(Nurseries from page 2)

the same time, they began propagating
native wetland plants for the conserva-
tion and restoration market. In an
excellent example of innovation, they
decided to combine the two projects.
The constructed wetland treatment
ponds will serve three functions. They
will: 1) biologically remove nitrates
and phosphates from greenhouse
irrigation water; 2) serve as a growing
area for the propagation of wetland
plants; and 3) function as a seed
production area. Currently, several
riparian plants are under culture
including Carex spp., Juncus spp.,
Scripus spp., and Eleocharis spp. The
future for constructed wetlands is high
because a variety of other municipal
and agricultural wastes can be biologi-
cally treated and nurseries will be
asked to produce planting stock for
these projects.

Ecosystem restoration: Restoring
damaged ecosystems is another obvious
market for plant materials from forest
and conservation nurseries. Exciting
changes are starting to occur. For
example, micropropagation technology
is being used to produce plants for
fire rehabilitation. For example,
frequent fires have changed the dom-
inant species composition on rangeland
in southern Idaho by eliminating
native shrubs, such as bitterbrush and
mountain big sage, and favoring weed
species. The Forest Research Nursery
at the University of Idaho is propagat-
ing two species of bitterbrush that are
“fire resistant." They sprout readily
after fire. Using the latest technology,
seedlings of these special ecotypes are
being mass produced and will eventu-
ally be used to help restore these
degraded rangelands.

Enhancing wildlife habitat: Natural
resource managers are beginning to
manage habitat for many nongame
species, especially those which are
threatened, sensitive, or endangered.
When the objective is to reestablish a
functioning, self-sustaining ecosystem,
key plants must be identified, propa-
gated, and outplanted to create a
community with specific compositional
and structural features. For example,
riparian habitat along the San Luis
Rey river in southern California is
being restored to encourage the
recovery of an endangered bird - the
least Bell’s vireo. Restoration ecologists
carefully surveyed the plant communi-
ty, then contracted with nurseries to
produce stock for the project. Six
different trees and a variety of other
plants were propagated. Initial surveys

"In an effort to increase
biodiversity levels, natural
resource specialists are using
nursery stock for innovative
planting projects..."

indicate that the project was successful
as pairs of least Bell’s vireos have
been spotted in the restored habitat.

Rehabilitation of recreation sites:
Recreation is one of the most rapidly-
growing uses of wildlands and due to
resource damage at many high-use
sites, rehabilitation has become neces-
sary. Recreation sites in quaking aspen
stands are a notable example. Al-
though aspen trees are highly desirable
from an aesthetic viewpoint, they have
thin bark and are easily damaged by
campers. Fungi invade the wounds,
causing cankers and killing the trees.
In Colorado, campgrounds in aspen
stands are being rehabilitated by
interplanting with conifer stock.
Increasing the plant diversity of these
stands makes them more resistant to
camper abuse and subsequent pest
problems.

Forest health: The forest health
issue will undoubtedly have a profound
impact on how we manage our forests
in the future. The role of forest and
conservation nurseries has not been
fully realized yet, but nurseries are
already participating in several
projects. In the Deschutes National
Forest in central Oregon, over 750,000
acres of lodgepole pine forests have
been decimated by the mountain pine
beetle. Absence of fire in the Blue
Mountains in Northeastern Oregon has
also converted many stands from open

savannahs of large ponderosa pine to
thickets of smaller Douglas-fir and
grand fir that are being defoliated by
the western spruce budworm. Forest
managers realize that they need to
lower stocking levels and increase
species diversity by converting these
stands back to pine and western larch.
Unfortunately, letting natural fires burn
or using prescribed buming could
severely damage the existing trees
because of the high fuel loads that
have developed. In addition, air
pollution concems make large scale
buming politically unacceptable in
many areas. Salvage logging and
thinning will solve the stand density
problem, but increasing stand diversity
will require interplanting and
underplanting. The public will not
want to wait decades or even centuries
for natural reproduction, so planting
nursery stock will be the fastest and
most efficient way to increase species
diversity. Creating landscapes with a
mosaic of different species and age
classes will increase overall forest
health and will help lower the poten-
tial for disastrous pest outbreaks.

As you can see, forest and conser-
vation nurseries are being asked to
play a greater role in implementing
biodiversity and ecosystem management
programs. They are willing and able
to respond to any need for plant
materials for a wide variety of natural
resource uses. Although nurseries have
been traditionally associated with
timber management and reforestation,
they should be viewed in a wider
context — as a vital part of all

vegetation management activities.
Source: adapted from Biodiversity and
Ecosystem Management: The Role of Forest and
Conservation Nurseries, Landis, T. et al, 1992
Proceedings, Western Forest Nursery Association
GTR RM-221.

Bug Killing Cherry Trees

The benefits of trees are many — but cherry trees that kill insects?

Its true, according to Montana State University professor George Evans.
Evans was experimenting with black cherry trees, a species that is being
found to prosper when planted in dryland areas of the inland Northwest,
just as it does naturally in the wetter areas of the Midwest and East. To
his surprise, Evans found the cherry leaves in his experimental plots
relatively untouched compared with the leaves of other trees that had been
munched by hordes of grasshoppers. More surprising, he found grasshop-
pers around the cherry trees laying on their backs kicking or already
dead. Apparently the leaf of black cherry is toxic to grasshoppers. Prelimi-
nary surveys indicate that four of five grasshoppers unlucky enough to
ingest the leaf end up in grasshopper heaven.

Source: Arbor Day, January/February, 1991

Inside Agroforestry 5


Soldier Creek Riparian Restoration Project

In November, 1992, Jerry Wohler, who owns
land in Shawnee County, Kansas, contacted the
Shawnee County Nonpoint Source Coordinator
regarding a streambank stabilization problem. He
had cropped land adjacent to Soldier Creek and
due to a lack of riparian vegetation, approximate-
ly 500 feet of streambank on the five acre site
was eroding and contributing a heavy sediment
load into the creek. Cultivation to the edge of the
bank was aggravating the problem. Wohler was
concerned about losing access to a portion of the
site, since the eroding streambank was only 50
feet away from the property line.

The Nonpoint Source Coordinator contacted
Rick Davis, Environmental Planning Consultant
for the Kansas Department of Health and Envi-
ronment, who coordinated what is now called the
Soldier Creek Riparian Restoration Project. Repre-

sentatives from several state and federal agencies, The 15- to 20-foot cedar trees were installed in an overlapped ‘fashion and anchored
with a duckbill anchor four- to five-feet into the bank.

including the Kansas Department of Health and
Environment, Shawnee County Conservation District, Soil
Conservation Service, Kansas Department of Wildlife and
Parks, State Conservation Commission, and Kansas State
and Extension Forestry, visited the site to discuss possible
solutions. They encouraged Wohler to consider long-range
Management objectives for the site, in addition to the
immediate need for streambank stabilization. Wohler ex-
pressed an interest in timber production and wildlife habitat
and a plan was developed. According to Davis, the primary
purpose of the project is streambank stabilization. But, by
also generating a cost-effective means to treat streambanks,
landowners might be more willing to look at solutions.
With alternative objectives, such as timber production and
wildlife habitat, the perception of taking agricultural land
“out of production” for the landowner is minimized.

The planning process of this project was something that
Davis was particularly careful with and proud of. Planning
the project from a mulit-agency perspective has provided
several benefits. First, it has provided a unified, ecosystem
approach rather than individual, unrelated management
plans developed by separate agencies. Second, a design and
management system was established that offered a series of
checks and balances. And third, a planning process was
established so that participating agencies can respond to
future projects more quickly and efficiently.

The Restoration Project was installed in three phases that
started in December, 1993 and were all finished by the end
of March, 1994, The first phase of the design consisted of

; 4 y: yeeee m installing a tree
=a revetment along
the toe of the
bank for two
purposes. The
cedar tree
revetment not
only traps
sediment from
the slumping
bank, but also as
it washes down

a eS
Site after tree revetment was installed

4 Inside Agroforestry

the stream. Sediment deposited behind the revetment allows
seed from pioneer species such as willow and cottonwood to
become established. Trees for the revetment were cut about
1 1/2 miles from the site on property owned by Wobler.
The 15- to 20-foot cedar trees were planted in an over-
lapped fashion and anchored with a duckbill anchor four- to
five-feet into the bank.

The second phase consisted of placing dormant willow
stakes on the slope to establish deep rooting. The stakes
were placed on a four-foot spacing and planted two feet
deep. Establishing this extensive root system quickly was
imperative to stabilizing the slope.

The third phase of the restoration project consisted of
planting the site to grass, shrubs, and trees to provide a
varied habitat. A variety of deciduous trees were selected for
species diversity and timber production. Patches of native
grass and deciduous shrubs will provide additional species
diversity for wildlife habitat.

The restoration project on Wohlers land to date has been
so positive that the landowner to the south, Randy Wolf,
has also contacted Davis to initiate a similar project on his
land. Davis feels that this is a great opportunity since Wolf
also has an outside bend of the stream similar to Wohlers.
However, since the slope on Wolf’s land is not as dramatic
and the area is slightly different, the design will vary.
Davis plans to use dormant willow stakes, without a tree
revetment, to provide immediate stabilization on the bank.
Several rows of trees will be planted above the bank for
long-term stabilization.

The varied treatments of the two sites will provide an
opportunity to compare streambank stabilization methods.
Both sites will then serve as demonstration projects and will
be used for field days to train agency personnel and encour-
age landowners to do riparian restoration work in the
future.

Much of the credit for the success of the Soldier Creek
Riparian Restoration Project goes to Rick Davis. He was
instrumental in the planning, coordination, and implementa-
tion of the first project and continues to oversee future
Progress of the next phase. Thank you, Rick!



Windbreak Evaluation
Software Available

Researcher Jim Brandle at the
University of Nebraska and John Kort at
the PFRA Shelterbelt Centre released the
second generation of their windbreak
evaluation software, WBECON, in
January, 1994. The new program offers
several major advantages over the first
generation model that was presented at
the International Windbreak and
Agroforestry Symposium in Ridgetown,
Ontario in 1991.

The program evaluates field wind-
break plantings for any rectangular shape
field with dimensions greater than 500
feet by 500 feet. It allows the user to select
from a number of windbreak tree species
and designs and allows additional tree
species to be added for local growing
conditions. The program considers 27
common crops and allows additional
crops to be added. It considers all input
Costs such as establishment and mainte-
nance costs, crop production costs, land
costs, and interest. Crop production
benefits are assumed to begin in the fifth
year after planting and are phased in as
the trees mature. Results of the analysis
include the annual economic return, the
total return on investment, and a net
present value based on the life of the
windbreak investment. Results can be
viewed on the screen or printed.

The program is designed primarily
for use by consultants, extension agents,
or other professionals and can be used by
producers too. The initialization portion
of the program allows the user to custom-
ize the analysis program to fit their
conditions making it usable almost
anywhere in both the United States and
Canada.

Copies of the program are available
by sending one 5 1/2 or 3 1/2 inch
formatted disk, double-sided and high-
density, and a computer disk mailing
envelope to: Jim Brandle, Department of
Forestry, Fisheries, and Wildlife, Univer-
sity of Nebraska-East Campus, Lincoln,
Nebraska 68583-0814 or to John Kort,
Shelterbelt Centre, PFRA, Indian Head,
Saskatchewan, Canada SOG 2K0.

erotorestry

USDA Forest Service, Lincoln, Nebraska

Spring. 1994

The Increasing Role of Nurseries in
Biodiversity and Ecosystem Management

With increasing emphasis on
biodiversity and ecosystem manage-
ment, the demand for a wide variety
of plant species is on the rise. Nurser-
ies all across the nation have
responded to this demand. In addition
to the traditional commercial timber
species, nurseries are now propagating
a wide variety of diverse plants, from
sedges and grasses to woody shrubs
and trees. In an effort to increase
biodiversity levels, natural resource
specialists are using nursery stock for
innovative planting projects like gene
conservation, resource protection,
ecosystem restoration, wildlife habitat

enhancement, rehabilitation of recre-
ation sites, and forest health.

For example, seedlings of turkey
oak, which had previously been
considered a weed tree, are being
grown for wildlife habitat. And, litle
bluestem seedlings are being produced
for a grassland restoration project in
Michigan.

To further examine this trend,
planting projects that promote
biodiversity and ecosystem management
are listed. Keep in mind that the
following list of projects is by no
means comprehensive.
——___—— (See Nurseries on page 2)

In addition to commercial timber species, nurseries are now propagating a wide variety of diverse

Plants, from sedges and grasses to woody shrubs and trees.

This Jssue

@ Message from the Manager...page 2

& Using Trees to Stabilize Slopes...page 3

Es

Streambank Stabilization Project in Kansas...page 4

© Bug Killing Cherry Trees...page 5


Message From the Manager

‘G ca

of agroforestry are becoming more unified, and
agroforestry science and practice is becoming more
broadly recognized,

The notion of conservation agroforestry is gaining
widespread acceptance. This encompasses the numerous
benefits from ecological interactions (physical and biologi-
cal) when trees and shrubs are integrated into cropping
and livestock systems. Sure, we still need to justify
agroforestry based on simple economics (a payoff from
tree products), but today the less tangible benefits from
agroforestry are perceived to have equal value. Land
stewardship has many stakeholders, whose interests need
to be defined and recognized. As agroforestry science and
practice evolve, and a unified understanding and vision
advance, so too will its credibility and acceptance.

I recently traveled to Nairobi, Kenya to coordinate on
agroforestry with ICRAF (International Centre for Re-
search in Agroforestry), a well-respected and effective
private organization with a worldwide mission to advance
agroforestry as a sustainable land-use system. My visits
and tours with ICRAF leaders and scientists made me
realize that various institutions are developing agroforestry
science and practices worldwide for exactly the same
reasons: to overcome environmental degradation, land
depletion, water impairment, loss of biodiversity, and to
establish a sustainable land-use system that will provide
for people's economic and social needs. These needs hold
true whether you are an agroforestry scientist in the
humid tropics or the semiarid Great Plains. Our strategic
research to develop methods, principles, technologies,
tools, and models can be shared globally. But adaptive
research by local networks is essential to locally adapt
and integrate appropriate technologies and evaluate the
cost and benefits. Agroforestry science is global;
agroforestry practice is local.

Another key element that is becoming widely recog-
nized and accepted is that agroforestry is a sustainable
land-use system, or is an essential component of a
sustainable land-use system. On a small farm or home

‘A column of important events and programs
as reported by CSA Program Manager Bill Rietveld

Coming Together

Agroforestry is coming of age. Concepts and definitions garden, a multilayer integrated tree/crop/livestock design is

a sustainable system to increase the productive capacity
from a limited land base. As part of a larger scale land-
use system, integrated agroforestry practices can substantially
contribute to attainment of sustainment development.
Agroforestry is one of the few management practices that
can mitigate serious environmental problems (such as non-
point source pollution), and simultaneously enhance the
economic and human components within the same system.

Perhaps we haven't thought of it before in these terms,
but agroforestry is part of an ecosystem-based approach to
sustainable land use. Today a holistic, integrated, multi-
resource, landscape scale approach to land management is
popular, and many agencies are shifting to an ecosystem or
watershed perspective. Now more than ever, people are
realizing that all disciplines of agricultural, environmental,
and natural resource science have something to offer to
attain the common goal of developing sustainable land-use
systems.

Ecosystem-based management is especially challenging on
private lands, compared to public lands. On private lands,
ecosystems transcend many boundaries: ownership, vegeta-
tion, use, political, and agency -- to name a few. Agency
programs and responsibilities overlap, and the agencies are
not the land stewards. Agencies only provide guidelines,
incentives, and assistance. Stewardship is a shared responsi-
bility, and the issue of private property rights needs to be
respected and clarified.

Ecosystem-based research on private lands needs to
develop an understanding of component interactions (espe-
cially interactions with the human component), identify
options, and evaluate the costs and benefits of each option
to various stakeholders. The outputs need to be scientifically
based information that policy makers and managers can
translate into appropriate guidelines, incentives, and assis-
tance programs.

Never before has there been stronger and more compel-
ling reasons to come together to blend and balance
expertise to develop solutions to shared problems.

(Nurseries from page 1)

Gene conservation: Most forestry
seedlings are sold by seed zone - a
numerical code corresponding to a
geographic area that is relatively
similar in climate and soil. Some
species that are widely distributed in
geographically isolated populations,
such as white fir, contain high levels
of genetic variability. Besides obvious
differences in physical characteristics,
researchers found that local ecotypes of
white fir differed significantly in traits

that will affect seedling survival and
growth such as cold tolerance and
date of bud break. So, besides ensur-
ing that only locally-adapted plant
materials will be used in forest and
conservation plantings, nurseries are
ensuring the preservation of a wide
variety of local genotypes by the use
of “source-identified” seed.

Resource protection and conserva-
tion: Water quality is being threatened
by many types of pollution. Growing

plants for constructed wetland treatment
systems is another way in which forest
and conservation nurseries can help
Protect natural resources. A few years
ago the Lone Peak Conservation Center
Nursery, which is operated by the Utah
Division of State Lands and Forestry,
worked with the USDA Soil Conserva-
tion Service to design a constructed
wetland to collect and treat runoff
water from their greenhouse. At about
——__---_— (See Nurseries on page 5)

2 Inside Agroforestry


Soil Bioengineering: Using Trees to Stabilize Slopes

By Gary W. Wells

Landscape Architect and Soil Bioengineering Team Leader
Midwest National Technical Center, USDA Soil Conservation Service

The value of vegetation to reduce
soil erosion has long been recognized.
Grasses and forbs are an integral part
of many conservation practices. Howev-
er, the value of woody vegetation to
reinforce slopes and to provide barriers
to earth movement has been over-
looked until recently. Soil bio-
engineering is a term used to describe
the use of live plant parts as a
structural component for soil reinforce-
ment and a barrier to earth movement.

"With increasing public concern
to find more environmentally
sensitive engineering solutions,
soil bioengineering will continue
to grow in popularity."

Soil bioengineering combines
biological elements with engineering
design principles to create environmen-
tally sensitive solutions to both upland
slope protection and streambank
stabilization. It is an applied science
that utilizes woody species that can
root from cuttings to create a living
structure. Initially the arrangement of
the cuttings provides mechanical
Protection for the soil. As the plants
grow, the roots reinforce the soil and
other species invade to create a self-
sustaining community.

With the renewed interest in
sustainable land management systems,
there has been a renaissance in the
use of plants to solve slope stability
problems. Even though soil bioengi-

Brushlayer and live facine being installed.

neering is a recent term, the concepts
date back to the fourteenth century in
Europe. In the 1930’s and 40’s, there
were several professionals using and
perfecting “living construction” tech-
niques. The Soil Conservation Service
was also evaluating soil bioengineering
techniques during the 1930's. After
World War II these techniques lost out
to more conventional engineering
solutions of concrete, rock, and steel.

Soil bioengineering combines
mechanical, biological, and ecological
concepts and requires an interdiscipli-
nary design approach. When properly
designed, soil bioengineering techniques
not only help to stabilize slopes, but
also improve infiltration, filter runoff,
transpire excess moisture, moderate
ground temperatures, improve habitat,
and enhance aesthetics. These tech-
niques also minimize site disturbance
and the need for large equipment,
which can also help to minimize
negative environmental impacts.

There are numerous soil bioengi-
neering techniques. They all utilize
dormant cuttings of indigenous plant
materials. Species that root easily from
cuttings, such as willow and dogwood
shrubs, are used and can be harvested
from local sources. Soil bioengineering
techniques include live staking, brush
mattress, brushlayer, live fascine, and
branchpacking. There are also several
techniques that can be used in combi-
nation with conventional engineering;
these include live cribwalls, joint
plantings, vegetated rock gabions, and
vegetated rock walls. The inert struc-
tural component provides immediate
slope protection, but as the plants

grow, the roots become the key
structural component.

An assessment of soil mechanics,
hydrology, geology, climate, and other
site conditions is needed to design the
appropriate soil bioengineering tech-
niques. Once designed, skilled
installers are needed for construction
and the site should be monitored for
survivability. Even though installation
is labor intensive, construction costs
have been 1/2 to 2/3 the cost of
conventional engineering solutions.

The Soil Conservation Service
recognizes soil bioengineering tech-
niques as a potential component in
planning resource conservation systems.
Initial efforts to develop technical
information include Chapter 18 of the
Engineering Field Handbook titled
“Soil Bioengineering for Upland Slope
Protection and Erosion Reduction."
Chapter 16 on streambank and shore-
line protection is also being updated to
include soil bioengineering information.
The agency is also evaluating several
demonstration projects to gain informa-
tion that will lead to the development
of design guidelines.

With increasing public concern to
find more environmentally sensitive
engineering solutions, soil bioengineer-
ing will continue to grow in pop-
ularity. It will not replace conventional
engineering solutions as there are
many situations where soil bioengineer-
ing techniques are inappropriate.
However, there are many opportunities
where these techniques can be used in
conjunction with conventional engineer-
ing to reduce costs and add environ-
mental value.

Three months after installation.

Inside Agroforestry 3