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Ancillary data such as slope, aspect, and
elevation, as well as soil moisture, depth to
frost, and tree crown cover are other data that
must be included as attributes to measure or
observe.
Characterization of forest stressors
FIA teams will collect data and information on
forest vegetation health, using forest stressor
guides provided by Forest Pest Management and
Forest Pest Research. Each tree will be observed
for stressors, including:
o Disease;
o Insects;
o Foliar health and vigor;
o Other physical damage or tree
stress indicators such as fire
scars; and
o Animal damage (due to possible
changes in plant species density
and composition).
Researchers also will evaluate the foliar health
and vigor of non-tree vegetation. Particular
observation emphasis will be given to plants
identified as stress indicators by the
literature, FIA cooperators, and other scientists
working in the field. Location of any stressed
vegetation on the horizontal-vertical profile
plot will be mapped on the H-V plot sketch map.
Quantification of changes in forest conditions
over time.
Changes in tree data and plant health and vigor
may be apparent from remeasurement observations.
Data will be quantified and stored in a format
allowing evaluations of correlations with forest
stressors.
Correlation of changes with forest stressors.
Change information will be evaluated against
forest stressors following each re-measurement
observation. A statistical analysis will be used
to identify significant relationships. Analyses
of these relationships will be performed in
conjunction with cooperating agencies.
Cooperators primarily will be responsible for
final statistical analyses of soil chemical
content and vegetation data collected, and for
their respective statistical relationships to
changes in vegetation health and vigor.
Cooperators also will evaluate data from any site
instrumentation.
USE OF REMOTE SENSING IN THE MONITORING
SYSTEM
Remote sensing will play a major role in this
monitoring system. Since most of the original
data were collected using AIRIS (LaBau and
Winterberger, 1988), we already have much
remotely sensed data. For example, at each
eight-hectare AIRIS site, Landsat multispectral
scanner (MSS)-based land cover classifications
(LCC) were extracted from the LCC maps of the
entire inventory unit. In addition,
more-detailed remotely sensed LCC data were
collected on 1:60,000 color infrared photos, and
still more intense data were collected on photos
at 1:3,500 to 1:7,500 scales.
We will continue using satellite- based LCC (MSS,
thematic mapper, and SPOT) whenever appropriate
and cost effective.
Newer satellite technology also will be used as
it is developed. One of the more promising and
rapidly developing technologies is NOAA's
Advanced Very High Resolution Radiometer (AVHRR).
AVHRR has some excellent applications for gross
monitoring of change in vegetation cover
(Hastings et al, 1988), as long as resolution
finer than 1,000 meters is not required. AVHRR
may work well for measuring areas impacted by
fire, extensive insect attack of forests, major
wind damage of vegetation, such as large timber
blowdowns, and similar catastrophic effects.
Other possible remote sensing tools include Side
Looking Airborne Radar (SLAR) and Synthetic
Aperture Radar (SAR) now under development.
Other applications may include such innovative
remote sensing applications as use of aerial
video remote sensors (Maggio and Baker, 1988),
aerial stand volume tables (Setzer and Mead,
1988), PC-driven stereo plotters, Geographic
Information Systems applications and continued
use of standard photogrammetric applications.
The monitoring design will be kept flexible
enough to permit use of new remote sensing
developments as they occur.
SUMMARY
The monitoring design proposed here uses
remeasurement of existing timber and non-timber
vegetation plots to detect changes in vegetation
health and vigor. The proposed monitoring grid
and monitoring techniques used to collect tree
and non-tree vegetation data are described.
The monitored plots initially are characterized
as to vegetation and plot condition. Then,
remeasurements are made to detect vegetation
changes that may be related to global climate
change. Next, correlations are derived to
establish relationships between the observed
changes and forest stress criteria. Forest
stress criteria are provided by Forest Pest
Management, forest researchers in the field,
cooperating academic study teams, and syntheses
of scientific literature on the subject.
Finally, cooperating research teams will conduct
additional analyses of the change relationships
in an attempt to model further expected changes.
Part of these analyses may involve inter-relating
chemical analyses of soil and vegetation with the
observed changes. Cooperation with other global
change research programs in Alaska will help
improve understanding of the impact of global
change in the Arctic, and the contribution of
boreal and sub-boreal forest ecosystems to global
models.
Hopefully, this type of ground-based monitoring
system will allow scientists to establish some
basic relationships between changes in forest
vegetation health and vigor and forest stressors
that may be related to global climate change.
This paper also advocates continued use of
several remote sensing techniques already being
used by Alaska Forest Inventory and Analysis,
including use of Landsat MSS vegetation
classifications on Landsat MSS, high- and low-
altitude color infrared aerial photos, use of