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

except for the retention of fine detail . Th e
tendency in constructing models on this base
has been to develop fine resolution mechanistic
models in which the variables defined a t
the finest resolution are in direct relation t o
all the other variables in the system . Variabl e
orientation seems to lead to variable sanctity .
One might make a case for the position that
the state variable approach was developed b y
engineers who have no conceptualizatio n
problem . They know what their variables are ,
and the relations among them, and they ar e
satisfied with mechanistic models .
The U-C structure is seen as a means o f
introducing holism, in addition to mechanism,
into the model conceptualization process . By
focusing on the subsystem structures, and b y
attempting to describe the behavior of the
system and subsystems at all levels in terms of
their behavior as objects, each system an d
subsystem is modeled at two levels, (1) holistically
and (2) mechanistically in terms of th e
holistic behavior of its subsystems . This
approach is held to be much more promising ,
from the point of view of development of
ecosystem theory, than the currently popula r
approach .
Acknowledgments
The work reported in this paper was supported
in part by National Science Foundatio n
Grant No. GB-20963 to the Coniferous Forest
Biome, U .S . Analysis of Ecosystems, International
Biological Program. This is Contribution
No . 23 to the Coniferous Forest Biome .
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