Environmentally Sound
Small-Scale
Forestry Projects
by
Peter F. Ffolliott
and
John L. Thames
Guidelines for Planning
Coordination in Development
Volunteers in Technical Assistance
CODEL
475
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York, NY 10115
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Illustrations by Linda Jacobs
Cover
designed by Susann Foster Brown
[C] 1983 CODEL
TABLE OF CONTENTS
PREFACE
AUTHORS' NOTE
Chapter I USERS
AND USES
Who
should use this manual?
What
is a small-scale forestry project?
What
purpose does this manual serve?
Chapter II A
PLANNING PROCESS
Why
plan?
How
should planning be approached?
What is the planning process?
Is
this process definitive?
Are
education and training necessary?
Chapter III
FORESTRY AND THE ENVIRONMENT
What
is meant by ecology and the environment?
What is forestry?
How
are forestry and the environment related?
What
are forest ecosystems?
How
do trees protect the productivity of ecosystems?
What
is meant by forest succession?
Is there an ecological
difference between natural and
man-made forests?
What
are limiting factors?
Can
environmental concepts be used in developing successful
small-scale forestry projects?
CHAPTER IV
UNDERSTANDING FORESTRY PRACTICES
Why
is it necessary to have a knowledge of good forestry
practices?
What
trees should be grown?
How
can forest growth be improved?
Why
is it important to protect forests from destructive
agents?
How
is the forest inventoried?
How
are trees harvested for wood products?
CHAPTER V
UNDERSTANDING INSTITUTIONAL LIMITATIONS
What
are institutional limitations?
Why
are legal considerations important?
When
are social considerations important?
How
are economic considerations incorporated into planning?
CHAPTER VI
BACKGROUND FOR PLANNING:
MULTIPLE-USE FORESTRY PROGRAMS
What
is meant by multiple -use?
When
should -multiple use forestry be practiced?
How
are multiple -use benefits and costs measured?
When
is multiple -use forestry environmentally sound?
Are
there alternatives to multiple -use?
CHAPTER VII
BACKGROUND FOR PLANNING:
HARVESTING TREES FOR WOOD PRODUCTS
What
wood products can be made?
Are
secondary and other by -products important?
When
should trees for wood products be harvested?
Can
wood products be harvested without environmental damage?
What
alternatives exist?
CHAPTER VIII
BACKGROUND FOR PLANNING:
FUELWOOD MANAGEMENT PROGRAMS
Why
is fuelwood management important?
What
is the heat content of wood?
How
are energy input and output relationships used in
planning?
Which
trees should be grown?
How
does fuelwood management affect the environment?
Can
fuelwood management be integrated with other forestry
activities?
CHAPTER IX
BACKGROUND FOR PLANNING:
AGRO-FORESTRY PROJECTS
What
is agro-forestry?
Is
there a general agro-forestry system?
What
are the environmental benefits of agro-forestry
projects?
What are the social and economic
benefits of agro-forests?
What
problems might arise in developing agro-forestry
projects?
What
are the elements in planning environmentally sound
agro-forestry projects?
CHAPTER X
BACKGROUND FOR PLANNING:
SHELTERBELT AND WIND-BREAK
PLANTINGS
What
are shelterbelts and wind-breaks?
How
do shelterbelts function?
How
should shelterbelts be structured?
What
patterns should be considered?
What
spacing should be used between shelterbelts?
What
characteristics should the plant species have?
How
are shelterbelts established?
How
should sheiterbelts be managed?
What
are the environmental effects of shelterbelts?
CHAPTER XI
BACKGROUND FOR PLANNING:
REFORESTATION AND AFFORESTATION
PROJECTS
What
is meant by reforestation and afforestation?
When
is it important to plan reforestation projects?
What
environmental factors are important?
What
tree species should be selected?
What
should be considered in obtaining planting stock?
Where
should seeds be obtained?
What
is necessary in planning site preparation?
CHAPTER XII OTHER
CONSIDERATIONS
Are
small-scale forestry projects not discussed important?
Is
additional information available?
APPENDIX:
Ecological MiniGuidelines for Small-Scale Community
Development Projects
BIBLIOGPAPHY
BIOGRAPHICAL NOTE
PREFACE
This manual is
the third volume of the Guidelines for Planning
Series. The first
volume, Environmentally Sound Small-Scale
Agricultural Projects, was published in 1979; it is now
available
in French and Spanish.
The second volume, Environmentally Sound
Small-Scale Water Projects, was published in 1981.
The booklets
can be ordered from VITA.
This manual has
been written for community development workers
in Third World countries who are not technicians in the area
of forestry, but who want some general guidelines for
planning
environmentally sound small-scale forestry projects.
The CODEL
Environment and Development Committee has guided
the development of the Guidelines for Planning Series and
this
volume. CODEL
acknowledges the contribution of the members of the
Committee who commented on drafts of the booklet:
Father John
Joe Braun, Missionaries of Africa,
Committee Chairperson
Ms.
Elizabeth Enloe, Church World Service
Mr. George
Gerardi, Attorney at Law
Mr. George
Mahaffey, The Peace Corps
Rev. John L.
Ostdiek, Franciscan Missionary Union of
Chicago
Dr. Ragnar
Overby, The World Bank
Ms. Agnes
Pall, International Division, YMCA
Mr. C. Anthony
Pryor, Center for Integrative Development
Mr. A. Keith
Smiley, Mohonk Consultations on the Earth's
Ecosystem
Dr. Gus
Tillman, Cary Arboretum
In addition, a
number of reviewers read a draft of the text
carefully. These
include:
J. E. M.
Arnold, U.N. Food and Agricultural
Organization
Michael
Diamond, International Division, YMCA
Hans
Gregersen, University of Minnesota
Sam Kunkle,
USDA Forest Service
Richard
Saunier, Organization of American States
Mervin
Stevens, UN Food and Agriculture Organization
and
other members of the forestry staff of
FAO
Fred Weber,
Forestry Specialist
The book was
also reviewed by VITA volunteers and AID
personnel.
Ms. Molly Kux,
AID Office of Forestry, Environment and
Natural Resources, has been uniquely helpful in identifying
the
authors and moving the project forward.
Ms. Kux and Mr. Albert
Printz, AID Environmental Coordinator, continue to support
and
encourage the Environment and Development Program and,
especially,
the Guidelines for Planning Series.
The AID Office
of Private and Voluntary Cooperation has
supported the development of the CODEL Environment and
Development
Program. CODEL
gratefully acknowledges their contribution to the
publication of this volume.
A special note
of gratitude is owed to Carol Roever who has
worked with the Environment and Development Program since
its
inception, and who contributed her accumulated expertise to
the
production of this booklet.
CODEL is pleased
to publish this book by two noted
authorities in the field of Watershed Resourses
Management. Short
biographies of the authors can be found at the end of the
book.
We welcome
comments from readers of the book. A
questionnaire
is enclosed for your convenience.
Please share your reactions
with us.
Boyd Lowry, Executive Director
Helen L. Vukasin, Environment and
Development Program
AUTHORS' NOTE
The need to plan
environmentally sound small-scale forestry
projects, especially in Third World countries, is increasing
as
greater demands are placed on forest-based resources.
This manual
has been written to assist development workers and others in
planning these projects.
It is impossible to consider all of the
possible multiple wood products from trees and multiple uses
of a
forest ecosystem in a given locale.
The authors hope that the
guidelines presented in this manual will furnish a point of
departure for environmentally sound planning of small-scale
forestry projects.
It is important
to note that planning guidelines for small-scale
forestry projects to be implemented in humid, temperate, or
arid forest ecosystems have been grouped together, whenever
possible.
Certainly, specific guidelines may be more appropriate to
one particular forest ecosystem than another.
However, it was the
authors' opinion that many guidelines are general in nature,
and
their applications may be independent of forest ecosystems.
To a large
extent, this booklet is intended to complement
others in the Guidelines for Planning Series co-published by
CODEL
and VITA:
Environmentally Sound Small-Scale Agricultural Projects
and Environmentally Sound Small-Scale Water Projects.
For their
contributions to and suggestions for the preparation
of this manual, the authors owe a debt to many, including:
Samuel H. Kunkle and John H. Dieterich, USDA Forest Service;
Richard E. Saunier, Organization of American States; Hans M.
Gregerson, University of Minnesota; J. E. M. Arnold and
Mervin
Stevens, UN Food and Agriculture Organization; Michael
Diamond,
National Council of the YMCA, Fred Weber, author of
Reforestation
in Arid Lands (VITA 1977), and Molly Kux, U.S. Agency for
International
Development.
Finally, the
authors wish to express their gratitude to Helen
L. Vukasin, CODEL, Environment and Development Program, for
her
support throughout the preparation of this manual.
Peter F. Ffolliott
University of Arizona
John L. Thames
Tucson, Arizona
CHAPTER I: USERS AND USES
An area in Kenya desperately needed water in 1976.
There were no
permanent sources of water and only one well in the local
community.
To help this situation, a cooperative project involving the
Kenya Forestry Department was initiated to build catchment
dams
and to plant trees in the Hurri Hills.
The Hurri Hills are the
lifeline of the Gabra people, who graze their cattle and
camels in
the hills.
Therefore, the wishes and needs of the tribe were
critical in planning the project.
As a result, the project personnel
worked with the community, after first carrying out research
to determine appropriate dam sites and trees to be planted.
Gabra elders participated in the supervision of the project,
and
local people were trained to maintain dams and to plant
trees.
Local labor was hired from as many households as possible.
Who should use this manual?
This manual can
be useful to development workers and those
interested in planning, implementation, or management of
small-scale
forestry projects who wish to:
--
Become aware of major factors that should be
considered
in planning
small-scale forestry projects,
--
Become acquainted with the potential of
forestry projects
to
contribute to the quality of life of rural
peoples and
to local economies,
--
Learn how to protect the life support system
of the
community
through environmental relationships between
forestry,
agriculture and other land use.
What is a small-scale forestry project?
The type of
forestry planning discussed in this manual is for
projects developed at a local farm level and primarily for
the
benefit of the local people.
These projects could include only
one or two farmsteads with land holdings of a few hectares,
or
they could involve an entire rural community in a
cooperative
effort extending over several hundred hectares.
<FIGURE 1>
49p02.gif (437x437)
Without
production in rural areas, people cannot be sustained.
Unless the land produces abundantly, on a sound ecological
basis, a country is in difficulty.
Nevertheless, people who work
the land are the most vulnerable members of society.
They are the
first to feel the effects of hard times.
Environmentally sound
forestry projects can help moderate the ups and downs of
local
economies by providing sustained products over long time
periods.
This should be a goal of planning small-scale forestry
projects.
What purpose does this manual provide?
Complete
planning involves the often more difficult task of
understanding and working within social and economic
constraints
which, invariably, prevail at national, regional, and local
levels
in all countries.
This is beyond the scope of this manual.
However,
it is hoped that this manual will enable development workers
to understand technical and environmental issues which are
the
ultimate basis for planning and implementing sound projects.
Specifically,
the manual has two main goals:
--
To promote technically planned and
environmentally sound
small-scale
forestry projects.
--
To assist in the transfer of technology by
using the
manual as a
tool for education and extension.
The purpose of
this manual is to present an introduction to
the planning of small-scale forestry projects, particularly
as
they may be integrated with agricultural and other land
uses. The
scope of the manual is limited to technical and
environmental
aspects of small-scale forestry projects.
CHAPTER II: A PLANNING PROCESS
Projects are not necessarily transferable from one region to
another, even if the projects are designed to eliminate the
same
problems. For
example, the Lorena stove, a stove which reduces
the amount of smoke output, has been beneficial in
Guatemala.
Lorena stoves were also introduced to villages in Africa to
reduce
smoke-related diseases and increase cooking
efficiencies. However,
in one area insect-carried diseases increased because
insects,
formerly kept away by the smoke from open hearths,
proliferated.
Consequently, the new stoves were abandoned pending a
solution to this new problem.
Why plan?
Most areas
capable of growing trees have limits in size and
ability to produce or sustain goods and services.
However, they
contribute to the well-being of people only if they are
properly
managed and protected.
To attain specific goals, a proper balance
is needed between social and economic benefits derived from
products
and uses, and the social and economic costs required for
operation and administration.
To achieve this balance, planning
is needed.
How should planning be approached?
Planning begins
with a dialogue whereby local people assess
their needs, define their goals and objectives, and agree on
methods for reaching the objectives.
The results of this dialogue
is a consensus which has emerged from discussions among
community
members and is endorsed by the community and development
worker.
This shared responsibility and understanding of an approach
to an
objective or problem is especially critical for small-scale
forestry
projects for two reasons:
--
Because economic and social issues are so
closely intertwined.
--
Because long periods of nurturing and
protection are
often needed
for forestry projects to yield noticeable
and
desired results.
Good planning
has not occurred if a development worker arrives
in a location and unilaterally decides that the village can
benefit from a woodlot project in an area used by villagers
to
graze their animals.
This early dialogue between villagers and
development workers (who share their knowledge and goals and
agree
upon a particular approach to solve a mutually agreed upon
problem)
makes it more likely that a mutually endorsed objective can
be achieved. Trees
are planted by people and cared for by people
to ultimately benefit the people.
The emphasis is on people, not
vegetation. Forests
and small-scale-forestry projects will
flourish only if the people care.
Whether or not they care depends,
in large part, upon their participation in the planning
process.
<FIGURE 2>
49p05.gif (393x393)
Planning to meet the needs
of local people -- food,
as well as fuel.
Planning can be
time-consuming. However, without this
communication
between development workers and villagers, a project is
likely to be delayed in its implementation or neglected
after it
has been implemented because project designs may be
inappropriate
for local conditions and needs.
A commitment to share the
decision-making process with the community does not
guarantee that
a plan will succeed, but it is a prerequisite for the
community
support needed to maintain a project.
Methods for
"animating" or facilitating village discussions
are discussed in various sources.
For example, the Lik-Lik Buk is
especially helpful.
Other references are listed in the bibliography
at the end of this manual.
What is the planning process?
Ideally, the
planning process follows a sequence of several
phases. Although the
overall process might be described in different
ways, the major steps are:
--
Identifying problems and objectives by the
local
community.
--
Establishing/identifying criteria of
acceptance with
those who
will carry on the project.
--
Evaluating various alternatives and
trade-offs involved
in selection of a project.
Various
quantitative techniques may be used to aid in completing
the basic phases of a planning process.
Some of these quantitative
techniques can be quite detailed and require the use of
computer programs and simulation techniques.
Customarily, a development
worker will not have ready access to computer programs
and simulation techniques.
In the latter
instances, it is helpful to have a checklist of
steps to be considered as planning proceeds.
The following diagram
illustrates the various stages in a planning process.
<FIGURE 3>
49p07.gif (600x600)
Explanation of
the checklist:
1. Define the
problem, both in terms of sociological and
economic
factors.
Villagers and
development workers must understand and
agree on the
problem to be addressed by the potential
project.
Special studies and information collecting
may
be needed once
the problem is defined. For instance,
if
a problem is
defined as lack of fuelwood within a
reasonable walking distance of a village,
information on
the village
population and history of cooking activities
may be needed,
as well as information on the history of
vegetation in
the area. Obviously, much of this
information
can come from the villagers knowledge of
the area
and
history. This information may be
supplemented by
information
from local universities or development
organizations
working in the area. Sometimes, this is
called the
"needs assessment" or "needs identification"
stage.
Whatever the label, a sound planning process
must include
gathering this information at an early
stage.
2. Specify goals
and objectives of the project.
Community
involvement in specifying objectives and setting
priorities
among them is critical. If the
community
is not
involved at this stage in the planning process,
there is
little chance that the project will be
maintained and
sustained over a long period of time.
3. Establish a
model of the system in which the project
will be
implemented.
After the
problem has been defined and the project
objectives
clarified, it becomes imperative to consider
how those objectives
can be met within the established
ecological and
cultural setting. Therefore, a model
should be
established of the physical and cultural setting
in which the
project will be implemented; this is a
representation
of how that part of the real world
operates.
It can be done in various forms -- simple
statements,
network diagrams, or sets of detailed mathematical
equations. The important thing
to remember is
that a
"model" should be as complete and accurate as
possible.
The "model" includes two types of
information:
cultural and
social descriptions, as well as information
about the
physical or ecological setting. This
information
can serve as baseline data which will be
useful when
the project is evaluated.
4. Specify
criteria of acceptance.
These are
guidelines against which project alternatives
can be
evaluated. No single set of criteria
will be
sufficient for
judging the applicability of a proposed
project.
ECONOMIC objectives, as outlined in the
chapter
on
institutional limitations, are often used as
acceptance
criteria. In addition, SOCIAL and
CULTURAL
criteria of
acceptance are of the utmost importance in
reviewing
alternative projects; e.g., will grazing patterns
be disrupted
in such a way and extent as to encourage
hostility
among groups in the community? Will
people be
available to control poaching?
In addition,
there are some general ECOLOGICAL guidelines
which can be
applied to the various types of
forestry
projects discussed in this manual.
These
guidelines
would require that projects:
*
Provide sustained benefits over long
periods of
time
while meeting current needs of the community.
*
Conserve forest ecosystem and protect the
diverse,
indigenous plant and animal populations.
*
Be developed to provide multiple benefits.
*
Maintain or improve soil productivity.
*
Use water efficiently and maintain or
enhance water
quality.
*
Use tree species appropriate to the local
climate.
*
Only use new species which have been tested
to
insure
suitability to local site.
*
Encourage the use of rapid growing, high
quality
trees.
*
Protect the forest from destructive agents.
*
Cut trees at appropriate biological and
cultural
times, if wood products are to be
harvested.
*
Harvest in a manner which does not disrupt
other
uses of
forest (soil protection, water production,
forage,
animal habitat) and which maintains site
productivity,
if wood products are to be harvested.
Criteria or guidelines which reflect the principles of
APPROPRIATE
TECHNOLOGY or appropriate development have to be considered
as well. These
require that a project should:
*
Make optimal use of locally available
material and
human
resources.
*
Have community support and involvement.
*
Be based on community-identified and/or
community-realized
needs.
*
Increase potential for community
self-reliance in
both
short and long-term.
*
Be compatible with available funding.
*
Make use of and adapt traditional
technologies.
*
Have reasonable time frame for the
community to
take
responsibility for the project.
*
Have potential for being maintained and
monitored
by the
community.
(These
appropriate technology guidelines are taken from an
earlier volume of the Guidelines for Planning Series,
Environmentally
Sound Small-Scale Water Projects.)
5. Formulate
alternatives,including both project
alternatives
and alternate implementation methods.
Because there
is seldom a "right way" to approach a
problem,
project alternatives and alternate implementation
methods need
to be considered in a creative, yet,
careful
way. The appropriateness of dogmas from
manuals
and traditions
should be examined in terms of the baseline
data collected
in the first step of planning and
the
constraints of the model developed in step 3.
Each
developmental
situation is unique; each project should
reflect the
uniqueness of the setting.
Remember, to
do nothing (meaning, not to implement any
small-scale
forestry project) is a valid alternative
which must be
considered.
6. Test
alternatives against specific criteria of
acceptance.
At this stage
of the planning process, trade-offs are
evaluated as
the course of action is selected.
Village
participation
continues to be essential. Does the
project
meet the
CULTURAL, ECOLOGICAL, and ECONOMIC criteria?
Is it
compatible with the model?
7. Select best
course of action, both in terms of a
specific
project and the methods for implementation.
8. Implement the
project.
9. Review and
critique progress of the project with the
villagers,
making adjustments as needed.
The data
collected when the "model" was formulated will
again be
useful here as the effects of the project are
monitored.
Is this process definitive?
No -- this is
not "the" definitive planning process.
The
above discussion makes the process sound very neat and
orderly.
Development workers with even limited experience know that
it is
anything but that.
The steps suggested here must be adapted to
suit individual situations.
Other checklists may be more appropriate
or may be used to supplement the steps discussed here.
For
instance, the Mini-Guidelines developed by Fred Weber (see
appendix
at the end of this manual) may be used to evaluate project
alternatives and evaluate trade-offs.
Regardless of the quantitative
techniques employed or checklists used, the key to good
planning is to achieve flexibility within predetermined
guidelines
of acceptance.
<FIGURE 4>
49p12.gif (317x393)
However, the
principles behind the process are important in
any developmental situation.
Cultural and ecological factors
usually coexist in a developmental setting.
It is always important
to maintain a continuing dialogue between development
workers
and community members, whereby resources and outlooks are
shared.
These principles are relevant to the development worker who
is
present when the planning is just beginning or who arrives
in the
midst of implementing a project.
The specific steps may be
changed, but the principles of the process endure.
Are education and training necessary?
<FIGURE 5>
49p13.gif (393x393)
Yes, both are
important.
The goal of development
is self-reliant
communities.
However, the
education and training,
which make this goal attainable,
are not one-directional.
Like the
dialogue in the planning
process, education and
training have to be two-directional:
a sharing
process between the resources
of a development
worker and the resources
and knowledge of the local
community. Because
forestry
projects may not show
immediate results like
agricultural projects
which can produce new
crops after one growing
season, it is critical
that dialogue and interaction
between all parties
involved be continuous and
conducted in a genuine
spirit of sharing.
CHAPTER III:
FORESTRY AND THE ENVIRONMENT
As in other tropical countries around the world, the rain
and dry
forests of Bolivia are being depleted at an alarming rate.
Clearing forests for agricultural and range use by small
farmers
and others contribute to the forest depletions.
Before anything
can be done to reverse the situation, involved agencies must
understand the ecology and limitations of the forests, as well
as
the situation of the small farmers with neither financial
means
nor know-how to utilize high technology.
What is meant by ecology and the environment?
<FIGURE 6>
49p14.gif (393x393)
The study of plants,
animals and humans (as
individuals, populations
and communities), in relation
to their biological
and physical surroundings
is called ecology.
Environment,
on the other
hand, refers collectively
to the biological and physical
surroundings of
plants, animals and humans.
Also, as dealt with in
this manual, the environment
includes cultural,
social, economic and legal
aspects that must be considered
when planning
sound small-scale forestry
projects.
What is forestry?
Forestry is the
practice of managing forests and associated
natural resources for desired goals, with ecology providing
a
basic foundation.
Forestry is also defined as a profession involving
the science, business, and art of managing, creating and
conserving forests and associated natural resources for the
continuing
use of their values by people.
It is important
to note that while growing trees is an essential
part of forestry, other vegetation (including grasses and
grass-like plants, forbs, and shrubs) and natural resources
(soil,
water, wildlife, recreation, and minerals) must be considered
in
planning environmentally sound small-scale forestry
projects. A
desire to produce wood products (such as saw timber,
fuelwood, or
fruits) should not lead to a disregard for the other values
of
natural resources.
How are forestry and the environment related?
Forest
activities, regardless of their purpose or scale, take
place within a complex system of biological, physical,
legal,
social, and economic factors, that comprise the environment.
Therefore, in planning a small-scale forestry project, all
of the
factors in this complex system need to be considered.
A development
worker will have to look beyond technical designs to
understand
the interrelationships among the environmental factors in
determining project feasibility.
What are forest ecosystems?
When viewing a
site for a proposed project a development
worker is looking at a kind of ecosystem.
An ecosystem is the
basic unit in ecology.
It is a complex system including plants,
animals, and humans in their environment that can be
mentally
isolated for purposes of planning.
Within forest
ecosystems, there are producers, consumers,
predators (and scavengers), and decomposers.
Forest plants are
producers and are able to convert sunlight and nutrients
into
plant tissues. Many
of these plant tissues are used as food by
consumers (such as insects, birds, rodents, domestic
animals, and
man). When consumers
eat other animals, they become predators.
Decomposers (chiefly bacteria and fungi), break down dead
organic
materials, absorb
some of the products of decomposition, and
release substances for use by producers.
Interactions among producers,
consumers, predators, and decomposers, which define a
"food web," must be analyzed when planning an
environmentally
sound project.
<FIGURE 7>
49p16.gif (486x486)
When a
small-scale forestry project is implemented, relationships
among living organisms and their environment are usually
changed. If there
have been no major changes in recent years, a
forest ecosystem is probably in balance.
In other words, it is
self-perpetuating and in equilibrium with the
environment. A
decision to change the ecosystem (for example, by harvesting
wood
products) must be made with an awareness of the existing
system,
and an understanding of how the change will affect the
balance
within that system.
How do trees protect the productivity of ecosystems?
Soils are basic
to the productivity of any ecosystem.
Trees
protect soils from wind by serving as wind-breaks, from
water by
intercepting rainfall (so that it can be more slowly
absorbed into
soils), and from the sun by providing shade.
This protection, in
turn, allows dead organic materials to decompose and
oxidize,
releasing nutrients for growth of forest plants.
Dead organic
materials on top of the soils also retain moisture,
providing
water for plant growth.
What can happen
when the protection of trees is taken away
and not replaced by other vegetation may be illustrated
through a
few examples:
--
Winds can pick up and blow away dead organic
materials
and,
thereby, dry out soils, resulting in a lessening of
inherent
site productivity.
--
Nutrient-rich soils may be dislodged by
intense rainfall
and carried
away by surface runoff, again lessening the
productivity
of a site.
--
Trees maintain soil porosity (a measure of
the space in
a soil body
not occupied by solids, important in determining
the degree
of soil aeration), absorb rainfall,
and help
retard runoff which, in turn, protects villages
and
agricultural crops from floods. With
the removal of
trees,
protection against flooding can also disappear.
--
Primary sources of saw timber, fuelwood, and
other wood
and non-wood
products are no longer available for local
needs, or
for marketing.
--
Diversity of plants and animals is affected,
with many
species
disappearing due to a loss of suitable habitat
(including
food and cover).
--
Recreational values such as hunting and
fishing are
often
detrimentally affected.
What is meant by forest succession?
The natural
process of change in the composition of a forest
ecosystem is called forest succession.
These changes take place
in response to changes in the environment and in response to
climatic and site
factors that are changed by the forest vegetation
itself. Primary
succession occurs on newly exposed sites
(such as lava flows and sand dunes), whereas secondary
succession
occurs after the previous forest plants are destroyed or
disturbed
(by fire or agricultural operations, for example).
If undisturbed
for a long time, forest ecosystems evolve from
initially bare areas into a final, stabilized type of
vegetation
into a dominant type of vegetation through a series of
successional
steps. This dominant
vegetation is called the climax
forest type. Once
established, no other tree species can naturally
invade and replace the climax, unless the type is subjected
to
an external form of destruction or disturbance.
Also, a change in
one or more of the climatic or site factors that brought the
forest climax into existence can result in the replacement
of the
type.
<FIGURE 8>
49p18.gif (353x437)
The development
worker should understand these successional
trends. Some
projects can have major impacts on succession, such
as causing erosion of top soils, or reducing the level of
water
tables. These
impacts, in turn, can either be reversible or
irreversible by natural processes.
If reversible, it is possible
to have regeneration of the forest; if irreversible the
results
may be deforestation or desertification.
Areas can be
found around the world where man cleared forests
hundreds of years ago, and the unprotected sites have
remained
barren and unproductive -- an example of the process of
desertification.
Is there an ecological difference between natural and
man-made
forests?
Yes -- there are
important ecological differences between
natural and man-made forests (or plantations) which must be
taken
into consideration when planning a small-scale forestry
project
that is environmentally sound.
<FIGURE 9>
49p19.gif (317x393)
Natural forests
regenerate naturally, either by natural seeding
or from vegetative reproduction of plants on the site.
Often,
but not always, natural forests are comprised of several
native
tree species, with the trees having different ages.
Once
established, and if not disturbed or destroyed, natural
forests will proceed along well defined successional
trends. It
may be necessary to hold back succession and to check the
natural
encroachment of the less valuable trees.
This is why controlled
burning to discourage forest succession is considered a good
forestry practice in some situations.
Man-made forests
are regenerated artificially, either by
sowing or planting -- this is a man-made forest ecosystem.
Depending upon the purpose, man-made forests often consist
of a
single tree species (either native or introduced), with the
trees
having one age.
What are limiting factors?
To occur and
thrive in a given situation, trees must have
basic nutrients which are necessary for reproduction and
growth.
These basic requirements vary with tree species and with the
situation. Basic
nutrients available in amounts closely approaching
the critical minimum need for reproduction and growth tend
to
be limiting factors.
Forest
ecosystems are inherently able to support a number of
plants, animals and humans.
The limits of this support are determined
by the availability of the essential materials for life;
this limit is referred to as the biological potential of the
site.
Obviously, the biological potential of a fertile flood plain
is
higher than that of an arid upland of the same area because
greater amounts of water, more nutrients, and better soils
are
available.
<FIGURE 10>
49p20.gif (353x486)
Often, the
biological potential can be improved by increasing
the availability of limiting factors.
For example, forest production
can often be increased by adding fertilizer or water; or, in
the case where pests (such as insects) are limiting, pest
control
may be required to improve the biological potential.
When considering
limiting factors, it is important to remember
that:
--
Satisfying the most obvious limiting factor
may not
solve the
problem. In fact, increasing the
availability
of one
limiting factor may reveal the presence of
another (as,
for example, when a forester adds fertilizer,
only to
discover that tree growth is limited by too
little water).
--
Changing existing conditions by increasing
the availability
of limiting
factors can harm organisms that have
adapted to
living under the existing conditions.
--
There are limits to the amounts of nutrients
and other
essential
materials that plants can utilize. Too
much
fertilizer
can be as detrimental as not enough.
Can environmental concepts be used in developing successful
small-scale
forestry projects?
By analyzing potential
ecological changes that can be brought
about by implementing a project, and by placing these
anticipated
changes (including both good and bad effects) into
perspective in
terms of environmental impacts, a development worker can
judge the
feasibility of the project with respect to possible
alternatives.
Sound planning
requires awareness of:
--
Environmental concepts as they relate to the
type of
forestry
project under consideration.
--
A basic planning process, as outlined in
Chapter 2 of
this manual.
CHAPTER
IV: UNDERSTANDING FORESTRY PRACTICES
In 1976, a unique afforestation project was funded by a PVO
in
India. It was unique
because all of the land in the project area
was supplied by small farmers, directly linking the fate of
the
farmers to the fate of the project.
The idea was to plant timber
and fuelwood trees on wastelands, and fruit trees on fallow
and
semi-wastelands.
Hopefully, the trees would provide income and
food, while acting to retain water in the soil.
By 1980, the soil
conditions had been improved, and enough income had been
generated
from sale of trees to distribute some of the receipts among
the
farmers.
Why is it necessary to have a knowledge of good forestry
practices?
It is important that a development worker
have some knowledge
of good forestry practices to predict whether ecological
changes
that result from small-scale forestry activities are
benefits or
constraints.
This manual is
not intended to be a "how to" reference on
technical forestry practices.
A list of references on forestry
practices for use in the planning of environmentally sound
small-scale
forestry projects can be found in a bibliography at the end
of this manual.
However, a brief introduction to principles of
selecting trees to grow, improving forest growth, protecting
forests from destructive agents, inventorying forest
characteristics,
and harvesting wood products can provide helpful background
in determining whether or not a given project should be
undertaken.
What trees should be grown?
Natural
regeneration of trees already in an area often dictates
the tree species which should be grown.
In these situations,
a development worker may have little choice but to develop
a project with existing tree species in mind.
Elsewhere, artificial
regeneration through planting of seeds or seedlings may be
needed. With respect
to artificial regeneration, a selection of
tree species must be made.
The question of
what tree species to plant is addressed best
at the local level.
Specific species of trees to be planted under
specific conditions requires planting guides.
Such guides, in
brief, should indicate what tree species are adaptable to
any
given soil, exposure, and degree of erosion.
Generalized planting
guides are available for use in many of the forest
ecosystems
throughout the world.
Often, those guides can be localized to
assist in the planning of a project.
Below are some
broad guidelines for choosing tree species.
See Bibliography for specific tree selection information.
--
Native tree species from the area for which
biological
and
silvacultural knowledge is available are usually the
safest
choice.
--
Introduced tree species should be used with
some caution
until their
suitability has been demonstrated by testing
in the area.
--
Whenever possible, select seeds or seedlings
of known
genetic
superiority.
--
Tree species (native or introduced) selected
for planting
should meet
the following requirements: ease of
obtaining
seed or seedlings, ease of establishment,
immunity to
insect or disease attacks, fast growth,
production
of useful forest products, social acceptability,
and
desirable wood-producing characteristics.
--
Seasonal precipitation patterns are
important determinants
of tree
species to grow; tree species native to
winter
rainfall areas usually will not thrive in summer
rainfall
areas, although tree species native to summer
rainfall
areas are likely to succeed in winter rainfall
areas.
--
As a general rule, tree species can be
successfully
moved from
their home to other sites on the same parallel
of latitude
because of the similarity in climate;
however,
some tree species are so exacting in their
requirements
that even a very small variation in season
or intensity
of site factors may cause failure.
--
Tree species to be planted must fit the
purpose in view,
whether it
be saw timber, fuelwood, wind-breaks, or
watershed
stabilization.
--
To insure successful results, regardless of
the tree
species selected,
the following considerations are important:
when to
plant, how to plant, site preparation
and spacing,
and care after planting.
How can forest growth be improved?
In many
respects, a forest is like a vegetable garden -- a
farmer cannot grow a good crop unless he does some weeding
and
thinning. It is the
same in a forest. When harvesting trees
for
wood products, consideration should be given to improving
the
quality and the condition for growth of the remaining trees
to get
a good wood crop in the future.
The following
diagrams and explanations illustrate situations
where weeding and thinning of trees may improve forest
growth.
<FIGURE 11>
49p24.gif (486x540)
--
Trees 1, 4, 7, and 10 are healthy trees with
full crowns
and are making rapid growth.
These should not be cut
until they
are large enough to be harvested as saw
timber, if
markets are available.
--
Tree 2 has a dead top, is subject to disease
and insect
damage, and
will probably die soon. This tree
should be
cut and
utilized.
--
Tree 3 hinders or suppresses growth of
nearby trees and
reproduction
underneath. It is called a "wolf
tree."
This tree
should be removed.
--
Tree 5 is a forked tree with poor form that
will never
permit its
use in high quality wood products. This
tree
should be
cut and utilized as soon as possible.
--
Tree 6 is a suppressed tree that will never
recover nor
amount to
anything of value. This tree should be
cut
and utilized
as fuelwood, poles, or posts.
--
Tree 8 is a crooked and poorly formed tree
(same recommendation
as for Tree
5).
--
Tree 9 originated as a stump sprout which,
quite possibly,
is rotten on
the inside or will be if it joins the
old stump
very high up. This tree should be cut
and
utilized.
--
Tree 11 has a weak and narrow crown and not
much promise
as a crop
tree. It is called a "whip
tree." This
tree should
be cut and utilized before it dies, breaks
off, or
blows down.
--
Tree 12 is a fire-scarred tree with a
decayed stem. It
should be
cut and utilized.
--
Tree 13 is a dead tree that is probably not
damaging
nearby
trees. If it cannot be used as a wood
product,
there may be
no object in cutting it. Often, a dead
tree may be
beneficial to wildlife.
--
Tree group 14 consists of trees that are
small in diameter
and are
growing too close together. These
should be
thinned,
leaving only the best formed and the most
desirable
ones, permitting their faster growth.
The cut
trees may
have value as fuelwood, poles, or posts.
The situations
illustrated above apply, in general, to
forests which have not been heavily grazed by domestic
animals,
and which have a fairly large number of trees.
In a heavily grazed
forest with a few trees, the best way to improve forest
growth may
be through complete protection.
It is important
to understand that weeding and thinning of
trees will not usually cause trees to grow taller.
Instead,
elimination of crowding among trees will increase diameter
growth,
which has a greater impact on future volume and value.
<FIGURE 12>
49p26.gif (437x600)
A practice that
may not directly improve forest growth, but
often enhances the value of commercial trees, is
pruning. As used
in forestry, pruning consists of cutting off the side
branches of
trees so that the wood subsequently formed on the stem will
be
free of knots.
Knot-free trees are of higher value for saw timber
and plywood; also, poles and posts cut from knot-free trees
possess
greater strength than those cut from knotty trees.
Why is it important to protect forests from destructive
agents?
All agricultural
crops have their enemies. Forests are
not
exceptions. In
particular, fire, insects, diseases, grazing by
domestic animals, and even man can destroy (or at least
reduce)
the productivity of unprotected forests.
Fire
<FIGURE 13>
49p27a.gif (437x437)
In spite of
public
campaigns about potential
fire damage, forest owners
often do not heed the
warnings. At times,
people
fail to understand
that small fires burning
slowly along the ground
can kill small trees, even
though larger trees are
not killed. Only
when a fire gets out of control and threatens
buildings and other holdings do they become aroused.
The components
of combustion - heat, oxygen, and fuel - are
often pictured as a triangle.
The "fire triangle," a graphical
representation of the three components of combustion, is
used in
training people to fight fires.
A fire fighter's job is to break
up this combination by:
removing the fuel, reducing or removing
the supply of oxygen, or reducing the temperature below the
kindling
point.
<FIGURE 14>
49p27b.gif (285x353)
The most
important step in the control of fire is prevention;
an enlightened public is the best form of fire prevention.
Under hazardous
conditions, fire-breaks, or barriers,
are
good insurance. A
satisfactory fire-break can be made by plowing
a strip about a harrow wide around a forest, and then
keeping it
open by subsequent harrowings.
Forest fires,
when they occur, are of three general types,
each of which requires a different form of control:
--
Ground fire, in which the organic soil is
burned, can be
controlled
by saturating the ground with water, if
available,
or by digging a trench down to mineral soil
around the
fire.
--
A crown fire, which spreads through the tops
of trees,
is the most
difficult for man to control; in fact, about
all that can
be done is to check such fires to warn
others of
its danger.
--
The most common type of fire is one that
burns on the
surface. It is most frequently
controlled by scraping
away
flammable fuels immediately ahead of the fire.
While often
destructive, controlled application of fire can
be prescribed in certain forest ecosystems to meet specific
management
objectives, including:
--
Fuel reduction
--
Seedbed preparation
--
Control of competing vegetation
--
Improvement of grazing
--
Wildlife habitat management
Prescribed
burning must be confined to a predetermined area
at an intensity of heat and rate of spread required to
produce the
desired effects. To
achieve success, a development worker should
consult with local fire management specialists in preparing
an
appropriate prescribed burning program.
Insects and Diseases
<FIGURE 15>
49p29a.gif (393x486)
Damage to a
forest
from insects and diseases
is, in general, in direct
proportion to the misuse
of the forest. Fire,
grazing by domestic animals,
and even excessive
cutting of a forest often
lowers the natural resistance
of trees, permitting
insect and disease pests
to get a foothold.
Also, trees growing in an unsuitable environment
can become weakened and invite hosts to epidemics.
When epidemics
occur, there is usually no practical control
except to remove and, if possible, utilize the infested or
diseased
trees. Artificial
control measures, such as the use of
insecticides, must be practiced with extreme care.
In some instances,
use of chemicals can be more damaging to an environment
than the existence of the pest being controlled by the
chemical.
Grazing by Domestic Livestock
<FIGURE 16>
49p29b.gif (353x437)
At times,
uncontrolled
grazing by domestic
animals can be more harmful
to trees (by destroying
seedlings and saplings
through browsing and trampling)
than almost any
other destructive agent.
Furthermore, a farmer or
herder who uses a forest
for a pasture can, under
certain situations, cause a loss not only to himself but to
the
livestock as well.
Forage grown under a forest cover can be
poorer, in both quantity and quality, than that grown in
open
pasture.
Man
<FIGURE 17>
49p30.gif (393x393)
Even though
people
may have the proper technology
to practice good
forestry, man can unknowingly
damage or destroy
forest crops. For
example,
it may become necessary,
through continuing
education and training, to
reinforce the concept of
protecting (and respecting)
highly vulnerable young trees.
Otherwise, mature and fully-stocked
forests may not be attained.
The key to the
problem may be motivation -- people may need
to be motivated to realize the results of protection and, as
a
consequence, a productive forest.
How is the forest inventoried?
A forest
inventory is concerned, for the most part, with
measurements of individual trees, forest stands, growth
rates, and
site quality.
Individual tree
measurements form a basis for estimating the
volume of standing trees that can be harvested for wood
products.
The most commonly made tree measurements are:
--
Diameter of the tree stem, usually taken at
1.3 meters
above the
ground for standardization and convenience;
diameters
are commonly measured in centimeters.
--
Height of the tree, either total or to the
top of that
part that
can be sold, heights are measured in terms of
meters.
Techniques of
obtaining diameter and height measurements are
outlined in references on forestry practices at the end of
this
manual.
Given knowledge
of diameter and height, the volume of a tree
can be determined from a volume table.
This table specifies the
volume of a tree, usually in terms of cubic meters, from
diameter
and height measurements.
If appropriate volume tables are not
available for use, consult local or regional foresters who
have
specific knowledge regarding the calculation or volume of
native
species.
Care should must
be exercised in estimating the volume of
shrubby trees with crooked, multiple stems, rather than
distinct
ones. Often, local
measurement customs may be employed in these
situations.
An important
objective of many forest inventories is to
obtain an estimate of the number of trees in relation to the
volume of trees, on a hectare basis, in a forest.
Unless there
are a few trees of exceptionally high quality involved in
which
case a complete tally may be made only a sample of trees is
selected for measurement.
In general, tree measurements recorded
on sample areas (one-tenth-hectare plots, for example) are
expanded
to the total area under consideration.
Many options of plot
size and sampling design exist; those selected by the
development
worker should be consistent with the purpose of the forest
inventory.
The average
growth of trees is, by definition, their volume
divided by their age.
While the volume of a tree is relatively
easy to approximate, determination of age is more
difficult. In
general, there are three common methods used to estimate the
age
of a tree -- by appearance (size, shape of crown, and
texture of
bark), by branch whorls, or by annual rings.
Unfortunately, tree
growth is not characterized by annual rings in many forest
ecosystems
of the world, particularly those occurring in the humid
tropics.
Knowledge of
average growth of trees is important in helping
to determine when wood products should be harvested from
trees.
Typically, average growth of trees increases slowly, attains
a
maximum, and then falls more gradually.
As mentioned in Chapter 7
of this manual, the ages at which maximum average growth is
attained
is often regarded as an ideal time to harvest trees for
wood products.
<FIGURE 18>
49p32.gif (353x353)
Evaluation of
site quality is important in identifying productivity,
both present and future, of forests.
Knowledge of
productivity, in turn, is useful in long-term planning.
Site
quality is the aggregate of all environmental factors
affecting
growth and survival of trees in a forest.
Various approaches, too
numerous to present in this manual, have been devised to
evaluate
site quality. The
approach selected by a development worker
should reflect local forest conditions and, to be useful,
require
only easily obtained measures for interpretation.
How are trees harvested for wood products?
Harvesting wood
products involves considerable skill, tools,
knowledge and equipment to do a creditable job.
Axes, saws,
wedges, and sledges are all that are necessary to
fell trees and cut them into desired lengths.
Power-chain saws
are finding their place in many harvesting operations.
However,
while they make the harvesting job easier, their high cost
can
make them uneconomical, except in large operations.
<FIGURE 19>
49p33a.gif (317x437)
After trees are
felled and cut into desired lengths, they
must be carried or pulled to a loading point.
If tree lengths are
too heavy to carry, a simple drag or sled can be used to
pull
them, using an available power source such as a tractor or a
domestic animal.
A universally
employed method of loading tree lengths on a
vehicle is the "cross-haul" method.
One end of a chain or cable
is attached to the underside of the vehicle to be loaded,
and the
other end is placed under the tree lengths to a tractor or
team of
domestic animals.
Two poles, large enough to bear the weight of
the tree lengths, are placed against the vehicle, as shown
below.
<FIGURE 20>
49p33b.gif (486x486)
Harvesting trees
for wood products should be done with an eye
toward good forestry practices.
Before a tree is cut, the following
questions should be answered:
--
Is the tree to be cut the size needed to be
usable?
--
Is the tree the best species available for
the intended
wood
product?
--
Is the tree ripe, or does it show signs of
deterioration
from old age
or from insects and diseases? Evidence
of
deterioration might suggest that the tree should be cut.
--
Is the tree growing rapidly, and does it
have a full
crown and
smooth bark? If so, the tree is
probably
vigorous and
perhaps should be retained as part of the
growing
stock for future harvesting.
--
What kind of plant reproduction will result
from the
cut?
It should be remembered that preventing
regeneration
of brush and
other comparatively worthless plant
species is
one of the principal aims of good forestry.
Throughout many
countries in the world, fuelwood is harvested
not by felling and cutting trees into desired lengths, but
rather
by simply picking up branchwood, leaves, and other woody
materials
from a forest floor.
Often, women and small children are responsible
for fuelwood gathering, which can take them far distances
from their homes.
<FIGURE 21>
49p34.gif (317x317)
Many secondary
and other by-products of the forest, such as
fruits and nuts, are also harvested through gathering
efforts,
again in many instances by women and children.
CHAPTER
V: UNDERSTANDING INSTITUTIONAL
LIMITATIONS
The Ministry of Natural Resources is the lawful Philippine
governmental
agency created to strike a balance between exploitation
and replenishment of natural resources, and between conservation
and use. The
objectives of the Ministry are: to
assess the
status of the country's natural resources for their
programmed
exploitation and use; to provide for their replacement; to
conserve,
revitalize, develop, and manage the country's natural
resources
for present and future generations; and to increase the
productivity of the country's natural resources in reference
to
their current exploitation and use.
What are institutional limitations?
In reality, two
sets of limitations determine the degree of
success of a small-scale forestry project.
First, there are
natural limitations, involving biological and physical
relationships.
Second, there are institutional limitations to forestry
activities, which are every bit as important as natural
limits in
the planning of an effective project.
Institutional
limitations, unlike natural limitations, are
established by man to meet specific conditions and,
therefore, can
be modified by man in response to changes in legal, social,
and
economic situations.
Why are legal considerations important?
Perhaps the most
important of the institutional limitations
of a small-scale forestry project involves legal
considerations,
which are limitations sanctioned by law.
In general, two primary
areas of law must be regarded in the formulation of a
project:
laws which address ownership and use of the products of
natural
resources, and laws which regulate the use of land or land
tenancy.
<FIGURE 22>
49p36.gif (393x393)
A development
worker should consult with local authorities to
be sure that a small-scale forestry project can be
implemented
within the existing legal framework.
When are social considerations important?
Legal
considerations, as discussed above, are "formalized
rules" that guide the conduct of man.
Less explicit, but equally
important, are guidelines derived from other cultural
features of
a society -- from tradition, religion and folklore.
As with laws,
these social
considerations must be reflected in the decision-making
process. Failure to
do so can lead to adverse reactions
that can severely restrict one's freedom.
Cultural
considerations determine, in part, the options
available to a planner of environmentally sound small-scale
forestry projects.
From the flood plains of the Mekong River
Basin to the fragile desert environments of northwestern
Africa,
situations can be found in which social patterns restrict
implementation
of a particular forestry practice.
Social
constraints are often difficult to assess.
They are
not usually susceptible to easy solution and can easily be
ignored. However, to
do so is folly. To increase the
possibility
of environmentally sound forest management, it is essential
to
include local people in planning objectives of the project.
Training and public education are also important.
How are economic considerations incorporated into planning?
A development
worker must select the best course of action in
implementing a forestry practice, given alternative
plans. The
decision among alternatives to select often requires
economic
considerations.
Although a part of the institutional framework,
economics involves certain patterns of rational analysis,
the
techniques of which are well known for many situations.
To make an
economic analysis of alternative courses of
action, three general objectives can form a basis of choice.
These objectives are:
--
Maximization of benefits.
--
Maximization of the returns on investment.
--
Achievement of a specified "production
goal" at the
least cost.
Analysis of
these objectives can give a development worker
and local people a better understanding of the economic
implications
of selecting a particular course of action.
To analyze the
first two objectives, responses to alternative
courses of action and costs of implementation must be
known. Some
information can be obtained from previous local
experience. If
the course of action is newly adopted, the development
worker can
seek available prediction techniques.
To satisfy the
third objective, goals should be established
for various levels of production.
These goals are most effective
if set according to values of local residents, coupled with
long-range
goals derived through the political process.
CHAPTER VI: BACKGROUND FOR
PLANNING:
MULTIPLE-USE FORESTRY PROGRAMS
Eucalyptus is a fast-growing tree, which is also valuable
for
lumber and fuelwood.
To plant more Eucalyptus in Upper Volta, all
ground cover was cleared, including bushes with edible
leaves.
The primary source of food for the local people was porridge
topped by a sauce made of these leaves.
As it turned out, the
Eucalyptus leaves are not edible.
Therefore, the health of the
local people was seriously impaired, as they lost an
important
food supply.
What is meant by multiple use?
The term
"multiple use" has many different meanings.
When
applied to land areas, multiple use refers to the management
of a
variety of natural resource products and uses on a unit of
land.
The relation of the natural resources to one another may be:
--
Competitive, where one must be sacrificed to
gain more
of another.
--
Complementary, where both increase or
decrease together.
--
Supplementary, where a change in one will
have no
influence on
another.
When applied to
a particular natural resource, multiple use
refers to the use of the natural resource for various
products and
uses. For example,
trees may be harvested for saw timber, fuelwood,
or posts, or they may be used to produce fruit, seeds or
flowers. Forage may
have value as feed for domestic livestock, or
for watershed stabilization.
Water may be used for drinking,
irrigation, or fish habitats.
Here again, the use can be competitive,
complementary, or supplementary.
In practice,
multiple use often involves both units of land
and natural resources.
Demands on a particular natural resource
(trees) for a specific use (fuelwood) place demands on the
land
area where the natural resources are produced (forests).
<FIGURE 23>
49p39.gif (600x600)
When should multiple-use forestry be practiced?
From a
biological, social, and economic standpoint, multiple-use
forestry should be practiced whenever possible.
A basic
objective of multiple-use forestry is to manage the natural
resources
of a forest for the most beneficial combination of present
and future uses. The
idea of maximizing the benefits derived from
the natural resources of a forest is not new, but it has
become
more important as people's demands for limited and often
interrelated
natural resource products and uses increase.
It is important
to keep in mind that multiple-use management
of forests can be achieved by any one of the following
options, or
by any combination of the three:
--
Concurrent and continuous use of the natural
resource
products and
uses obtainable from a forest which ensures
production
of different goods and services from the same
area.
--
Alternating or rotating uses of natural
resources for
specified
periods of time.
--
Geographical separation of uses so that
multiple-use is
practiced
across a mosaic of strata in a forest.
All of these
options are valid multiple-use forest management
practices which can be applied in the most suitable
combinations.
From society's
point of view, multiple-use forest management
can involve a broader set of requirements than concern an
individual
person. Generally,
society is more interested in preserving
benefits for future generations, while an individual often
makes
decisions based on desires to satisfy relatively short-term
needs.
If possible, effective multiple-use forestry projects should
accommodate
the full spectrum of today's needs and provide for
tomorrow's requirements.
How are multiple-use benefits and costs measured?
Deciding whether
or not a project is worthwhile requires
measurements of anticipated benefits derived from all of the
natural resource products and uses of a forest and of costs
that
will to be incurred in implementing the project.
Measurement and
analyses of benefits and costs associated with alternative
projects
may be necessary before a development worker can select the
best course of action.
<FIGURE 24>
49p40.gif (393x486)
Measurement of Benefits
Benefits include
those obtained from fuelwood, timber, forage
for animals, both domestic and wild, water production,
recreation,
etc. Estimates of
these anticipated benefits can be obtained from
earlier work, from local experience, or through prediction
techniques.
Measurements of
natural resource products and uses can be
summarized in a table form, known as a "product
mix." Such a
table describes multiple -use by quantitatively presenting
all of
the products and uses obtained from a particular area.
A product
mix developed before a project is implemented can form a
reference
for comparison with product mixes representing conditions
after
implementation.
These comparisons show what is gained and lost in
multiple-use terms and therefore provide a basis for
determining
project feasibility.
TABLE 1
Product mix for alternative forestry practices being
considered
for implementation in a hypothetical temperature forest
ecosystem.
Item
[T.sub.0] [T.sub.1]
[T.sub.2]
[T.sub.3]
Uneven-
Even-
As is Convert
aged
aged
Timber cut ([m.sup.3])
0.0 9.0
4.9
3.8
Timber growth ([m.sup.3])
4.2 2. 5
5.5
5.2
Livestock (kg gain)
0.068 0.48
0.0045
0.27
Wildlife
0.021 0.034
0.032
0.033
(number of deer)
Water (cm)
15.0 22.0
16.0
18.0
(*) On one hectare, if things remain as they are
([T.sub.0]), the annual
output will be
4.2 cubic meters ([m.sup.3]) of timber growth, enough
forage for 0.068
kilograms (kg) of livestock gain, 0.021 deer,
and 15
centimeters (cm) of water. No timber
will be cut.
(*) With conversion of moist sites to grass ([T.sub.1]) the
annual output
will be 2.5 cubic
meters of timber growth, enough forage for
0.48 kilograms of livestock gain, 0.034 deer,
and 22 centimeters
of water.
Approximately 9.0 cubic meter of timber will
be cut
on each hectare.
(*) Columns [T.sub.2] and [T.sub.3] contain the elements of
uneven- and even-aged
forest management
systems, respectively.
(*) It is important to note that, if [T.sub.0] was judged as
best by
assessing the
advantages and disadvantages in natural resource
product and use
response, the existing management system should
be continued.
It may be necessary to convert physical
expression of what is
gained and lost in multiple-use terms to corresponding
expressions
of monetary or other economic value.
If information is available,
this conversion can be achieved by simply multiplying physical
units by appropriate monetary values on a per unit
basis. In most
cases, it may not be possible to assign specific monetary
values
to the products and uses.
However, other indicators of economic
worth can possibly be assumed through personal judgements of
local
situations.
Measurement of Costs
Costs of
implementing small-scale forestry projects usually
reflect a given economic situation over time.
Information on
costs that reflect local conditions may be available and, if
so,
can be used to estimate costs of implementing various
projects.
Otherwise, a development worker may have to:
--
Estimate necessary inputs of labor time,
equipment time,
supervision
time (if required), and materials.
--
Determine overall costs by multiplying the
above inputs
by current
wage rates, machine rates, and material
costs, and
then summing the product.
Here again,
monetary values may have to be approximated from
personal judgements of local conditions and customs.
Economic Analysis
As mentioned in
Chapter 5 of this manual, to make an economic,
analysis of a project, such as a small-scale multiple-use
forestry
project, general objectives are usually considered to form a
basis
for choice. In
reality, an economic analysis of such projects
consists of several economic analyses, each of which is
designed
to help a development worker and local people make a better
decision.
Individual
economic analysis may yield a "one-answer solution"
the problem of selecting a project that maximizes returns
to the land. A group
of economic analyses, based on different
criteria, will result in an array of items for
decision-making.
Such an array could include the following:
--
Estimates of multiple -use production (such
as cubic
meters of
saw timber or kilograms of forage) associated
with
alternative small-scale forestry projects.
--
Estimates of implementation costs of project
alternatives.
--
Least-cost solutions for different goals of
multiple-use
forestry.
--
Gross and net benefits associated with a
range of possible
project
alternatives.
--
Investment returns and benefit-cost ratios
associated
with
different project alternatives.
--
Project cost over time by using carefully selected
discounts
and interest rates which will be applied for
the entire
length of the rotation.
Consult Bibliography for additional information.
When is multiple-use forestry environmentally sound?
With careful
planning, and consideration of all of the possible
natural resource products and uses obtainable in a forest,
multiple-use forestry can be practiced in an environmentally
sound
manner. Perhaps the
concept of planning for multiple-use can be
illustrated with an example.
Under certain
conditions, harvesting of wood products and
grazing domestic animals are two uses that can occur
together,
making full use of many forest ecosystems.
Harvesting trees for
wood products reduces the forest cover, which can improve
forage
in terms of quantity and quality.
With improved forage, it may be
possible for additional domestic animals to be grazed.
In these
situations, it can be to the advantage of a development
worker and
local people to consider potential multiple benefits from
both
uses, and plan accordingly.
However, it
should also be remembered that in other situations,
particularly in arid ecosystems, forage can only grow in
the shaded micro-environments underneath trees, as survival
is not
possible in the open.
Here, it may become necessary to favor one
use as dominant, even though multiple-use may be a desired
goal.
<FIGURE 25>
49p44.gif (317x486)
Whether
harvesting (and more generally, growing) trees and
grazing by domestic animals can be joint uses of a forest
also
depends, in large part, on the kinds of animals being
grazed. A
development worker should realize that:
--
Grazing by cattle can be harmful in forests
comprised of
seedlings
and young succulent trees; cattle often browse
and trample
these trees.
--
Grazing by goats and sheep, which eat almost
anything,
is
particularly damaging to forest ecosystems.
Therefore,
use of a
forest by these animals may have to be
limited.
--
Similarly, grazing by hogs can be quite
destructive, as
they uproot
seedlings and young succulent trees to eat
the fleshy
roots.
In general, when
forests are used for harvesting trees for
wood products and grazing by domestic animals, carefully
planned
harvesting operations can be carried out in conjunction with
controlled grazing to minimize detrimental environmental
consequences.
Are there alternatives to multiple-use?
Early use of
forests, either natural or man-made, usually
emphasized a single product -- such as a particular wood
product.
Although these forests had the potential for other uses,
little
attention was paid by local people to those natural resource
products and uses that were abundant.
As development
takes place in Third World countries, peoples'
tastes change and cash income becomes available or
increases.
Primary products and uses resulting from forests being
managed for
a single product may not meet demand.
Consequently, pressure is
on the planner of small-scale forestry projects to recognize
multiple-use possibilities and to effectively maximize the
various
possible uses of the forest in planning projects.
CHAPTER VII: BACKGROUND FOR
PLANNING:
HARVESTING TREES FOR WOOD PRODUCTS
Under the direction of the Food and Agriculture Organization
(FAO)
of the United Nations, new forest plantations were created
in
Andhra Pradesh, India.
Plans called for these plantations to be
fenced in until ready for harvesting.
However, local farmers who
were desperately in need of lumber and fuelwood, and not
aware of
the possible future benefits of the plantations, poached so
heavily
that the new crop of trees was destroyed.
What wood products can be made?
Forests can be
managed in a manner that is similar to agricultural
croplands, although forestry is a long -term business
while agricultural crops are usually grown on annual
seasonal
rotations. Like
other crops, trees for wood products are harvested
and used locally or sold for profit.
Considerations in
harvesting trees for wood products involve recognition of
the
various products possible, understanding the specifications
and
quality standards of the products, and knowledge of when to
harvest
and when to market the products.
The discussion
below focuses on a selection of wood products
commonly produced in Third World Countries.
For a more detailed
discussion of the subject, see the bibliography at end of
this
manual.
Fuelwood
As discussed in
Chapter 8 of this manual, an increasingly
important use of the forest is for fuelwood.
In general, most
reasonably well seasoned tree species can be used for
fuel. However,
the value of a tree for cooking and heating purposes is
roughly equivalent to its weight.
For a given volume, heavier
woods generally produce greater amounts of energy.
Usually, there
are no specifications or quality standards for fuelwood,
except
those established locally.
Charcoal
Charcoal is the
carbon residue of partially burned wood.
(In
making charcoal, enough air is admitted to a kiln to burn
the
gases driven off by the burning wood, but not enough to
consume
the residue.) The
process of making charcoal is complex and
requires technical information beyond the scope of this
manual.
See Bibliography.
Poles, Posts and Pilings
Poles, posts and
pilings are examples of round wood products.
Soundness, straightness, and a gradual taper from butt to
top are
general requirements for good round wood products.
Sizes are
variable, depending upon specific uses and local
demands. Some
tree species do not decay or are termite-resistant; others
are
not. When poles and
posts are to be cut from trees subject to
decay or termites, treatment with chemical preservatives may
be
required. If
chemical preservatives are used, care must be exercised
to prevent harmful effects to both the environment and the
handlers of the products.
Chemicals should be chosen carefully
and warnings on the labels observed.
Saw Timber
Tree lengths
intended for sawing into boards, planks, or
other construction materials are known as saw timber.
Many tree
species that grow to sufficient size are potentially usable.
General criteria for saw timber are:
--
Tree lengths up to 30 centimeters and larger
in diameter,
and at least
5 meters to the nearest branch of
appreciable
size.
--
Tree lengths that are reasonably straight
and sound.
There are many
saw timer specifications and quality standards
in practice. The
development worker should start with local
customs and marketing opportunities, and then by working
with the
community, improve standards and create new markets.
Pulpwood
Wood that is
converted into paper products is known as pulpwood.
Not all tree species can be used for pulpwood, although the
yield of pulp is higher in the heavier woods.
Establishing a pulp
and paper mill requires guaranteed sources and quality of
wood.
Such projects generally do not provide a market for small
producers.
Other
Local demands
for other wood products may also exist, and a
development worker should be aware of these production and
marketing
possibilities. Other
wood products include bolts for handles,
mine timber, excelsior.
Are secondary and other by-products important?
Oils, resins,
gums and pharmaceutical materials can play a
role that is as important (if not more so) to local people
than
sawtimber, pulpwood, and other more marketable wood
products.
Also, many fruits and nuts from forest plants provide
foodstuffs
for both local consumption and sale.
The value of
these secondary and other by-products of forests
is often overlooked in small-scale forestry activities.
Therefore,
a development worker, in consultation with local people,
should include the demand for these products in planning.
When should trees for wood products be harvested?
Regardless of
the wood product, both biological factors and
economic considerations dictate when trees should be
harvested for
a particular wood product.
From a
biological standpoint, trees should not be cut until
they have grown at least to the minimum size required for
product
utilization.
However, after attaining minimum size, the question
is what is the optimum or most advantageous size for
harvest?
Often, foresters
are guided by average growth rates of
forests in determining when to harvest trees for wood
products.
As mentioned in Chapter 4 of this manual, trees should not
usually
be allowed to grow beyond the point of maximum average
growth,
which is the age of maximum growth productivity.
Foresters call
this age the rotation age.
<FIGURE 26>
49p49.gif (437x437)
Biological
factors, in addition to average growth rates, must
often be considered by a development worker when determining
the
time to harvest trees for wood products.
These factors include:
--
Pathological factors, which affect the
growth of forests
both in
terms of mortality and the amount of defect in
living
trees. As forests increase in age, they
become
increasingly
subject to diseases such as heart-rotting
fungi.
--
Entomological factors, which affect growth
of forests in
a manner
similar to pathological factors; also, entomological
factors
direct attention toward forest composition,
age
structure, and vigor. Forests comprised
of a
single tree
species, all of which are essentially the
same size,
are particularly susceptible to attack by
destructive
insects. In addition, as trees get
older
and decline
in vigor, they become more susceptible to
attack.
--
Silvicultural factors often influence
decisions as to
time of
harvesting. Among the more important
silvicultural
factors are seed production
characteristics,
methods of
obtaining regeneration, competition from less
desirable
tree species, and maintenance of desirable
soil
conditions.
Economic
considerations also help determine when to harvest
trees for wood products.
For example, if the decision is based
solely on market factors, the time to harvest is when profit
is
maximized. Profit is
maximized when returns generated from harvesting
wood and selling a wood product minus costs incurred in
harvesting and processing the wood, are the greatest.
The age at
which profit is maximized is often less than the rotation
age
determined through biological considerations.
Other factors
that one may need to consider in deciding when
to harvest trees for a particular wood product include:
--
Local harvesting techniques, which could
limit the
handling of
large tree lengths.
--
Available manpower, which could restrict the
extent of a
harvesting
operation.
--
Existing market outlets, which dictate the
kind of wood
required for
wood products and affect demand on particular
kinds of
trees.
In general, the
time when trees should be harvested for wood
products is quite variable.
Rotations of 8 to 12 years, for
example, can be prescribed for fuelwood plantations in arid
regions; on the other hand, rotations approaching 100 years
are
often followed in more temperate forests set aside for saw
timber
production. Rotation
ages are unknown in many tropical forest
ecosystems, such as mangrove.
Can trees for wood products be harvested without
environmental
damage?
Serious
environmental consequences result when harvesting is
done without regard for other potential forest uses.
Many desirable
environmental effects can be achieved, however, through a
well-planned harvesting operation that is conducted
correctly.
To plan an
environmentally sound small-scale harvesting
operation, in which wood products are obtained with minimum
damage
to the environment, the development worker should recognize
that
forests may also serve other purposes such as soil
protection and
water production, grazing by domestic animals, wildlife
habitat,
and recreational activities.
Soil Protection and Water Production
Harvesting of
wood products may have to be curtailed or
modified when soils are in such a critical position that
they
require a forest cover to hold them in place.
In such situations,
the value of protection is usually greater than the use of
trees
for wood products.
Similarly, if
substantial erosion will develop as a result of
harvesting operations, subsequent costs of stabilizing the
soils
could make harvesting trees for wood products excessively
expensive.
Again, harvesting may have to be restricted to prevent
environmental damage.
In many forest
ecosystems throughout the world, it has been
demonstrated that water production from upstream watersheds
can be
affected by forestry practices.
In certain situations,
water
yields are increased after the removal of forest cover, with
the
increase attributed to a decrease in
evapotranspiration. The
increased water, in turn, can be beneficial to people living
in
areas of limited water supplies.
Uncontrolled
removal of forest cover can also increase peak
water flows in streams (especially following major storm
events),
causing the flooding of valuable downstream lands.
In addition,
these large volumes of water frequently accelerate erosion
processes
and carry increased sediment loads.
<FIGURE 27>
49p52.gif (317x437)
Therefore, it is
important that harvesting operations be
carefully planned when soil protection and water production
goals
are included in the project.
To obtain a proper balance:
--
Forego harvesting trees for wood products on
sites where
a forest
cover is necessary to hold soils in place, or
where the
removal of the forest cover will result in
harmful
erosion. (Quite often, so-called
"protection
forests" are found on steep slopes or in such inaccessible
places that
harvesting is very difficult.)
--
Take care to minimize detrimental impacts on
soils when
it does
become necessary to harvest trees for wood
products on
the above sites; this can be accomplished by
harvesting
only when soils are relatively stable and not
subject to
erosion (either by wind action or by the
movement of
water); by using light equipment to pull
tree lengths
to a loading point; and by imposing practices
to remove
debris left after harvesting that minimize
the
disturbance to soil surface.
--
Harvest trees for wood products as well as
increase
water
production by exercising good forestry practices.
Keep in mind that forests can be
managed to reduce
evapotranspiration, thereby increasing water yields;
this can be
accomplished by a reduction in forest densities,
converting
from a forest cover type to an herbaceous
cover type (grasses, forbs, or shrubs)
that uses
less water,
or by a combination of both.
--
Do not remove all of the forest cover from
extensive
areas
(particularly those on steep slopes with shallow
soils),
especially if downstream lands are subject to
flooding. Also, leave some
forest cover in areas subject
to wind
exposure.
Grazing by Domestic Animals
As mentioned in
Chapter 6 of this manual, growing trees for
wood products and grazing by domestic animals can occur
together
in many forest ecosystems.
In these situations, it can be advantageous
to consider possible benefits from both uses.
Grazing may have
to be eliminated (or at least restricted)
during actual harvesting operations, particularly in
environments
with unstable soils that are subject to erosion.
If not curtailed,
the combined impact of harvesting trees for wood products
and continued grazing by domestic animals can result in
serious
environmental damage.
Also, it may
become necessary to limit grazing during the
period immediately following a harvesting operation, if the
area
is to be reforested by planting seeds or seedlings soon
after
harvesting. Once the
trees have become well established and
beyond the reach of animals, controlled grazing can usually
be
resumed.
Wildlife Habitat
Another possible
use of forests compatible with growing trees
for wood products is wildlife production, whether or not for
food.
As trees grow in size, more shade is cast onto the
ground-cover,
altering plant species composition and density.
With changes in
ground-cover conditions, wildlife populations often change
in kind
and amount.
By harvesting
trees for wood products with an eye toward
specific food and cover requirements for wildlife, desired
game
and non-game habitats can be maintained or created.
For example,
careful planning and execution of harvesting operations,
according
to good forestry practices, creates multiple edges and
otherwise
increases diversity in forests which, in turn, can increase
the abundance of game and non-game animals.
Recreational Activities
Certain areas,
depending upon their natural qualities, should
not be disturbed. As
long as harvesting operations are in accordance
with good forestry practices, however, recreational
activities
will probably not be jeopardized.
Opening up roads and, if
necessary, installing bridges to remove wood products can
enhance
recreational opportunities but may also lead to increased
colonization
by subsistence farmers.
What alternatives exist?
Forest owners
who raise trees for wood products do so because
they expect returns in excess of expenditures of money,
time, and
effort necessary to grow the trees.
When returns are large, the
owner is usually interested in growing more trees and in
maintaining
the forest in a productive condition.
However, if returns are
small (or if there are no returns at all), the owner may
decide to
abandon the commercial forestry enterprise altogether.
Wood products
are often considered to be a principal operation
in forestry.
Therefore, the value of the trees is often
realized only when they are harvested.
For commercial projects
such as these, there is no real alternative.
But, as discussed in
Chapter 6 of this manual, the development worker and the
local
people must keep in mind that forests should be managed for
the
most beneficial combination of present and future uses,
including
both tangible uses (such as deriving wealth from the selling
of
wood products) and intangible uses (including soil
protection,
water production, and wildlife habitat).
CHAPTER
VIII: BACKGROUND FOR PLANNING:
FUELWOOD MANAGEMENT PROGRAMS
A fuelwood plantation program implemented by the Government
of
India was spared the resentment and sabotage that afflicted
many
other programs because it took the local farmers into
account. It
educated the people about the need for leaving the
plantations
intact, appointed them "guardians of the forests"
and employed
them in various positions as part of the project.
Not only did
the local people leave the new plantations unmolested, but
they
guarded them from other poachers.
Why is fuelwood management important?
Throughout the
world, demands for fuelwood are increasing.
Many households and even whole communities in Third World
countries
are entirely dependent upon wood for cooking and heating.
With increasing
demands for fuelwood, both natural and man-made
forests are often subjected to environmentally unsound
harvesting
practices, including complete deforestation.
Frequent and
continuous harvesting of fuelwood and other forest biomass
for
energy poses dangers of soil compaction, soil erosion, and
nutrient
and organic material depletion.
Environmental consequences of
these dangers include dislodging of plant, animal, and human
populations, degradation of soils and site productivities,
and
reduction of genetic diversities of native species.
Over time, it is
likely that even more people will become
dependent on fuelwood for energy.
If properly managed, use of
woody materials as energy, has obvious advantages:
a dependable
and renewable supply of energy; an even spread of
developmental
activities through reforestation of marginal lands; and the
generation of employment opportunities in rural areas which
are
invariably closer to forests.
The world stands
to gain from the use of fuelwood and other
forest biomass for energy, necessitating environmentally
sound
planning.
What is the heat content of wood?
The heat content
of wood is proportional to the density (or
weight per unit of volume) of wood.
Laboratory tests have shown
that the heat content of a kilogram of wood, regardless of
the
tree species, is nearly 21,000 kilojoules.
A joule is a unit of
energy approximately equal to 0.24 of a small calorie, the
latter
being the amount of heat required at a pressure of one
atmosphere
to raise the temperature of one gram of water one degree
Celsius.
With the
information outlined in the diagram on the following
page, the heat content of a cubic meter of wood can be
estimated.
How are energy input and output relationships used in
planning?
Converting wood
energy for human use also requires an energy
input, the latter being a human effort or the use of other
fuels.
In an energy balance calculation, this energy input should
be
subtracted from the total energy to determine the energy
gain
through wood utilization.
Some forest
ecosystems require energy input only at the time
of fuelwood harvesting and during its transportation to the
point
of use. Other
forest ecosystems require a continuous energy input
from the beginning to the end of a rotation; additional
energy is
also needed in harvesting, transporting, and (if necessary)
processing
the crop.
<FIGURE 28>
49p57.gif (534x594)
To plan an
environmentally
sound small-scale
fuelwood management program,
and a program that
produces a net energy
gain, a development worker
and the local people
should recognize the relative
advantages and disadvantages
associated with
fuelwood management in
different kinds of forests.
<FIGURE 29>
49p58.gif (353x317)
Natural Forests
A Natural Forest
Natural forests usually
have a mixture of native
tree species and ages over
a relatively large area.
In terms of producing
woody materials for
energy, these forests have
several advantages:
--
Humans need invest no energy in the
establishment of the
forest,
since the forest regenerates itself naturally.
--
Less energy is usually needed to maintain
the forest in
an
acceptable growing condition.
--
Net energy production in these forests can
be quite
high,
particularly in young stands.
<FIGURE 30>
49p59.gif (437x437)
Disadvantages of
managing
natural forests of
a multiple tree species
are well known, and include
the facts that:
-- Little information is
available to describe
overall growth rates.
-- Forest management is
relatively complex, and
techniques are only partially
developed.
-- Harvesting wood for
wood products, including
fuelwood, is frequently
difficult.
-- Reproduction of shade-intolerant
trees, if desired,
can present a
problem.
A major energy
investment from human sources occurs at the
end of a rotation, primarily for harvesting, transporting,
and
processing the crop.
Man-Made Forests
Man-made forests
usually consist of an age sequence of one-aged
blocks of a single tree species, often planted with uniform
spacing. As a source
of fuelwood and biomass for energy, these
forests seem to be an attractive proposition because:
--
Management can be prescribed relatively
precisely and be
carried out
by skilled workers.
--
Growth over a rotation can be forecasted
relatively
accurately,
and the rotation length can be adjusted to
give maximum
or optimum production to meet specified
energy
needs.
--
Net energy production is relatively large
(larger than
for natural
forests in many situations).
--
Management and utilization can be mechanized
more easily
than in
natural forests
--
Management of man-made forests, particularly
in
temperate
zones, is founded on a long history of
research. There is a growing
body of information on
management
of arid forest lands and tropical rain
forests.
Questions about
the use of man-made forests as a source of
energy arise from the following concerns.
--
They can present a greater risk of fire,
insects and
disease, and loss of soil
fertility.
--
Aesthetic, wildlife, and recreational values
may be
diminished.
--
Quite often, there is a heavy investment of
financial
resources
and energy in establishment and maintenance.
--
Once planted, options for alternative land
and natural
resource
uses are restricted.
A major
investment of energy from human sources is required
for rotation, and to harvest, transport, and process the
crop.
Agro-Forestry
As discussed in
Chapter 9 of this manual, growing of trees in
conjunction with production of agricultural crops and, at
times,
with grazing by domestic livestock is called
agro-forestry. Trees
grown within many agro-forestry systems can be utilized as
fuelwood.
Advantages of agro-forestry in fuelwood management are:
--
Tree species are either self-regenerating or
readily
available
for planting.
--
Maintenance and protection costs are usually
minimal.
--
Energy output is profitable at the level of
the village,
even for the
farmer.
--
No major capital investments are needed.
--
Transportation costs are minimal.
There are also
disadvantages:
--
Planting trees in conjunction with agricultural
crops
may reduce
the yield and quality of both crops, in some
cases.
--
Soil fertility may be reduced, particularly
in "slash-and-burn"
situations.
Which trees should be grown?
As mentioned in
Chapter 4 of this manual, a development
worker may not have a choice in the tree species which will
be
grown, particularly in natural forests.
When a selection can be
made, however, there are desirable characteristics that
should be
stressed for choosing tree species to grow for
fuelwood. However,
the question of what specific tree species should be grown
can
best be answered on a local basis.
Some desirable characteristics
are:
--
Tree species with relatively high wood
densities
(meaning,
high weights per unit volume) and energy
yields
should be favored whenever possible.
--
A relatively short rotation period is often
an objective
of fuelwood
management programs -- when this is so,
selection of
rapidly growing tree species (especially in
the
establishment and initial growth stages) should be
made.
--
Production of wood for energy is sometimes a
by-product.
With some
species of prosopis, for example, branches are
harvested
for firewood although the trees are used to
provide live
fencing.
Also, as
mentioned in Chapter 4 of this manual, if a tree
species is to be introduced, in this case for fuelwood, it
is
important to test its suitability before making a commitment
to a
large scale planting.
How does fuelwood management affect the environment?
Effects on the
environment from harvesting fuelwood (specifically,
a total exploitation of forests for energy purposes) are
essentially the same as those resulting from a total forest
removal
for saw timber, pulpwood, or other wood products.
What follows
is a brief discussion of some of the more important
environmental
impacts which might be expected when natural and man-made
forests
are intensively harvested for fuel, and proper management is
lacking.
Natural Forests
Removal of trees
and dead organic materials for fuel also
removes nutrients from a site, withdraws food from soil
microorganisms
upon which the nutrient cycle depends, and reduces the
productivity of soils.
Other consequences may be increased soil
compaction, loss of soil porosity, an increase in erosion,
leaching
and nutrient loss, and a reduction (or even complete
suppression)
of natural regeneration.
Intensive gathering of fuelwood
and other forest biomass for cooking and heating may result
in a
loss of nutrient capital and, therefore, a loss of
productive
capacity. Whenever
possible, a balance should be achieved between
a demand for fuelwood and the need to maintain site
productivity.
<FIGURE 31>
49p63.gif (437x437)
Removal of dead
organic materials from a forest floor (such
as residues from harvesting other wood products) is often a
practice
in areas of high fuelwood use and may result in much harsher
climates near the ground.
Removal of these materials can increase
solar radiation and re-radiation, cause extreme
temperatures,
result in a drier soil surface, and reduce the subsequent
accumulation
of biomass.
It should be
mentioned, however, that by not removing at
least some of the large amounts of residues of harvesting
operations,
these materials will become fuels for wildfires.
Here,
controlled removal and use of residues for energy can have
desirable
consequences.
Removal of
forest cover by intensively harvesting fuelwood
can result in destruction of habitats for certain wildlife
species,
causing many of these species to migrate to other areas.
Damage is greater where forests are cleared, although even
where
selective cutting is practiced, wildlife species are
adversely
affected.
Again,
selective, as well as clearcut harvesting for wood
products often results in accumulations of residues that may
discourage regeneration and make forest management for high
quality
wood products more difficult.
Regeneration of forests, both
naturally and artificially, can be facilitated by the
removal of
these residues for energy use.
<FIGURE 32>
49p64.gif (437x437)
Removal of
residues of harvesting operations can improve
local acceptance of cut areas, since regeneration occurs
sooner
and use of forests for many other purposes is established
more
quickly after cutting.
Clearcut areas may be marginally more
acceptable if residues are removed than otherwise.
The quality of
regeneration may be improved by removal of
unmerchantable, small, and otherwise defective trees for
energy
use, provided that suitable seed sources are available and
planting
is undertaken.
When weeding and
thinning are practiced to improve the quality
and the condition for growth of the remaining trees, use of
the
cut trees for energy is often a custom.
In general, finding a use
for weedings and thinnings can make this practice more
attractive.
Man-Made Forests
In many Third
World countries, man-made forests that are
maintained for continued fuelwood production are probably
desirable.
Many of the environmental impacts that have already been
discussed with respect to the exploitation of natural
forests are
applicable to short rotations of man-made forests, but often
with
greater intensity (such as 10 to 20 years).
Short rotation
tree crops, such as those undertaken in fuelwood
management, provide a quickly recurring harvest of biomass
devoid of aesthetic and organic benefits associated with
natural
forests. However, by
satisfying urgent needs for fuelwood, manmade
forests can furnish a safety valve against local pressures
to
exploit natural forests in energy-short societies.
Can fuelwood management be integrated with other forestry
activities?
It is entirely
possible, and in many instances quite appropriate,
to integrate fuelwood management with other forestry
activities.
The development worker should encourage such an integration
whenever feasible.
However, in encouraging integration, it
is important to consider the following points.
--
Identify, disseminate, and apply existing
knowledge of
the
management and use of forests (both natural and man-made)
for
sustained and maximum energy yields, with
consideration given to environmental effects, such as
prevention
of soil erosion in the tropics and control of
desertification in arid and semi-arid zones.
--
Take into account the most important social
and economic
impacts,
including the problem of increasing distances
required to secure
domestic fuels.
--
Develop new silvicultural and forest
management systems
to maximize
energy yields within the framework of
multiple-use. The most promising
options appear to be
short
rotation forestry, whole tree utilization, growing
coppice
forests (in which renewal of a newly cutover
area depends
primarily on vegetative reproduction like
sprouting),
and intermixing of so-called high energy
crops (such
as sugar cane) with tree species.
--
Encourage local (particularly rural)
communities to
accept new
forest management practices and technologies.
There is an
indispensable need to bridge the gap between
theoretical
insight and practice. Social and
cultural
understanding is a key element.
Coupled with environmental
education,
appreciation of local practices can
lead to
implementation of effective forest management
and use.
CHAPTER
IX: BACKGROUND FOR PLANNING:
AGRO-FORESTRY PROJECTS
With problems of deforestation in mind, and with an
appreciation
of Panama's needs for fuelwood and new agricultural lands,
the
Agency for International Development (AID) of the United
States
mounted a carefully planned and coordinated program of
agro-forestry,
forest resources, and agriculture.
This integrated
program has been considered one of AID's most successful
environmentally-sound
development of projects, as it relates directly to
the needs of local people.
What is agro-forestry?
The forest
ecosystems of the world, and particularly the
Third World, are being subjected to ever increasing pressure
by
subsistence farmers and herders.
Agro-forestry offers a means of
bringing the activities of rural people into greater harmony
with
the forest environment by developing a complementary
association
between trees and agricultural crops.
Agro-forestry is
the integration of forestry and agriculture.
It combines growing trees with production of agricultural
crops
and, in some agro-forestry systems, grazing by domestic
livestock
simultaneously or sequentially on the same unit of
land. The
objective of agro-forestry is to create sustainable land
management
strategies which increase the overall yields of the land,
and
which are also compatible with the environment and local
cultural
practices.
Properly
applied, agro-forestry is a system that is both
productive and environmentally sound and it has the
potential not
only to increase food, fuel, and income for farmers or
herders on
marginal lands, but also to help stop destruction of the
world's
forests lands.
Is there a general agro-forestry system?
There is no
universal agro-forestry system. Each
set of
conditions found in a particular forest ecosystem require a
different
agro-forestry system.
Often, more than one agro-forestry
system can be applied to any single set of conditions.
Some of the many
agro-forestry systems are listed below:
--
Agri-silviculture systems -- the management
of land for
the
production of agricultural crops and forest products.
--
Silvo-pastoral systems -- the management of
forests for
the
production of wood, as well as for raising domestic
livestock.
--
Agro-silvo-pastoral systems -- the
management of land
for the
production of agricultural crops, forest products,
and domestic
animals.
--
Multi-purpose forest tree production systems
-- the
regeneration and management of forest
tree species for
wood,
leaves, and quite often, fruits that are suitable
for food
and/or fodder.
Primitive
agro-forestry has been practiced by forest dwellers
for thousands of years.
It is only recently that scientific
attention has been focused on these practices.
This has occurred
because forest ecosystems are being heavily impacted by ever
increasing populations and because of a realization that
western
agricultural methods are usually inappropriate.
Ideally, an
agro-forestry landscape would be dominated by
trees. Trees would
be in woodlots, in the middle of agricultural
plots, dotted on pastures, or in rows on the perimeters of
fields
to serve as fences and wind-breaks.
With such a system, a farmer
could produce his energy needs, building and fencing
materials, as
well as improving the soil fertility, fodder, and food
supply.
Wildlife would be sustained to supply extra protein.
A surplus
for market might even be produced.
Below are some case examples of agro-forestry systems:
-- In Indonesia, the
state forest corporation has a program
for developing
forests, not only as providers of wood
and protectors of
the environment, but as sources of
food, medicinal herbs,
resin, and silk. This system
also involves
growing rice between young tree plants; it
has more than
doubled paddy production within two years.
-- Bangladesh has a
pilot
scheme underway
to
settle 300
families on 600
hectares to grow
bamboo
and practice
horticulture.
-- In the highlands
of
Colombia, cattle
are
grazed on Kikuyu
grass
under alder
plantations.
Alder roots fix
nitrogen
in the soil which
increases
forage yields.
-- It was found in
Senegal
that millet
yields (an
important grain
staple),
when grown under
nitrogen
fixing Acacia
trees, were
increased as much
as 250
percent and were
350 percent
higher in
protein.
<FIGURE 33>
49p68.gif (393x393)
-- Farmers in
Central America imitate the structure and
diversity of
tropical forests by planting a variety of
crops with
different growth habits. Plots as small
as
0.1-hectare may
contain a dozen or more species, each
with a different
form: coconut or papaya with a lower
layer of citrus,
a shrub layer of coffee or cacao, tall
and low annuals
such as corn and beans, and finally a
spreading ground
cover of squash.
-- New Zealand sheep
ranchers have found that their animals
are able to
maintain their body temperatures with less
energy loss in
the modified climate of pastures in open
tree stands.
The combined production of timber and
sheep provides a
greater net profit than does either
forests or
pasture alone.
Although there
may be social, economic, and physical constraints
on the proper development of a forest ecosystem, with
imagination and careful study, the potential benefits of
agro-forestry
can be great.
What are the environmental benefits of agro-forestry
projects?
Among the
environmental benefits of many agro-forestry
systems are:
--
Recycling of nutrients by trees when their
leaves,
flowers,
fruit, and branches fall to the ground and
decompose. This addition of
biomass also provides mulch
which can
reduce tillage and lower evaporation rates.
--
Tapping of moisture and nutrients by trees
at depths not
reached by
agricultural crops or pasture plants.
--
The ability of trees to more efficiently
extract and
recycle
nutrients from soil through the
activities of
mycorrhizae
(the structure
formed when
a beneficial
fungus
invades a tree
root,
generally improving
the roots
ability to function).
Phosphate-releasing
ability of
some tree-root
mycorrhizae
can also be of
advantage in
providing the
essential
nutrients to
associated
agricultural
crops.
Most legumes and
the plants
of some other
families fix
nitrogen from
the air in a
form available
for plant
use.
<FIGURE 34>
49p70.gif (393x393)
--
Protection against erosion
by the
perennial
roots of
trees. Tree
roots can
also improve soil permeability by favoring the
formation of
stable aggregates and by penetrating tight
soils and
some types of hardpans.
--
Improvement in the quantity and diversity of
wildlife by
providing
a greater variety of ecological niches.
Predators of
harmful insects and rodents are
particularly
desirable.
--
The provision of support for some types of
climbing
crops (black
pepper, for example).
--
An increase in diversity and spatial arrangement
of
plant
species which can sometimes deter insect
proliferation.
--
Manipulation of light by pruning tree crowns
to control
flowering or
fruiting of associated crops and of the
trees
themselves.
--
Modification of a microclimate favorable to
reducing
temperature
extremes, raising humidity, lowering wind
velocities,
and reducing rainfall energies.
--
An approximation of natural ecological
systems that more
effectively
use vertical space and capture solar energy
more
efficiently.
What are the social and economic benefits of agro-forests?
A major problem
facing subsistence farmers and herders in
many Third World countries is obtaining a steady supply of
food or
income throughout the year, as agriculture only produces at
irregular
harvesting intervals.
Conventional forestry practices are
usually unattractive to farmers because of problems of cash
flow
and the long investment period.
Agro-forestry offers opportunities
for subsistence farmers and herders to diversify production
of wood and non-wood products to maintain regular employment
and
income during periods between harvests of agricultural
crops.
There is
considerable scope in designing agro-forestry systems
with high productivity by utilizing plant and/or animal
species most acceptable to local people.
Specific social and
economic benefits include:
--
Economic insurance provided by the store of
saleable
wood.
--
Lessening of the danger of catastrophic
losses that can
occur with
monocultures which are dependent upon the
vagaries of
climate, markets, pest outbreaks, and the
availability
of fertilizer, machine parts and
pesticides.
--
Direct economic benefits of fuelwood, fence
posts,
poles,
sawlogs, fruits, fodder, honey, medicinal products,
and other
forest products, without having to
transport or
buy them from other sources.
--
The presence of trees which usually reduces
weeding
costs.
--
Use of trees to mark property boundaries,
and sometimes
to serve as
shelterbelts (see Chapter 10 of this manual)
or as a
guard against land usurpation.
--
Increased opportunity to move from
destructive land uses
which return
profits over the short term to environmentally
sound
practices with long-term benefits without
diminishing
productivity.
--
Early reduction of the economic investment
of establishing
tree crops
by the proceeds of thinning and tree
crown
manipulation to produce fodder, fence posts, and
fuel.
What problems might arise in developing agro-forestry
projects?
An aim of a
small-scale agro-forestry project is to develop a
desirable replacement that at least matches the productivity
of
any existing or alternative system.
There are some potential
disadvantages that should be considered in planning an
agro-forestry
project for a specific area.
Environmental Considerations
--
Shading by tree crowns can lower the yields
and quality
of
associated agricultural crops beneath the trees.
--
Competition between trees and associated
crops for
nutrients
and water can reduce production of either or
both crops.
--
Competition for space both below and above
ground can
reduce
overall yields.
--
Tree harvesting can cause mechanical damage
to associated
crops.
--
The presence of trees can make mechanization
or tilling
by hand
difficult.
--
The moisture content of the air layer at the
level of
the
associated agricultural crops may be increased and
favor fungal
and bacterial diseases.
--
Trees take up and store nutrients over long
periods of
time.
There can be a loss of nutrients from site
when
the trees
are harvested.
--
Trees retain part of the precipitation in
their crowns,
which can be
important in dry areas of light rains.
In
some cases,
stemflow can adversely redistribute precipitation
from heavy
rains.
--
The environment of an agro-forestry system
may promote
populations
of animal pests.
Social and Economic Considerations
--
In some cases, economic yields of
agro-forestry systems
can be lower
than for monocultures, even though the long
term
environmental advantage may be great.
--
In other cases, the combined value of trees
and
associated
agricultural crops may be eventually higher
than that of
a monoculture. Where population
densities
are high in
relation to land resources, survival often
depends upon
agricultural crop cycles. There may be
resistance
by the rural poor to planting and managing
trees whose
products can only be realized over much
longer
cycles.
--
Agro-forestry involves complex associations
and, therefore,
is less
amenable to experimentation and analyses
than are
monocultures. This problem is
compounded by
the scarcity
of trained personnel for improving existing
or
developing new systems.
--
There is generally a lack of knowledge of
the potentials
of
agro-forestry on the part of decision makers.
Consequently,
they may be
reluctant to release funds for
experimentation. Without
adequate experience, there is
a danger of
creating resentment at both the rural and
decision
making levels from unsuccesful projects based
on
insufficient information. The
development of projects
based upon
reports of "miracle trees" is an example.
What are the elements in planning environmentally sound agro-forestry
projects?
Agro-forestry
projects can vary in complexity from simple
schemes to improve the practice of shifting cultivation to
intensely
managed intercropping systems.
An ultimate goal of agro-forestry
projects, however, is the conservation of the forest
ecosystem while satisfying the needs of local farmers for
goods
and income.
Planning any
type of agro-forestry project will require:
--
Surveys of needs, customs, and abilities of
local
people;
these needs might also include the possibilities
of
developing cottage industries.
--
Study of both existing and potential markets
for future
development.
--
Examination of constraints of economics,
infrastructure,
and the
organization of local community working groups.
--
Decisions on which agro-forestry systems
would be most
appropriate
for local community needs, the ecological
setting, and
existing markets.
--
Selection of management techniques,
including planting
and
harvesting schedules, to maximize yields of both
trees and
farm crops.
--
Provisions for monitoring production and
changes in soil
fertility;
this information should be used as feedback
to improve
the system.
For
intercropping (agro-forestry systems designed for a mixture
of trees and farm crops), careful consideration must be
given
to the following:
<FIGURE 35>
49p75.gif (393x393)
--
Optimum mixtures and
spacing
patterns of trees
and farm crops, which maximize
the
production of
both.
(Particular care
should be
given to possible
complementary and conflicting
relationships
between
species.)
--
Foliage characteristics and leaf fall of the
various
species, and
their influence on competition
for solar
energy and nutrients.
--
Shade tolerance of agricultural species and
the
effect of
forest species on energy levels at the
forest
floor.
It is important
to keep in mind that a agro-forestry project
depends not only on the quantity and quality of joint
products
that may be produced, but also largely upon the
socio-political
strategies built into the project.
CHAPTER X:
BACKGROUND FOR PLANNING:
SHELTERBELT AND WIND-BREAK PLANTINGS
In the 1970's when the drought began in Mauritania, nomads
settled
on the green dunes of Nouakchott.
They naturally chopped down the
surrounding Euphorbia bushes and Mesquite trees.
As the number of
people increased, the remaining vegetation was
trampled. Without
trees, and as the drought became worse, the dunes became
destabilized
and the sands began to shift.
In response to this situation,
a PVO funded a project to replant indigenous Euphorbia
bushes and Mesquite trees as wind-breaks.
These plant species
survived remarkably well, considering the shortage of
rainfall.
What are shelterbelts and wind-breaks?
Shelterbelts are
barriers of live vegetation, usually trees
and shrubs, planted in one or more rows at right angles to
the
direction of prevailing wind,.
Their primary purpose is to reduce
the velocity of winds across agricultural crops and pastures
or
around buildings and livestock enclosures.
Shelterbelts have been used successfully in
temperate
climates since the middle of the 19th century.
They have been
effective in improving the microclimate, reducing wind
erosion,
increasing crop and livestock yields, reducing heating
costs, and
providing fodder, fuelwood, and other wood products.
It has also
been demonstrated that shelterbelts can be even more
effective
under the harsher conditions of arid lands.
On these lands, the
value of thrifty tree species may be even higher than that
of
other products of land use.
A distinction is
often made between shelterbelts and wind-breaks,
but there is no consistent agreement on differences in the
terms. The term
shelterbelt is most often used to describe wind
barriers around agricultural fields and pastures, while the
term
wind-breaks is commonly used to describe wind barriers
around
buildings, gardens, and orchards.
Both shelterbelts and wind-breaks
serve the same purpose and the terms are often used
synonymously,
as they are in this manual.
Planning a shelterbelt operation requires a
development
worker to consult with local inhabitants to determine goals
of
establishment and management, and to provide a foundation
for
long-term development.
How do shelterbelts function?
When wind approaches
a shelterbelt, its velocity is moderated
on both sides of the shelter.
When the shelterbelt is dense and
not very permeable to wind, most of the flow is deflected
upward.
Pressure on the down-wind side is reduced, causing
turbulence
which greatly reduces velocity, but only for a relatively
short
distance down-wind of the shelter.
If a shelter is
more permeable to wind, the wind flow is
divided -- part of the flow is deflected upward (as with the
less
permeable belt) and part penetrates through the belt.
There is
usually less turbulence and the reduction in velocity is
felt a
greater distance down-mind.
For both
permeable and impermeable shelterbelts, the effect
on wind velocity is related to the height (H) of the tallest
trees
in the belt and is expressed in multiples of this
height. Normally,
the effect is felt at distances of 20H to 40H.
Therefore,
shelterbelts should:
--
Be permeable with a vertical crown density
of about 50
to 60
percent, but no greater than 80 percent.
--
Have the greatest height possible for tree
species
adaptable to
the area.
--
Have a suitable width and structure.
<FIGURE 36>
49p78.gif (540x540)
How should shelterbelts be structured?
Shelterbelts are
most often planned so that they will develop
a triangular cross section, with the highest trees in the
center
flanked by shorter trees and shrubs on the edges.
However, rectangular
cross sections are quite adequate for shelterbelts of two
to four rows, provided that at least two of the rows have
foliage
down to the ground.
A decision on
how wide a shelterbelt should be depends upon
the amount of land which can be economically devoted to
planting,
and the minimum number of the rows required to maintain the
desired
permeability.
Actually, narrow shelterbelts of moderate
density are just as effective as wide belts.
Shelterbelts of
five rows are generally efficient in both
humid and dry climates, and they are not difficult to
maintain.
However, in considering economic worth, account must be
taken of
possible
multiple-uses of the shelterbelt.
For example, wood
products, shelter for animals and bees, food and cover for
wildlife,
and fodder for livestock may be important considerations in
addition to wind protection.
For these considerations, shelterbelts
of more than five rows may be desirable.
One-row shelterbelts
are risky since holes may develop and funnel the winds.
Spacing within
rows depends in part upon the tree and shrub
species planted and the type of management to be followed
once the
plants mature. In
general, seedlings are planted close together
to obtain early closure.
As the plants mature, every other one is
removed. Final spacing within rows should be from 1 to 1.5
meters
for shrubs and 2 to 3 meters for trees.
Spacing between rows
should range from 3 to 4 meters to allow for subsequent
cultivation.
<FIGURE 37>
49p79.gif (437x437)
What patterns should be
considered?
Design of
shelterbelt
systems largely depends
upon the velocities and
directions of local winds.
If there are definite prevailing
winds, a series of
parallel shelterbelts
should be established,
preferably at right angles
but no less than 45 degrees
to the direction of
the winds. More
often,
winds blow from various
directions which would require a checkerboard pattern.
In some
cases, dense shelterbelts may be planted across the major
wind
directions and less dense belts planted across minor
directions.
In irrigated
areas, shelterbelts should be located mainly
along irrigation channels.
In rolling topography, shelterbelts
are more effective if planted along ridgetops.
Therefore, a
compromise is sometimes necessary to take into account both
the
direction of winds and the cultural and physical
characteristics
of the area.
For sheltering
livestock, a compact shelterbelt in a U, V, X
or square configuration can be used.
Shelterbelts around buildings
are often planted in L-shaped pattern across the prevailing
winds.
<FIGURE 38>
49p80.gif (540x540)
Shelterbelt Planting in an L-shaped Pattern
Shelterbelts
should be planted a suitable distance from
buildings to prevent excessive snow accumulation due to
downdrafts
on the leeward side of the shelter in cold climates.
In the case
of permeable shelterbelts, snow accumulations extend from
about
10H to 25H.
In hot and dry
climates, dense shelterbelts placed too close
to buildings may result in oppressive heat.
These belts should be
permeable and located at least 30 to 45 meters (but no
greater
than 90 to 120 meters) from the buildings.
What spacing should be used between shelterbelts?
Planning the
spacing of shelterbelts depends upon site factors,
climatic patterns, and growth rates of the tree and shurb
species. Normally,
shelterbelts should be spaced at about 20
times the height of the tallest trees, particularly across
the
major wind direction.
If a checkerboard pattern is used, shelterbelts
across minor wind directions may be spaced up to 60 times
the height. Since
height growth of arid land species is not great
(only 10 to 15 meters under irrigation), the best that one
can
plan for in those areas is an average of 200 to 300 meters
between
major shelterbelts.
What characteristics should the plant species have?
Native and
introduced three and shurb species which have
proven their adaptability to the soils and climate of the
region
should be used in shelterbelt plantings.
In addition to the
characteristics listed in Chapter 5 of this manual, plants
selected
should have certain other characteristics, including:
--
Resistance to the force of winds.
--
Strong tap roots.
(Lateral rooted tree and shurb
species will
compete with fields and pastures they are
supposed to
protect).
--
Dense, uniform crowns, thrifty growth,
perennial
foliage, and adequate height.
--
Resistance to disease, and insects, and cold
or heat.
--
Value for wood or other products (such as
forage).
Although use of
a single tree or shrub species simplifies
management, it is not often that one plant will have all of
the
above attributes.
Often, two or more species will be required to
develop a shelterbelt that will provide adequate
protection. For
example, the low growth form of acacia makes it useful for
planting
in the outer rows of shelterbelts in dry climates; the inner
rows may consist of tamarisk, casvania, and eucalyptus.
Single
plant species, particularly those that sprout after cutting
(such
as eucalyptus), can sometimes be managed to provide full
vertical
shelter by alternately cutting the outer rows of trees and
allowing
the cut trees to complete the shelter.
<FIGURE 39>
49p82a.gif (540x540)
How are shelterbelts established?
<FIGURE 40>
49p82b.gif (317x317)
The first step
in
planning a shelterbelt
system involves identification
of the need for the
technique by local farmers.
Following need
identification, a commitment
to undertake such
a project should be accompanied
by training and formation of a community organization.
Cooperative efforts are essential to set goals, purchase or
grow
planting stock, obtain equipment, organize work crews, and
to
carry out management objectives.
<FIGURE 41>
49p83a.gif (393x393)
Technical
essentials
include site preparation,
careful handling of planting
stock from the nursery
to the planting site,
protection against fire
and grazing animals, and
cultivation after planting
at least several times
each season. Source
of
seed is, of course, equally
important in the growing of planting stock for any locality.
Terracing and contour planting may be necessary in some
areas.
Often, a soil-improving crop of legumes may be grown between
the
rows of plantings in the belt for the first few years to
foster
growth of the belt.
<FIGURE 42>
49p83b.gif (285x285)
In dry climates,
irrigation
after planting is
necessary. The soil
should be well prepared
and a permanent source of
water should be assured.
A water transportation and
application system must be
planned. The number
of
waterings and the amount
of water applied depends
upon climate, species, and soil.
For example, in a sandy loam
area receiving 150 to 200 millimeters of rainfall with a dry
season of 8 months, about 6 applications of 10 liters for
each
seedling is probably sufficient to assure survival.
In both dry
and humid climates, survival of 90 or 95 percent is
considered
necessary for shelterbelts.
<FIGURE 43>
49p84.gif (285x285)
At least two
cultivations
must be planned during the first
few years following establishment,
and at least one cultivation must
be made during the following two
or three years.
Heavier soil will
require more intensive cultivation.
Root pruning of some
species which have spreading root
systems, such as eucalyptus, must
also be planned.
These roots can
grow into adjacent fields and compete with crops.
How should shelterbelts be managed?
Properly managed
shelterbelts can yield products from thinnings,
sanitation cuts, prunings, and rotational cuts without
greatly reducing the barrier effects.
Indeed, cuttings are often
necessary to maintain the structure and vitality of the
shelterbelt.
For example, to stimulate height growth and the formation
of straight stems, pruning of the lower branches early in
the
development of the belt is advisable.
Coppicing trees will require
the greatest amount of pruning.
To stimulate diameter
growth, thinning can be required.
For some tree species, thinning
could be started during the fourth or fifth year.
Sanitary cuts
and thinnings will occasionally be necessary during the life
of
the shelterbelt to remove dead, diseased, or insect-infested
trees.
Rotational cuts
will provide the greatest quantity of wood
products. Each
successive cutting can be dome so that at least
half of the rows are left standing.
Therefore, half of a five-row
shelterbelt can be cut; meanwhile, the other half should
furnish
the necessary protection until the regrowth of the first cut
reaches the desired density.
It should be planned that the first
cut is done on the down-wind side at about half the normal
rotation
age. Starting with
the second cut, a normal period of
rotation could be followed.
Replanting, of course, follows each
cut. In the case of
two-row shelterbelts, one row is cut and the
second is left standing.
The cutting
cycle for shelterbelts depends upon the growth
rate of the trees and shrubs.
However, a rough estimate for tree
species used for wood products is 15 to 20 years (roughly
the same
as the rotation cycle).
What are the environmental effects of shelterbelts?
The effects of
shelterbelts are almost without exception
beneficial to the environment.
Major effects include:
--
Lessened evaporation and transpiration,
increased water
available
for plant use, and reduced water stress.
--
Increased snow catch in cold climates and
improved soil
moisture
relations.
--
Decreased wind damage to plants and animals.
--
Checked wind erosion and lessened sand
movement and its
abrasive
action.
--
Controlled air temperature by leveling out
extreme
fluctuation.
--
Provision of organic material for soil
handling and
improvement.
--
Provision of an aesthetic value in areas
where trees are
scarce.
In arid regions,
where water is limited and where shelterbelts
must be watered, favorable environmental effects must be
carefully weighed against the value of water.
Adverse environmental
effects can also occur if the trees harbor birds, insects or
disease organisms which are harmful to the crops.
Any symbiotic
relationship (in which two dissimilar organisms live
together in
close association) between diseases of specific crops to be
grown
and the alternate hosts of the diseases should be studied
before
shelterbelt species are selected.
CHAPTER XI: BACKGROUND FOR
PLANNING:
REFORESTATION AND AFFORESTATION PROJECTS
To improve the natural forest, the Government of Malaysia
has
conducted a cooperative tree-planting program with local
villagers.
As local people were hired to do the planting, they were
quite protective of the plantations.
As a result, poaching and
grazing damage have been minimal.
What is meant by reforestation and afforestation?
The term
reforestation is normally used when an area that
once supported forests is to be reforested; this includes
areas
such as abandoned agricultural lands, bush lands, or areas
already
forested but poorly stocked or stocked with inferior species
that
should be replaced with more productive species.
The term afforestation
is generally applied to projects whose goal is to plant
areas previously devoid of trees.
Most often, the term is used
for forestry projects in arid regions.
Actually,
differences between the two terms are slight and
need not be belabored.
The term reforestation will be used in
this manual to mean planting treeless areas, changing the
composition
of existing forests, or converting from other land uses to
environmentally sound forest production.
When is it important to plan reforestation projects?
Throughout most
of the Third World countries, native forests
have been greatly depleted, and in many cases, completely
eradicated.
Plans for the reforestation of these areas cannot be made
too soon. Forests
are essential to the quality of life and, in
most cases, to life itself and the life support system.
As the number of
people living in these areas increases, the
quality of the land on which they must live simultaneously
declines.
Unless solutions are implemented, the impact will be felt
not only locally but globally.
The consequences of not initiating
effective solutions immediately are accelerated soil loss
and land
deterioration, environmental degradation, and further
impoverishment
of the world population.
As mentioned in
Chapter 3 of this manual, if undisturbed for
a long time, forest ecosystems will evolve through successional
steps into a climax type.
Once established, no other tree species
can naturally invade and replace the climax, except if the
type is
subjected to some external form of disturbance.
Forest succession
is one of the basic concepts of ecology.
Practical implications of forest succession
in tree planting
means that climax tree species cannot be grown successfully
on
severely degraded sites; conversely, pioneer species, if
planted
on good sites, will eventually give way to climax
species. This
principle is especially important in planning reforestation
of
depleted sites. The
original vegetative cover of these sites has
been stripped and the topsoil is gone.
To attempt to reforest
with climax types may be difficult or impossible even though
the
land may once have supported magnificent forests.
Conditions may
be so bad that the area will only support shrubs and other
pioneer
plant species.
Reforestation might require planning a series of
successional vegetative stages to arrive at a desired forest
cover.
What environmental factors are important?
In planning a
reforestation project, forest successions
should be studied by a development worker -- this includes
studies
of historical records and interviews with local
inhabitants. Physical
and climatic factors prevailing in the area can also be very
important. Some that
should be considered are:
--
Soils -- texture, structure, depth, water
holding capacity,
and
fertility as they may affect plant species
adaptability.
--
Precipitation -- amount and distribution
through the
seasons and
how they may affect planting and survival.
--
Temperature -- seasonal fluctuations and
extremes which
may affect
transport, storage, and planting of seedlings.
--
Site factors -- aspect, slope, topography,
and geology
as they may
affect plant species selection.
--
Wind -- direction, velocity, and dryness as
they may
affect
survival in certain areas.
All factors that
influence the water balance are critical for
survival and growth of every plant.
This is particularly true in
arid regions.
Attention should be given to lower valleys and
flats that receive runoff and soil materials from higher up,
since
these sites may receive water several times the natural
rainfall.
Therefore, these areas may have the potential for growing
higher
value species than have the upland sites of the area to be
reforested.
Activities of
man and his animals usually have the greatest
impact on a forest ecosystem and can be severe constraints
on
reforestation.
Questions to ask in planning are:
Is fire now
being used in agriculture or for range improvement?
Are grazing
lands held in common and how heavy is land use?
What are the
foraging habits of grazing animals (browsers, bark eaters,
and
grazers)? Is it
customary for the area to be reforested to support
herds of domestic livestock with a variety of food
preferences?
Answers to these
and other questions may require control of
both human and animal activity, enforcement of rules
limiting
access to the area to be reforested, and development of a
fire
control program.
What tree species should be selected?
In addition to
the general criteria listed in Chapter 5 of
this manual, the choice of tree species to be planted should
be
made on the basis of adaptability to the local environment,
and
ability to meet the needs of local inhabitants.
Generally,
native species growing in the area and conforming
to local needs and traditions are the safest choice for
reforestation.
However, there may be no native trees, or the native
species may not produce the products desired in some
areas. In
such instances, the possibilities of introducing tree
species with
characteristics superior to those of native species should
be
considered.
Generally,
introduced species should be used with a great
deal of caution until their performance has been
demonstrated by
trials in the area.
Transfer of either native or introduced
species from one locality to another should be governed
primarily
by similarity of climate and soil in the new area within the
natural range of the species.
Erosion control
is often used as justification for reforestation
projects. Certainly,
this is a worthy objective, but projects
can fail unless they also yield other products of direct
value to the local inhabitants.
Careful thought must be given by
a development worker to the properties of the wood and the
growth
characteristics of the tree species which make them valuable
to
local economies.
When trees are
grown for lumber, qualities such as
straightness, strength, and workability are desirable.
Posts and
poles require durability in addition to strength and
straightness.
Fuelwood species should have a high caloric value and low
water
content, and produce large volumes of wood.
Trees with dense wood
make the best charcoal.
Deciduous trees without spines and with
leaves high in nutrients (such as many legumes) make good
forage
species. If gum extraction
is one potential use of the forest,
high yield species and varieties will, of course, be
preferred.
In certain
cases, it is possible to select trees which will
serve several purposes, such as tall trees with flowers
which will
attract bees, or good charcoal producing shrubs bearing
essential
oils or leaves for fodder.
More often, two or more species will
be necessary to provide the products desired and to take
advantage
of differences in planting sites within the area to be
reforested.
What should be considered in obtaining planting stock?
In undertaking a
small -scale reforestation project, it is
safest to obtain seedlings from a permanent nursery in the
region.
However, if the nursery is too far from the planting site or
if
none exists, establishment of a small temporary nursery may
be the
only alternative.
The closer the nursery is to the planting site,
the better.
Elaborate site preparation for such a nursery is not
required and temporary buildings as shelter will
suffice. Plans
for a dependable supply of water (preferably a gravity
system) are
critical.
Persons working
at the nursery should have training. At
a
minimum, this should include a permanently employed overseer
and
several assistants if only on a temporary basis.
Unless it is
planned to use bare root stock for reforestation,
the temporary nursery site need not be located on fertile
soils. Instead, the
seedlings can be grown in containers filled
with soil. There are
any number of containers which can be used.
These range from unfired, hand made clay pots to
compartmentalized
styrofoam trays and individual containers made of peat (both
of
which are produced commercially).
Bag or tube containers made of
inexpensive plastic film and filled with soil are very
popular in
many parts of the world.
Growing seedlings in containers is labor
intensive, but great efficiency may not be an important
consideration
for small scale operations.
Plastic fiIm and
other types of containers
minimize damage to the
seedling and drying out of
the root system; they also
do not require temporary
storage facilities at the
planting site as do bare
root stock. However,
the
labor of transporting containerized
seedlings to
the planting site can be
great. If flexible
containers
are used, a source
of cohesive (but not
too
heavy), soil must be used.
<FIGURE 44>
49p91.gif (437x437)
Where should seeds be obtained?
If it is
necessary to establish a small nursery, the origin
of seed for the tree species to be planted is of utmost
importance.
A source of high quality seeds must be found early in the
planning stages.
Failures have often occurred by using seed from
inferior trees or from trees which grow in unsuitable
environments.
The following principles should be considered:
--
Seed collection should be based on the
similarity
between the
climate of the collection zone and the
planting
zone.
--
If native species are to be used, collection
should be
limited to
local seeds of known origin. Generally,
the
safest
choice should be seed trees within about 200
kilometers
distance and within 500 meters elevation of
the planting
site.
--
In the case of introduced tree species,
seeds should be
collected
under environmental conditions as similar as
possible to
those of the area to be reforested. It
is
important
when seeds are ordered from abroad to consider
the exact
geographic location of the source. For
example, the
seeds of eucalyptus from one province in
Australia
may be more resistant to salinity than those
from another
origin.
--
Seeds should not be collected from each tree
in a forest
stand, only
from carefully selected, superior trees
which are
distinguished by such qualities as
straightness, fast growth, and branching habit.
Planning may
require provisions for training local people in
seed collecting.
Once the seeds are collected, provision must be
made for extracting, cleaning, and drying.
Most tree species do
not produce seeds each year but have abundant seed years 2
to 5
years apart. For
that reason, plans should include storage
facilities. Seeds of
some species may require refrigeration.
Other species can be stored at room temperatures for
extended
periods without losing viability.
What is necessary in planning site preparation?
Site preparation
will probably have to be considered in
reforestation. In
humid climates, preparation is usually minimal,
particularly on abandoned agricultural lands.
On brush lands, the
shrub species present must either be removed or subdued by
cutting
and/or burning until the newly planted seedlings can become
established. Where
there are undesirable tree species, girdling
or cutting may have to precede planting.
In dry climates,
site preparation can be more complicated.
It may be necessary to consider massive treatments (such as
deep
plowing or the construction of terraces) to hold the limited
water
from precipitation.
Other less intense land treatments could
include furrows, trenches, pits, or berms constructed along
contours.
In very dry areas, it may be necessary to plan water
harvesting systems in which runoff from a larger catchment
area is
diverted onto a smaller area where trees are planted.
On severely
eroded land that is heavily gullied, whether in
humid or in dry climates, extensive site preparation may
have to
be considered. Soil
conservation structures (including gully
plugs, rock dams, or temporary brush dams) may have to be
planned.
In severe cases, preparation of these sites may have to
precede
planting by several years.
Use of grasses
to help stabilize the site until trees become
established may be necessary.
Reforestation of these lands may
require careful planning from aerial photos, if available,
or maps
to locate suitable points for control structures.
The structures
should then be designed to maintain the stability of the
site
until the trees can take over.
In humid climates, the time required
may only be one or two growing seasons; in dry climates the
time may extend up to a decade.
CHAPTER XII: OTHER
CONSIDERATIONS
Trees have been replanted on the Algerian slopes by a PVO in
an
attempt to stop the incursion of the Sahara.
Algerian peasants
engaged in the project were furnished seedlings, and given
wages
and food. They were
also educated about the need for reforestation
and involved in all stages of planting, terracing, and road
building. Since
Algeria is an oil exporting country, the need for
fuelwood is not as acute as in other places -- as a result,
of the
100 million trees planted, about 80% survived.
Where local farmers
were involved, they protected the new plantations, and the
incidence of poaching was negligible.
In areas where local involvement
was slighted, hardly any trace of the project remains.
Are small-scale forestry projects not discussed important?
Absolutely --
this manual cannot mention the full range of
small-scale forestry projects that could be considered for a
given
locale. Instead,
examples of some of the more common projects
have been discussed.
It is important that development workers and
others interested in planning, implementation, or management
of
these projects thoroughly explore all possibilities for
creatively
using a particular forest ecosystem in the most beneficial
manner.
Regardless of
the small-scale forestry project to be undertaken,
it is necessary to keep in mind the need to plan
environmentally
sound projects that are responsive to the needs and well
being of local people.
Is additional information available?
Yes -- depending
upon the specific project being considered
and the particular forest ecosystem involved, additional
reference
information may be available to assist development workers
in
planning environmentally sound small-scale projects.
To this end,
the bibliography at the end of this manual could provide
background
information for the initial stages of a planning process.
APPENDIX:
ECOLOGICAL GUIDELINES
FOR
COMMUNITY DEVELOPMENT PROJECTS
Mini-Guidelines
The following
short-form version of the CILSS/Club du Sahel
Ecologic Guidelines has been developed to meet the needs of development
workers at the community level.
The original version is
available at cost from the CODEL Office, Environment and
Development
Program. This paper
is a response prepared by Fred R. Weber
as a result of discussions with PVOs at CODEL workshops on
Environment and Development.
In its basic
form, the guidelines presented will permit
analysis of proposed activities and a design that will
minimize
negative impacts. It
is designed for small-scale projects under
$250, 000. The
Mini-Guidelines is being circulated to PVOs to
invite reaction and response.
It is hoped agencies will try out
the Mini-Guidelines in the field and report back on the
experience.
Responses should be addressed to Mini-Guidelines,
Environment
and Development Program, CODEL, 79 Madison Avenue, New York,
New York 10016. All
communications will be forwarded to Fred
Weber.
The general
approach is the same as for the complete
CILSS/Club du Sahel Ecologic Guidelines.
Methods and procedure,
however, have been condensed in a form that is less time
consuming
and can be carried out by project design personnel not
formally
trained or experienced in environmental analysis.
Introduction to the Guidelines
Begin with any
project in the community development area:
wells construction, school gardens, poultry raising, village
woodlots,
access roads, and so forth.
Any community activity will, in
one form or another, affect the environment somehow.
Especially
if "environment" is regarded in its broadest form,
not only the
physical aspects are affected but also health, economics,
social
and cultural components.
The objective of
this exercise is to try to predict as far as
possible, the various impacts the proposed activity will
have in
both negative and positive terms.
A project normally is designed
with specific results in mind.
An attempt is made to provide
well-defined, "targeted" inputs to bring about
some improvement
to the people in the field.
What is less clear is the nature and
extent of incidental consequences these activities might
bring
about that are less desirable, in fact often adverse or
negative.
In reality, more
often than not, the good will have to be
taken with some bad.
Choices often involve trade-offs.
The trick
then consists of developing a system where these trade-offs
ultimately
are as favorable as
possible in terms of the people
involved.
Instructions
To identify
areas where possible adverse effects may occur,
the basic questions that should always be asked, is:
How Will Proposed
Project Activities Affect_______________?
If we insert in
this question the components that together
make up the environment, we will get answers (and possible
warning
flags) for those situations where otherwise negative
consequences
"inadvertently" may result.
Explanation of Columns
1. In the table on
page 100, ask yourself the basic question for
each of the 18
lines (described below) and assign the following
values in Column
3.
Very positive,
clear and decisive positive impact
+2
Some, but
limited positive impact
+1
No effect, not
applicable, no impact
0
Some definite,
but limited negative impact
-1
Very specific or extensive negative
impact -2
2. A brief
explanation of the factors in columns 1 and 2:
Surface Water --
runoff: peak and yields.
How does the
project activity
affect runoff? How does it affect the
peaks
(flood
discharges)? How does it affect the
amount of water
that will flow
(yield)?
Groundwater --
Its quantity, recharge rates, etc.
Also, does
the project
alter its chemical composition?
Vegetation --
Accent on natural vegetation. Will
natural
cover be reduced
(bad) or increased (good)? How will
natural
regeneration be
affected? Will there be additional (or
fewer) demands
on trees, bushes, grass, etc.?
Soils -- Will
the project increase or drain soil fertility?
Where land
surfaces are affected by the project, is "optimal"
land use
affected favorably or adversely? Will
erosion be
more or less
likely?
Other -- Basic
questions dealing with improvement or deterioration
of factors such
as wildlife, fisheries, natural features.
Also does the
project follow some existing overall
natural resource
management plan?
Food -- Will
people have more food and/or a more complete
diet?
Disease vectors
-- A very important point and one that is
often
overlooked: Will the project create
more standing
water?
Will the project increase (or create) fast
flowing
water?
How will it affect existing water courses?
Population
density -- How much will population density increase
as a result of
the activities? What contamination
conditions will
be altered? How?
Will more Health Care
Services be
required?
Other -- Toxic
chemical, exposure to animal borne diseases,
etc.
Agricultural productivity -- Per capita food
production
(staples or cash
crops), yields.
Volume of good
or services -- Will the project provide more
goods (food,
firewood, water, etc.) or less?
Common resources
-- (Water, pasture, trees, etc.) Will
the
project require
people to use more or less water, pastures,
etc.?
Will it eliminate any of these resources now
available?
Will it restrict
access to these resources?
Project
equitability -- How are benefits distributed?
Who
will profit from
these activities? Special segments of
the
population?
How "fairly" will the benefits be
shared.
Government
services, administration -- Will the project
demand more
work, "coverage" of government services?
Will it
cause an
additional load on the administration:
more people,
recurrent costs,
etc.?
Education and
training -- How will it affect existing education/training
facilities?
Strain or support?
Or will it
provide alternates?
What about traditional learning (bush
schools, etc.)?
Community
Development -- Will it encourage it, or will it
affect already
on-going efforts? If so, is this good
or bad?
Traditional land
use -- Will it restrict existing use,
harvesting,
grazing patterns? Many projects promote
"better"
land use but at
the (social) cost of some one or some group
being restricted
from using land, vegetation, water the way
they have been
used to.
Energy -- How
will the project affect the demand for (or
supply of)
firewood? Will it increase the
dependency on
fossil fuels?
3. Column 4:
This is an arbitrary number based on
experience.
4. Column 5:
Choose an adjustment factor between 1.0 and
5.0
depending on
whether a large number of people and/or large
areas are
affected. If a large segment of the
population is
affected
(say: over 1,000 people), use a factor
of 2.5. If
1,000 hectares
or more are involved, use 2.5 also. If both
large numbers of
people and extensive area are affected,
combine the
two: use up to 5.0.
Never use a factor less
than 1.0.
5. Compute the
adjusted score by multiplying columns 3, 4 and 5.
Enter result in
column 6. Make sure to carry positive
and
negative signs.
6. In Column
7: List all impacts that are positive.
7. In Column
8: List all impacts that are negative.
8. Now take another
look at Column 8. Here you'll find a
summary
of the negative
aspects of your proposed activity.
Beginning
with the largest
values (scores), determine what
measures you can
incorporate into your project, what alternate
approaches can
be followed to reduce these negative
values, one by
one. This may not always be possible,
but try
to modify your
plans so that the sum of all negative impacts
will be as small
as possible. (Tabulate the new,
improved
scores in Column
10.)
Modify, adjust,
redesign your project so that the total of
all "negative impacts" is an small as
possible. This is the
essence of "ecologically sound project design."
<FIGURE 45>
49p100.gif (600x600)
BIBLIOGRAPHY
Selected
references on topics presented in this manual are
listed below. For
convenience, references have been arbitrarily
grouped by categories.
However, in many instances, a particular
reference covers more than a single topic.
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Guidelines for Project Evaluation.
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Industrial
Development
Organization, Project Formulation and Evaluation
Series No. 2.
Applied Communication in Developing Countries:
Ideas and
Observations.
1973.
The Dag Hammarskjold Foundation.
Introduction to Planning Forestry Development.
1974.
FAO Forestry
Series No. 7.
Project Appraisal and Planning for Developing
Countries. 1974.
Basic Books, Inc.,
New York.
Economic Analysis of Projects.
1975. John Hopkins
University
Press, Baltimore.
From the Village to the Medium:
An Experience in Development
Communication.
1976.
Communication Foundation for Asia.
Report on the FAO/SIDA Workshop on Forestry Development
Planning
for Countries of the
Near East and South Asia, Dehra Dun, India,
29 November--17
December 1976. 1977.
FAO Forestry Series No.
38.
Development of Arid and Semi-Arid Lands:
Obstacles and Prospects.
1977.
UNESCO, MAB Technical Notes No. 6.
Report on the FAO/SIDA Workshop on Forestry Development
Planning
for Countries of
Southeast Asia, Manilla, Philippines, 16
August--September
1976. 1977.
FAO Forestry Series No. 39.
Local Responses to Global Problems:
A Key to Meeting Basic Human
Needs.
1978.
Worldwatch Institute, Washington, D.C.
Forestry: Sector
Policy Paper. 1978.
World Bank, New York.
Environmental Design Considerations for Rural Development
Projects.
1980.
U.S. Agency for International Development,
Washington, D.C.
Forestry and the Environment
Ecological Guidelines for Development in Tropical Rain
Forests.
1977.
International Union for Conservation of
Nature and Natural
Resources.
Mediterranean Forests and Maquis:
Ecology Conservation and Management.
1977.
UNESCO.
Forest Influences:
An Introduction to Ecological Forestry.
1962,
reprinted in
1978. FAO.
Tropical Forest Ecosystems:
A State-of-Knowledge Report.
1978.
UNESCO, UNEP, and
FAO.
Man in His Working Environment.
1979. International Labor
Organization.
Planting for the Future:
Forestry for Human Needs. 1979.
Worldwatch
Institute, Washington, D.C.
Tropical Woodlands and Forest Ecosystems.
1980.
United Nations
Environment
Programme.
The Socio-Economic Effects of Forest Management on Lives of
People
Living in the
Area: The Case of Central American and
Some Caribbean
Countries.
1981.
Centro Agronomico Tropical de Investigacion
y Ensenanza,
Turrialba, Costa Rica.
Forestry Practices
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Tropical
Forests. 1973.
FAO Forestry Series No. 3.
Logging and Log Transport in Tropical High Forest.
1974.
FAO
Forestry Development
Paper No. 18.
Tree Planting Practices in the African Savannas.
1974.
FAO
Forestry Development
Paper No. 19.
Forest Assessment, by Dammis Heinsdijk.
1975.
Centre for Agricultural
Publishing and
Documentation, Wageningen.
Report on the Second FAO/SIDA Training Course on Forestry
Inventory,
Ibadan, Nigeria, 12
August--September 1974. 1975.
FAO
Forestry Series No.
14.
The Methodology of Conservation of Forest Genetic Resources:
Report on a Pilot
Study. 1975.
FAO.
Forest Fire Control.
1953, reprinted in 1978. FAO.
Forest Influences:
An Introduction to Ecological Forestry.
1962,
reprinted in
1978. FAO.
Forestry for Local Community Development.
1978.
FAO Forestry
Paper No. 7.
Introduction to Forest Genetics.
1976. Jonathan W.
Wright. New
York:
Academic Press.
Institutional Limitations
Forest Resource Economics.
1972. The Ronald Press, New
York.
A Legal and Institutional Framework for Natural Resource
Management,
by G. J. Cano.
1975.
FAO Legislative Study No. 9.
Guide to Practical Project Appraisal:
Social Benefit-Cost Analysis
in Developing
Countries. 1978.
United Nations Project Formulation
and Evaluation
Series No. 3.
Economic Analysis of Forestry Projects.
1979.
FAO Forestry Paper
No. 17.
Economic Analysis of Forestry Projects:
Case Studies.
1979. FAO
Forestry Paper No.
17, Suppl. 1.
Economic Analysis of Forestry Projects:
Readings.
1980. FAO
Forestry Paper No. 17, Suppl. 2.
Multiple Use Forestry
Ecological Guidelines for the Use of Natural Resources in
the
Middle East and
Southwest Asia. 1975.
International Union for
Conservation of
Nature and Natural Resources.
The Use of Ecological Guidelines for Development in the
American
Humid Tropics.
1975.
International Union for Conservation of
Nature and Natural
Resources.
The Use of Ecological Guidelines for Development in Tropical
Forest Areas of
Southeast Asia. 1975.
International Union for
Conservation of
Nature and Natural Resources.
Ecological Guidelines for Tropical Coastal Development.
1976.
International Union
for Conservation for Nature and Natural
Resources.
Management of Natural Resources in Africa:
Traditional Strategies
and Modern
Decision-Making. 1978.
UNESCO, MAB Technical Note
No. 9.
Ecological Guidelines for Balanced Land Use, Conservation
and
Development in High
Mountains. 1979.
International Union for
Conservation of
Nature and Natural Resources.
IUFRO/MAB Conference:
Research on Multiple Use of Forest Resources.
1980.
U.S. Department of Agriculture, Forest
Service,
General Technical
Report WO-25.
Economic Analysis of Forestry Projects.
1979.
Hans M. Gregersen
and Arnoldo H.
Contreras. FAO Forestry Paper 17.
Economic Analysis of Forestry Projects.
1980.
Supplement to
Forestry Paper 17.
Harvesting Wood Products
Guide for Planning Pulp and Paper Enterprises.
1973.
FAO Forestry
and Forest Products
Series No. 18.
The Transfer of Technology to Developing Countries:
The Pulp and
Paper Industry.
1974.
United Nations Institute for Training and
Research.
Underexploited Tropical Plants with Promising Economic
Value.
1975.
National Academy of Sciences, Washington,
D.C.
Harvesting Man-Made Forests in Developing Countries.
1976.
FAO
Forestry Series No.
21.
The Marketing of Tropical Wood.
Wood Species from South American
Tropical Moist
Forests. 1976.
FAO Forestry Paper No. 5.
Assessment of Logging Costs from Forest Inventories in the
Tropics --1.
Principles and
Methodology. 1978.
FAO Forestry Paper
No. 10/1.
Assessment of Logging Costs from Forest Inventories in the
Tropics--2.
Data Collection and
Calculations. 1978.
FAO Forestry
Paper No. 10/2.
Pulping and Paper-Making Properties of Fast-Growing
Plantation
Wood Species,
1980. FAO Forestry Paper No. 19/1 and
No. 19/2.
Charcoal Making for Small Enterprise:
An Illustrated Training
Manual.
1975.
D. E. Earle and A. Earle.
Switzerland: ILO.
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Biological and Sociological Basis for a Rational Use of
Forest
Resources for Energy
and Organics, Proceedings of an International
Workshop, May 6-11,
1979, Michigan State University, East
Lansing Michigan,
Stephen G. Boyce, editor. 1979.
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of Agriculture,
Forest Service, Southeastern Forest Experiment
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Ashville, North Carolina.
Proceedings of the USAID Asia Bureau Conference on Energy,
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and
Environment. 1979.
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Washington, D.C.
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1980.
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D.C.
Agro Forestry Projects
Integrating Forest and Small-Scale Farm Systems in Middle
America.
1977.
Agro-Ecosystems No. 3.
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An Appraisal of Some IDRC Supported
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1980.
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Utilization and Conservation,
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1981.
Centro Agronomico
Tropical de
Investigacion y Ensenanza, Turrialba, Costa Rica.
Quantification of Current Agroforestry Practices and
Controlled
Research Plots in
Costa Rica. 1981.
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de Investigacion y
Ensenanza, Turrialba, Costa Rica.
Shelterbelt and Wind-break Plantings
Protection of Plants Against Adverse Weather.
1971.
World Meteorological
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Planning and Management of Farmstead Windbreaks.
1972.
Iowa
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1974. U.S. Department of
Agriculture,
Soil Conservation
Service, Washington, D.C.
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1976.
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Nebraska.
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1976.
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D.C.
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Savanna Afforestation in Africa.
Lecture Notes for the FAO/DANIDA
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Forest Nursery and Establishment Techniques
for African Savannas
and Papers from the Symposium on Savanna
Afforestation with
the Support of the Danish International
Development Agency,
Kaduna, Nigeria 1976. 1977.
FAO Forestry
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Establishment Techniques for Forest Plantations.
1978.
FAO Forestry
Paper No. 8.
Forest Tree Nursery Soil Management and Related
Practices. 1979.
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Natural Resources, Toronto.
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Countries.
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BIOGRAPHICAL NOTE
Peter F. Ffolliott is Professor, School of Renewable Natural
Resources,
University of Arizona, Tucson, Arizona.
His current
teaching and
research interests relate to natural
resource
inventory and evaluation systems to analyze timber,
water, range,
and wildlife values. Previous work
experience
was with the
Rocky Mountain Forest and Range Experiment
Station, USDA
Forest Service, where he was employed as a
Research
Forester. He earned B.S. and M.F.
degrees in
Forestry from
the University of Minnesota, and a Ph.D. in
Watershed
Management from the University of Arizona.
John L. Thames is Professor, School of Renewable Natural
Resources,
University of Arizona, Tucson, Arizona.
Currently,
his teaching and
research activities focus on watershed
resource
development, and soil and water conservation.
Previous
work included
assignments as a Research Forester with
the US Army
Corps of Engineers and as a Forest Hydrologist
with the
Southern Forest Experiment Station, USDA Forest
Service.
He earned a B.S. degree in Forestry from
the University
of Florida, a
M.S. degree in Plant Physiology from
the University
of Mississippi, and a Ph.D. in Watershed
Management from
the University of Arizona.
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