~ , . ~ ~ ~ ~ . ~ ^ ~ ~ ~ ~ ~ .
ef#Hs a~~not~gene~=l~ly~pisedi~on~kn -~l~edge~#f~#c~lnvento#~6f~the
rids'~s*~cst+rieedes~.~lteJa~9r~propo~iSn~6f~tree~speCi6~< ~r+#nt~
ii~E~t~stins a!nd:Et~ed~!ng~!~rog~ m#~are~)om ~ Operates #*io~s~(see
4pp#~nd~i~ by. Efforts are~/eeied! (~#dd~inf6rm/#on~on (opical~6d
s~bbopich~l reef ~t~espede~s~# so#.th~and sdEthea~st Asia tropical
. , .. , . ~ ~ . s . . .
i~Ci~/ E a~d~ta~n~3e~cASE6s)2no~s~divtisi~ in~r)~andso~fh~edd
:: ~::S~S~:sEsEsSSSE::~: ~ ~ : ~ EEL :~::::::~:~:E : EE ~,~:E E:E~ ::S~ : ~ ::: S::~E:::E~ I: I::::
sp~ie~ipccu~#ve~reenh(#4ippiS]~a~d~d)cidu^~s ~rests(~.S
Carol, ~l~dia~Cbundl~df A~ ~l~l~Research>~# ~Oelhi,pers~nal
co~#n~aboq;~Oc~*er1989).~ ~
At this ~ en p~mscon~sere~the~ehe~c ~sou~sEo~fspecie~s
that hA~venocurentp~du~ion value and that age outside any ecosystem
~ I .
In Cogs Bay, O~gon, ~ ship loads logs bound far Japan. Credit: Tames P Blair
~Nabosnal Gegg~phic View.
OCR for page 7
Executive Summary / 7
reserve or protected area. One notable example is the Central America
and Mexico Coniferous Resources Cooperative at North Carolina State
University which holds unique collections of several potentially useful
species. Conservation of species that serve vital functions for ecosystems,
commercial production, recreation, or other social values, but that are
not now included in protected areas, has also been neglected. Tabebuia
impetiginosa in Brazil, for example, is useful for its wood as well as other
functions, is vulnerable to loss, but is not being conserved in any in
situ or ex situ program. A need exists not only to expand current efforts,
but also to coordinate the setting of priorities to increase the number
and diversity of species conserved.
STRUCTURE OF GENETIC VARIATION IN TREES
Managing the genetic resources of trees requires an understanding
of the biological dynamics of the populations in which they exist. In
particular, knowledge of the diversity and distribution of genes in a
tree population is crucial to genetic management, because genetic
information makes it possible to predict the likelihood of gene loss in a
population and to develop strategies to prevent such depletion. Under-
standing genetic structure in a tree species will make it possible to
collect the genetic diversity of natural populations efficiently and to
ensure their conservation.
The extent and pattern of genetic diversity in forest trees are strongly
influenced by their mating systems and the movement of genes between
dispersed populations of the same species (gene flow). Mating systems
in forest trees are varied and range from mechanisms to ensure
outcrossing (pollination by other individuals in the population), such
as among Pious (pine) species, to mechanisms for inbreeding (self-
pollination), such as among some Eucalyptus species. Designing reserves
for trees, that is, their sizes, shapes, and distributions, requires an
understanding of reproductive biology. However, knowledge in this
area remains limited, especially for tropical species.
Gene flow affects the degree to which individual populations of trees
are genetically isolated. An understanding of this is important when
designing in situ reserves or ex situ conservation stands to ensure that
genetic diversity is preserved. Gene flow, and thus gene distribution,
is also important when collecting samples from tree populations to
obtain a range of genetic diversity for ex situ conservation.
Measuring genetic diversity in trees has typically been done by either
provenance testing or electrophoretic analysis of enzymes. The former
-
1
OCR for page 8
8 / Forest Trees
involves visual observations of the differences between tree samples
grown under similar conditions at different sites. Trees, especially
exotics, grown in unsuitable provenances may die, have dieback, or
display unsuitable form. The latter compares the number and variety
of specific classes of enzymes present in the samples being tested.
Both techniques show that forest trees, in general, contain considerable
genetic variation. It is not known, however, to what degree the variation
revealed by electrophoretic surveys reflects genetic differences in the
capacity of individual trees to compete or adapt. Further, electrophoretic
variation can be indicative of genetic variation, but results from electro-
phoretic analyses also can be affected by physiological states or envi-
ronmental conditions. Thus, the degree to which electrophoretic data
can be correlated with the data from provenance testing is ambiguous;
sometimes the data are similar, but often, as in the case of Pseudotsuga
(Douglas fir), they are quite different (El-Kassaby, 1982~.
Despite the heterogeneity of forest trees, genes may not be distributed
randomly in a tree population and, thus, sampling of the diversity
within a population may be complicated. Current data suggest that for
wind-pollinated, widely spread species sampling a small number of
populations may be sufficient (Hamrick, 1983), but for species like
Liriodendron tulipifera (tulip tree) and Quercus velutirla (red oak), which
grow in many isolated populations, sampling a larger number may be
required to ensure an unbiased sample of genetic diversity.
Geographic, climatic, and biological factors affect the distribution of
genes in a species. For the majority of forest trees, however, knowledge
of genetic structure is sparse, and knowledge of the degree to which
such characteristics as drought tolerance, growth, and disease resistance
are heritable is still deficient, although growing. Such information is
necessary to develop reliable and effective methods of sampling the
total genetic diversity of tree populations.
RECOMMENDATIONS
Important opportunities for confronting the challenges of managing
the world's forest tree resources have been identified. New and increased
efforts will be needed in developing and applying genetic management
techniques. Research and development are required to address funda-
mental issues and information needs. Institutional efforts, particularly
at the national level, must be strengthened. Finally leadership is urgently
needed to develop and facilitate a global strategy for conserving and
managing the world's tree genetic resources.
OCR for page 9
E~r I / ~
Pugh ~.^re~station measly, hazy ~u=~lvptus toes am used far salad dune
fixation in Sen~e~l.. This effort is pay of local {o~munit~y development activities
and land reclean proiiec~ fir agriculture Credit: Food and Subculture
^ . . ~
~ ~anl~tl^-
Gc"~dc ems {e~4
^ connation of in situ and ax situ. techniques ~i~l.l be needed for
any rabbi, re~io~nal/ or national efforts to conserve and manage the
g~net~reyources of geese in site an-d ~y situ methods. a~ Ken as
compJemen~/ not opposing, Methodologies. In situ cpn~seration
provides the oppo~u#! to preserve the b~oa~desf An. of spsedes' but
ax situ collations may ~ among app~p~riate~ Ruben guess to sac.
well~st~died, or threatened poppl~ti~ons is desired.
^~r ~ Sea ~i ~ SO Hems
ma.
1~ rife ~) ~ sari ,~ !~ =~s~. !, J~i use Beef fag
Cast ~ so ~i fo ens of ~sf ~ Fuji i~r S~; l)
s>6 #f ~ few
~E~ortstoco~nse~rveand~manage tree ge~neLcresour~e~sd!o~notencom-
pass global needs. Deficiencies exist ~oth.~.~n information and in the
exten.tofactivities.For many species of~cognized potential~aiue new
eggs are needed Pyrex gnu conserva~on.In bopicaland sub ~ p\~1
. . ~
. .
OCR for page 10
101 Forest Trees
regions, where species diversity is greatest, many more species should
be conserved in situ.
In Situ Management
Long-term, in situ genetic management plans should be developed, especially
for tropical and subtropical species.
In situ management of trees typically refers to conservation in
undisturbed nature reserves, managed nature reserves, and national
parks. It can also include planned and managed plantings of trees
within the native environment of the species. This is somewhat different
from in situ management for crop plants, wherein such planted stands
are generally considered a form of ex situ conservation.
The design of in situ conservation schemes is still primitive. Little is
known of the nature of current and future stresses that can affect even
local mortality and extinction rates for most tree species. Until more is
known about the population sizes and structures necessary to prevent
genetic loss, a large degree of genetic redundancy for conserved species
will be needed.
Ex Situ Management
Development and application of technologies for the ex situ conservation of
pollen, seed, and tissue cultures, as a supplement to in situ maintenance, should
be encouraged.
One example of ex situ management is the organization by several
working groups of the International Union of Forestry Research Orga-
nizations (IUFRO) of a large number of collections and tests in Europe
of species that are native to North America. Ex situ methods also include
maintenance of seed, pollen, tissue cultures, or other sources of genetic
material for propagation. Seed storage of many tree species is both
possible and practiced, but the long times to maturity and genetic
instability during regeneration can make obtaining a new crop of fresh
seed an expensive and uncertain process. For many important species
of genera such as Quercus (oak), Shorea (mahogany), and Hopea, seeds
are short-lived or die when dried for storage. Ex situ methods of tissue
culture and cryogenic storage (i.e., storage in or suspended above liquid
nitrogen at temperatures from -150°C to -196°C) could enable long-
term maintenance of such species, but further effort is needed to apply
these to many tree species. In the future, genetic information in the
form of DNA (deoxyribonucleic acid) libraries may be maintained for
tree species.
OCR for page 11
Executive Summary 111
Tree collections held as seed are primarily for short- or medium-term
storage for use in afforestation (the planting of trees in unforested areas)
and reforestation activities. Few programs have long-term objectives,
and at present the techniques for regenerating most of these collections
are not clearly defined. Methods for the rapid regeneration of stored
seed collections are urgently needed.
Ex situ stands or planted forests should be developed that can serve as living
seed banks, as test and evaluation stands, or as both.
The use of ex situ stands of trees for conservation purposes can be
applied to many more species than are now included. Relatively small
areas can be part of a conservation network that ensures the survival
and availability of genetic materials and that provides data on perform-
ance over a variety of sites. The integration of such conservation networks
with breeding programs and in situ programs could provide a vital link
between conserving and effectively using the total gene pool of a species.
No global programs to foster such linkages exist, although the Food
and Agriculture Organization (FAO) of the United Nations, the Nitrogen
Fixing Tree Association, and the Oxford Forestry Institute (OFI) have
initiated such programs in a few instances, for example, in Leucaena and
. . .
Acacla species.
Exploration, Testing, and Breeding
Additional cooperative efforts among nations are needed to develop coordinated
programs for exploring, collecting, and evaluating tree genetic resources.
When a species is indigenous to several countries and is useful in
others, coordinated efforts can have many benefits, such as reducing
the number of collection missions needed but allowing a broad range
of environments to be sampled. Many eucalypts, Gmelina, teak, and
some tropical pines and hardwoods are among the species included in
cooperative programs today.
Forest genetic resources programs should conserve species that lack clear
present or potential value and those that have known potential value.
No programs exist to conserve the genetic resources of species that
lack clear potential production value or that are not adequately included
within ecosystem reserve areas. Few groups or institutions promote the
management or conservation of many species that might serve vital
functions for ecosystem productivity, recreation, or other diffuse values,
but remain outside protected areas.
Breeding programs are needed for many species, especially those
new to genetic management programs. For many hundreds of species
OCR for page 12
the Amazon aver ~sin, 8~1, ~ clad of din Mast ~ ~s~r^~
as 1~ ~ Moron and loss of pi, Whim in tug prompt agrees Flag
in peon toasty, Me greatest edges at management are Mused
of ~ seed collection stands/ which are ~se!ndally lard, mass-~~lecSon
populations. fit ~ species am in brewing programs sufEdently
intense Mat ex site con~^abon is included as part of We program.
Only ~ R~v ofthela~t~rspedes~s~uch asf\~idfs~&y ~~z'~f!(Do~as
fall Scads ad, gad P. (West Indian pines), Reincluded in
in~nationalcooperabon programs for genetic management.
~ell~s~tablished species of widespread com~nerc~I use, souse po~puIa
OCR for page 13
Executive Summary 113
lions of which have been widely sampled in parks, test stands, and
breeding and production stands. However, many of these species are
incompletely sampled for conservation purposes. All of them lack clear
programs for using genotypes or populations as introductions or sub-
stitutes for their current breeding populations. The number of tree
species with clear potential for future use that could be managed in
breeding or prebreeding operations is at least twice the number of
species currently used, and their inclusion would quadruple the number
of populations used.
Programs are needed to ensure long-term storage (including cold storages of
tree germplasm and to coordinate efforts to maintain managed stands.
Of the available techniques for gene conservation, heavy reliance is
placed on managing living stands, both ex situ and in situ. Programs
for long-term storage as seed, pollen, or tissues are very limited. As
long as interest remains, stand management should continue, but it is
vulnerable to lapses in funding and control and to environmental
changes.
Global Data Base
A global data base on the status of tree genetic resources should be established
and continuously updated. It should include listings of ongoing conservation
activities, breeding programs, test stands, and other activities pertinent to
conserving trees.
A data base would facilitate identifying species for conservation or
for addition to testing and breeding programs. It would foster interaction
among regional and national programs, support and encourage training
at the international, regional, and local levels, support research and its
application to managing forest tree germplasm, and provide a central
source for assembling and disseminating data to national and regional
programs. It would thus amplify the considerable efforts of the FAO's
Panel of Experts on Forest Genetic Resources.
Research and Development
Genetic Variation
To support conservation efforts, study of the patterns of genetic variation in
tree populations should be accelerated and expanded in scope, especially in the
tropics and subtropics.
Genetic variation has been surveyed in a wide range of species, but
the existing data base is largely derived from the study of conifers in
OCR for page 14
141 Forest Trees
the north temperate zone. Despite the very different reproductive
mechanisms of many tropical species, a preliminary analysis reveals
that levels of genetic divergence within populations are similar to those
observed for temperate tree species. However, further study is needed
before this information can be generally applied to conserving tropical
tree species.
Inventory
Increased efforts are needed to provide an accurate inventory of forest trees.
Even as new research is initiated, tree populations are being changed
and eroded. The scale of change, both in the area affected and the
speed of change, has vastly increased. The loss of species and genetic
variation in populations due to deforestation may be slowed if critical
populations are targeted and saved. Similarly, the effects of regional
population or global climatic changes might be counteracted in the
future by constructing new populations from conserved populations
and collections. To do this, knowledge of what is in these forests is
needed.
Genetic Structures
Research is needed to elucidate the distribution and structure of genetic
variation especially for tropical trees-and to support conservation efforts.
Information on reproductive systems, the genetic architecture of
populations, and the requisite population sizes of trees is essential for
the design of in situ and ex situ conservation stands. Understanding
the subtle factors that create or destroy genetic diversity provides the
scientific foundation for managing tree genetic variation. Differences in
the mating systems of many tree species and the ecological instability
of stand boundaries can strongly affect genetic variation among popu-
lations. This must be considered when managing a sampled set of
genotypes or conservation stands. However, the interactions of species
and the structure of populations, especially in tropical species, are
poorly understood. Obtaining such knowledge for tropical regions,
where tree species occur in low densities as part of complex ecosystems,
can be especially difficult.
Climate Change and Pollution
More comprehensive study should be made of the effects of global climatic
change and pollution on forest tree species.
OCR for page 15
Executive Summary 115
In the temperate regions pollution from industrial and transportation
activities, combined with other stresses, is causing severe decline in
forest vigor. Trees are dying prematurely in most industrialized countries
and in some developing countries. Research efforts are in progress to
understand the causal agents and biochemical pathways through which
soil, water, and trees themselves are affected by pollution. In Germany
alone more than 1,000 government-sponsored projects are examining
the effects of pollution on forests. The Executive Board of the IUFRO
has established the Special Task Force on Pollution to coordinate research
and information on this problem, and reviews of the state of knowledge
formed a major part of its Eighteenth World Congress in Montreal
during 1990.
Institutions
i]
The current status of tree genetic resource conservation activity is
nadequate to prevent future losses in genetic diversity. Major inter-
national efforts in the use of forest tree genetic resources originated in
the late 1960s, with the guidance and support of the FAO and several
national institutions, mostly from developed countries. Since then,
institutional interest has been stimulated because tree improvement
programs have demonstrated that economic benefits can be realized
from using genetic resources to improve forest production and because
increasing environmental awareness, including recognition of defores-
tation and species loss, has led to increased recognition of the need to
preserve gene resources.
New Programs
The capacity of national and regional institutions to manage tree genetic
resources, especially in areas where loss of species and populations is most
severe, should be enlarged and strengthened. Forest genetic resource conservation
programs should be formalized and included in national plans for forestry,
biological diversity, and breeding or other forms of genetic management.
The in situ and ex situ conservation efforts of national governments
require focus, coordination, and support. In the nonindustrialized world
demand is growing for production forestry, especially for fuelwood and
fodder in dry areas, but also for timber and other wood products. There
is a need to establish breeding populations for nearly all species that
are prime candidates for such uses. Preliminary breeding programs
have been initiated with some previously wild species. However, several
hundred species of potential value, especially in arid zones and the
OCR for page 16
161 Forest Trees
This tropical rain forest at 500 m near Serra dos Carajas is part of the world's
largest closed rain forest, estimated to be 357 million ha in size, located in
Brazil. Credit: Calvin R. Sperling.
tropics, are not yet included in such programs and continue to be at
high risk of loss.
The precise, future global needs for forest genetic resources are not
possible to predict, but the widest possible genetic base should be
maintained to provide the best array of future options. The programs
of national and regional institutions to conserve, describe, document,
improve, and distribute forest genetic resources are critical activities,
and they urgently need to become more active and more effective.
Techniques for establishing priorities must be developed. The particular
requirements and challenges of countries and regions may vary, but
the overall goal is to conserve and maintain a broad range of forest tree
genetic resources for current and future use and as a foundation for
conserving the world's biological diversity.
Funding and Personnel
Sustained political support and expanded independent funding must be
provided for long-term forest conservation operations, for professional and
OCR for page 17
~ - /~
^ ~'
v~u~y ~ And ~
gear Sears glide, has ban flexed to
/ sf~ f=~,lf~, ~) Or so ~ i~sf~ff~f/~s fluff Acts far
fag off ~ If ~) I
For many nations the funds available to protects It souses mav
be insu~cien.t Bar genetic o~bjecSves. ^~l~ou~h fiats is at the n.~ho~nal level
that needs and p!d~odti~es must be elucidated and abed "~the-ground"
activities must occu~r,esta~blishin.g end ~ste~ring~s~che:f~rts will Squid
U)~ galore ~ Bad ~lpoLbo~andEnanck~suppo~.Nado~(pr ms
#1 Benin nabs Or the Thor ^ ~ bee In,
parEculatly Them species of current or Stud use am concede.
F~quendy,such ^ Tuscan occur th~oughexLdngna~onaldepa~men~
or minisid~es es~bIished to ad~dressth~e needs ~f~nabo~na.lfo~ests, but
their program ms must be extended to include ge!neLc resources The
education and twining of pro~ssio~nals and technicians in feast genetic
Assume conservation must also be expanded to provide sufid~nt
technicaland sappy spa to meet urgent needs that ~iIlresu~lt item
the increased antic ~
~Regionalinstitutions could assist member countries in developing
national and cooperative ac~vides elated to Crest ~eneLc ~sour)
conservatio~n.lhey could provide funds ~rp~rogm ~son~fO~~st genetic
OCR for page 18
181 Forest Trees
resources, inventories, seed collection, nurseries, testing, ex situ stands,
scientific exchange within and outside the region, training, and research.
Regional programs would be uniquely suited to addressing the needs
and facilitating activities for national programs that have common
interests and priorities with regard to managing tree resources and the
species of concern.
Developing a Global Strategy
Addressing the world's needs for tree genetic resources will require
a global strategy that focuses on in situ and ex situ conservation,
research, and institution building at national, regional, and international
levels.
International Leadership
An international institution should be established or designated to provide
leadership, coordination, and facilitation for the global management of the
world's tree genetic resources at national, regional, and international levels.
In situ and ex situ strategies should compose complementary elements
of an integrated program. With limited resources to accomplish this
task, coordination among the many national, regional, and international
groups and institutions is needed to focus efforts on critical needs, to
avoid unnecessary duplication of effort, and to ensure optimal coverage.
The comprehensive management of the tree resources of the world's
forests requires leadership to coordinate existing efforts and foster new
ones. Institutions, such as the FAO, OFI, Centro Agronomico Tropical
de Inve stigacion y En senanza , Centre Technique F ore slier Tropical, and
others discussed in this report, conduct important work at multiple
national and international levels. There are, however, omissions both
in priorities and methods of conservation. An international institution
to coordinate and to facilitate the global conservation and management
of forest genetic resources is required. The main function of such an
institution would be to maintain an ongoing assessment of the status
of forest genetic conservation worldwide and to foster the study,
collection, documentation, evaluation, and utilization of tree genetic
resources.
Global leadership could be provided through a shared effort of the
FAO and a forestry body created within the International Board for
Plant Genetic Resources (IBPGR). These efforts could be augmented by
expertise from other international, regional, and national agencies. Such
global cooperation would enable the initiation of efforts more rapidly
OCR for page 19
Executive Summary / 19
than if an entirely new program were established. The FAO historically
has played an important role in developing forest programs and
disseminating information. The technical and scientific capacities of the
IBPGR would enhance FAO's efforts. For both institutions such an
arrangement will require some administrative adjustment and additional
funding.
Trees are an integral part of the natural world and they are essential
to life. Trees have always been indispensable to the functioning of
human society. It has become apparent in recent decades, however,
that the world risks losing much of this invaluable resource. If society
is to conserve the biological diversity encompassed in the world's trees
and the forests and habitats they create, then renewed efforts are
needed. The demand by a burgeoning population for the products and
benefits of trees requires greater efforts to develop varieties adapted to
human needs. Similarly, the remaining world forests, and the diversity
they contain, must be protected from the increasing pressure to consume
them. This is no longer the responsibility of a few nations, but will be
achieved only through a global, cooperative effort.
OCR for page 20
Representative terms from entire chapter:
forest trees
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