We also need more information about key indicator
plant species, observation standards, and
symptoms of change in health and vigor of
vegetation, as related to forest stressors. The
methods needed to integrate this information
likely will be provided by the Forest Insect and
Disease Research staff of the US Forest Service,
the Soil Conservation Service, and other
cooperators who provide guides on indicator
plants and basic forest stressors.
Some ongoing research will help identify
stressing agents and their relationships to
vegetation and climate. One promising area is
forest pest research. For example, black-headed
budworm (Acleris gloverana (Wals.)) infestations
in Alaska have been linked to temperature
changes. Hard (1974) suggested that the budworm
has little tolerance for cold. So, budworm
populations are lower around Prince William Sound
because forests there are slightly cooler.
But within the past decade budworm outbreaks have
occurred in Prince William Sound as well as in
interior Alaska. All subsided before the
infestation became of consequence. Apparently
the Prince William Sound temperature range
includes the budworm's minimum tolerance level.
If area temperatures are, in fact, at a budworm
survival threshold, and if global warming is
occurring, the population might have less trouble
surviving in the sound in the future. These are
the kinds of forest stressor indicators that may
show up in a monitoring system*.
Similar research on spruce bark beetle
(Dendroctonus rufipennis Kby) in southcentral
Alaska suggests that temperature changes affect
bark beetle populations (Hard, In Press). But
the risk of bark beetle outbreak also may be
affected by whether spruce stands are open
canopied (Reynolds and Hard, In Press). and the
risk varies by plant community. Therefore,
forest foliar cover is another dynamic to monitor
in terms of risk from insect attack. If foliar
cover of forests is decreased by climatic change,
bark beetle attacks may increase. However, other
stressors probably will become apparent before
foliar cover decreases noticeably. Additionally,
that data may be site-specific in certain
situations.
Investigators also must monitor other forest pest
areas, including tree anatomy, fungi, foliage
color, and site characteristics. Numerous other
possible indicators or variables also may point
to vegetation stress. Research and synthesis
must be done to begin understanding them.
Additional cooperative effort is needed to
determine what information and data is necessary
for chemical evaluation of soils and foliage.
Monitoring for permafrost and soil temperature
changes may require special procedures. The
USDA's Soil Conservation Service and the
University of Alaska will be asked to assist in
these two study areas.
* Personal conversation with John S. Hard,
Research Entomologist, Institute of Northern
Forestry, Anchorage, Alaska.
Researchers also must determine the observation
requirements for key vegetation indicator
species. Plants that should be observed may
vary, depending on the particular plant community
and level of stress. Instruments needed to
monitor forest health will vary, depending on
research proposals and guidance from cooperators.
A fascinating challenge now facing researchers is
the identification of attributes through remote
sensing. The state of remote sensing art is
advancing rapidly with the development of new
sensors and new techniques for monitoring
vegetation changes. Much attention will be given
to these developments in the final study plan.
Researchers will seek guidance on these and other
issues from cooperators such as the Institute of
Northern Forestry, University of Alaska, Cold
Regions Research and Engineering Laboratory,
Institute for Arctic and Alpine Research, Bureau
of Land Management, U.S. Fish and Wildlife
Service, Soil Conservation Service, National
Forest Systems, and others.
At least two Information Needs Assessment
workshops (LaBau, 1987) will be held prior to
launching this monitoring plan. All possible
cooperators will be involved, in order to
identify a full spectrum of data elements that
need collection.
THE GENERAL MONITORING CONCEPT
This proposed monitoring design should be
considered just one iteration of a much broader,
and continually changing, monitoring scheme. The
broader scheme involves a wide spectrum of
cooperators whose individual monitoring programs
will be conducted independently, but in a manner
complementary to the others.
For instance, this plan is designed to interface
with a plan developed by the Anchorage EROS Field
Office of the US Geological Survey (USGS) . The
USGS research program, "Baseline Studies for
Monitoring Global Climatic Change in the Arctic
Environment: A Remote Sensing-Spatial Database
Approach" (Shasby, 1989) , proposes to monitor
eight of the 12 sites shown in Figure 1. In
addition, an attempt will be made to include as
many of the Research Natural Areas of Alaska in
the monitoring framework. The plots, distributed
across Alaska, are in areas considered to have
special potential for providing early indications
of global climate change. The study will
emphasize analysis and integration of digital
satellite data, and digital earth sciences
databases developed in geographic information
systems for site- specific studies.
Similar plans are being developed by the
University of Alaska, Bureau of Land Management
and National Park Service. Any other general
plans for monitoring changes in vegetation health
and vigor in Alaska should be designed to
coordinate and cooperate with these efforts.
The Anchorage Forestry Sciences Laboratory (AFSL)
is planning its vegetation health and vigor
monitoring design to work closely with the other
programs.
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