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Forest Health Assessment: Science to
Policy Link-an Interesting Challenge1
Harry Hirvonen 2
Ahstract-The Canadian Forest Service has recently completed a
national health assessment of Canada's major forests. This assessment is a major departure from historical reporting on forest health
within Canada. A broad defmition of forest health is used which
includes impacts on forest ecosystems from air pollution, land use
activities as well as endemic influences such as insects and drough t.
The national ecological classification of Canada is used as the
reporting framework. The combination of an ecological reporting
framework, a broad defmition of forest health, the need to link
science with policy questions and the need to report in a concise,
nontechnical manner created interesting challenges to the completion of the Assessment. Some of these challenges were sciencebased, some were philosophical and others were institutional.
Canada is a forest nation with 45% of the country's
landscape being forested. Canadians are stewards of 10% of
the world's forests. These forest ecosystems form much of
the ecological backbone of the country. They are a source of
recreation, of inspiration, and of wealth to a large number of
Canadians. Forests are essential in providing habitat, food
and shelter to wildlife. Our forests are home to 140,000
wildlife species. The nation is also the world's largest exporter of forest products, contributing $32 billion to the
country's balance of trade and providing 840,000 jobs to
Canadians (Natural Resources Canada 1998). Without sustained healthy forests, Canada would be devastated environmentally, culturally, and economically.
To maintain healthy forests, we have to understand how
they function, their ecological interactions at various spatial
scales and how these interactions are influenced by human
intervention. We must draw on our collective scientific
research and monitoring results and initiatives to determine what is happening, how it is occurring and why is it
taking place.
This synthesis and assessment of forest health is not an
exacting science. Information is often drawn from disparate
sources and is of varying rigour and quality. There are very
few straightforward cause and effect relations. In fact, in the
literature, there are often, divergent conclusions based on a
similar data, reflecting the various interpretations placed
on the source data.
Ipaper presented at the North American Science Symposium: Toward a
Unified Framework for Inventorying and Monitoring Forest Ecosystem
Resources, Guadalajara, Mexico, November 1-6,1998.
2Harry Hirvonen is Science Advisor, Forest Health, Canadian Forest
Service (CFS), Natural Resources Canada, located CFS Headquarters,
Ottawa, Ontario, Canada
476
In the end, the assessment, with its inevitable imperfections must be communicated to Canadians in a credible,
clear and concise manner. Otherwise, all the science and
research behind the assessment is essentially for nought.
Translation from science jargon to everyday language is
always an interesting exercise. To put it mildly, determination of forest health is not straightforward.
In 1997, the Forest Health Network, one ofthe ten Science
and Technology Networks of the Canadian Forest Service,
undertook this challenge with the view to publish, by the end
of 1998, Canada's first national Forest Health Assessment.
This Assessment is one of a family of products to be produced
that communicates to various audiences, from the scientist
to the school pupil, the status and change in the health of
Canadian forests (Forest Health Network 1998). This paper
focuses on the process and hurdles associated with producing this assessment.
What Does Forest Health Really
Mean? --------------------------------------In tracking and reporting on forest health, the first hurdle
to overcome is the understanding of what forest health
means. This term continues to be freely tossed around the
global forest sector as ifits meaning is intuitive to all. It may
be intuitive, but it is also hard to pin down. Existing views
may differ widely (McLaughlin and Percy 1998; O'Laughlin
et al. 1994). As examples, if one's primary purpose is timber
production, forest health is an issue about dying or threatened trees, most often illustrated through management
activities aimed at reducing insect and disease infestations.
For wildlife specialists, it is largely about forest habitat, its
availability and condition. Other perspectives may incorporate aesthetic, recreational or spiritual values to define
forest health. These perspectives have value and validity, as
long the limited focus is understood.
Because of these varying concepts of forest health, efforts
to define it are largely meaningless. The Canadian Council
of Forest Ministers states that the Canadian forest sector,
collectively, has the obligation to "maintain and enhance the
long-term health of forest ecosystems for the benefit of all
living things both nationally and globally while providing
environmental, economic and social and cultural opportunities for the benefit of present and future generations."
(Canadian Council of Forest Ministers 1998). This is a
classic motherhood statement that sounds nice but really
offers no direction. What it does imply is that forest health
must be considered in a holistic sense considering all values
of the forest ecosystem. The emphasis is on the forest
ecosystem and not on anyone element.
USDA Forest Service Proceedings RMRS-P-12. 1999
In this broad ecological context, we may view a healthy
forest as one that maintains the qualities that society values
including biodiversity, resiliency, wildlife habitat, aesthetic
appeal and resource sustainability. (Forest Health Network
1998). Inherent in this perspective is a spatial connotation.
Forest health is not viewed as a single tree issue or even a
stand issue, but in a regional context. Certainly, if one's
favourite urban tree is showing signs of decline, it may be
very important; or, if a highly valued commercial plantation
is ravaged by insects, it is an immediate concern. But stand
health and single tree health are different from forest
ecosystem health. The former are not really sustainability
issues. Ecosystem "Sustainability" is both a long-term and
regional concept. One must think not of species alone but of
ecological cycles, interactions among ecosystems and changing dynamics over time.
Forest health is also all about measuring, tracking and
reporting on impacts on forest ecosystems from stressors.
Stress, simply put, is an unusual load on the ecosystem. It
may stem from natural factors such as drought or indigenous insects or from human-induced factors such as air
pollution or land use. Normally, forest ecosystems are adapted
to frequently occurring climatic and endemic biotic events
and may even rely on these events to perpetuate themselves.
Extreme natural events may result in irreversible harm to
desirable forests, but our ability to foresee and mitigate
these events is minimal.
Human-induced stressors on forest ecosystems we can
influence, alter and mitigate. Thus, this assessment concentrates on interactions between forest ecosystems and human
influences. Such influences include air pollution, introduction of non-native species, and land use activities, including
forest management. Resultant effects may be beneficial,
negligible or harmful to the ecosystem. Impacts may occur
directly on forest species, or indirectly through impacts on
ecological processes such as nutrient cycling. They may alter
life cycles of native insect and disease populations (Fleming
and Volney 1995) or predispose ecosystems to decline from
natural influences of wind, .drought and other climatic elements. What we are really striving for is to identify and
document changes to forest health due to anthropogenic
stress from those changes attributable to inherent natural
variation.
Forest Health Assessment: How We
Went About It -----------------------------
forced to carry out these assessments without a true understanding of what a healthy forest ecosystem consists of in
terms of measurable parameters. Without a baseline, the
answer to the question: are things better or worse? is
unclear. The assessment process, necessarily becomes more
qualitative and often more intuitive then we would like. The
synthesis tests the interpretive anq. comfort limits of scientists, who by nature, tend to be conservative and cautious
with unproven cause/effect relationships.
Policy analysts and decision-makers however, have immediate questions to answer from both the public and their
political masters. Available science-based conclusions and
results serve to provide direction as much as possible. Yet,
the immediacy of the issue extends the meaning of "sciencebased" for these decision-makers. And perhaps rightly so,
Our frontline people with the public do not have the luxury
of waiting for incontrovertible proof of cause and effect. They
do their best with what they have. We, as scientists, must
actively participate in this "interpretive" process. If we
collectively, as forest scientists, are not willing to make the
link between science and policy, others, with their own
agendas will do it for us.
Basic Principles
Three underlying principles served to direct our forest
health assessment:
• We must think, plan and act in terms of ecosystems.
Political and other jurisdictional boundaries are not
conducive to the assessment of any ecosystem as ecological interactions and relationships inevitably transcend
these boundaries.
• Natural disturbances or influences on forest ecosystems
such as wildfire, native insects and diseases, and climatic events are essential to the health of forest ecosystems. They are the drivers of ecological sustainability.
• Human activi ties impact on forest processes and ecological functions; some activities are benign, others could be
devastating. Forest ecosystems considered as being minimally infl uenced by human activity are generally viewed
as healthy.
Our Approach
1) be able to discern changes in forest ecosystems caused
by human interference from the natural ecological
variability inherent in these systems.
ii have a clear mental and measurable image, of a heal thy
forest; in essence a benchmark by which to measure
forest health.
In the development ofthis assessment, it was necessary to
define clearly what we meant by an "assessment." The term
'science assessment,' has become almost meaningless because of its ubiquitous attachment to a multiplicity of studies. It has been used for literature reviews, status reports and
for comprehensive encyclopedias about given topic areas.
Our task was to focus the exercise, to set out some guiding
principles. The primary purpose was to communicate to an
interested public the status and concerns regarding the
health of Canada's major forest ecosystems. This clear,
directed purpose meant that the language of the final report
had to be nontechnical. In doing this, it also had to:
Unfortunately, basic information or agreement on these
conditions does not exist. Yet, strong pressure to assess the
health of our forests is continuous from both the public and
the decision-makers who must answer to this public. We are
• provide an ecologically-based, concise synthesis of published results for a forest health issue of concern;
• be effects-oriented addressing what is happening, why it
is happening and how it is happening; and
The Conundrum
Under ideal assessment conditions, we would:
USDA Forest Service Proceedings RMRS-P-12. 1999
477
• provide the link between science and policy. Policy is
driven by public priorities and concerns. Issues high on
the public agenda must become high on the agenda ofthe
scientific community and addressed by that community.
• had a limited target length of pages. This focuses the
discussion, eliminates filler and forces the contributors
to stick to their key messages.
The 1998 national forest health assessment, in putting
theory to practice:
Regional Issue-Based _ _ _ _ __
• used the national ecological framework of Canada for
reporting purposes: This ecological framework delineates the country into 15 ecological zones (ecozones) and
hierarchical subdivisions (Ecological Stratification Working Group 1996). Nine ofthese ecozones have a substantial forest component. These nine ecozones served as the
reporting framework for our national forest health assessment. Arbitrary, ecologically inappropriate, jurisdictional boundaries were ignored. This approach also
emphasized the diversity of Canadian forests. Canadian
forests are a mosaic of many forest ecosystem. The
ecological framework points out the absurdity of discussing Canadian forests as a single entity.
• concentrated on effects: Methodologies, status, philosophy, and general musings were left for other venues of
communication and for other audiences. The authors
were to provide the key messages with just enough
dialogue around these messages to set the context.
• was issue oriented. Issues such as, harvest of old growth,
increase in plantations, biodiversity and acid rain are at
the fore in the minds of the public. We had to address
these and other forest health issues although our information base may have been limited. Ignoring discussion
of these issues was not an option. If the assessment did
not address these issues, at least in a cursory manner,
the entire assessment would be suspect to a large segment of the public.
• linked with monitoring and indicators, to the degree
possible. The forest health assessment is all about tracking change over time and determination of the ecological
impacts of any such change. This assessment considered, as general reference, the four ecological criteria of
the initiative to develop Canadian Criteria and Indicators of sustainable forest management: conserving biological diversity, ecosystem condition and productivity,
conserving soil and water resources and global ecological cycles (Canadian Council of Forest Ministers 1997).
• relied on partnerships. Forest health is an issue that
transcends the Canadian Forest Service. Except for the
Territories, provincial agencies and private landowners,
after all, are the land managers of most of Canada's
forests. As well, several federal agencies have regulatory
and general interest in our forest ecosystems. The breadth
and depth of issues involve research and monitoring
initiatives of all these organizations. Only through partnerships, can a national assessment of forest health be
carried out.
• used nontechnical language. The intended audience includes both those involved with policy and the general
public. The use of science jargon has limited communicative value with these groups. No matter how good the
message, if we cannot communicate it effectively, we
have no message.
478
I do acknowledge that an issue perspective limits the
opportunity to present forest health as a holistic concept.
Important ecological interactions and impacts may be missed.
Yet, the decision to proceed in this manner relates to one of
communication. Despite inherent constraints, I feel that,
through an issues approach, the Assessment becomes manageable and responds directly to both policy and public
issues and concerns. The use of ecozones as a reporting
framework allows for application of the ecological perspective to the synthesis. The use of the common headings of
"changing atmospheric conditions," "changing landscape
conditions," and "changing biodiversity" allows for national
consistency, yet regional flexibility.
Changing atmospheric conditions-Topic areas include effects from potential climate change, acid rain, tropospheric ozone (smog), and ultraviolet radiation. A major gap
exists in that no information is available on the effects of
toxic chemicals on forest ecosystems. The CFS, itself, does
not have an active research program in this issue area.
Effects from acid rain are drawn from the recently released
report by the Canadian Forest Service 'Effects of Acidic
Deposition on Canada's Forests' (Hall et al. 1998). Discussion on potential effects from ultraviolet radiation is based
on the Canadian forest sector contribution to the report
Ozone Science- A Canadian Perspective on the Changing
Ozone Layer released as part of the 10 th Anniversary meetings ofthe Montreal Protocol on Ozone-depleting Substances
held in Montreal in the Fall of 1997 (Wardle et al. 1997).
Changing landscape conditions-Factors influencing
changing landscape conditions include, harvesting regimes,
regeneration after harvesting, fire and insect and disease
infestations. For the latter, data are limited on human
influence on cycles and intensity of infestation. Discussion
focuses on impacts on commercial forest tree species. Fire is
a major ecological factor in the evolution of Canadian forests.
Data are sparse however, on fire severity and the ecological
impacts of fire suppression. Key references include the 1996/
1997 national State of the Forests Report produced by CFS,
the forest health monitoring database ofCFS, the National
Forestry Database of the Canadian Council of Forest Ministers and CFS Information Reports on the nature and extent
of insect and disease infestations.
Changing biodiversity-Indicators of biodiversity
change include protected areas (area, but not representatively was available, which remains a major gap in information needed), threatened species and ecosystems and exotic
or non-native species. Exotic species are of particular interest in assessing the health of Canadian Forests. They are
generally aggressive, lacking natural enemies and may
replace or reduce indigenous species within the forest. Certain species cause severe economic harm as they attack and
kill or reduce the vigour of commercial forest species.
USDA Forest Service Proceedings RMRS-P-12. 1999
Plantations, old growth and rare forest ecosystems were
discussed as to their overall implications to forest health of
specific ecozones.
The Obstacles _ _ _ _ _ _ __
We have an acceptable concept of forest health. We can
visualize what a forest health assessment is all about. On
the surface, it seemed like a relatively straightforward task
of carrying it out. It was not. The hurdles were many, some
institutional and others practical, most of which resulted in
interesting, ifnotfrustrating, bumps along the way. The key
ones included:
Monitoring ecological change for forest ecosystems-There is no capability in Canada to measure status
and change over time within our forest ecosystems. Without
an understanding of change, how can we determine natural
fluctuation from a human-induced one? There is no valid
basis for determination of whether things are getting better
or worse. The lack of ecological monitoring data severely
tested the interpretive limits of the assessment.
Ecological framework-We must think, plan and act in
terms of ecosystems. The problem is that much of the
available background data, reports and related infrastructure is linked to institutional rather than ecological boundaries. This fact caused, and continues to cause, problems in
the synthesis of forest health by ecozone.
The compulsion to generalize-One hears on a regular
basis that the forests of Canada are generally healthy. This
statemen t may be true, but it is also meaningless. It ignores,
albeit unintentionally, the diversity and mosaic of forest
ecosystems that characterize our nation. We are not one
forest, but many forests. Each has its own physical and
biological characteristics and stressors wi th varying degrees
of impact. Yet, ecological generalities relating to 'healthy
forests' pervade our literature. These generalizations serve
little else but to unobtrusive background, a sort of "ecological muzak."
.
This demand to generalize is fed, in part, by in terna tional
sources requesting the state, condition and health of Canada's
forests. Such requests inevitably seek an overall statement
for the country. We must resist this; Canada is not a small
country. We have ecoregions, the fine subdivisions of ecozones
that are larger than many European countries (Ecological
Stratification Working Group 1996).
It is also fed, in part, by politicians and others who seek
simplistic answers to complicated questions. Determination
of forest health is not a mathematical problem having a yes
or no answer. The country is too diverse for a national index
or statement on forest health. We should not continue
promulgate Canada as one large relatively homogenous
forest.
Striving for the bottom line: Historically, ecological
scientists have been reluctant to deliver results clearly.
Oftentimes, more effort is put on caveats than results. We
are the masters of the waIDe. How do we become more
proactive without sacrificing ecological integrity. More is
required of risk modeling, of interpretation of results and of
transmitting our collective experience. We must be willing
USDA Forest Service Proceedings RMRS-P-12. 1999
to test the limits of quantitative evidence, contribute our
professional judgement to the ecological debate and, dare I
say it, make the best of qualitative evidence. Still, the issue
of scientific rigour is one that the assessment was continually addressing.
Communication-We must communicate results ofresearch and monitoring in a meaningful manner to the
intended audience, which inevitably is the interested public.
This task is part translation of scientific English and French
to normal English and French and part the art of communication. The way I look at much of the forest research that we
do is that, ifin the end, the value and results of this research
cannot be communicated in a manner that my seventeen
year old daughter understands then that research is of
questionable value. The assessment is based on science but,
in fact, has a healthy dose of art attached to it to facilitate
communication.
The Major Gaps _ _ _ _ _ __
Currently there is no capability in place in Canada to
measure ecological change over time. There is an urgent
need for a national ecological monitoring program. Without
this CFS, and its provincial partners, cannot meet requirements imposed by Canadian Council of Forest Ministers to
measure and tract ecological criteria and indicators of sustainable forest management. Neither can we meet our
obligations for international reporting as required under the
criteria and indicators of the Montreal Process for sustainable forest management within temperate and boreal
countries.
Canada lacks any field studies or monitoring programs to
assess regional or nationwide risks of the nation's forests to
tropospheric ozone and UV-B. Research has shown that
several Canadian tree species are sensitive to UV-B episodes
(Percy and Cameron 1997). As well, lakes and wetlands and
associated wildlife within our forests have been adversely
impacted by high levels ofUV-B or through the accumulative affect of UV-B with acid rain (Schindler et al. 1996).
Research into the risk that toxic chemicals and heavy
metals may impose to Canadian forest wildlife and ecosystems is very limited. Lack of published information prevent
an assessment of these pollutants on Canadian forest
ecosystems.
Very little information exists on what one may consider as
the inheren t biodiversi ty and ecological functions associated
with what are considered as "healthy forest ecosystems." We
need to define and establish such baseline data from which
we could assess "change." We need to know whether our
management activities are helping or hindering our progress
towards ecological sustainability.
Summary
Determination of the health of Canadian forests is not an
exact science. The definition of 'health' is more qualitative
than quantitative. Rarely, will we be able to satisfy ourselves of direct human-induced cause and ecological effect.
Risk and uncertainty will remain as constants in forest
health assessment.
479
Currently, the state of nationwide forest health monitoring, and ecological monitoring in general, is inadequate for
determination of ecosystem change over time. A national
ecological monitoring program involving forest and nonforest land is a prerequisite to meet our national and international obligations on measuring and reporting progress
towards sustainable development.
Despite lack of consistent trend information for national
reporting purposes, the status of the health of our forests,
and predictions for the future are essential, and, in fact,
demanded by public and decision-makers. This fact puts
scientists in a dilemma. It forces science to its interpretive
limit relying often on qualitative information and sketchy
statistical validity for many issues of forest health. Yet,
advice and interpretations must be provided even ifbased on
less than solid evidence. Decisions will be made whether or
not appropriate supporting information and advice are
available.
The initial conclusions presented in this paper serve to
reflect the interdisciplinary nature of any science assessment even if it has a specific focus such as forest health. With
diminishing funds and the complex nature of many of our
environmental stressors, interdisciplinary and cooperative
research and monitoring among provincial federal, industrial and university groups is essential.
Interdisciplinary science is one requirement, communication of results is another. Ifwe, as scientists, cannot communicate our results and concerns in a manner that the public
and decision-makers understand, our work is futile and
exposed to cutbacks. Communication involves a couple of
prerequisites. Firstly, we must relate information and advice in a manner and language understandable by our
intended audience. The forest health program of the CFS is
developing a family of products to reach a wide variety of
audiences from peers to children. We are good at communicating with our peers, not so good with others. Remember, it
is most often the "others" that determine our research and
operating budgets.
Basic and long-term research are both essential. What is
needed is a continuing profile' from existing research and
monitoring initiatives that address the short-term policy
and public concerns. If properly carried out, long-term research would be buffered from constant scrutiny. We must
remember that the synthesis and reporting of results from
ecological research and monitoring to a broad audience is
part science and part art and it is often the art portion that
allows the science to continue.
480
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