PE EIE[R-Rg RESEARCH ON - HJ Andrews Experimental Forest

have been developed . Prior to their development
the overall ecosystem model will be for
the most part a translation of simple graphica l
and verbal models into mathematical language
with many aspects of the system interpolate d
on the basis of empirical submodels or eve n
crude estimates .
Ultimately both total systems models an d
submodels will require testing. This testing
will indicate the further research needed to
answer new questions or refine parts of existing
models . The modeling team plays a role in
assisting in the design of such new research. I n
this way the model building plays an essentia l
feedback role in the program .
In addition, both subsystem models an d
larger ecosystem models require estimates of
parameters and available data often appear s
inadequate. In these circumstances, it is neces -
sary to test the sensitivity of the model to th e
errors of estimation. Does it make a great deal
of difference if the estimates are crude? If
not, the model may proceed . If it does make a
significant difference, additional observation s
are required and further research in such area s
is necessary. Obviously, such sensitivity tests
cannot be made until models are fairly wel l
developed ; some models will be at this stage
this year.
Specific Goals
The goal of our Coniferous Biome research
is development of a basic understanding of
coniferous forest ecosystems, including both
terrestrial and aquatic components, so tha t
ecological constraints on and opportunitie s
for increased production of fiber, food, water ,
and wildlife can be recognized . The overall
strategy includes identification of the majo r
components and processes, both physical an d
organic, within the ecosystem, and definition
of their interrelationships . The definition of
interrelationships will be accomplished
through a systems analysis and modeling pro -
gram . As an overall guide for Biome research ,
we recognize the following general objectives :
1. To determine the major factors, both components
and processes, that control the
productivity and distribution of organisms
in coniferous forest ecosystems, includin g
(a) an analysis of the structure and distribution
of the principal resources, (b) definition
of the functional relationships between
biotic, decomposer, consumer, and
producer components of the systems, an d
(c) analysis of the forms and degrees of
stability in these systems .
2. To examine the linkage of terrestrial an d
aquatic components in coniferous fores t
ecosystems, including (a) water, energy ,
and transport of chemicals (including pesticides),
(b) direct transport of terrestrial
products into the aquatic system, e .g. ,
through litter fall and surface erosion, an d
(c) return of organic and inorganic materia l
from the aquatic to the terrestrial environment
through movements of fish, birds ,
and insects .
3. To determine how various manipulation s
influence the structure and function of
coniferous forest ecosystems using bot h
unit watersheds and plot studies . Special
attention is directed to the influences of
manipulations on (a) stability and productivity
of these systems and (b) the linkage s
between terrestrial and aquatic components
of the systems.
4. To understand population dynamics of
those major components of each trophic
level which appear to influence significantly
the sustained productivity and stability
of various coniferous forest ecosystems
within the Biome .
5. To produce models of temporal and spatia l
variations in coniferous forest ecosystem s
or system components. These models will
include factors affecting productivity an d
stability of the systems and the linkages between
terrestrial and aquatic environments ,
forecasting the behavior of these systems
and their relationships to human manipulation
.
6. To apply to specific models in the solutio n
of major use problems in the Biome are a
and assist other groups or agencies to d o
likewise .
Since these long-term objectives provid e
only general guidance, considerable time an d
effort is spent in defining annual researc h
tasks in order to focus the research an d
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