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

Proceedings-Research on Coniferous Forest Ecosystems-A symposium .
Bellingham, Washington-March 23-24, 197 2
An environmental grid fo r
classifying coniferous
forest ecosystems
R . H . Waring,
K . L . Reed,
W. H . Emmingham
School of Forestry
Oregon State Universit y
Corvallis, Orego n
Abstract
To develop models which will predict primary production and forest composition across the Biome, we
suggest that the environment be defined operationally-as it affects certain plant responses . Models can be
developed which indicate how water, nutrients, light, temperature, and mechanical factors interact through th e
plant to control primary production and plant composition. Plant responses including water stress, stomatal
behavior, foliar nutrition, and phenology, among others, were coupled to environmental variables to create plan t
response indices for soil moisture, temperature, transpiration, and soil fertility . By correlating indicator species
with plant response indices, an ecosystem can be defined environmentally without direct measurements . Other
processes including biogeochemical cycling, consumer population dynamics, and hydrologic functions may als o
be related to the environmental grid.
Introduction
Diversity in environment and vegetation i s
characteristic of the Coniferous Forest Biome .
Such diversity is esthetically pleasing but presents
formidable problems of classification .
Classification is necessary, however, if we ar e
to understand the processes which affect the
composition and allow for continued productivity
of the forests and related water, wild -
life, and recreational resources .
If we could understand how the environment
influences forest growth and composition,
we would be well on the way toward
reassessing our past management successe s
and failures . We could also make our detailed
ecosystem studies more widely applicable in
both time and space, thus providing a frame -
work for intelligent land management. Th e
problem lies (a) in identifying which proper -
ties of the environment should be measured ,
(b) coupling these to important biological
processes, and (c) finally in predicting certai n
key properties of ecosystems .
In this paper we attempt to establish a conceptual
basis for evaluating environment, then
test the general approach, and finally suggest
necessary modifications to permit extensio n
across the Coniferous Forest Biome .
General Theory
The Operational Environment
Excellent descriptions of vegetation and
regional physiography exist for many region s
of the world . In the Pacific Northwest the
most thorough treatments have been provide d
by Daubenmire (1952), Krajina (1965), and
Franklin and Dyrness (1969) . Detailed
physiographic classification such as that developed
by Hills (1959) has proven most use-
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