits forest productivity. Soil com­
paction and disturbance alter soil struc­
ture and pore space, disrupting flows of
gases and water essential to soil organ­
isms and plants. Only when bulk den­
sities are low can roots readily exploit
the soil for water and nutrients. Plants,
especially large trees, also require a
well-distributed root system to provide
host of invertebrates, fungi and other
physical support and avoid windthrow.
food for small mammals and birds.
forest owners should:
microorganisms that are themselves
Forest floor depth and composition
result from past natural environment
and human-caused disturbance such as
To keep their soils healthy, family
•
Minimize severity of human­
caused disturbance. Activities that
extensively displace or compact mineral
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planting their trees since 1977
FSCUS
1155 30th Street NW
Suite 300
Washington, DC 20007
ra
FAX
wee
8
•
202.342.0413
202.342.6589
www.fscus.org
jJ_
T.M.P. is a licensed and bonded reforestation company. Douglas-fir
and other species of seedlings are available for your planting needs.
FSC
NORTHWEST WOODLANDS
422 Tucker Road
•
SUMMER 2001
•
Thomas R. Fox, President
Winlock, WA 98596 • (360) 978-4305
•
fax
(360) 978-5747
soil are undesirable, especially on steep
topography (which is more likely to
rent condition should be evaluated
tern resiliency.
•
carefully on a site-specific basis wher­
Learn more about your soils and
ever activities with heavy equipment
erode) or shallow soils (which inherent­
their response to heavy equipment and
ly have limited volume for rooting).
natural disturbance. Does rain enter
are proposed. Published soil survey
your soil rapidly? Can you easily
reports b y the Natural Resources
and large woody debris to replenish
break through your soils with your
Conservation Service can provide use-
what is lost through both natural
shovel? S oil characteristics and cur-
•
Ensure adequate sources of small
- CONTINUED ON PAGE 10-
events and human activities. L arge
debris protects soil and forest floor,
especially on slopes, b y forming natu­
ral barriers to erosion. Small debris
helps buffer the soil from compaction;
decomposing debris renews organic
.FARMfoRESTRY
matter in the mineral soil and keeps
vital nutrients cycling.
•
ASSOCIATION
Control vegetation if necessary to
ensure adequate survival of seedlings,
but retain some plant cover. Intensive
silviculture characterizes many shrubs
and hardwoods as "brush" and slates
CORPORATE PATRON PR.O(jR.AM
them for removal as vegetative com­
petitors. Yet these plants, often first to
colonize sites after disturbance, stabi­
lize sites and lay the foundation for
later successional species.
•
Promote conditions (for example.
plant cover and woody debris) that
moderate climate near the soil surface.
Harsh sites, such as those with extreme­
ly dry or cold soils, are most suscepti­
ble to reduced productivity and ecosys-
WFFA kicked off a new program in Janu ary designed to seek
tinancial support from businesses in our local communities. T he
money generated from this program will help to educate members t o
improve forest stewardship and to increase public awareness of the
importa nce of family tree farms. It will also allow us to continue our
efforts to represent the small forest landowner o n the local, state and
federal levels dealing with issues that will shape our future.
t:lte-foiLIJwiltj Corporai;e, Pa:troHS:
aJtd
Please-joist; UG in;
goLD ($1,000)
.
.
.
.
.
. . . • • . • . . • . . .
• . . . . • . • . . . .
Boise Cascade, Kettle Falls. WA
Soil Sdence Tenns (From the Soil Science Society ofAmerica)
of a
Weyerhaeuser, Timberlands Division, Federal Way, WA
SILVER. ($500)
JD Lumber. Inc., Priest River, ID
soil to produce a certain yield of crops or
other plants with a specified system of
management.
Soil structure-The combination or
arrangement of primary soil particles
(sand. silt, clay) into secondary units or
peds. The secondary units
are
character­
ized on the basis of size, shape and grade
(degree of distinctness).
Bulk
density-The
mass (weight) of
dry soil per unit bulk volume.
Soil series-The
lowest category of
U.S. system of soil taxonomy. Soil series
are commonly used to name dominant or
codominant polypedons represented on
detailed soil maps. The soil series serve
as
a major vehicle to transfer soil informa­
tion and research knowledge from one soil
area to another.
• . . •
. . • . . . . • . . . • .
Great Western Lumber Co., Everson, WA
Washington Citizens for World Trade, Port Angeles, WA
West Fork Timber Co. LLC, Tacoma. WA
• • • • • . . • • . . . . • . •
Kevin Godbout
Jeff Weimer
Paul Kriegel
Anonymous
Jerry Hendricks
Scott Swanson
• • • • • .
• • • • • • . • • • . • . • • • . • • • • • • • •
Forest Land Services, Inc., Stanwood, WA
Jon Buse
Lake Industries LLC, Granite Falls, WA
Olympic Resource Management, Poulsbo, WA
Port of Olympia, Olympia. WA
Bob Hild
Dave Nunes
Nick Handy
Riley Creek Lumber Co., Laclede, ID
Bob Boeh
Vaagan Bros. Lumber Co Colville, WA
Simpson Timber Co., Seattle, WA
.•
Weyerhaeuser Real Estate Company, Federal Way, WA
W illiamson Consulting, Colville, WA
Court Stanley
Gerry Millman
IP Pacific Timberlands, Inc., Puyallup, WA
($250)
• . • . • . . . . • • . . • • . • . • . • • . • . • • • • •
Goodyear Nelson Hardwood Lumber Co., Bellingham, WA
BMNZE
. • • • • • • •
Glen Pearson
Port Blakely Tree F arms, Tumwater, WA
.
Soil productivity-The capacity
. • • . . • . . .
Steve Tveit
Pacific Lumber & Shipping Co., Seattle, WA
Glossary of .
Hubert Sager and
Robert Heater
John Goxman
Peter Constable
Maurice Williamson
NORTHWEST WOODLANDS
•
SUMMER 2001
•
9
-- CONTfNUED FROM PAGE 9-
ful information about soil series on
your land and their characteristics.
Current productivity of some forest
soils can· be improved. Their poor pro­
ductive capacity could result from past
human activities or from natural limita­
tions in their soil-forming factors (par­
ent material, climate, organisms, topog­
raphy, time and their interactions).
Quality soil develops when each of
these factors has been favorable. For
example, in the Northwest, many forest
soils are developing on parent material
deposited by glaciers or volcanic flows
Forestry Consulting
Don Pence, Forester, (208) 667-2796 (home/fax)
Ned Pence, Forester Arleen Pence, Business Manager (208) 88H833 (phone/fax), P.O. Box 8484, Moscow, 10 83843
THE YANKEE GROUP
required for
these geologic
deposits to
weather to days
and to accumu­
late organic
matter. Both
clay and soil
humus are
important for
moisture and
nutrient reten­
tion and supply.
Cable yarding in this recent clearcut harvest resulted in limited
amount of bare soil, despite the steep slope.
tilization to correct native or induced
K<:Jth and Elizabeth Coulter
a.s. Forest Management
M.S. Forest Engineering
23526 Lewis Dr., Philomath, OR 97370
Phone/Fax: (541) 929-6173
yankee@theyankeegroup.Gom
Visit us on the web: www.theyankeegroup.rom
tion. then lesser amounts of nitrogen
would need replacement.
When sufficient (but not excessive)
nutrient deficiencies. These shortages
limit soil processes, hence growth of
amounts of growth-limiting nutrients
soil organisms and aboveground vege­
are applied. the soil ecosystem and
tation. including trees. The practicality
dependent larger ecosystems usually
of using fertilizers to replace nutrients
develop faster. Applying nitrogen fer­
lost in harvesting (exported) and in site
tilizer is a proven means of accelerating
preparation is worth considering for
production of large trees in some forest
narurally inferrile soils. Such losses of
types in the Pacific NorthwesL About
nitrogen range from 400 to over 1.000
Professional Foresters Oregon Professional Loggers +
time and favor­
Soil fertility can be improved by fer­
PENCE CONTRACTING
+
Muchmore
able climate are
Improving Soil Productivity
.,.. I
less than 15.000
years ago.
70 percent of coast Douglas-fir stands
pounds N per acre. For full replace­
grow faster after application of about
ment. however, more would have to be
200 pounds N per
added because not all applied N is cap­
stands of western hemlock and other
tured by the trees, vegetation and soil.
species is less predictable. though
Thus, conservation of existing nutrients
sometimes successful. Other benefits
is a preferable alternative. If less wood
of fertilization include darker green
volume, especially tree crowns, were
foliage and higher quality forage for
harvested or destroyed in site prepara-
animals. Fertilizing with elements
PO Box 33815
Portland OR 97292
Assisi Software (503) 233-6417
www.assisisoft.com
Software for Forest Management
.Assisi Coznpile:&"TM 2000
Cruise Compilation & Inventory
Volume & Value Estimation
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10. NORTHWEST WOODLANDS. SUMMER 2001
JCre: response by
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Software Has Never Been This Easy!"
other than N has received limited
benefit degraded soils. For example,
research. West of the Cascade Range,
tilling or ripping compacted soil can
elements other than N have seldom pro­
improve soil structure or density; and
vided adequate stimulation of tree
removing trees can increase the decom­
growth to justify the additional costs.
position rate of the forest floor by phys­
East of the Cascades, their benefits to
ically disturbing it, changing the micro­
tree
per.formance are better recognized.
Intensive silviculture prescribes fer­
tilizers to increase growth; refertiliza­
tion is conventionally scheduled at
about 10-year intervals. Multiple-use
forestry (creation of wildlife habitat or
restoration forestry) shares this goal to
accelerate growth and development of
large rrees. Current urgings for longer
rotations and less intensive harvesting
and sire preparation could reduce the
climate and providing conditions for
understory vegetation.
Other Sources of
Information
The accompanying articles in this
issue of Northwest Woodlands provide
additional information. Funher reading
and esp(!cially increasing your personal
observations and experience will
improve your soil management. •
RicHARD E. M1:LLER is a member of the
need for frequent fertilization because:
Washington Farm Forestry Association
(1) fewer nutrients would be exported
andformer research soil scientist with
in harvested material; (2) moreN could
the Pacific Northwest Research Station.
be added by the natural process ofN­
fixation: and
(3)
nutrient needs of older
trees could be satisfied by internal
Further Reading
and Other Sources of Information about Soils Perry, D. A.;
1989.
leurisse , R., et aJ., eds.
Maintaining the long-term pro­
ductivity of Pacific Nonhwest forest
ecosystems. TllD.ber Press, Portland,
OR. 256 pp.
Chappell.
H. N.; Weetman, G. F.;
E., eds. 1992. Forest fertil­
Miller. R.
i:.arion: Sustaining and improving
nutrition and growth of western
forests. College of Forest Resources,
University ofWashington, Seattle.
Forest Institute of Resources
Contribution No. 73. 302 pp.
USDA Natural Resources Conservation
Service, Soil Biology Primer (PA­
1637), 101 SW Ylain, Suite 1600,
USDA, Forest Service. He can be
Portland. OR 97204-3221: 503-41­
reached via email at millersoils@
soi1/mlra..httnl.
aol.com.
recycling of nutrients.
3012; www.or.ncrs.usda.gov/
USDA Natural Resources Conservation
Service
Other remedial rreatments can also
Soil Survey Division:
www.statlab.iastate.edu/soils/home­
page.htmUmain.honl
Soil Quality /nsrirute:
www.statlab.ia.state.edu/surveyiSQI/
Soil Science Society of America.
Division S7-Forest and Range
WILBUR-ELLIS
Soils
http://soilslab.cfr.washington.edu/
S-7fmdex.htm
IOfAS TO GROW WlfH
Summer Site Preparation Herbicides:
Accord Concentrate® Arsenal Applicators Concentrate® Esco
Chopper» Ous
Start your seedlings out right!
Supplying the forest
industry since 1970
SEEDLINGS AND
TRANSPLANTS
ALDRICH BERRY
FARM & NURSERY, INC.
190 Aldrich Road
Mossyrock, WA 98564
For information on these or any other herbicides, call:
Bruce Alber or Kurt Spingath
3145 NW Yean
•
P.O. Box 8838
•
Portland, OR 97208
1-800-452-5625
Spokane Office: Wayne Stewart, 1-800-727-9186
Phone (206) 983-3138
Reforestation seedlings for SW Washington HORT'HWESTWOODI.ANOS. SUMMER 2001
•
11