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Our design will focus on three areas: 
o Detection of change in plant 
health and vigor; 
o Analysis of causes of change; 
and 
o Research into further 
understanding of the affect 
of global climate change 
The inventory and research analysis efforts will 
be directed in four phases, including: 
o Characterization of plot 
vegetation composition and 
biomass; 
o Characterization of forest 
stressors; 
o Quantification of changes in 
forest conditions ove time; 
and 
o Correlation of changes with 
forest stressors. 
FIA will emphasize detecting variations in health 
and vigor of forest and related vegetation. This 
basic detection effort will focus primarily on 
the first three phases. The US Forest Service's 
Forest Pest Management researchers will provide 
important assistance in characterizing forest 
stressors. The last phase, which involves major 
analysis functions, will be a joint effort among 
all cooperators, with FIA taking a supporting 
role. 
A PROPOSED VEGETATION MONITORING CONCEPT 
The Alaska forest health and vigor monitoring 
frame will use plots established between 1983 and 
1989 for the Alaska Integrated Resource Inventory 
System (AIRIS) (LaBau and Schreuder, 1983). Some 
239 ground-visited AIRIS-type plots are located 
systematically across the Tanana, Susitna and 
Copper River drainages, and throughout Southeast 
Alaska. 
The monitoring frame will use another 129 plots 
(with existing horizontal- vertical vegetation 
observation data) on the Kenai Peninsula. All 
together, the program will have 368 plots. 
The 239 AIRIS ground plots are located about 40 
kilometers apart. Most include three unique 
vegetation polygons, as classified according to 
the Alaska Vegetation Classification System 
(Viereck and Dyrness, 1980). Each polygon 
contains two horizontal-vertical profile plots 
where data of tree and non-tree vegetation 
profiles were recorded, along with standard 
tree/plot data. The 120 plots on the Kenai 
sample unit evaluated only one vegetation polygon 
each. Two profile plots were located at each 
site. I propose that a subset of these permanent 
plots be used as monitoring sites for observing 
changes in forest and associated plant health and 
vigor. 
A monitoring frame from some 800 polygons will be 
established. A minimum of three polygons, and a 
maximum of 10 polygons in each unique vegetation 
group (keying on Viereck's Level 3 classes) will 
be selected for establishment of monitoring 
plots. 
Variable- and fixed-area plots respond 
differently in measuring forest change 
attributes, depending on the type of attribute 
being measured (Scott and Alegria, 1990). The 
variable-area tree plots will be measured on the 
first revisit to the monitored areas. However, 
fixed-area plots will be overlaid on the 
variable-area plots, and the new fixed-area tree 
plots will be used in conjunction with the 
fixed-area vegetation profile plots in all 
subsequent re- measurements. Studies will not 
attempt to correlate fixed and variable plot 
data. 
Characterization of plot vegetation 
conditions. 
Characterization of vegetation conditions at each 
re-visited monitoring plot will come from data 
collected on the following tree and vegetation 
attributes: 
Diameter to 1 mm diameter breast high (dbh) 
on all trees 25 mm and larger. Diameters will 
be measured at a point marked on the bole of 
the tree for subsequent re- measurement. 
Tree height to .1 meter on all trees 25 mm 
dbh and larger. Heights will be recorded 
along with an azimuth and distance to a 
monumented measurement point. 
Tree crown dimensions, including its 
geometric description. 
Tree age on the first two trees in each 5 cm 
class on each plot location. Cores will be 
collected on all these trees and returned to 
the office for detailed dendro-chronology 
evaluations. Cores will be collected one 
decimeter below the point of measurement to 
avoid causing future distortion of diameter 
measurements associated with boring 
locations. 
Vegetation profiles of plant species 
occurrence and foliar cover by layers as they 
occur on each horizontal-vertical profile 
plot. 
Tree data will be recorded in a manner that 
allows comparisons with data recorded on the 
previous visit. Quality control procedures will 
allow checks against previous estimates, after 
new estimates are made, but prior to leaving the 
plot area. This will assure that any errors made 
on the previous visit are reconciled to the new 
data recorded. And, it will assure that no new 
data errors are made relative to data recorded 
previously. 
All trees larger than 25 mm in diameter and 
breast high will be mapped on new fixed-area 
plots. All variable-area plot trees already will 
have an azimuth and distance recorded from plot 
center to tree center for ease of relocation. 
Such mapping will help scientists revisiting a 
plot in the future to find specific trees and 
note any changes. 
Options will remain open for including such 
additional variables as soil and plant chemistry. 
However, inclusion of these variables in the 
monitoring system will depend on research experts 
providing meaningful criteria and attributes for 
measurement or observation.